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scrolledwindow: Kinetic scrolling support
[~andy/gtk] / gtk / gtkscrolledwindow.c
1 /* GTK - The GIMP Toolkit
2  * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with this library. If not, see <http://www.gnu.org/licenses/>.
16  */
17
18 /*
19  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
20  * file for a list of people on the GTK+ Team.  See the ChangeLog
21  * files for a list of changes.  These files are distributed with
22  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
23  */
24
25 #include "config.h"
26
27 #include <math.h>
28
29 #include "gtkbindings.h"
30 #include "gtkmarshalers.h"
31 #include "gtkscrollable.h"
32 #include "gtkscrollbar.h"
33 #include "gtkscrolledwindow.h"
34 #include "gtkwindow.h"
35 #include "gtkviewport.h"
36 #include "gtkdnd.h"
37 #include "gtkmain.h"
38 #include "gtkprivate.h"
39 #include "gtktypebuiltins.h"
40 #include "gtkintl.h"
41 #include "gtkviewport.h"
42 #include "gtkwidgetprivate.h"
43 #include "a11y/gtkscrolledwindowaccessible.h"
44
45 /**
46  * SECTION:gtkscrolledwindow
47  * @Short_description: Adds scrollbars to its child widget
48  * @Title: GtkScrolledWindow
49  * @See_also: #GtkScrollable, #GtkViewport, #GtkAdjustment
50  *
51  * #GtkScrolledWindow is a #GtkBin subclass: it's a container
52  * the accepts a single child widget. #GtkScrolledWindow adds scrollbars
53  * to the child widget and optionally draws a beveled frame around the
54  * child widget.
55  *
56  * The scrolled window can work in two ways. Some widgets have native
57  * scrolling support; these widgets implement the #GtkScrollable interface.
58  * Widgets with native scroll support include #GtkTreeView, #GtkTextView,
59  * and #GtkLayout.
60  *
61  * For widgets that lack native scrolling support, the #GtkViewport
62  * widget acts as an adaptor class, implementing scrollability for child
63  * widgets that lack their own scrolling capabilities. Use #GtkViewport
64  * to scroll child widgets such as #GtkGrid, #GtkBox, and so on.
65  *
66  * If a widget has native scrolling abilities, it can be added to the
67  * #GtkScrolledWindow with gtk_container_add(). If a widget does not, you
68  * must first add the widget to a #GtkViewport, then add the #GtkViewport
69  * to the scrolled window. The convenience function
70  * gtk_scrolled_window_add_with_viewport() does exactly this, so you can
71  * ignore the presence of the viewport.
72  *
73  * The position of the scrollbars is controlled by the scroll
74  * adjustments. See #GtkAdjustment for the fields in an adjustment - for
75  * #GtkScrollbar, used by #GtkScrolledWindow, the "value" field
76  * represents the position of the scrollbar, which must be between the
77  * "lower" field and "upper - page_size." The "page_size" field
78  * represents the size of the visible scrollable area. The
79  * "step_increment" and "page_increment" fields are used when the user
80  * asks to step down (using the small stepper arrows) or page down (using
81  * for example the PageDown key).
82  *
83  * If a #GtkScrolledWindow doesn't behave quite as you would like, or
84  * doesn't have exactly the right layout, it's very possible to set up
85  * your own scrolling with #GtkScrollbar and for example a #GtkGrid.
86  */
87
88
89 /* scrolled window policy and size requisition handling:
90  *
91  * gtk size requisition works as follows:
92  *   a widget upon size-request reports the width and height that it finds
93  *   to be best suited to display its contents, including children.
94  *   the width and/or height reported from a widget upon size requisition
95  *   may be overidden by the user by specifying a width and/or height
96  *   other than 0 through gtk_widget_set_size_request().
97  *
98  * a scrolled window needs (for implementing all three policy types) to
99  * request its width and height based on two different rationales.
100  * 1)   the user wants the scrolled window to just fit into the space
101  *      that it gets allocated for a specifc dimension.
102  * 1.1) this does not apply if the user specified a concrete value
103  *      value for that specific dimension by either specifying usize for the
104  *      scrolled window or for its child.
105  * 2)   the user wants the scrolled window to take as much space up as
106  *      is desired by the child for a specifc dimension (i.e. POLICY_NEVER).
107  *
108  * also, kinda obvious:
109  * 3)   a user would certainly not have choosen a scrolled window as a container
110  *      for the child, if the resulting allocation takes up more space than the
111  *      child would have allocated without the scrolled window.
112  *
113  * conclusions:
114  * A) from 1) follows: the scrolled window shouldn't request more space for a
115  *    specifc dimension than is required at minimum.
116  * B) from 1.1) follows: the requisition may be overidden by usize of the scrolled
117  *    window (done automatically) or by usize of the child (needs to be checked).
118  * C) from 2) follows: for POLICY_NEVER, the scrolled window simply reports the
119  *    child's dimension.
120  * D) from 3) follows: the scrolled window child's minimum width and minimum height
121  *    under A) at least correspond to the space taken up by its scrollbars.
122  */
123
124 #define DEFAULT_SCROLLBAR_SPACING  3
125 #define TOUCH_BYPASS_CAPTURED_THRESHOLD 30
126
127 /* Kinetic scrolling */
128 #define FRAME_INTERVAL (1000 / 60)
129 #define MAX_OVERSHOOT_DISTANCE 50
130 #define FRICTION_DECELERATION 0.003
131 #define OVERSHOOT_INVERSE_ACCELERATION 0.003
132 #define RELEASE_EVENT_TIMEOUT 1000
133
134 struct _GtkScrolledWindowPrivate
135 {
136   GtkWidget     *hscrollbar;
137   GtkWidget     *vscrollbar;
138
139   GtkCornerType  real_window_placement;
140   guint16  shadow_type;
141
142   guint    window_placement_set   : 1;
143   guint    hscrollbar_policy      : 2;
144   guint    vscrollbar_policy      : 2;
145   guint    hscrollbar_visible     : 1;
146   guint    vscrollbar_visible     : 1;
147   guint    window_placement       : 2;
148   guint    focus_out              : 1; /* Flag used by ::move-focus-out implementation */
149
150   gint     min_content_width;
151   gint     min_content_height;
152
153   /* Kinetic scrolling */
154   GdkEvent              *button_press_event;
155   GdkWindow             *overshoot_window;
156   GdkDevice             *drag_device;
157   guint                  kinetic_scrolling         : 1;
158   guint                  capture_button_press      : 1;
159   guint                  in_drag                   : 1;
160   guint                  last_button_event_valid   : 1;
161
162   guint                  release_timeout_id;
163   guint                  deceleration_id;
164
165   gdouble                last_button_event_x_root;
166   gdouble                last_button_event_y_root;
167
168   gdouble                last_motion_event_x_root;
169   gdouble                last_motion_event_y_root;
170   guint32                last_motion_event_time;
171
172   gdouble                x_velocity;
173   gdouble                y_velocity;
174
175   gdouble                unclamped_hadj_value;
176   gdouble                unclamped_vadj_value;
177 };
178
179 typedef struct
180 {
181   GtkScrolledWindow     *scrolled_window;
182   gint64                 last_deceleration_time;
183
184   gdouble                x_velocity;
185   gdouble                y_velocity;
186   gdouble                vel_cosine;
187   gdouble                vel_sine;
188 } KineticScrollData;
189
190 enum {
191   PROP_0,
192   PROP_HADJUSTMENT,
193   PROP_VADJUSTMENT,
194   PROP_HSCROLLBAR_POLICY,
195   PROP_VSCROLLBAR_POLICY,
196   PROP_WINDOW_PLACEMENT,
197   PROP_WINDOW_PLACEMENT_SET,
198   PROP_SHADOW_TYPE,
199   PROP_MIN_CONTENT_WIDTH,
200   PROP_MIN_CONTENT_HEIGHT,
201   PROP_KINETIC_SCROLLING
202 };
203
204 /* Signals */
205 enum
206 {
207   SCROLL_CHILD,
208   MOVE_FOCUS_OUT,
209   LAST_SIGNAL
210 };
211
212 static void     gtk_scrolled_window_set_property       (GObject           *object,
213                                                         guint              prop_id,
214                                                         const GValue      *value,
215                                                         GParamSpec        *pspec);
216 static void     gtk_scrolled_window_get_property       (GObject           *object,
217                                                         guint              prop_id,
218                                                         GValue            *value,
219                                                         GParamSpec        *pspec);
220
221 static void     gtk_scrolled_window_destroy            (GtkWidget         *widget);
222 static void     gtk_scrolled_window_screen_changed     (GtkWidget         *widget,
223                                                         GdkScreen         *previous_screen);
224 static gboolean gtk_scrolled_window_draw               (GtkWidget         *widget,
225                                                         cairo_t           *cr);
226 static void     gtk_scrolled_window_size_allocate      (GtkWidget         *widget,
227                                                         GtkAllocation     *allocation);
228 static gboolean gtk_scrolled_window_scroll_event       (GtkWidget         *widget,
229                                                         GdkEventScroll    *event);
230 static gboolean gtk_scrolled_window_captured_event     (GtkWidget         *widget,
231                                                         GdkEvent          *event);
232 static gboolean gtk_scrolled_window_focus              (GtkWidget         *widget,
233                                                         GtkDirectionType   direction);
234 static void     gtk_scrolled_window_add                (GtkContainer      *container,
235                                                         GtkWidget         *widget);
236 static void     gtk_scrolled_window_remove             (GtkContainer      *container,
237                                                         GtkWidget         *widget);
238 static void     gtk_scrolled_window_forall             (GtkContainer      *container,
239                                                         gboolean           include_internals,
240                                                         GtkCallback        callback,
241                                                         gpointer           callback_data);
242 static gboolean gtk_scrolled_window_scroll_child       (GtkScrolledWindow *scrolled_window,
243                                                         GtkScrollType      scroll,
244                                                         gboolean           horizontal);
245 static void     gtk_scrolled_window_move_focus_out     (GtkScrolledWindow *scrolled_window,
246                                                         GtkDirectionType   direction_type);
247
248 static void     gtk_scrolled_window_relative_allocation(GtkWidget         *widget,
249                                                         GtkAllocation     *allocation);
250 static void     gtk_scrolled_window_adjustment_changed (GtkAdjustment     *adjustment,
251                                                         gpointer           data);
252 static void     gtk_scrolled_window_adjustment_value_changed (GtkAdjustment     *adjustment,
253                                                               gpointer           data);
254
255 static void  gtk_scrolled_window_update_real_placement (GtkScrolledWindow *scrolled_window);
256
257 static void  gtk_scrolled_window_get_preferred_width   (GtkWidget           *widget,
258                                                         gint                *minimum_size,
259                                                         gint                *natural_size);
260 static void  gtk_scrolled_window_get_preferred_height  (GtkWidget           *widget,
261                                                         gint                *minimum_size,
262                                                         gint                *natural_size);
263 static void  gtk_scrolled_window_get_preferred_height_for_width  (GtkWidget           *layout,
264                                                         gint                 width,
265                                                         gint                *minimum_height,
266                                                         gint                *natural_height);
267 static void  gtk_scrolled_window_get_preferred_width_for_height  (GtkWidget           *layout,
268                                                         gint                 width,
269                                                         gint                *minimum_height,
270                                                         gint                *natural_height);
271
272 static void  gtk_scrolled_window_realize               (GtkWidget           *widget);
273 static void  gtk_scrolled_window_unrealize             (GtkWidget           *widget);
274 static void  gtk_scrolled_window_map                   (GtkWidget           *widget);
275 static void  gtk_scrolled_window_unmap                 (GtkWidget           *widget);
276 static void  gtk_scrolled_window_grab_notify           (GtkWidget           *widget,
277                                                         gboolean             was_grabbed);
278
279 static gboolean _gtk_scrolled_window_set_adjustment_value      (GtkScrolledWindow *scrolled_window,
280                                                                 GtkAdjustment     *adjustment,
281                                                                 gdouble            value,
282                                                                 gboolean           allow_overshooting,
283                                                                 gboolean           snap_to_border);
284
285 static guint signals[LAST_SIGNAL] = {0};
286
287 G_DEFINE_TYPE (GtkScrolledWindow, gtk_scrolled_window, GTK_TYPE_BIN)
288
289
290 static void
291 add_scroll_binding (GtkBindingSet  *binding_set,
292                     guint           keyval,
293                     GdkModifierType mask,
294                     GtkScrollType   scroll,
295                     gboolean        horizontal)
296 {
297   guint keypad_keyval = keyval - GDK_KEY_Left + GDK_KEY_KP_Left;
298   
299   gtk_binding_entry_add_signal (binding_set, keyval, mask,
300                                 "scroll-child", 2,
301                                 GTK_TYPE_SCROLL_TYPE, scroll,
302                                 G_TYPE_BOOLEAN, horizontal);
303   gtk_binding_entry_add_signal (binding_set, keypad_keyval, mask,
304                                 "scroll-child", 2,
305                                 GTK_TYPE_SCROLL_TYPE, scroll,
306                                 G_TYPE_BOOLEAN, horizontal);
307 }
308
309 static void
310 add_tab_bindings (GtkBindingSet    *binding_set,
311                   GdkModifierType   modifiers,
312                   GtkDirectionType  direction)
313 {
314   gtk_binding_entry_add_signal (binding_set, GDK_KEY_Tab, modifiers,
315                                 "move-focus-out", 1,
316                                 GTK_TYPE_DIRECTION_TYPE, direction);
317   gtk_binding_entry_add_signal (binding_set, GDK_KEY_KP_Tab, modifiers,
318                                 "move-focus-out", 1,
319                                 GTK_TYPE_DIRECTION_TYPE, direction);
320 }
321
322 static void
323 gtk_scrolled_window_class_init (GtkScrolledWindowClass *class)
324 {
325   GObjectClass *gobject_class = G_OBJECT_CLASS (class);
326   GtkWidgetClass *widget_class;
327   GtkContainerClass *container_class;
328   GtkBindingSet *binding_set;
329
330   widget_class = (GtkWidgetClass*) class;
331   container_class = (GtkContainerClass*) class;
332
333   gobject_class->set_property = gtk_scrolled_window_set_property;
334   gobject_class->get_property = gtk_scrolled_window_get_property;
335
336   widget_class->destroy = gtk_scrolled_window_destroy;
337   widget_class->screen_changed = gtk_scrolled_window_screen_changed;
338   widget_class->draw = gtk_scrolled_window_draw;
339   widget_class->size_allocate = gtk_scrolled_window_size_allocate;
340   widget_class->scroll_event = gtk_scrolled_window_scroll_event;
341   widget_class->focus = gtk_scrolled_window_focus;
342   widget_class->get_preferred_width = gtk_scrolled_window_get_preferred_width;
343   widget_class->get_preferred_height = gtk_scrolled_window_get_preferred_height;
344   widget_class->get_preferred_height_for_width = gtk_scrolled_window_get_preferred_height_for_width;
345   widget_class->get_preferred_width_for_height = gtk_scrolled_window_get_preferred_width_for_height;
346   widget_class->realize = gtk_scrolled_window_realize;
347   widget_class->unrealize = gtk_scrolled_window_unrealize;
348   widget_class->map = gtk_scrolled_window_map;
349   widget_class->unmap = gtk_scrolled_window_unmap;
350   widget_class->grab_notify = gtk_scrolled_window_grab_notify;
351
352   container_class->add = gtk_scrolled_window_add;
353   container_class->remove = gtk_scrolled_window_remove;
354   container_class->forall = gtk_scrolled_window_forall;
355   gtk_container_class_handle_border_width (container_class);
356
357   class->scrollbar_spacing = -1;
358
359   class->scroll_child = gtk_scrolled_window_scroll_child;
360   class->move_focus_out = gtk_scrolled_window_move_focus_out;
361   
362   g_object_class_install_property (gobject_class,
363                                    PROP_HADJUSTMENT,
364                                    g_param_spec_object ("hadjustment",
365                                                         P_("Horizontal Adjustment"),
366                                                         P_("The GtkAdjustment for the horizontal position"),
367                                                         GTK_TYPE_ADJUSTMENT,
368                                                         GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT));
369   g_object_class_install_property (gobject_class,
370                                    PROP_VADJUSTMENT,
371                                    g_param_spec_object ("vadjustment",
372                                                         P_("Vertical Adjustment"),
373                                                         P_("The GtkAdjustment for the vertical position"),
374                                                         GTK_TYPE_ADJUSTMENT,
375                                                         GTK_PARAM_READWRITE | G_PARAM_CONSTRUCT));
376   g_object_class_install_property (gobject_class,
377                                    PROP_HSCROLLBAR_POLICY,
378                                    g_param_spec_enum ("hscrollbar-policy",
379                                                       P_("Horizontal Scrollbar Policy"),
380                                                       P_("When the horizontal scrollbar is displayed"),
381                                                       GTK_TYPE_POLICY_TYPE,
382                                                       GTK_POLICY_AUTOMATIC,
383                                                       GTK_PARAM_READABLE | GTK_PARAM_WRITABLE));
384   g_object_class_install_property (gobject_class,
385                                    PROP_VSCROLLBAR_POLICY,
386                                    g_param_spec_enum ("vscrollbar-policy",
387                                                       P_("Vertical Scrollbar Policy"),
388                                                       P_("When the vertical scrollbar is displayed"),
389                                                       GTK_TYPE_POLICY_TYPE,
390                                                       GTK_POLICY_AUTOMATIC,
391                                                       GTK_PARAM_READABLE | GTK_PARAM_WRITABLE));
392
393   g_object_class_install_property (gobject_class,
394                                    PROP_WINDOW_PLACEMENT,
395                                    g_param_spec_enum ("window-placement",
396                                                       P_("Window Placement"),
397                                                       P_("Where the contents are located with respect to the scrollbars. This property only takes effect if \"window-placement-set\" is TRUE."),
398                                                       GTK_TYPE_CORNER_TYPE,
399                                                       GTK_CORNER_TOP_LEFT,
400                                                       GTK_PARAM_READABLE | GTK_PARAM_WRITABLE));
401   
402   /**
403    * GtkScrolledWindow:window-placement-set:
404    *
405    * Whether "window-placement" should be used to determine the location 
406    * of the contents with respect to the scrollbars. Otherwise, the 
407    * "gtk-scrolled-window-placement" setting is used.
408    *
409    * Since: 2.10
410    */
411   g_object_class_install_property (gobject_class,
412                                    PROP_WINDOW_PLACEMENT_SET,
413                                    g_param_spec_boolean ("window-placement-set",
414                                                          P_("Window Placement Set"),
415                                                          P_("Whether \"window-placement\" should be used to determine the location of the contents with respect to the scrollbars."),
416                                                          FALSE,
417                                                          GTK_PARAM_READABLE | GTK_PARAM_WRITABLE));
418   g_object_class_install_property (gobject_class,
419                                    PROP_SHADOW_TYPE,
420                                    g_param_spec_enum ("shadow-type",
421                                                       P_("Shadow Type"),
422                                                       P_("Style of bevel around the contents"),
423                                                       GTK_TYPE_SHADOW_TYPE,
424                                                       GTK_SHADOW_NONE,
425                                                       GTK_PARAM_READABLE | GTK_PARAM_WRITABLE));
426
427   /**
428    * GtkScrolledWindow:scrollbars-within-bevel:
429    *
430    * Whether to place scrollbars within the scrolled window's bevel.
431    *
432    * Since: 2.12
433    */
434   gtk_widget_class_install_style_property (widget_class,
435                                            g_param_spec_boolean ("scrollbars-within-bevel",
436                                                                  P_("Scrollbars within bevel"),
437                                                                  P_("Place scrollbars within the scrolled window's bevel"),
438                                                                  FALSE,
439                                                                  GTK_PARAM_READABLE));
440
441   gtk_widget_class_install_style_property (widget_class,
442                                            g_param_spec_int ("scrollbar-spacing",
443                                                              P_("Scrollbar spacing"),
444                                                              P_("Number of pixels between the scrollbars and the scrolled window"),
445                                                              0,
446                                                              G_MAXINT,
447                                                              DEFAULT_SCROLLBAR_SPACING,
448                                                              GTK_PARAM_READABLE));
449
450   /**
451    * GtkScrolledWindow:min-content-width:
452    *
453    * The minimum content width of @scrolled_window, or -1 if not set.
454    *
455    * Since: 3.0
456    */
457   g_object_class_install_property (gobject_class,
458                                    PROP_MIN_CONTENT_WIDTH,
459                                    g_param_spec_int ("min-content-width",
460                                                      P_("Minimum Content Width"),
461                                                      P_("The minimum width that the scrolled window will allocate to its content"),
462                                                      -1, G_MAXINT, -1,
463                                                      GTK_PARAM_READWRITE));
464
465   /**
466    * GtkScrolledWindow:min-content-height:
467    *
468    * The minimum content height of @scrolled_window, or -1 if not set.
469    *
470    * Since: 3.0
471    */
472   g_object_class_install_property (gobject_class,
473                                    PROP_MIN_CONTENT_HEIGHT,
474                                    g_param_spec_int ("min-content-height",
475                                                      P_("Minimum Content Height"),
476                                                      P_("The minimum height that the scrolled window will allocate to its content"),
477                                                      -1, G_MAXINT, -1,
478                                                      GTK_PARAM_READWRITE));
479
480   /**
481    * GtkScrolledWindow:kinetic-scrolling:
482    *
483    * The kinetic scrolling behavior flags. Kinetic scrolling
484    * only applies to devices with source %GDK_SOURCE_TOUCHSCREEN
485    *
486    * Since: 3.4
487    */
488   g_object_class_install_property (gobject_class,
489                                    PROP_KINETIC_SCROLLING,
490                                    g_param_spec_boolean ("kinetic-scrolling",
491                                                          P_("Kinetic Scrolling"),
492                                                          P_("Kinetic scrolling mode."),
493                                                          TRUE,
494                                                          GTK_PARAM_READABLE |
495                                                          GTK_PARAM_WRITABLE));
496   /**
497    * GtkScrolledWindow::scroll-child:
498    * @scrolled_window: a #GtkScrolledWindow
499    * @scroll: a #GtkScrollType describing how much to scroll
500    * @horizontal: whether the keybinding scrolls the child
501    *   horizontally or not
502    *
503    * The ::scroll-child signal is a
504    * <link linkend="keybinding-signals">keybinding signal</link>
505    * which gets emitted when a keybinding that scrolls is pressed.
506    * The horizontal or vertical adjustment is updated which triggers a
507    * signal that the scrolled windows child may listen to and scroll itself.
508    */
509   signals[SCROLL_CHILD] =
510     g_signal_new (I_("scroll-child"),
511                   G_TYPE_FROM_CLASS (gobject_class),
512                   G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
513                   G_STRUCT_OFFSET (GtkScrolledWindowClass, scroll_child),
514                   NULL, NULL,
515                   _gtk_marshal_BOOLEAN__ENUM_BOOLEAN,
516                   G_TYPE_BOOLEAN, 2,
517                   GTK_TYPE_SCROLL_TYPE,
518                   G_TYPE_BOOLEAN);
519
520   /**
521    * GtkScrolledWindow::move-focus-out:
522    * @scrolled_window: a #GtkScrolledWindow
523    * @direction_type: either %GTK_DIR_TAB_FORWARD or
524    *   %GTK_DIR_TAB_BACKWARD
525    *
526    * The ::move-focus-out signal is a
527    * <link linkend="keybinding-signals">keybinding signal</link>
528    * which gets emitted when focus is moved away from the scrolled
529    * window by a keybinding.
530    * The #GtkWidget::move-focus signal is emitted with @direction_type
531    * on this scrolled windows toplevel parent in the container hierarchy.
532    * The default bindings for this signal are
533    * <keycombo><keycap>Tab</keycap><keycap>Ctrl</keycap></keycombo>
534    * and
535    * <keycombo><keycap>Tab</keycap><keycap>Ctrl</keycap><keycap>Shift</keycap></keycombo>.
536    */
537   signals[MOVE_FOCUS_OUT] =
538     g_signal_new (I_("move-focus-out"),
539                   G_TYPE_FROM_CLASS (gobject_class),
540                   G_SIGNAL_RUN_LAST | G_SIGNAL_ACTION,
541                   G_STRUCT_OFFSET (GtkScrolledWindowClass, move_focus_out),
542                   NULL, NULL,
543                   _gtk_marshal_VOID__ENUM,
544                   G_TYPE_NONE, 1,
545                   GTK_TYPE_DIRECTION_TYPE);
546   
547   binding_set = gtk_binding_set_by_class (class);
548
549   add_scroll_binding (binding_set, GDK_KEY_Left,  GDK_CONTROL_MASK, GTK_SCROLL_STEP_BACKWARD, TRUE);
550   add_scroll_binding (binding_set, GDK_KEY_Right, GDK_CONTROL_MASK, GTK_SCROLL_STEP_FORWARD,  TRUE);
551   add_scroll_binding (binding_set, GDK_KEY_Up,    GDK_CONTROL_MASK, GTK_SCROLL_STEP_BACKWARD, FALSE);
552   add_scroll_binding (binding_set, GDK_KEY_Down,  GDK_CONTROL_MASK, GTK_SCROLL_STEP_FORWARD,  FALSE);
553
554   add_scroll_binding (binding_set, GDK_KEY_Page_Up,   GDK_CONTROL_MASK, GTK_SCROLL_PAGE_BACKWARD, TRUE);
555   add_scroll_binding (binding_set, GDK_KEY_Page_Down, GDK_CONTROL_MASK, GTK_SCROLL_PAGE_FORWARD,  TRUE);
556   add_scroll_binding (binding_set, GDK_KEY_Page_Up,   0,                GTK_SCROLL_PAGE_BACKWARD, FALSE);
557   add_scroll_binding (binding_set, GDK_KEY_Page_Down, 0,                GTK_SCROLL_PAGE_FORWARD,  FALSE);
558
559   add_scroll_binding (binding_set, GDK_KEY_Home, GDK_CONTROL_MASK, GTK_SCROLL_START, TRUE);
560   add_scroll_binding (binding_set, GDK_KEY_End,  GDK_CONTROL_MASK, GTK_SCROLL_END,   TRUE);
561   add_scroll_binding (binding_set, GDK_KEY_Home, 0,                GTK_SCROLL_START, FALSE);
562   add_scroll_binding (binding_set, GDK_KEY_End,  0,                GTK_SCROLL_END,   FALSE);
563
564   add_tab_bindings (binding_set, GDK_CONTROL_MASK, GTK_DIR_TAB_FORWARD);
565   add_tab_bindings (binding_set, GDK_CONTROL_MASK | GDK_SHIFT_MASK, GTK_DIR_TAB_BACKWARD);
566
567   g_type_class_add_private (class, sizeof (GtkScrolledWindowPrivate));
568
569   gtk_widget_class_set_accessible_type (widget_class, GTK_TYPE_SCROLLED_WINDOW_ACCESSIBLE);
570 }
571
572 static void
573 gtk_scrolled_window_init (GtkScrolledWindow *scrolled_window)
574 {
575   GtkScrolledWindowPrivate *priv;
576
577   scrolled_window->priv = priv = G_TYPE_INSTANCE_GET_PRIVATE (scrolled_window,
578                                                               GTK_TYPE_SCROLLED_WINDOW,
579                                                               GtkScrolledWindowPrivate);
580
581   gtk_widget_set_has_window (GTK_WIDGET (scrolled_window), FALSE);
582   gtk_widget_set_can_focus (GTK_WIDGET (scrolled_window), TRUE);
583
584   priv->hscrollbar = NULL;
585   priv->vscrollbar = NULL;
586   priv->hscrollbar_policy = GTK_POLICY_AUTOMATIC;
587   priv->vscrollbar_policy = GTK_POLICY_AUTOMATIC;
588   priv->hscrollbar_visible = FALSE;
589   priv->vscrollbar_visible = FALSE;
590   priv->focus_out = FALSE;
591   priv->window_placement = GTK_CORNER_TOP_LEFT;
592   gtk_scrolled_window_update_real_placement (scrolled_window);
593   priv->min_content_width = -1;
594   priv->min_content_height = -1;
595
596   gtk_scrolled_window_set_kinetic_scrolling (scrolled_window, TRUE);
597   gtk_scrolled_window_set_capture_button_press (scrolled_window, TRUE);
598 }
599
600 /**
601  * gtk_scrolled_window_new:
602  * @hadjustment: (allow-none): horizontal adjustment
603  * @vadjustment: (allow-none): vertical adjustment
604  *
605  * Creates a new scrolled window.
606  *
607  * The two arguments are the scrolled window's adjustments; these will be
608  * shared with the scrollbars and the child widget to keep the bars in sync 
609  * with the child. Usually you want to pass %NULL for the adjustments, which 
610  * will cause the scrolled window to create them for you.
611  *
612  * Returns: a new scrolled window
613  */
614 GtkWidget*
615 gtk_scrolled_window_new (GtkAdjustment *hadjustment,
616                          GtkAdjustment *vadjustment)
617 {
618   GtkWidget *scrolled_window;
619
620   if (hadjustment)
621     g_return_val_if_fail (GTK_IS_ADJUSTMENT (hadjustment), NULL);
622
623   if (vadjustment)
624     g_return_val_if_fail (GTK_IS_ADJUSTMENT (vadjustment), NULL);
625
626   scrolled_window = g_object_new (GTK_TYPE_SCROLLED_WINDOW,
627                                     "hadjustment", hadjustment,
628                                     "vadjustment", vadjustment,
629                                     NULL);
630
631   return scrolled_window;
632 }
633
634 /**
635  * gtk_scrolled_window_set_hadjustment:
636  * @scrolled_window: a #GtkScrolledWindow
637  * @hadjustment: horizontal scroll adjustment
638  *
639  * Sets the #GtkAdjustment for the horizontal scrollbar.
640  */
641 void
642 gtk_scrolled_window_set_hadjustment (GtkScrolledWindow *scrolled_window,
643                                      GtkAdjustment     *hadjustment)
644 {
645   GtkScrolledWindowPrivate *priv;
646   GtkBin *bin;
647   GtkWidget *child;
648
649   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
650   if (hadjustment)
651     g_return_if_fail (GTK_IS_ADJUSTMENT (hadjustment));
652   else
653     hadjustment = (GtkAdjustment*) g_object_new (GTK_TYPE_ADJUSTMENT, NULL);
654
655   bin = GTK_BIN (scrolled_window);
656   priv = scrolled_window->priv;
657
658   if (!priv->hscrollbar)
659     {
660       gtk_widget_push_composite_child ();
661       priv->hscrollbar = gtk_scrollbar_new (GTK_ORIENTATION_HORIZONTAL, hadjustment);
662       gtk_widget_set_composite_name (priv->hscrollbar, "hscrollbar");
663       gtk_widget_pop_composite_child ();
664
665       gtk_widget_set_parent (priv->hscrollbar, GTK_WIDGET (scrolled_window));
666       g_object_ref (priv->hscrollbar);
667       gtk_widget_show (priv->hscrollbar);
668     }
669   else
670     {
671       GtkAdjustment *old_adjustment;
672
673       old_adjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
674       if (old_adjustment == hadjustment)
675         return;
676
677       g_signal_handlers_disconnect_by_func (old_adjustment,
678                                             gtk_scrolled_window_adjustment_changed,
679                                             scrolled_window);
680       gtk_range_set_adjustment (GTK_RANGE (priv->hscrollbar),
681                                 hadjustment);
682     }
683   hadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
684   g_signal_connect (hadjustment,
685                     "changed",
686                     G_CALLBACK (gtk_scrolled_window_adjustment_changed),
687                     scrolled_window);
688   g_signal_connect (hadjustment,
689                     "value-changed",
690                     G_CALLBACK (gtk_scrolled_window_adjustment_value_changed),
691                     scrolled_window);
692   gtk_scrolled_window_adjustment_changed (hadjustment, scrolled_window);
693   gtk_scrolled_window_adjustment_value_changed (hadjustment, scrolled_window);
694
695   child = gtk_bin_get_child (bin);
696   if (GTK_IS_SCROLLABLE (child))
697     gtk_scrollable_set_hadjustment (GTK_SCROLLABLE (child), hadjustment);
698
699   g_object_notify (G_OBJECT (scrolled_window), "hadjustment");
700 }
701
702 /**
703  * gtk_scrolled_window_set_vadjustment:
704  * @scrolled_window: a #GtkScrolledWindow
705  * @vadjustment: vertical scroll adjustment
706  *
707  * Sets the #GtkAdjustment for the vertical scrollbar.
708  */
709 void
710 gtk_scrolled_window_set_vadjustment (GtkScrolledWindow *scrolled_window,
711                                      GtkAdjustment     *vadjustment)
712 {
713   GtkScrolledWindowPrivate *priv;
714   GtkBin *bin;
715   GtkWidget *child;
716
717   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
718   if (vadjustment)
719     g_return_if_fail (GTK_IS_ADJUSTMENT (vadjustment));
720   else
721     vadjustment = (GtkAdjustment*) g_object_new (GTK_TYPE_ADJUSTMENT, NULL);
722
723   bin = GTK_BIN (scrolled_window);
724   priv = scrolled_window->priv;
725
726   if (!priv->vscrollbar)
727     {
728       gtk_widget_push_composite_child ();
729       priv->vscrollbar = gtk_scrollbar_new (GTK_ORIENTATION_VERTICAL, vadjustment);
730       gtk_widget_set_composite_name (priv->vscrollbar, "vscrollbar");
731       gtk_widget_pop_composite_child ();
732
733       gtk_widget_set_parent (priv->vscrollbar, GTK_WIDGET (scrolled_window));
734       g_object_ref (priv->vscrollbar);
735       gtk_widget_show (priv->vscrollbar);
736     }
737   else
738     {
739       GtkAdjustment *old_adjustment;
740       
741       old_adjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
742       if (old_adjustment == vadjustment)
743         return;
744
745       g_signal_handlers_disconnect_by_func (old_adjustment,
746                                             gtk_scrolled_window_adjustment_changed,
747                                             scrolled_window);
748       gtk_range_set_adjustment (GTK_RANGE (priv->vscrollbar),
749                                 vadjustment);
750     }
751   vadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
752   g_signal_connect (vadjustment,
753                     "changed",
754                     G_CALLBACK (gtk_scrolled_window_adjustment_changed),
755                     scrolled_window);
756   g_signal_connect (vadjustment,
757                     "value-changed",
758                     G_CALLBACK (gtk_scrolled_window_adjustment_value_changed),
759                     scrolled_window);
760   gtk_scrolled_window_adjustment_changed (vadjustment, scrolled_window);
761   gtk_scrolled_window_adjustment_value_changed (vadjustment, scrolled_window);
762
763   child = gtk_bin_get_child (bin);
764   if (GTK_IS_SCROLLABLE (child))
765     gtk_scrollable_set_vadjustment (GTK_SCROLLABLE (child), vadjustment);
766
767   g_object_notify (G_OBJECT (scrolled_window), "vadjustment");
768 }
769
770 /**
771  * gtk_scrolled_window_get_hadjustment:
772  * @scrolled_window: a #GtkScrolledWindow
773  *
774  * Returns the horizontal scrollbar's adjustment, used to connect the
775  * horizontal scrollbar to the child widget's horizontal scroll
776  * functionality.
777  *
778  * Returns: (transfer none): the horizontal #GtkAdjustment
779  */
780 GtkAdjustment*
781 gtk_scrolled_window_get_hadjustment (GtkScrolledWindow *scrolled_window)
782 {
783   GtkScrolledWindowPrivate *priv;
784
785   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
786
787   priv = scrolled_window->priv;
788
789   return (priv->hscrollbar ?
790           gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)) :
791           NULL);
792 }
793
794 /**
795  * gtk_scrolled_window_get_vadjustment:
796  * @scrolled_window: a #GtkScrolledWindow
797  * 
798  * Returns the vertical scrollbar's adjustment, used to connect the
799  * vertical scrollbar to the child widget's vertical scroll functionality.
800  * 
801  * Returns: (transfer none): the vertical #GtkAdjustment
802  */
803 GtkAdjustment*
804 gtk_scrolled_window_get_vadjustment (GtkScrolledWindow *scrolled_window)
805 {
806   GtkScrolledWindowPrivate *priv;
807
808   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
809
810   priv = scrolled_window->priv;
811
812   return (priv->vscrollbar ?
813           gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)) :
814           NULL);
815 }
816
817 /**
818  * gtk_scrolled_window_get_hscrollbar:
819  * @scrolled_window: a #GtkScrolledWindow
820  *
821  * Returns the horizontal scrollbar of @scrolled_window.
822  *
823  * Returns: (transfer none): the horizontal scrollbar of the scrolled window,
824  *     or %NULL if it does not have one.
825  *
826  * Since: 2.8
827  */
828 GtkWidget*
829 gtk_scrolled_window_get_hscrollbar (GtkScrolledWindow *scrolled_window)
830 {
831   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
832
833   return scrolled_window->priv->hscrollbar;
834 }
835
836 /**
837  * gtk_scrolled_window_get_vscrollbar:
838  * @scrolled_window: a #GtkScrolledWindow
839  * 
840  * Returns the vertical scrollbar of @scrolled_window.
841  *
842  * Returns: (transfer none): the vertical scrollbar of the scrolled window,
843  *     or %NULL if it does not have one.
844  *
845  * Since: 2.8
846  */
847 GtkWidget*
848 gtk_scrolled_window_get_vscrollbar (GtkScrolledWindow *scrolled_window)
849 {
850   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), NULL);
851
852   return scrolled_window->priv->vscrollbar;
853 }
854
855 /**
856  * gtk_scrolled_window_set_policy:
857  * @scrolled_window: a #GtkScrolledWindow
858  * @hscrollbar_policy: policy for horizontal bar
859  * @vscrollbar_policy: policy for vertical bar
860  * 
861  * Sets the scrollbar policy for the horizontal and vertical scrollbars.
862  *
863  * The policy determines when the scrollbar should appear; it is a value
864  * from the #GtkPolicyType enumeration. If %GTK_POLICY_ALWAYS, the
865  * scrollbar is always present; if %GTK_POLICY_NEVER, the scrollbar is
866  * never present; if %GTK_POLICY_AUTOMATIC, the scrollbar is present only
867  * if needed (that is, if the slider part of the bar would be smaller
868  * than the trough - the display is larger than the page size).
869  */
870 void
871 gtk_scrolled_window_set_policy (GtkScrolledWindow *scrolled_window,
872                                 GtkPolicyType      hscrollbar_policy,
873                                 GtkPolicyType      vscrollbar_policy)
874 {
875   GtkScrolledWindowPrivate *priv;
876   GObject *object = G_OBJECT (scrolled_window);
877   
878   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
879
880   priv = scrolled_window->priv;
881
882   if ((priv->hscrollbar_policy != hscrollbar_policy) ||
883       (priv->vscrollbar_policy != vscrollbar_policy))
884     {
885       priv->hscrollbar_policy = hscrollbar_policy;
886       priv->vscrollbar_policy = vscrollbar_policy;
887
888       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
889
890       g_object_freeze_notify (object);
891       g_object_notify (object, "hscrollbar-policy");
892       g_object_notify (object, "vscrollbar-policy");
893       g_object_thaw_notify (object);
894     }
895 }
896
897 /**
898  * gtk_scrolled_window_get_policy:
899  * @scrolled_window: a #GtkScrolledWindow
900  * @hscrollbar_policy: (out) (allow-none): location to store the policy 
901  *     for the horizontal scrollbar, or %NULL.
902  * @vscrollbar_policy: (out) (allow-none): location to store the policy
903  *     for the vertical scrollbar, or %NULL.
904  * 
905  * Retrieves the current policy values for the horizontal and vertical
906  * scrollbars. See gtk_scrolled_window_set_policy().
907  */
908 void
909 gtk_scrolled_window_get_policy (GtkScrolledWindow *scrolled_window,
910                                 GtkPolicyType     *hscrollbar_policy,
911                                 GtkPolicyType     *vscrollbar_policy)
912 {
913   GtkScrolledWindowPrivate *priv;
914
915   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
916
917   priv = scrolled_window->priv;
918
919   if (hscrollbar_policy)
920     *hscrollbar_policy = priv->hscrollbar_policy;
921   if (vscrollbar_policy)
922     *vscrollbar_policy = priv->vscrollbar_policy;
923 }
924
925 static void
926 gtk_scrolled_window_update_real_placement (GtkScrolledWindow *scrolled_window)
927 {
928   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
929   GtkSettings *settings;
930
931   settings = gtk_widget_get_settings (GTK_WIDGET (scrolled_window));
932
933   if (priv->window_placement_set || settings == NULL)
934     priv->real_window_placement = priv->window_placement;
935   else
936     g_object_get (settings,
937                   "gtk-scrolled-window-placement",
938                   &priv->real_window_placement,
939                   NULL);
940 }
941
942 static void
943 gtk_scrolled_window_set_placement_internal (GtkScrolledWindow *scrolled_window,
944                                             GtkCornerType      window_placement)
945 {
946   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
947
948   if (priv->window_placement != window_placement)
949     {
950       priv->window_placement = window_placement;
951
952       gtk_scrolled_window_update_real_placement (scrolled_window);
953       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
954       
955       g_object_notify (G_OBJECT (scrolled_window), "window-placement");
956     }
957 }
958
959 static void
960 gtk_scrolled_window_set_placement_set (GtkScrolledWindow *scrolled_window,
961                                        gboolean           placement_set,
962                                        gboolean           emit_resize)
963 {
964   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
965
966   if (priv->window_placement_set != placement_set)
967     {
968       priv->window_placement_set = placement_set;
969
970       gtk_scrolled_window_update_real_placement (scrolled_window);
971       if (emit_resize)
972         gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
973
974       g_object_notify (G_OBJECT (scrolled_window), "window-placement-set");
975     }
976 }
977
978 /**
979  * gtk_scrolled_window_set_placement:
980  * @scrolled_window: a #GtkScrolledWindow
981  * @window_placement: position of the child window
982  *
983  * Sets the placement of the contents with respect to the scrollbars
984  * for the scrolled window.
985  * 
986  * The default is %GTK_CORNER_TOP_LEFT, meaning the child is
987  * in the top left, with the scrollbars underneath and to the right.
988  * Other values in #GtkCornerType are %GTK_CORNER_TOP_RIGHT,
989  * %GTK_CORNER_BOTTOM_LEFT, and %GTK_CORNER_BOTTOM_RIGHT.
990  *
991  * See also gtk_scrolled_window_get_placement() and
992  * gtk_scrolled_window_unset_placement().
993  */
994 void
995 gtk_scrolled_window_set_placement (GtkScrolledWindow *scrolled_window,
996                                    GtkCornerType      window_placement)
997 {
998   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
999
1000   gtk_scrolled_window_set_placement_set (scrolled_window, TRUE, FALSE);
1001   gtk_scrolled_window_set_placement_internal (scrolled_window, window_placement);
1002 }
1003
1004 /**
1005  * gtk_scrolled_window_get_placement:
1006  * @scrolled_window: a #GtkScrolledWindow
1007  *
1008  * Gets the placement of the contents with respect to the scrollbars
1009  * for the scrolled window. See gtk_scrolled_window_set_placement().
1010  *
1011  * Return value: the current placement value.
1012  *
1013  * See also gtk_scrolled_window_set_placement() and
1014  * gtk_scrolled_window_unset_placement().
1015  **/
1016 GtkCornerType
1017 gtk_scrolled_window_get_placement (GtkScrolledWindow *scrolled_window)
1018 {
1019   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), GTK_CORNER_TOP_LEFT);
1020
1021   return scrolled_window->priv->window_placement;
1022 }
1023
1024 /**
1025  * gtk_scrolled_window_unset_placement:
1026  * @scrolled_window: a #GtkScrolledWindow
1027  *
1028  * Unsets the placement of the contents with respect to the scrollbars
1029  * for the scrolled window. If no window placement is set for a scrolled
1030  * window, it obeys the "gtk-scrolled-window-placement" XSETTING.
1031  *
1032  * See also gtk_scrolled_window_set_placement() and
1033  * gtk_scrolled_window_get_placement().
1034  *
1035  * Since: 2.10
1036  **/
1037 void
1038 gtk_scrolled_window_unset_placement (GtkScrolledWindow *scrolled_window)
1039 {
1040   GtkScrolledWindowPrivate *priv;
1041
1042   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
1043
1044   priv = scrolled_window->priv;
1045
1046   if (priv->window_placement_set)
1047     {
1048       priv->window_placement_set = FALSE;
1049
1050       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
1051
1052       g_object_notify (G_OBJECT (scrolled_window), "window-placement-set");
1053     }
1054 }
1055
1056 /**
1057  * gtk_scrolled_window_set_shadow_type:
1058  * @scrolled_window: a #GtkScrolledWindow
1059  * @type: kind of shadow to draw around scrolled window contents
1060  *
1061  * Changes the type of shadow drawn around the contents of
1062  * @scrolled_window.
1063  * 
1064  **/
1065 void
1066 gtk_scrolled_window_set_shadow_type (GtkScrolledWindow *scrolled_window,
1067                                      GtkShadowType      type)
1068 {
1069   GtkScrolledWindowPrivate *priv;
1070
1071   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
1072   g_return_if_fail (type >= GTK_SHADOW_NONE && type <= GTK_SHADOW_ETCHED_OUT);
1073
1074   priv = scrolled_window->priv;
1075
1076   if (priv->shadow_type != type)
1077     {
1078       priv->shadow_type = type;
1079
1080       if (gtk_widget_is_drawable (GTK_WIDGET (scrolled_window)))
1081         gtk_widget_queue_draw (GTK_WIDGET (scrolled_window));
1082
1083       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
1084
1085       g_object_notify (G_OBJECT (scrolled_window), "shadow-type");
1086     }
1087 }
1088
1089 /**
1090  * gtk_scrolled_window_get_shadow_type:
1091  * @scrolled_window: a #GtkScrolledWindow
1092  *
1093  * Gets the shadow type of the scrolled window. See 
1094  * gtk_scrolled_window_set_shadow_type().
1095  *
1096  * Return value: the current shadow type
1097  **/
1098 GtkShadowType
1099 gtk_scrolled_window_get_shadow_type (GtkScrolledWindow *scrolled_window)
1100 {
1101   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), GTK_SHADOW_NONE);
1102
1103   return scrolled_window->priv->shadow_type;
1104 }
1105
1106 /**
1107  * gtk_scrolled_window_set_kinetic_scrolling:
1108  * @scrolled_window: a #GtkScrolledWindow
1109  * @kinetic_scrolling: %TRUE to enable kinetic scrolling
1110  *
1111  * Turns kinetic scrolling on or off.
1112  * Kinetic scrolling only applies to devices with source
1113  * %GDK_SOURCE_TOUCHSCREEN.
1114  *
1115  * Since: 3.4
1116  **/
1117 void
1118 gtk_scrolled_window_set_kinetic_scrolling (GtkScrolledWindow *scrolled_window,
1119                                            gboolean           kinetic_scrolling)
1120 {
1121   GtkScrolledWindowPrivate *priv;
1122
1123   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
1124
1125   priv = scrolled_window->priv;
1126   if (priv->kinetic_scrolling == kinetic_scrolling)
1127     return;
1128
1129   priv->kinetic_scrolling = kinetic_scrolling;
1130   if (priv->kinetic_scrolling)
1131     {
1132       _gtk_widget_set_captured_event_handler (GTK_WIDGET (scrolled_window),
1133                                               gtk_scrolled_window_captured_event);
1134     }
1135   else
1136     {
1137       _gtk_widget_set_captured_event_handler (GTK_WIDGET (scrolled_window), NULL);
1138       if (priv->release_timeout_id)
1139         {
1140           g_source_remove (priv->release_timeout_id);
1141           priv->release_timeout_id = 0;
1142         }
1143       if (priv->deceleration_id)
1144         {
1145           g_source_remove (priv->deceleration_id);
1146           priv->deceleration_id = 0;
1147         }
1148     }
1149   g_object_notify (G_OBJECT (scrolled_window), "kinetic-scrolling");
1150 }
1151
1152 /**
1153  * gtk_scrolled_window_get_kinetic_scrolling:
1154  * @scrolled_window: a #GtkScrolledWindow
1155  *
1156  * Returns the specified kinetic scrolling behavior.
1157  *
1158  * Return value: the scrolling behavior flags.
1159  *
1160  * Since: 3.4
1161  */
1162 gboolean
1163 gtk_scrolled_window_get_kinetic_scrolling (GtkScrolledWindow *scrolled_window)
1164 {
1165   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), FALSE);
1166
1167   return scrolled_window->priv->kinetic_scrolling;
1168 }
1169
1170 /**
1171  * gtk_scrolled_window_set_capture_button_press:
1172  * @scrolled_window: a #GtkScrolledWindow
1173  * @capture_button_press: %TRUE to capture button presses
1174  *
1175  * Changes the behaviour of @scrolled_window wrt. to the initial
1176  * event that possibly starts kinetic scrolling. When @capture_button_press
1177  * is set to %TRUE, the event is captured by the scrolled window, and
1178  * then later replayed if it is meant to go to the child widget.
1179  *
1180  * This should be enabled if any child widgets perform non-reversible
1181  * actions on #GtkWidget::button-press-event. If they don't, and handle
1182  * additionally handle #GtkWidget::grab-broken-event, it might be better
1183  * to set @capture_button_press to %FALSE.
1184  *
1185  * This setting only has an effect if kinetic scrolling is enabled.
1186  *
1187  * Since: 3.4
1188  */
1189 void
1190 gtk_scrolled_window_set_capture_button_press (GtkScrolledWindow *scrolled_window,
1191                                               gboolean           capture_button_press)
1192 {
1193   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
1194
1195   scrolled_window->priv->capture_button_press = capture_button_press;
1196 }
1197
1198 /**
1199  * gtk_scrolled_window_get_capture_button_press:
1200  * @scrolled_window: a #GtkScrolledWindow
1201  *
1202  * Return whether button presses are captured during kinetic
1203  * scrolling. See gtk_scrolled_window_set_capture_button_press().
1204  *
1205  * Returns: %TRUE if button presses are captured during kinetic scrolling
1206  *
1207  * Since: 3.4
1208  */
1209 gboolean
1210 gtk_scrolled_window_get_capture_button_press (GtkScrolledWindow *scrolled_window)
1211 {
1212   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), FALSE);
1213
1214   return scrolled_window->priv->capture_button_press;
1215 }
1216
1217
1218 static void
1219 gtk_scrolled_window_destroy (GtkWidget *widget)
1220 {
1221   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
1222   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1223
1224   if (priv->hscrollbar)
1225     {
1226       g_signal_handlers_disconnect_by_func (gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)),
1227                                             gtk_scrolled_window_adjustment_changed,
1228                                             scrolled_window);
1229       gtk_widget_unparent (priv->hscrollbar);
1230       gtk_widget_destroy (priv->hscrollbar);
1231       g_object_unref (priv->hscrollbar);
1232       priv->hscrollbar = NULL;
1233     }
1234   if (priv->vscrollbar)
1235     {
1236       g_signal_handlers_disconnect_by_func (gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)),
1237                                             gtk_scrolled_window_adjustment_changed,
1238                                             scrolled_window);
1239       gtk_widget_unparent (priv->vscrollbar);
1240       gtk_widget_destroy (priv->vscrollbar);
1241       g_object_unref (priv->vscrollbar);
1242       priv->vscrollbar = NULL;
1243     }
1244
1245   if (priv->release_timeout_id)
1246     {
1247       g_source_remove (priv->release_timeout_id);
1248       priv->release_timeout_id = 0;
1249     }
1250   if (priv->deceleration_id)
1251     {
1252       g_source_remove (priv->deceleration_id);
1253       priv->deceleration_id = 0;
1254     }
1255
1256   if (priv->button_press_event)
1257     {
1258       gdk_event_free (priv->button_press_event);
1259       priv->button_press_event = NULL;
1260     }
1261
1262   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->destroy (widget);
1263 }
1264
1265 static void
1266 gtk_scrolled_window_set_property (GObject      *object,
1267                                   guint         prop_id,
1268                                   const GValue *value,
1269                                   GParamSpec   *pspec)
1270 {
1271   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (object);
1272   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1273
1274   switch (prop_id)
1275     {
1276     case PROP_HADJUSTMENT:
1277       gtk_scrolled_window_set_hadjustment (scrolled_window,
1278                                            g_value_get_object (value));
1279       break;
1280     case PROP_VADJUSTMENT:
1281       gtk_scrolled_window_set_vadjustment (scrolled_window,
1282                                            g_value_get_object (value));
1283       break;
1284     case PROP_HSCROLLBAR_POLICY:
1285       gtk_scrolled_window_set_policy (scrolled_window,
1286                                       g_value_get_enum (value),
1287                                       priv->vscrollbar_policy);
1288       break;
1289     case PROP_VSCROLLBAR_POLICY:
1290       gtk_scrolled_window_set_policy (scrolled_window,
1291                                       priv->hscrollbar_policy,
1292                                       g_value_get_enum (value));
1293       break;
1294     case PROP_WINDOW_PLACEMENT:
1295       gtk_scrolled_window_set_placement_internal (scrolled_window,
1296                                                   g_value_get_enum (value));
1297       break;
1298     case PROP_WINDOW_PLACEMENT_SET:
1299       gtk_scrolled_window_set_placement_set (scrolled_window,
1300                                              g_value_get_boolean (value),
1301                                              TRUE);
1302       break;
1303     case PROP_SHADOW_TYPE:
1304       gtk_scrolled_window_set_shadow_type (scrolled_window,
1305                                            g_value_get_enum (value));
1306       break;
1307     case PROP_MIN_CONTENT_WIDTH:
1308       gtk_scrolled_window_set_min_content_width (scrolled_window,
1309                                                  g_value_get_int (value));
1310       break;
1311     case PROP_MIN_CONTENT_HEIGHT:
1312       gtk_scrolled_window_set_min_content_height (scrolled_window,
1313                                                   g_value_get_int (value));
1314       break;
1315     case PROP_KINETIC_SCROLLING:
1316       gtk_scrolled_window_set_kinetic_scrolling (scrolled_window,
1317                                                  g_value_get_boolean (value));
1318       break;
1319     default:
1320       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1321       break;
1322     }
1323 }
1324
1325 static void
1326 gtk_scrolled_window_get_property (GObject    *object,
1327                                   guint       prop_id,
1328                                   GValue     *value,
1329                                   GParamSpec *pspec)
1330 {
1331   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (object);
1332   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1333
1334   switch (prop_id)
1335     {
1336     case PROP_HADJUSTMENT:
1337       g_value_set_object (value,
1338                           G_OBJECT (gtk_scrolled_window_get_hadjustment (scrolled_window)));
1339       break;
1340     case PROP_VADJUSTMENT:
1341       g_value_set_object (value,
1342                           G_OBJECT (gtk_scrolled_window_get_vadjustment (scrolled_window)));
1343       break;
1344     case PROP_WINDOW_PLACEMENT:
1345       g_value_set_enum (value, priv->window_placement);
1346       break;
1347     case PROP_WINDOW_PLACEMENT_SET:
1348       g_value_set_boolean (value, priv->window_placement_set);
1349       break;
1350     case PROP_SHADOW_TYPE:
1351       g_value_set_enum (value, priv->shadow_type);
1352       break;
1353     case PROP_HSCROLLBAR_POLICY:
1354       g_value_set_enum (value, priv->hscrollbar_policy);
1355       break;
1356     case PROP_VSCROLLBAR_POLICY:
1357       g_value_set_enum (value, priv->vscrollbar_policy);
1358       break;
1359     case PROP_MIN_CONTENT_WIDTH:
1360       g_value_set_int (value, priv->min_content_width);
1361       break;
1362     case PROP_MIN_CONTENT_HEIGHT:
1363       g_value_set_int (value, priv->min_content_height);
1364       break;
1365     case PROP_KINETIC_SCROLLING:
1366       g_value_set_boolean (value, priv->kinetic_scrolling);
1367       break;
1368     default:
1369       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
1370       break;
1371     }
1372 }
1373
1374 static void
1375 traverse_container (GtkWidget *widget,
1376                     gpointer   data)
1377 {
1378   if (GTK_IS_SCROLLED_WINDOW (widget))
1379     {
1380       gtk_scrolled_window_update_real_placement (GTK_SCROLLED_WINDOW (widget));
1381       gtk_widget_queue_resize (widget);
1382     }
1383   else if (GTK_IS_CONTAINER (widget))
1384     gtk_container_forall (GTK_CONTAINER (widget), traverse_container, NULL);
1385 }
1386
1387 static void
1388 gtk_scrolled_window_settings_changed (GtkSettings *settings)
1389 {
1390   GList *list, *l;
1391
1392   list = gtk_window_list_toplevels ();
1393
1394   for (l = list; l; l = l->next)
1395     gtk_container_forall (GTK_CONTAINER (l->data), 
1396                           traverse_container, NULL);
1397
1398   g_list_free (list);
1399 }
1400
1401 static void
1402 gtk_scrolled_window_screen_changed (GtkWidget *widget,
1403                                     GdkScreen *previous_screen)
1404 {
1405   GtkSettings *settings;
1406   guint window_placement_connection;
1407
1408   gtk_scrolled_window_update_real_placement (GTK_SCROLLED_WINDOW (widget));
1409
1410   if (!gtk_widget_has_screen (widget))
1411     return;
1412
1413   settings = gtk_widget_get_settings (widget);
1414
1415   window_placement_connection = 
1416     GPOINTER_TO_UINT (g_object_get_data (G_OBJECT (settings), 
1417                                          "gtk-scrolled-window-connection"));
1418   
1419   if (window_placement_connection)
1420     return;
1421
1422   window_placement_connection =
1423     g_signal_connect (settings, "notify::gtk-scrolled-window-placement",
1424                       G_CALLBACK (gtk_scrolled_window_settings_changed), NULL);
1425   g_object_set_data (G_OBJECT (settings), 
1426                      I_("gtk-scrolled-window-connection"),
1427                      GUINT_TO_POINTER (window_placement_connection));
1428 }
1429
1430 static void
1431 gtk_scrolled_window_draw_scrollbars_junction (GtkScrolledWindow *scrolled_window,
1432                                               cairo_t *cr)
1433 {
1434   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1435   GtkAllocation wid_allocation, hscr_allocation, vscr_allocation;
1436   GtkStyleContext *context;
1437   GdkRectangle junction_rect;
1438   gboolean is_rtl;
1439
1440   is_rtl = gtk_widget_get_direction (GTK_WIDGET (scrolled_window)) == GTK_TEXT_DIR_RTL;
1441   gtk_widget_get_allocation (GTK_WIDGET (scrolled_window), &wid_allocation);
1442   gtk_widget_get_allocation (GTK_WIDGET (priv->hscrollbar), &hscr_allocation);
1443   gtk_widget_get_allocation (GTK_WIDGET (priv->vscrollbar), &vscr_allocation);
1444
1445   junction_rect.x = 0;
1446   junction_rect.y = 0;
1447   junction_rect.width = vscr_allocation.width;
1448   junction_rect.height = hscr_allocation.height;
1449   
1450   if ((is_rtl && 
1451        (priv->real_window_placement == GTK_CORNER_TOP_RIGHT ||
1452         priv->real_window_placement == GTK_CORNER_BOTTOM_RIGHT)) ||
1453       (!is_rtl && 
1454        (priv->real_window_placement == GTK_CORNER_TOP_LEFT ||
1455         priv->real_window_placement == GTK_CORNER_BOTTOM_LEFT)))
1456     junction_rect.x = hscr_allocation.width;
1457
1458   if (priv->real_window_placement == GTK_CORNER_TOP_LEFT ||
1459       priv->real_window_placement == GTK_CORNER_TOP_RIGHT)
1460     junction_rect.y = vscr_allocation.height;
1461
1462   context = gtk_widget_get_style_context (GTK_WIDGET (scrolled_window));
1463   gtk_style_context_save (context);
1464   gtk_style_context_add_class (context, GTK_STYLE_CLASS_SCROLLBARS_JUNCTION);
1465
1466   gtk_render_background (context, cr,
1467                          junction_rect.x, junction_rect.y,
1468                          junction_rect.width, junction_rect.height);
1469   gtk_render_frame (context, cr,
1470                     junction_rect.x, junction_rect.y,
1471                     junction_rect.width, junction_rect.height);
1472
1473   gtk_style_context_restore (context);
1474 }
1475
1476 static gboolean
1477 gtk_scrolled_window_draw (GtkWidget *widget,
1478                           cairo_t   *cr)
1479 {
1480   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
1481   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1482   GtkAllocation relative_allocation;
1483   cairo_pattern_t *pattern = NULL;
1484   GtkStyleContext *context;
1485   GtkWidget *child;
1486
1487   context = gtk_widget_get_style_context (widget);
1488   gtk_scrolled_window_relative_allocation (widget, &relative_allocation);
1489
1490   /* Use child's background if possible */
1491   child = gtk_bin_get_child (GTK_BIN (widget));
1492
1493   if (child && gtk_widget_get_has_window (child))
1494     pattern = gdk_window_get_background_pattern (gtk_widget_get_window (child));
1495
1496   if (pattern &&
1497       cairo_pattern_get_type (pattern) == CAIRO_PATTERN_TYPE_SOLID)
1498     {
1499       cairo_set_source (cr, pattern);
1500
1501       cairo_rectangle (cr, relative_allocation.x, relative_allocation.y,
1502                        relative_allocation.width, relative_allocation.height);
1503       cairo_fill (cr);
1504     }
1505   else
1506     gtk_render_background (context, cr,
1507                            relative_allocation.x, relative_allocation.y,
1508                            relative_allocation.width, relative_allocation.height);
1509
1510   if (priv->hscrollbar_visible && 
1511       priv->vscrollbar_visible)
1512     gtk_scrolled_window_draw_scrollbars_junction (scrolled_window, cr);
1513
1514   if (priv->shadow_type != GTK_SHADOW_NONE)
1515     {
1516       gboolean scrollbars_within_bevel;
1517
1518       gtk_style_context_save (context);
1519       gtk_style_context_add_class (context, GTK_STYLE_CLASS_FRAME);
1520
1521       gtk_widget_style_get (widget, "scrollbars-within-bevel", &scrollbars_within_bevel, NULL);
1522
1523       if (!scrollbars_within_bevel)
1524         {
1525           GtkStateFlags state;
1526           GtkBorder padding, border;
1527
1528           state = gtk_widget_get_state_flags (widget);
1529           gtk_style_context_get_padding (context, state, &padding);
1530           gtk_style_context_get_border (context, state, &border);
1531
1532           relative_allocation.x -= padding.left + border.left;
1533           relative_allocation.y -= padding.top + border.top;
1534           relative_allocation.width += padding.left + padding.right + border.left + border.right;
1535           relative_allocation.height += padding.top + padding.bottom + border.top + border.bottom;
1536         }
1537       else
1538         {
1539           relative_allocation.x = 0;
1540           relative_allocation.y = 0;
1541           relative_allocation.width = gtk_widget_get_allocated_width (widget);
1542           relative_allocation.height = gtk_widget_get_allocated_height (widget);
1543         }
1544
1545       gtk_render_frame (context, cr,
1546                         relative_allocation.x,
1547                         relative_allocation.y,
1548                         relative_allocation.width,
1549                         relative_allocation.height);
1550
1551       gtk_style_context_restore (context);
1552     }
1553
1554   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->draw (widget, cr);
1555
1556   return FALSE;
1557 }
1558
1559 static void
1560 gtk_scrolled_window_forall (GtkContainer *container,
1561                             gboolean      include_internals,
1562                             GtkCallback   callback,
1563                             gpointer      callback_data)
1564 {
1565   GtkScrolledWindowPrivate *priv;
1566   GtkScrolledWindow *scrolled_window;
1567
1568   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (container));
1569   g_return_if_fail (callback != NULL);
1570
1571   GTK_CONTAINER_CLASS (gtk_scrolled_window_parent_class)->forall (container,
1572                                               include_internals,
1573                                               callback,
1574                                               callback_data);
1575   if (include_internals)
1576     {
1577       scrolled_window = GTK_SCROLLED_WINDOW (container);
1578       priv = scrolled_window->priv;
1579
1580       if (priv->vscrollbar)
1581         callback (priv->vscrollbar, callback_data);
1582       if (priv->hscrollbar)
1583         callback (priv->hscrollbar, callback_data);
1584     }
1585 }
1586
1587 static gboolean
1588 gtk_scrolled_window_scroll_child (GtkScrolledWindow *scrolled_window,
1589                                   GtkScrollType      scroll,
1590                                   gboolean           horizontal)
1591 {
1592   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1593   GtkAdjustment *adjustment = NULL;
1594   
1595   switch (scroll)
1596     {
1597     case GTK_SCROLL_STEP_UP:
1598       scroll = GTK_SCROLL_STEP_BACKWARD;
1599       horizontal = FALSE;
1600       break;
1601     case GTK_SCROLL_STEP_DOWN:
1602       scroll = GTK_SCROLL_STEP_FORWARD;
1603       horizontal = FALSE;
1604       break;
1605     case GTK_SCROLL_STEP_LEFT:
1606       scroll = GTK_SCROLL_STEP_BACKWARD;
1607       horizontal = TRUE;
1608       break;
1609     case GTK_SCROLL_STEP_RIGHT:
1610       scroll = GTK_SCROLL_STEP_FORWARD;
1611       horizontal = TRUE;
1612       break;
1613     case GTK_SCROLL_PAGE_UP:
1614       scroll = GTK_SCROLL_PAGE_BACKWARD;
1615       horizontal = FALSE;
1616       break;
1617     case GTK_SCROLL_PAGE_DOWN:
1618       scroll = GTK_SCROLL_PAGE_FORWARD;
1619       horizontal = FALSE;
1620       break;
1621     case GTK_SCROLL_PAGE_LEFT:
1622       scroll = GTK_SCROLL_STEP_BACKWARD;
1623       horizontal = TRUE;
1624       break;
1625     case GTK_SCROLL_PAGE_RIGHT:
1626       scroll = GTK_SCROLL_STEP_FORWARD;
1627       horizontal = TRUE;
1628       break;
1629     case GTK_SCROLL_STEP_BACKWARD:
1630     case GTK_SCROLL_STEP_FORWARD:
1631     case GTK_SCROLL_PAGE_BACKWARD:
1632     case GTK_SCROLL_PAGE_FORWARD:
1633     case GTK_SCROLL_START:
1634     case GTK_SCROLL_END:
1635       break;
1636     default:
1637       g_warning ("Invalid scroll type %u for GtkScrolledWindow::scroll-child", scroll);
1638       return FALSE;
1639     }
1640
1641   if ((horizontal && (!priv->hscrollbar || !priv->hscrollbar_visible)) ||
1642       (!horizontal && (!priv->vscrollbar || !priv->vscrollbar_visible)))
1643     return FALSE;
1644
1645   if (horizontal)
1646     {
1647       if (priv->hscrollbar)
1648         adjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
1649     }
1650   else
1651     {
1652       if (priv->vscrollbar)
1653         adjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
1654     }
1655
1656   if (adjustment)
1657     {
1658       gdouble value = gtk_adjustment_get_value (adjustment);
1659       
1660       switch (scroll)
1661         {
1662         case GTK_SCROLL_STEP_FORWARD:
1663           value += gtk_adjustment_get_step_increment (adjustment);
1664           break;
1665         case GTK_SCROLL_STEP_BACKWARD:
1666           value -= gtk_adjustment_get_step_increment (adjustment);
1667           break;
1668         case GTK_SCROLL_PAGE_FORWARD:
1669           value += gtk_adjustment_get_page_increment (adjustment);
1670           break;
1671         case GTK_SCROLL_PAGE_BACKWARD:
1672           value -= gtk_adjustment_get_page_increment (adjustment);
1673           break;
1674         case GTK_SCROLL_START:
1675           value = gtk_adjustment_get_lower (adjustment);
1676           break;
1677         case GTK_SCROLL_END:
1678           value = gtk_adjustment_get_upper (adjustment);
1679           break;
1680         default:
1681           g_assert_not_reached ();
1682           break;
1683         }
1684
1685       gtk_adjustment_set_value (adjustment, value);
1686
1687       return TRUE;
1688     }
1689
1690   return FALSE;
1691 }
1692
1693 static void
1694 gtk_scrolled_window_move_focus_out (GtkScrolledWindow *scrolled_window,
1695                                     GtkDirectionType   direction_type)
1696 {
1697   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1698   GtkWidget *toplevel;
1699   
1700   /* Focus out of the scrolled window entirely. We do this by setting
1701    * a flag, then propagating the focus motion to the notebook.
1702    */
1703   toplevel = gtk_widget_get_toplevel (GTK_WIDGET (scrolled_window));
1704   if (!gtk_widget_is_toplevel (toplevel))
1705     return;
1706
1707   g_object_ref (scrolled_window);
1708
1709   priv->focus_out = TRUE;
1710   g_signal_emit_by_name (toplevel, "move-focus", direction_type);
1711   priv->focus_out = FALSE;
1712
1713   g_object_unref (scrolled_window);
1714 }
1715
1716 static void
1717 gtk_scrolled_window_relative_allocation (GtkWidget     *widget,
1718                                          GtkAllocation *allocation)
1719 {
1720   GtkAllocation widget_allocation;
1721   GtkScrolledWindow *scrolled_window;
1722   GtkScrolledWindowPrivate *priv;
1723   gint sb_spacing;
1724   gint sb_width;
1725   gint sb_height;
1726
1727   g_return_if_fail (widget != NULL);
1728   g_return_if_fail (allocation != NULL);
1729
1730   scrolled_window = GTK_SCROLLED_WINDOW (widget);
1731   priv = scrolled_window->priv;
1732
1733   /* Get possible scrollbar dimensions */
1734   sb_spacing = _gtk_scrolled_window_get_scrollbar_spacing (scrolled_window);
1735   gtk_widget_get_preferred_height (priv->hscrollbar, &sb_height, NULL);
1736   gtk_widget_get_preferred_width (priv->vscrollbar, &sb_width, NULL);
1737
1738   /* Subtract some things from our available allocation size */
1739   allocation->x = 0;
1740   allocation->y = 0;
1741
1742   if (priv->shadow_type != GTK_SHADOW_NONE)
1743     {
1744       GtkStyleContext *context;
1745       GtkStateFlags state;
1746       GtkBorder padding, border;
1747
1748       context = gtk_widget_get_style_context (widget);
1749       state = gtk_widget_get_state_flags (widget);
1750
1751       gtk_style_context_save (context);
1752       gtk_style_context_add_class (context, GTK_STYLE_CLASS_FRAME);
1753
1754       gtk_style_context_get_border (context, state, &border);
1755       gtk_style_context_get_padding (context, state, &padding);
1756
1757       allocation->x += padding.left + border.left;
1758       allocation->y += padding.top + border.top;
1759
1760       gtk_style_context_restore (context);
1761     }
1762
1763   gtk_widget_get_allocation (widget, &widget_allocation);
1764   allocation->width = MAX (1, (gint) widget_allocation.width - allocation->x * 2);
1765   allocation->height = MAX (1, (gint) widget_allocation.height - allocation->y * 2);
1766
1767   if (priv->vscrollbar_visible)
1768     {
1769       gboolean is_rtl;
1770
1771       is_rtl = gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL;
1772   
1773       if ((!is_rtl && 
1774            (priv->real_window_placement == GTK_CORNER_TOP_RIGHT ||
1775             priv->real_window_placement == GTK_CORNER_BOTTOM_RIGHT)) ||
1776           (is_rtl && 
1777            (priv->real_window_placement == GTK_CORNER_TOP_LEFT ||
1778             priv->real_window_placement == GTK_CORNER_BOTTOM_LEFT)))
1779         allocation->x += (sb_width +  sb_spacing);
1780
1781       allocation->width = MAX (1, allocation->width - (sb_width + sb_spacing));
1782     }
1783   if (priv->hscrollbar_visible)
1784     {
1785
1786       if (priv->real_window_placement == GTK_CORNER_BOTTOM_LEFT ||
1787           priv->real_window_placement == GTK_CORNER_BOTTOM_RIGHT)
1788         allocation->y += (sb_height + sb_spacing);
1789
1790       allocation->height = MAX (1, allocation->height - (sb_height + sb_spacing));
1791     }
1792 }
1793
1794 static gboolean
1795 _gtk_scrolled_window_get_overshoot (GtkScrolledWindow *scrolled_window,
1796                                     gint              *overshoot_x,
1797                                     gint              *overshoot_y)
1798 {
1799   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1800   GtkAdjustment *vadjustment, *hadjustment;
1801   gdouble lower, upper, x, y;
1802
1803   /* Vertical overshoot */
1804   vadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
1805   lower = gtk_adjustment_get_lower (vadjustment);
1806   upper = gtk_adjustment_get_upper (vadjustment) -
1807     gtk_adjustment_get_page_size (vadjustment);
1808
1809   if (priv->unclamped_vadj_value < lower)
1810     y = priv->unclamped_vadj_value - lower;
1811   else if (priv->unclamped_vadj_value > upper)
1812     y = priv->unclamped_vadj_value - upper;
1813   else
1814     y = 0;
1815
1816   /* Horizontal overshoot */
1817   hadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
1818   lower = gtk_adjustment_get_lower (hadjustment);
1819   upper = gtk_adjustment_get_upper (hadjustment) -
1820     gtk_adjustment_get_page_size (hadjustment);
1821
1822   if (priv->unclamped_hadj_value < lower)
1823     x = priv->unclamped_hadj_value - lower;
1824   else if (priv->unclamped_hadj_value > upper)
1825     x = priv->unclamped_hadj_value - upper;
1826   else
1827     x = 0;
1828
1829   if (overshoot_x)
1830     *overshoot_x = x;
1831
1832   if (overshoot_y)
1833     *overshoot_y = y;
1834
1835   return (x != 0 || y != 0);
1836 }
1837
1838 static void
1839 _gtk_scrolled_window_allocate_overshoot_window (GtkScrolledWindow *scrolled_window)
1840 {
1841   GtkAllocation window_allocation, relative_allocation, allocation;
1842   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
1843   GtkWidget *widget = GTK_WIDGET (scrolled_window);
1844   gint overshoot_x, overshoot_y;
1845
1846   if (!gtk_widget_get_realized (widget))
1847     return;
1848
1849   gtk_widget_get_allocation (widget, &allocation);
1850   gtk_scrolled_window_relative_allocation (widget, &relative_allocation);
1851   _gtk_scrolled_window_get_overshoot (scrolled_window,
1852                                       &overshoot_x, &overshoot_y);
1853
1854   window_allocation = relative_allocation;
1855   window_allocation.x += allocation.x;
1856   window_allocation.y += allocation.y;
1857
1858   /* Handle displacement to the left/top by moving the overshoot
1859    * window, overshooting to the bottom/right is handled in
1860    * gtk_scrolled_window_allocate_child()
1861    */
1862   if (overshoot_x < 0)
1863     window_allocation.x += -overshoot_x;
1864
1865   if (overshoot_y < 0)
1866     window_allocation.y += -overshoot_y;
1867
1868   window_allocation.width -= ABS (overshoot_x);
1869   window_allocation.height -= ABS (overshoot_y);
1870
1871   gdk_window_move_resize (priv->overshoot_window,
1872                           window_allocation.x, window_allocation.y,
1873                           window_allocation.width, window_allocation.height);
1874 }
1875
1876 static void
1877 gtk_scrolled_window_allocate_child (GtkScrolledWindow *swindow,
1878                                     GtkAllocation     *relative_allocation)
1879 {
1880   GtkWidget     *widget = GTK_WIDGET (swindow), *child;
1881   GtkAllocation  allocation;
1882   GtkAllocation  child_allocation;
1883   gint           overshoot_x, overshoot_y;
1884
1885   child = gtk_bin_get_child (GTK_BIN (widget));
1886
1887   gtk_widget_get_allocation (widget, &allocation);
1888
1889   gtk_scrolled_window_relative_allocation (widget, relative_allocation);
1890   _gtk_scrolled_window_get_overshoot (swindow, &overshoot_x, &overshoot_y);
1891
1892   /* Handle overshooting to the right/bottom by relocating the
1893    * widget allocation to negative coordinates, so these edges
1894    * stick to the overshoot window border.
1895    */
1896   if (overshoot_x > 0)
1897     child_allocation.x = -overshoot_x;
1898   else
1899     child_allocation.x = 0;
1900
1901   if (overshoot_y > 0)
1902     child_allocation.y = -overshoot_y;
1903   else
1904     child_allocation.y = 0;
1905
1906   child_allocation.width = relative_allocation->width;
1907   child_allocation.height = relative_allocation->height;
1908
1909   gtk_widget_size_allocate (child, &child_allocation);
1910 }
1911
1912 static void
1913 gtk_scrolled_window_size_allocate (GtkWidget     *widget,
1914                                    GtkAllocation *allocation)
1915 {
1916   GtkScrolledWindow *scrolled_window;
1917   GtkScrolledWindowPrivate *priv;
1918   GtkStyleContext *context;
1919   GtkStateFlags state;
1920   GtkBorder padding, border;
1921   GtkBin *bin;
1922   GtkAllocation relative_allocation;
1923   GtkAllocation child_allocation;
1924   GtkWidget *child;
1925   gboolean scrollbars_within_bevel;
1926   gint sb_spacing;
1927   gint sb_width;
1928   gint sb_height;
1929
1930   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (widget));
1931   g_return_if_fail (allocation != NULL);
1932
1933   scrolled_window = GTK_SCROLLED_WINDOW (widget);
1934   bin = GTK_BIN (scrolled_window);
1935   priv = scrolled_window->priv;
1936
1937   /* Get possible scrollbar dimensions */
1938   sb_spacing = _gtk_scrolled_window_get_scrollbar_spacing (scrolled_window);
1939   gtk_widget_get_preferred_height (priv->hscrollbar, &sb_height, NULL);
1940   gtk_widget_get_preferred_width (priv->vscrollbar, &sb_width, NULL);
1941
1942   context = gtk_widget_get_style_context (widget);
1943   state = gtk_widget_get_state_flags (widget);
1944
1945   gtk_style_context_save (context);
1946   gtk_style_context_add_class (context, GTK_STYLE_CLASS_FRAME);
1947
1948   gtk_style_context_get_padding (context, state, &padding);
1949   gtk_style_context_get_border (context, state, &border);
1950
1951   gtk_widget_style_get (widget, "scrollbars-within-bevel", &scrollbars_within_bevel, NULL);
1952
1953   gtk_widget_set_allocation (widget, allocation);
1954   gtk_style_context_restore (context);
1955
1956   if (priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
1957     priv->hscrollbar_visible = TRUE;
1958   else if (priv->hscrollbar_policy == GTK_POLICY_NEVER)
1959     priv->hscrollbar_visible = FALSE;
1960   if (priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
1961     priv->vscrollbar_visible = TRUE;
1962   else if (priv->vscrollbar_policy == GTK_POLICY_NEVER)
1963     priv->vscrollbar_visible = FALSE;
1964
1965   child = gtk_bin_get_child (bin);
1966   if (child && gtk_widget_get_visible (child))
1967     {
1968       gint child_scroll_width;
1969       gint child_scroll_height;
1970       gboolean previous_hvis;
1971       gboolean previous_vvis;
1972       guint count = 0;
1973
1974       /* Determine scrollbar visibility first via hfw apis */
1975       if (gtk_widget_get_request_mode (child) == GTK_SIZE_REQUEST_HEIGHT_FOR_WIDTH)
1976         {
1977           if (gtk_scrollable_get_hscroll_policy (GTK_SCROLLABLE (child)) == GTK_SCROLL_MINIMUM)
1978             gtk_widget_get_preferred_width (child, &child_scroll_width, NULL);
1979           else
1980             gtk_widget_get_preferred_width (child, NULL, &child_scroll_width);
1981           
1982           if (priv->vscrollbar_policy == GTK_POLICY_AUTOMATIC)
1983             {
1984               /* First try without a vertical scrollbar if the content will fit the height
1985                * given the extra width of the scrollbar */
1986               if (gtk_scrollable_get_vscroll_policy (GTK_SCROLLABLE (child)) == GTK_SCROLL_MINIMUM)
1987                 gtk_widget_get_preferred_height_for_width (child, 
1988                                                            MAX (allocation->width, child_scroll_width), 
1989                                                            &child_scroll_height, NULL);
1990               else
1991                 gtk_widget_get_preferred_height_for_width (child,
1992                                                            MAX (allocation->width, child_scroll_width), 
1993                                                            NULL, &child_scroll_height);
1994               
1995               if (priv->hscrollbar_policy == GTK_POLICY_AUTOMATIC)
1996                 {
1997                   /* Does the content height fit the allocation height ? */
1998                   priv->vscrollbar_visible = child_scroll_height > allocation->height;
1999                   
2000                   /* Does the content width fit the allocation with minus a possible scrollbar ? */
2001                   priv->hscrollbar_visible = 
2002                     child_scroll_width > allocation->width - 
2003                     (priv->vscrollbar_visible ? sb_width + sb_spacing : 0);
2004                   
2005                   /* Now that we've guessed the hscrollbar, does the content height fit
2006                    * the possible new allocation height ? */
2007                   priv->vscrollbar_visible = 
2008                     child_scroll_height > allocation->height - 
2009                     (priv->hscrollbar_visible ? sb_height + sb_spacing : 0);
2010                   
2011                   /* Now that we've guessed the vscrollbar, does the content width fit
2012                    * the possible new allocation width ? */
2013                   priv->hscrollbar_visible = 
2014                     child_scroll_width > allocation->width - 
2015                     (priv->vscrollbar_visible ? sb_width + sb_spacing : 0);
2016                 }
2017               else /* priv->hscrollbar_policy != GTK_POLICY_AUTOMATIC */
2018                 {
2019                   priv->hscrollbar_visible = priv->hscrollbar_policy != GTK_POLICY_NEVER;
2020                   priv->vscrollbar_visible = child_scroll_height > allocation->height - 
2021                     (priv->hscrollbar_visible ? sb_height + sb_spacing : 0);
2022                 }
2023             }
2024           else /* priv->vscrollbar_policy != GTK_POLICY_AUTOMATIC */
2025             {
2026               priv->vscrollbar_visible = priv->vscrollbar_policy != GTK_POLICY_NEVER;
2027               
2028               if (priv->hscrollbar_policy == GTK_POLICY_AUTOMATIC)
2029                 priv->hscrollbar_visible = 
2030                   child_scroll_width > allocation->width - 
2031                   (priv->vscrollbar_visible ? 0 : sb_width + sb_spacing);
2032               else
2033                 priv->hscrollbar_visible = priv->hscrollbar_policy != GTK_POLICY_NEVER;
2034             }
2035         } 
2036       else /* GTK_SIZE_REQUEST_WIDTH_FOR_HEIGHT */
2037         {
2038           if (gtk_scrollable_get_vscroll_policy (GTK_SCROLLABLE (child)) == GTK_SCROLL_MINIMUM)
2039             gtk_widget_get_preferred_height (child, &child_scroll_height, NULL);
2040           else
2041             gtk_widget_get_preferred_height (child, NULL, &child_scroll_height);
2042           
2043           if (priv->hscrollbar_policy == GTK_POLICY_AUTOMATIC)
2044             {
2045               /* First try without a horizontal scrollbar if the content will fit the width
2046                * given the extra height of the scrollbar */
2047               if (gtk_scrollable_get_hscroll_policy (GTK_SCROLLABLE (child)) == GTK_SCROLL_MINIMUM)
2048                 gtk_widget_get_preferred_width_for_height (child, 
2049                                                            MAX (allocation->height, child_scroll_height), 
2050                                                            &child_scroll_width, NULL);
2051               else
2052                 gtk_widget_get_preferred_width_for_height (child, 
2053                                                            MAX (allocation->height, child_scroll_height), 
2054                                                            NULL, &child_scroll_width);
2055               
2056               if (priv->vscrollbar_policy == GTK_POLICY_AUTOMATIC)
2057                 {
2058                   /* Does the content width fit the allocation width ? */
2059                   priv->hscrollbar_visible = child_scroll_width > allocation->width;
2060                   
2061                   /* Does the content height fit the allocation with minus a possible scrollbar ? */
2062                   priv->vscrollbar_visible = 
2063                     child_scroll_height > allocation->height - 
2064                     (priv->hscrollbar_visible ? sb_height + sb_spacing : 0);
2065                   
2066                   /* Now that we've guessed the vscrollbar, does the content width fit
2067                    * the possible new allocation width ? */
2068                   priv->hscrollbar_visible = 
2069                     child_scroll_width > allocation->width - 
2070                     (priv->vscrollbar_visible ? sb_width + sb_spacing : 0);
2071                   
2072                   /* Now that we've guessed the hscrollbar, does the content height fit
2073                    * the possible new allocation height ? */
2074                   priv->vscrollbar_visible = 
2075                     child_scroll_height > allocation->height - 
2076                     (priv->hscrollbar_visible ? sb_height + sb_spacing : 0);
2077                 }
2078               else /* priv->vscrollbar_policy != GTK_POLICY_AUTOMATIC */
2079                 {
2080                   priv->vscrollbar_visible = priv->vscrollbar_policy != GTK_POLICY_NEVER;
2081                   priv->hscrollbar_visible = child_scroll_width > allocation->width - 
2082                     (priv->vscrollbar_visible ? sb_width + sb_spacing : 0);
2083                 }
2084             }
2085           else /* priv->hscrollbar_policy != GTK_POLICY_AUTOMATIC */
2086             {
2087               priv->hscrollbar_visible = priv->hscrollbar_policy != GTK_POLICY_NEVER;
2088               
2089               if (priv->vscrollbar_policy == GTK_POLICY_AUTOMATIC)
2090                 priv->vscrollbar_visible = 
2091                   child_scroll_height > allocation->height - 
2092                   (priv->hscrollbar_visible ? 0 : sb_height + sb_spacing);
2093               else
2094                 priv->vscrollbar_visible = priv->vscrollbar_policy != GTK_POLICY_NEVER;
2095             }
2096         }
2097
2098       /* Now after guessing scrollbar visibility; fall back on the allocation loop which 
2099        * observes the adjustments to detect scrollbar visibility and also avoids 
2100        * infinite recursion
2101        */
2102       do
2103         {
2104           previous_hvis = priv->hscrollbar_visible;
2105           previous_vvis = priv->vscrollbar_visible;
2106           gtk_scrolled_window_allocate_child (scrolled_window, &relative_allocation);
2107
2108           /* Explicitly force scrollbar visibility checks.
2109            *
2110            * Since we make a guess above, the child might not decide to update the adjustments 
2111            * if they logically did not change since the last configuration
2112            */
2113           if (priv->hscrollbar)
2114             gtk_scrolled_window_adjustment_changed 
2115               (gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)), scrolled_window);
2116
2117           if (priv->vscrollbar)
2118             gtk_scrolled_window_adjustment_changed 
2119               (gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)), scrolled_window);
2120
2121           /* If, after the first iteration, the hscrollbar and the
2122            * vscrollbar flip visiblity... or if one of the scrollbars flip
2123            * on each itteration indefinitly/infinitely, then we just need both 
2124            * at this size.
2125            */
2126           if ((count &&
2127                previous_hvis != priv->hscrollbar_visible &&
2128                previous_vvis != priv->vscrollbar_visible) || count > 3)
2129             {
2130               priv->hscrollbar_visible = TRUE;
2131               priv->vscrollbar_visible = TRUE;
2132
2133               gtk_scrolled_window_allocate_child (scrolled_window, &relative_allocation);
2134
2135               break;
2136             }
2137           
2138           count++;
2139         }
2140       while (previous_hvis != priv->hscrollbar_visible ||
2141              previous_vvis != priv->vscrollbar_visible);
2142     }
2143   else
2144     {
2145       priv->hscrollbar_visible = priv->hscrollbar_policy == GTK_POLICY_ALWAYS;
2146       priv->vscrollbar_visible = priv->vscrollbar_policy == GTK_POLICY_ALWAYS;
2147       gtk_scrolled_window_relative_allocation (widget, &relative_allocation);
2148     }
2149
2150   if (priv->hscrollbar_visible)
2151     {
2152       if (!gtk_widget_get_visible (priv->hscrollbar))
2153         gtk_widget_show (priv->hscrollbar);
2154
2155       child_allocation.x = relative_allocation.x;
2156       if (priv->real_window_placement == GTK_CORNER_TOP_LEFT ||
2157           priv->real_window_placement == GTK_CORNER_TOP_RIGHT)
2158         child_allocation.y = (relative_allocation.y +
2159                               relative_allocation.height +
2160                               sb_spacing +
2161                               (priv->shadow_type == GTK_SHADOW_NONE ?
2162                                0 : padding.top + border.top));
2163       else
2164         child_allocation.y = 0;
2165
2166       child_allocation.width = relative_allocation.width;
2167       child_allocation.height = sb_height;
2168       child_allocation.x += allocation->x;
2169       child_allocation.y += allocation->y;
2170
2171       if (priv->shadow_type != GTK_SHADOW_NONE)
2172         {
2173           if (!scrollbars_within_bevel)
2174             {
2175               child_allocation.x -= padding.left + border.left;
2176               child_allocation.width += padding.left + padding.right + border.left + border.right;
2177             }
2178           else if (GTK_CORNER_TOP_RIGHT == priv->real_window_placement ||
2179                    GTK_CORNER_TOP_LEFT == priv->real_window_placement)
2180             {
2181               child_allocation.y -= padding.top + border.top;
2182             }
2183           else
2184             {
2185               child_allocation.y += padding.top + border.top;
2186             }
2187         }
2188
2189       gtk_widget_size_allocate (priv->hscrollbar, &child_allocation);
2190     }
2191   else if (gtk_widget_get_visible (priv->hscrollbar))
2192     gtk_widget_hide (priv->hscrollbar);
2193
2194   if (priv->vscrollbar_visible)
2195     {
2196       if (!gtk_widget_get_visible (priv->vscrollbar))
2197         gtk_widget_show (priv->vscrollbar);
2198
2199       if ((gtk_widget_get_direction (widget) == GTK_TEXT_DIR_RTL && 
2200            (priv->real_window_placement == GTK_CORNER_TOP_RIGHT ||
2201             priv->real_window_placement == GTK_CORNER_BOTTOM_RIGHT)) ||
2202           (gtk_widget_get_direction (widget) == GTK_TEXT_DIR_LTR && 
2203            (priv->real_window_placement == GTK_CORNER_TOP_LEFT ||
2204             priv->real_window_placement == GTK_CORNER_BOTTOM_LEFT)))
2205         child_allocation.x = (relative_allocation.x +
2206                               relative_allocation.width +
2207                               sb_spacing +
2208                               (priv->shadow_type == GTK_SHADOW_NONE ?
2209                                0 : padding.left + border.left));
2210       else
2211         child_allocation.x = 0;
2212
2213       child_allocation.y = relative_allocation.y;
2214       child_allocation.width = sb_width;
2215       child_allocation.height = relative_allocation.height;
2216       child_allocation.x += allocation->x;
2217       child_allocation.y += allocation->y;
2218
2219       if (priv->shadow_type != GTK_SHADOW_NONE)
2220         {
2221           if (!scrollbars_within_bevel)
2222             {
2223               child_allocation.y -= padding.top + border.top;
2224               child_allocation.height += padding.top + padding.bottom + border.top + border.bottom;
2225             }
2226           else if (GTK_CORNER_BOTTOM_LEFT == priv->real_window_placement ||
2227                    GTK_CORNER_TOP_LEFT == priv->real_window_placement)
2228             {
2229               child_allocation.x -= padding.left + border.left;
2230             }
2231           else
2232             {
2233               child_allocation.x += padding.left + border.left;
2234             }
2235         }
2236
2237       gtk_widget_size_allocate (priv->vscrollbar, &child_allocation);
2238     }
2239   else if (gtk_widget_get_visible (priv->vscrollbar))
2240     gtk_widget_hide (priv->vscrollbar);
2241
2242   _gtk_scrolled_window_allocate_overshoot_window (scrolled_window);
2243 }
2244
2245 static gboolean
2246 gtk_scrolled_window_scroll_event (GtkWidget      *widget,
2247                                   GdkEventScroll *event)
2248 {
2249   GtkScrolledWindowPrivate *priv;
2250   GtkScrolledWindow *scrolled_window;
2251   GtkWidget *range;
2252
2253   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (widget), FALSE);
2254   g_return_val_if_fail (event != NULL, FALSE);  
2255
2256   scrolled_window = GTK_SCROLLED_WINDOW (widget);
2257   priv = scrolled_window->priv;
2258
2259   if (event->direction == GDK_SCROLL_UP || event->direction == GDK_SCROLL_DOWN)
2260     range = priv->vscrollbar;
2261   else
2262     range = priv->hscrollbar;
2263
2264   if (range && gtk_widget_get_visible (range))
2265     {
2266       GtkAdjustment *adjustment = gtk_range_get_adjustment (GTK_RANGE (range));
2267       gdouble delta;
2268
2269       delta = _gtk_range_get_wheel_delta (GTK_RANGE (range), event->direction);
2270       gtk_adjustment_set_value (adjustment, gtk_adjustment_get_value (adjustment) + delta);
2271
2272       return TRUE;
2273     }
2274
2275   return FALSE;
2276 }
2277
2278 static gboolean
2279 _gtk_scrolled_window_set_adjustment_value (GtkScrolledWindow *scrolled_window,
2280                                            GtkAdjustment     *adjustment,
2281                                            gdouble            value,
2282                                            gboolean           allow_overshooting,
2283                                            gboolean           snap_to_border)
2284 {
2285   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2286   gdouble lower, upper, *prev_value;
2287
2288   lower = gtk_adjustment_get_lower (adjustment);
2289   upper = gtk_adjustment_get_upper (adjustment) -
2290     gtk_adjustment_get_page_size (adjustment);
2291
2292   if (adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)))
2293     prev_value = &priv->unclamped_hadj_value;
2294   else if (adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)))
2295     prev_value = &priv->unclamped_vadj_value;
2296   else
2297     return FALSE;
2298
2299   if (snap_to_border)
2300     {
2301       if (*prev_value < 0 && value > 0)
2302         value = 0;
2303       else if (*prev_value > upper && value < upper)
2304         value = upper;
2305     }
2306
2307   if (allow_overshooting)
2308     {
2309       lower -= MAX_OVERSHOOT_DISTANCE;
2310       upper += MAX_OVERSHOOT_DISTANCE;
2311     }
2312
2313   *prev_value = CLAMP (value, lower, upper);
2314   gtk_adjustment_set_value (adjustment, value);
2315
2316   return (*prev_value != value);
2317 }
2318
2319 static gboolean
2320 scrolled_window_deceleration_cb (gpointer user_data)
2321 {
2322   KineticScrollData *data = user_data;
2323   GtkScrolledWindow *scrolled_window = data->scrolled_window;
2324   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2325   GtkAdjustment *hadjustment, *vadjustment;
2326   gint old_overshoot_x, old_overshoot_y, overshoot_x, overshoot_y;
2327   gdouble value;
2328   gint64 current_time;
2329   guint elapsed;
2330
2331   hadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
2332   vadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
2333
2334   _gtk_scrolled_window_get_overshoot (scrolled_window,
2335                                       &old_overshoot_x, &old_overshoot_y);
2336
2337   current_time = g_get_monotonic_time ();
2338   elapsed = (current_time - data->last_deceleration_time) / 1000;
2339   data->last_deceleration_time = current_time;
2340
2341   if (hadjustment && priv->hscrollbar_visible)
2342     {
2343       value = priv->unclamped_hadj_value + (data->x_velocity * elapsed);
2344
2345       if (_gtk_scrolled_window_set_adjustment_value (scrolled_window,
2346                                                      hadjustment,
2347                                                      value, TRUE, TRUE))
2348         data->x_velocity = 0;
2349     }
2350   else
2351     data->x_velocity = 0;
2352
2353   if (vadjustment && priv->vscrollbar_visible)
2354     {
2355       value = priv->unclamped_vadj_value + (data->y_velocity * elapsed);
2356
2357       if (_gtk_scrolled_window_set_adjustment_value (scrolled_window,
2358                                                      vadjustment,
2359                                                      value, TRUE, TRUE))
2360         data->y_velocity = 0;
2361     }
2362   else
2363     data->y_velocity = 0;
2364
2365   _gtk_scrolled_window_get_overshoot (scrolled_window,
2366                                       &overshoot_x, &overshoot_y);
2367
2368   if (overshoot_x == 0)
2369     {
2370       if (old_overshoot_x != 0)
2371         {
2372           /* Overshooting finished snapping back */
2373           data->x_velocity = 0;
2374         }
2375       else if (data->x_velocity > 0)
2376         {
2377           data->x_velocity -= FRICTION_DECELERATION * elapsed * data->vel_sine;
2378           data->x_velocity = MAX (0, data->x_velocity);
2379         }
2380       else if (data->x_velocity < 0)
2381         {
2382           data->x_velocity += FRICTION_DECELERATION * elapsed * data->vel_sine;
2383           data->x_velocity = MIN (0, data->x_velocity);
2384         }
2385     }
2386   else if (overshoot_x < 0)
2387     data->x_velocity += OVERSHOOT_INVERSE_ACCELERATION * elapsed;
2388   else if (overshoot_x > 0)
2389     data->x_velocity -= OVERSHOOT_INVERSE_ACCELERATION * elapsed;
2390
2391   if (overshoot_y == 0)
2392     {
2393       if (old_overshoot_y != 0)
2394         {
2395           /* Overshooting finished snapping back */
2396           data->y_velocity = 0;
2397         }
2398       else if (data->y_velocity > 0)
2399         {
2400           data->y_velocity -= FRICTION_DECELERATION * elapsed * data->vel_cosine;
2401           data->y_velocity = MAX (0, data->y_velocity);
2402         }
2403       else if (data->y_velocity < 0)
2404         {
2405           data->y_velocity += FRICTION_DECELERATION * elapsed * data->vel_cosine;
2406           data->y_velocity = MIN (0, data->y_velocity);
2407         }
2408     }
2409   else if (overshoot_y < 0)
2410     data->y_velocity += OVERSHOOT_INVERSE_ACCELERATION * elapsed;
2411   else if (overshoot_y > 0)
2412     data->y_velocity -= OVERSHOOT_INVERSE_ACCELERATION * elapsed;
2413
2414   if (old_overshoot_x != overshoot_x ||
2415       old_overshoot_y != overshoot_y)
2416     {
2417       if (overshoot_x >= 0 || overshoot_y >= 0)
2418         {
2419           /* We need to reallocate the widget to have it at
2420            * negative offset, so there's a "gravity" on the
2421            * bottom/right corner
2422            */
2423           gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
2424         }
2425       else if (overshoot_x < 0 || overshoot_y < 0)
2426         _gtk_scrolled_window_allocate_overshoot_window (scrolled_window);
2427     }
2428
2429   if (overshoot_x != 0 || overshoot_y != 0 ||
2430       data->x_velocity != 0 || data->y_velocity != 0)
2431     return TRUE;
2432   else
2433     {
2434       priv->deceleration_id = 0;
2435       return FALSE;
2436     }
2437 }
2438
2439 static void
2440 gtk_scrolled_window_cancel_deceleration (GtkScrolledWindow *scrolled_window)
2441 {
2442   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2443
2444   if (priv->deceleration_id)
2445     {
2446       g_source_remove (priv->deceleration_id);
2447       priv->deceleration_id = 0;
2448     }
2449 }
2450
2451 static void
2452 gtk_scrolled_window_start_deceleration (GtkScrolledWindow *scrolled_window)
2453 {
2454   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2455   KineticScrollData *data;
2456   gdouble angle;
2457
2458   data = g_new0 (KineticScrollData, 1);
2459   data->scrolled_window = scrolled_window;
2460   data->last_deceleration_time = g_get_monotonic_time ();
2461   data->x_velocity = priv->x_velocity;
2462   data->y_velocity = priv->y_velocity;
2463
2464   /* We use sine/cosine as a factor to deceleration x/y components
2465    * of the vector, so we care about the sign later.
2466    */
2467   angle = atan2 (ABS (data->x_velocity), ABS (data->y_velocity));
2468   data->vel_cosine = cos (angle);
2469   data->vel_sine = sin (angle);
2470
2471   scrolled_window->priv->deceleration_id =
2472     gdk_threads_add_timeout_full (G_PRIORITY_DEFAULT,
2473                                   FRAME_INTERVAL,
2474                                   scrolled_window_deceleration_cb,
2475                                   data, (GDestroyNotify) g_free);
2476 }
2477
2478 static gboolean
2479 gtk_scrolled_window_release_captured_event (GtkScrolledWindow *scrolled_window)
2480 {
2481   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2482
2483   /* Cancel the scrolling and send the button press
2484    * event to the child widget
2485    */
2486   if (!priv->button_press_event)
2487     return FALSE;
2488
2489   if (priv->drag_device)
2490     {
2491       gtk_device_grab_remove (GTK_WIDGET (scrolled_window), priv->drag_device);
2492       priv->drag_device = NULL;
2493     }
2494
2495   if (priv->capture_button_press)
2496     {
2497       GtkWidget *event_widget;
2498
2499       event_widget = gtk_get_event_widget (priv->button_press_event);
2500
2501       if (!_gtk_propagate_captured_event (event_widget,
2502                                           priv->button_press_event,
2503                                           gtk_bin_get_child (GTK_BIN (scrolled_window))))
2504         gtk_propagate_event (event_widget, priv->button_press_event);
2505
2506       gdk_event_free (priv->button_press_event);
2507       priv->button_press_event = NULL;
2508     }
2509
2510   if (_gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
2511     gtk_scrolled_window_start_deceleration (scrolled_window);
2512
2513   return FALSE;
2514 }
2515
2516 static gboolean
2517 gtk_scrolled_window_calculate_velocity (GtkScrolledWindow *scrolled_window,
2518                                         GdkEvent          *event)
2519 {
2520   GtkScrolledWindowPrivate *priv;
2521   gdouble x_root, y_root;
2522   guint32 _time;
2523
2524 #define STILL_THRESHOLD 40
2525
2526   if (!gdk_event_get_root_coords (event, &x_root, &y_root))
2527     return FALSE;
2528
2529   priv = scrolled_window->priv;
2530   _time = gdk_event_get_time (event);
2531
2532   if (priv->last_motion_event_x_root != x_root ||
2533       priv->last_motion_event_y_root != y_root ||
2534       ABS (_time - priv->last_motion_event_time) > STILL_THRESHOLD)
2535     {
2536       priv->x_velocity = (priv->last_motion_event_x_root - x_root) /
2537         (gdouble) (_time - priv->last_motion_event_time);
2538       priv->y_velocity = (priv->last_motion_event_y_root - y_root) /
2539         (gdouble) (_time - priv->last_motion_event_time);
2540     }
2541
2542   priv->last_motion_event_x_root = x_root;
2543   priv->last_motion_event_y_root = y_root;
2544   priv->last_motion_event_time = _time;
2545
2546 #undef STILL_THRESHOLD
2547
2548   return TRUE;
2549 }
2550
2551 static gboolean
2552 gtk_scrolled_window_captured_button_release (GtkWidget *widget,
2553                                              GdkEvent  *event)
2554 {
2555   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
2556   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2557   GtkWidget *child;
2558   gboolean overshoot;
2559   guint button;
2560   gdouble x_root, y_root;
2561
2562   if (gdk_event_get_button (event, &button) && button != 1)
2563     return FALSE;
2564
2565   child = gtk_bin_get_child (GTK_BIN (widget));
2566   if (!child)
2567     return FALSE;
2568
2569   gtk_device_grab_remove (widget, priv->drag_device);
2570   priv->drag_device = NULL;
2571
2572   if (priv->release_timeout_id)
2573     {
2574       g_source_remove (priv->release_timeout_id);
2575       priv->release_timeout_id = 0;
2576     }
2577
2578   overshoot = _gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL);
2579
2580   if (priv->in_drag)
2581     gdk_device_ungrab (gdk_event_get_device (event), gdk_event_get_time (event));
2582   else
2583     {
2584       /* There hasn't been scrolling at all, so just let the
2585        * child widget handle the button press normally
2586        */
2587       gtk_scrolled_window_release_captured_event (scrolled_window);
2588
2589       if (!overshoot)
2590         return FALSE;
2591     }
2592   priv->in_drag = FALSE;
2593
2594   if (priv->button_press_event)
2595     {
2596       gdk_event_free (priv->button_press_event);
2597       priv->button_press_event = NULL;
2598     }
2599
2600   gtk_scrolled_window_calculate_velocity (scrolled_window, event);
2601
2602   /* Zero out vector components without a visible scrollbar */
2603   if (!priv->hscrollbar_visible)
2604     priv->x_velocity = 0;
2605   if (!priv->vscrollbar_visible)
2606     priv->y_velocity = 0;
2607
2608   if (priv->x_velocity != 0 || priv->y_velocity != 0 || overshoot)
2609     {
2610       gtk_scrolled_window_start_deceleration (scrolled_window);
2611       priv->x_velocity = priv->y_velocity = 0;
2612       priv->last_button_event_valid = FALSE;
2613     }
2614   else
2615     {
2616       gdk_event_get_root_coords (event, &x_root, &y_root);
2617       priv->last_button_event_x_root = x_root;
2618       priv->last_button_event_y_root = y_root;
2619       priv->last_button_event_valid = TRUE;
2620     }
2621
2622   if (priv->capture_button_press)
2623     return TRUE;
2624   else
2625     return FALSE;
2626 }
2627
2628 static gboolean
2629 gtk_scrolled_window_captured_motion_notify (GtkWidget *widget,
2630                                             GdkEvent  *event)
2631 {
2632   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
2633   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2634   gint old_overshoot_x, old_overshoot_y;
2635   gint new_overshoot_x, new_overshoot_y;
2636   GtkWidget *child;
2637   GtkAdjustment *hadjustment;
2638   GtkAdjustment *vadjustment;
2639   gdouble dx, dy;
2640   GdkModifierType state;
2641   gdouble x_root, y_root;
2642
2643   gdk_event_get_state (event, &state);
2644   if (!(state & GDK_BUTTON1_MASK))
2645     return FALSE;
2646
2647   child = gtk_bin_get_child (GTK_BIN (widget));
2648   if (!child)
2649     return FALSE;
2650
2651   /* Check if we've passed the drag threshold */
2652   gdk_event_get_root_coords (event, &x_root, &y_root);
2653   if (!priv->in_drag)
2654     {
2655       if (gtk_drag_check_threshold (widget,
2656                                     priv->last_button_event_x_root,
2657                                     priv->last_button_event_y_root,
2658                                     x_root, y_root))
2659         {
2660           if (priv->release_timeout_id)
2661             {
2662               g_source_remove (priv->release_timeout_id);
2663               priv->release_timeout_id = 0;
2664             }
2665
2666           priv->last_button_event_valid = FALSE;
2667           priv->in_drag = TRUE;
2668         }
2669       else
2670         return TRUE;
2671     }
2672
2673   gdk_device_grab (priv->drag_device,
2674                    gtk_widget_get_window (widget),
2675                    GDK_OWNERSHIP_WINDOW,
2676                    TRUE,
2677                    GDK_BUTTON_RELEASE_MASK | GDK_BUTTON1_MOTION_MASK,
2678                    NULL,
2679                    gdk_event_get_time (event));
2680
2681   priv->last_button_event_valid = FALSE;
2682
2683   if (priv->button_press_event)
2684     {
2685       gdk_event_free (priv->button_press_event);
2686       priv->button_press_event = NULL;
2687     }
2688
2689   _gtk_scrolled_window_get_overshoot (scrolled_window,
2690                                       &old_overshoot_x, &old_overshoot_y);
2691
2692   hadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
2693   if (hadjustment && priv->hscrollbar_visible)
2694     {
2695       dx = (priv->last_motion_event_x_root - x_root) + priv->unclamped_hadj_value;
2696       _gtk_scrolled_window_set_adjustment_value (scrolled_window, hadjustment,
2697                                                  dx, TRUE, FALSE);
2698     }
2699
2700   vadjustment = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
2701   if (vadjustment && priv->vscrollbar_visible)
2702     {
2703       dy = (priv->last_motion_event_y_root - y_root) + priv->unclamped_vadj_value;
2704       _gtk_scrolled_window_set_adjustment_value (scrolled_window, vadjustment,
2705                                                  dy, TRUE, FALSE);
2706     }
2707
2708   _gtk_scrolled_window_get_overshoot (scrolled_window,
2709                                       &new_overshoot_x, &new_overshoot_y);
2710
2711   if (old_overshoot_x != new_overshoot_x ||
2712       old_overshoot_y != new_overshoot_y)
2713     {
2714       if (new_overshoot_x >= 0 || new_overshoot_y >= 0)
2715         {
2716           /* We need to reallocate the widget to have it at
2717            * negative offset, so there's a "gravity" on the
2718            * bottom/right corner
2719            */
2720           gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
2721         }
2722       else if (new_overshoot_x < 0 || new_overshoot_y < 0)
2723         _gtk_scrolled_window_allocate_overshoot_window (scrolled_window);
2724     }
2725
2726   gtk_scrolled_window_calculate_velocity (scrolled_window, event);
2727
2728   return TRUE;
2729 }
2730
2731 static gboolean
2732 gtk_scrolled_window_captured_button_press (GtkWidget *widget,
2733                                            GdkEvent  *event)
2734 {
2735   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
2736   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2737   GtkWidget *child;
2738   GtkWidget *event_widget;
2739   GdkDevice *source_device;
2740   GdkInputSource source;
2741   gdouble x_root, y_root;
2742   guint button;
2743
2744   /* If scrollbars are not visible, we don't do kinetic scrolling */
2745   if (!priv->vscrollbar_visible && !priv->hscrollbar_visible)
2746     return FALSE;
2747
2748   source_device = gdk_event_get_source_device (event);
2749   source = gdk_device_get_source (source_device);
2750
2751   if (source != GDK_SOURCE_TOUCHSCREEN)
2752     return FALSE;
2753
2754   event_widget = gtk_get_event_widget (event);
2755
2756   /* If there's another scrolled window between the widget
2757    * receiving the event and this capturing scrolled window,
2758    * let it handle the events.
2759    */
2760   if (widget != gtk_widget_get_ancestor (event_widget, GTK_TYPE_SCROLLED_WINDOW))
2761     return FALSE;
2762
2763   /* Check whether the button press is close to the previous one,
2764    * take that as a shortcut to get the child widget handle events
2765    */
2766   gdk_event_get_root_coords (event, &x_root, &y_root);
2767   if (priv->last_button_event_valid &&
2768       ABS (x_root - priv->last_button_event_x_root) < TOUCH_BYPASS_CAPTURED_THRESHOLD &&
2769       ABS (y_root - priv->last_button_event_y_root) < TOUCH_BYPASS_CAPTURED_THRESHOLD)
2770     {
2771       priv->last_button_event_valid = FALSE;
2772       return FALSE;
2773     }
2774
2775   priv->last_button_event_x_root = priv->last_motion_event_x_root = x_root;
2776   priv->last_button_event_y_root = priv->last_motion_event_y_root = y_root;
2777   priv->last_motion_event_time = gdk_event_get_time (event);
2778   priv->last_button_event_valid = TRUE;
2779
2780   if (gdk_event_get_button (event, &button) && button != 1)
2781     return FALSE;
2782
2783   child = gtk_bin_get_child (GTK_BIN (widget));
2784   if (!child)
2785     return FALSE;
2786
2787   if (priv->hscrollbar == event_widget || priv->vscrollbar == event_widget)
2788     return FALSE;
2789
2790   priv->drag_device = gdk_event_get_device (event);
2791   gtk_device_grab_add (widget, priv->drag_device, TRUE);
2792
2793   gtk_scrolled_window_cancel_deceleration (scrolled_window);
2794
2795   /* Only set the timeout if we're going to store an event */
2796   if (priv->capture_button_press)
2797     priv->release_timeout_id =
2798       gdk_threads_add_timeout (RELEASE_EVENT_TIMEOUT,
2799                                (GSourceFunc) gtk_scrolled_window_release_captured_event,
2800                                scrolled_window);
2801
2802   priv->in_drag = FALSE;
2803
2804   if (priv->capture_button_press)
2805     {
2806       /* Store the button press event in
2807        * case we need to propagate it later
2808        */
2809       priv->button_press_event = gdk_event_copy (event);
2810       return TRUE;
2811     }
2812   else
2813     return FALSE;
2814 }
2815
2816 static gboolean
2817 gtk_scrolled_window_captured_event (GtkWidget *widget,
2818                                     GdkEvent  *event)
2819 {
2820   gboolean retval = FALSE;
2821   GtkScrolledWindowPrivate *priv = GTK_SCROLLED_WINDOW (widget)->priv;
2822
2823   switch (event->type)
2824     {
2825     case GDK_TOUCH_BEGIN:
2826     case GDK_BUTTON_PRESS:
2827       retval = gtk_scrolled_window_captured_button_press (widget, event);
2828       break;
2829     case GDK_TOUCH_END:
2830     case GDK_BUTTON_RELEASE:
2831       if (priv->drag_device)
2832         retval = gtk_scrolled_window_captured_button_release (widget, event);
2833       else
2834         priv->last_button_event_valid = FALSE;
2835       break;
2836     case GDK_TOUCH_UPDATE:
2837     case GDK_MOTION_NOTIFY:
2838       if (priv->drag_device)
2839         retval = gtk_scrolled_window_captured_motion_notify (widget, event);
2840       break;
2841     case GDK_LEAVE_NOTIFY:
2842     case GDK_ENTER_NOTIFY:
2843       if (priv->in_drag &&
2844           event->crossing.mode != GDK_CROSSING_GRAB)
2845         retval = TRUE;
2846       break;
2847     default:
2848       break;
2849     }
2850
2851   return retval;
2852 }
2853
2854 static gboolean
2855 gtk_scrolled_window_focus (GtkWidget        *widget,
2856                            GtkDirectionType  direction)
2857 {
2858   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
2859   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2860   GtkWidget *child;
2861   gboolean had_focus_child;
2862
2863   had_focus_child = gtk_container_get_focus_child (GTK_CONTAINER (widget)) != NULL;
2864
2865   if (priv->focus_out)
2866     {
2867       priv->focus_out = FALSE; /* Clear this to catch the wrap-around case */
2868       return FALSE;
2869     }
2870   
2871   if (gtk_widget_is_focus (widget))
2872     return FALSE;
2873
2874   /* We only put the scrolled window itself in the focus chain if it
2875    * isn't possible to focus any children.
2876    */
2877   child = gtk_bin_get_child (GTK_BIN (widget));
2878   if (child)
2879     {
2880       if (gtk_widget_child_focus (child, direction))
2881         return TRUE;
2882     }
2883
2884   if (!had_focus_child && gtk_widget_get_can_focus (widget))
2885     {
2886       gtk_widget_grab_focus (widget);
2887       return TRUE;
2888     }
2889   else
2890     return FALSE;
2891 }
2892
2893 static void
2894 gtk_scrolled_window_adjustment_changed (GtkAdjustment *adjustment,
2895                                         gpointer       data)
2896 {
2897   GtkScrolledWindowPrivate *priv;
2898   GtkScrolledWindow *scrolled_window;
2899
2900   g_return_if_fail (adjustment != NULL);
2901   g_return_if_fail (data != NULL);
2902
2903   scrolled_window = GTK_SCROLLED_WINDOW (data);
2904   priv = scrolled_window->priv;
2905
2906   if (priv->hscrollbar &&
2907       adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)))
2908     {
2909       if (priv->hscrollbar_policy == GTK_POLICY_AUTOMATIC)
2910         {
2911           gboolean visible;
2912
2913           visible = priv->hscrollbar_visible;
2914           priv->hscrollbar_visible = (gtk_adjustment_get_upper (adjustment) - gtk_adjustment_get_lower (adjustment) >
2915                                       gtk_adjustment_get_page_size (adjustment));
2916
2917           if (priv->hscrollbar_visible != visible)
2918             gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
2919         }
2920     }
2921   else if (priv->vscrollbar &&
2922            adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)))
2923     {
2924       if (priv->vscrollbar_policy == GTK_POLICY_AUTOMATIC)
2925         {
2926           gboolean visible;
2927
2928           visible = priv->vscrollbar_visible;
2929           priv->vscrollbar_visible = (gtk_adjustment_get_upper (adjustment) - gtk_adjustment_get_lower (adjustment) >
2930                                       gtk_adjustment_get_page_size (adjustment));
2931
2932           if (priv->vscrollbar_visible != visible)
2933             gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
2934         }
2935     }
2936 }
2937
2938 static void
2939 gtk_scrolled_window_adjustment_value_changed (GtkAdjustment *adjustment,
2940                                               gpointer       user_data)
2941 {
2942   GtkScrolledWindow *scrolled_window = user_data;
2943   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
2944
2945   /* Allow overshooting for kinetic scrolling operations */
2946   if (priv->drag_device || priv->deceleration_id)
2947     return;
2948
2949   /* Ensure GtkAdjustment and unclamped values are in sync */
2950   if (priv->vscrollbar &&
2951       adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar)))
2952     priv->unclamped_vadj_value = gtk_adjustment_get_value (adjustment);
2953   else if (priv->hscrollbar &&
2954            adjustment == gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar)))
2955     priv->unclamped_hadj_value = gtk_adjustment_get_value (adjustment);
2956 }
2957
2958 static void
2959 gtk_scrolled_window_add (GtkContainer *container,
2960                          GtkWidget    *child)
2961 {
2962   GtkScrolledWindowPrivate *priv;
2963   GtkScrolledWindow *scrolled_window;
2964   GtkBin *bin;
2965   GtkWidget *child_widget;
2966   GtkAdjustment *hadj, *vadj;
2967
2968   bin = GTK_BIN (container);
2969   child_widget = gtk_bin_get_child (bin);
2970   g_return_if_fail (child_widget == NULL);
2971
2972   scrolled_window = GTK_SCROLLED_WINDOW (container);
2973   priv = scrolled_window->priv;
2974
2975   if (gtk_widget_get_realized (GTK_WIDGET (bin)))
2976     gtk_widget_set_parent_window (child, priv->overshoot_window);
2977
2978   _gtk_bin_set_child (bin, child);
2979   gtk_widget_set_parent (child, GTK_WIDGET (bin));
2980
2981   hadj = gtk_range_get_adjustment (GTK_RANGE (priv->hscrollbar));
2982   vadj = gtk_range_get_adjustment (GTK_RANGE (priv->vscrollbar));
2983
2984   if (GTK_IS_SCROLLABLE (child))
2985     g_object_set (child, "hadjustment", hadj, "vadjustment", vadj, NULL);
2986   else
2987     g_warning ("gtk_scrolled_window_add(): cannot add non scrollable widget "
2988                "use gtk_scrolled_window_add_with_viewport() instead");
2989 }
2990
2991 static void
2992 gtk_scrolled_window_remove (GtkContainer *container,
2993                             GtkWidget    *child)
2994 {
2995   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (container));
2996   g_return_if_fail (child != NULL);
2997   g_return_if_fail (gtk_bin_get_child (GTK_BIN (container)) == child);
2998
2999   g_object_set (child, "hadjustment", NULL, "vadjustment", NULL, NULL);
3000
3001   /* chain parent class handler to remove child */
3002   GTK_CONTAINER_CLASS (gtk_scrolled_window_parent_class)->remove (container, child);
3003 }
3004
3005 /**
3006  * gtk_scrolled_window_add_with_viewport:
3007  * @scrolled_window: a #GtkScrolledWindow
3008  * @child: the widget you want to scroll
3009  *
3010  * Used to add children without native scrolling capabilities. This
3011  * is simply a convenience function; it is equivalent to adding the
3012  * unscrollable child to a viewport, then adding the viewport to the
3013  * scrolled window. If a child has native scrolling, use
3014  * gtk_container_add() instead of this function.
3015  *
3016  * The viewport scrolls the child by moving its #GdkWindow, and takes
3017  * the size of the child to be the size of its toplevel #GdkWindow. 
3018  * This will be very wrong for most widgets that support native scrolling;
3019  * for example, if you add a widget such as #GtkTreeView with a viewport,
3020  * the whole widget will scroll, including the column headings. Thus, 
3021  * widgets with native scrolling support should not be used with the 
3022  * #GtkViewport proxy.
3023  *
3024  * A widget supports scrolling natively if it implements the
3025  * #GtkScrollable interface.
3026  */
3027 void
3028 gtk_scrolled_window_add_with_viewport (GtkScrolledWindow *scrolled_window,
3029                                        GtkWidget         *child)
3030 {
3031   GtkBin *bin;
3032   GtkWidget *viewport;
3033   GtkWidget *child_widget;
3034
3035   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
3036   g_return_if_fail (GTK_IS_WIDGET (child));
3037   g_return_if_fail (gtk_widget_get_parent (child) == NULL);
3038
3039   bin = GTK_BIN (scrolled_window);
3040   child_widget = gtk_bin_get_child (bin);
3041
3042   if (child_widget)
3043     {
3044       g_return_if_fail (GTK_IS_VIEWPORT (child_widget));
3045       g_return_if_fail (gtk_bin_get_child (GTK_BIN (child_widget)) == NULL);
3046
3047       viewport = child_widget;
3048     }
3049   else
3050     {
3051       viewport =
3052         gtk_viewport_new (gtk_scrolled_window_get_hadjustment (scrolled_window),
3053                           gtk_scrolled_window_get_vadjustment (scrolled_window));
3054       gtk_container_add (GTK_CONTAINER (scrolled_window), viewport);
3055     }
3056
3057   gtk_widget_show (viewport);
3058   gtk_container_add (GTK_CONTAINER (viewport), child);
3059 }
3060
3061 /*
3062  * _gtk_scrolled_window_get_spacing:
3063  * @scrolled_window: a scrolled window
3064  * 
3065  * Gets the spacing between the scrolled window's scrollbars and
3066  * the scrolled widget. Used by GtkCombo
3067  * 
3068  * Return value: the spacing, in pixels.
3069  */
3070 gint
3071 _gtk_scrolled_window_get_scrollbar_spacing (GtkScrolledWindow *scrolled_window)
3072 {
3073   GtkScrolledWindowClass *class;
3074     
3075   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), 0);
3076
3077   class = GTK_SCROLLED_WINDOW_GET_CLASS (scrolled_window);
3078
3079   if (class->scrollbar_spacing >= 0)
3080     return class->scrollbar_spacing;
3081   else
3082     {
3083       gint scrollbar_spacing;
3084       
3085       gtk_widget_style_get (GTK_WIDGET (scrolled_window),
3086                             "scrollbar-spacing", &scrollbar_spacing,
3087                             NULL);
3088
3089       return scrollbar_spacing;
3090     }
3091 }
3092
3093
3094 static void
3095 gtk_scrolled_window_get_preferred_size (GtkWidget      *widget,
3096                                         GtkOrientation  orientation,
3097                                         gint           *minimum_size,
3098                                         gint           *natural_size)
3099 {
3100   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3101   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
3102   GtkBin *bin = GTK_BIN (scrolled_window);
3103   gint extra_width;
3104   gint extra_height;
3105   gint scrollbar_spacing;
3106   GtkRequisition hscrollbar_requisition;
3107   GtkRequisition vscrollbar_requisition;
3108   GtkRequisition minimum_req, natural_req;
3109   GtkWidget *child;
3110   gint min_child_size, nat_child_size;
3111
3112   scrollbar_spacing = _gtk_scrolled_window_get_scrollbar_spacing (scrolled_window);
3113
3114   extra_width = 0;
3115   extra_height = 0;
3116   minimum_req.width = 0;
3117   minimum_req.height = 0;
3118   natural_req.width = 0;
3119   natural_req.height = 0;
3120
3121   gtk_widget_get_preferred_size (priv->hscrollbar,
3122                                  &hscrollbar_requisition, NULL);
3123   gtk_widget_get_preferred_size (priv->vscrollbar,
3124                                  &vscrollbar_requisition, NULL);
3125
3126   child = gtk_bin_get_child (bin);
3127   if (child && gtk_widget_get_visible (child))
3128     {
3129       if (orientation == GTK_ORIENTATION_HORIZONTAL)
3130         {
3131           gtk_widget_get_preferred_width (child,
3132                                           &min_child_size,
3133                                           &nat_child_size);
3134
3135           if (priv->hscrollbar_policy == GTK_POLICY_NEVER)
3136             {
3137               minimum_req.width += min_child_size;
3138               natural_req.width += nat_child_size;
3139             }
3140           else
3141             {
3142               gint min_content_width = priv->min_content_width;
3143
3144               if (min_content_width >= 0)
3145                 {
3146                   minimum_req.width = MAX (minimum_req.width, min_content_width);
3147                   natural_req.width = MAX (natural_req.width, min_content_width);
3148                   extra_width = -1;
3149                 }
3150               else
3151                 {
3152                   minimum_req.width += vscrollbar_requisition.width;
3153                   natural_req.width += vscrollbar_requisition.width;
3154                 }
3155             }
3156         }
3157       else /* GTK_ORIENTATION_VERTICAL */
3158         {
3159           gtk_widget_get_preferred_height (child,
3160                                            &min_child_size,
3161                                            &nat_child_size);
3162
3163           if (priv->vscrollbar_policy == GTK_POLICY_NEVER)
3164             {
3165               minimum_req.height += min_child_size;
3166               natural_req.height += nat_child_size;
3167             }
3168           else
3169             {
3170               gint min_content_height = priv->min_content_height;
3171
3172               if (min_content_height >= 0)
3173                 {
3174                   minimum_req.height = MAX (minimum_req.height, min_content_height);
3175                   natural_req.height = MAX (natural_req.height, min_content_height);
3176                   extra_height = -1;
3177                 }
3178               else
3179                 {
3180                   minimum_req.height += vscrollbar_requisition.height;
3181                   natural_req.height += vscrollbar_requisition.height;
3182                 }
3183             }
3184         }
3185     }
3186
3187   if (priv->hscrollbar_policy == GTK_POLICY_AUTOMATIC ||
3188       priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
3189     {
3190       minimum_req.width = MAX (minimum_req.width, hscrollbar_requisition.width);
3191       natural_req.width = MAX (natural_req.width, hscrollbar_requisition.width);
3192       if (!extra_height || priv->hscrollbar_policy == GTK_POLICY_ALWAYS)
3193         extra_height = scrollbar_spacing + hscrollbar_requisition.height;
3194     }
3195
3196   if (priv->vscrollbar_policy == GTK_POLICY_AUTOMATIC ||
3197       priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
3198     {
3199       minimum_req.height = MAX (minimum_req.height, vscrollbar_requisition.height);
3200       natural_req.height = MAX (natural_req.height, vscrollbar_requisition.height);
3201       if (!extra_width || priv->vscrollbar_policy == GTK_POLICY_ALWAYS)
3202         extra_width = scrollbar_spacing + vscrollbar_requisition.width;
3203     }
3204
3205   minimum_req.width  += MAX (0, extra_width);
3206   minimum_req.height += MAX (0, extra_height);
3207   natural_req.width  += MAX (0, extra_width);
3208   natural_req.height += MAX (0, extra_height);
3209
3210   if (priv->shadow_type != GTK_SHADOW_NONE)
3211     {
3212       GtkStyleContext *context;
3213       GtkStateFlags state;
3214       GtkBorder padding, border;
3215
3216       context = gtk_widget_get_style_context (GTK_WIDGET (widget));
3217       state = gtk_widget_get_state_flags (GTK_WIDGET (widget));
3218
3219       gtk_style_context_save (context);
3220       gtk_style_context_add_class (context, GTK_STYLE_CLASS_FRAME);
3221
3222       gtk_style_context_get_padding (context, state, &padding);
3223       gtk_style_context_get_border (context, state, &border);
3224
3225       minimum_req.width += padding.left + padding.right + border.left + border.right;
3226       minimum_req.height += padding.top + padding.bottom + border.top + border.bottom;
3227       natural_req.width += padding.left + padding.right + border.left + border.right;
3228       natural_req.height += padding.top + padding.bottom + border.top + border.bottom;
3229
3230       gtk_style_context_restore (context);
3231     }
3232
3233   if (orientation == GTK_ORIENTATION_HORIZONTAL)
3234     {
3235       if (minimum_size)
3236         *minimum_size = minimum_req.width;
3237       if (natural_size)
3238         *natural_size = natural_req.width;
3239     }
3240   else
3241     {
3242       if (minimum_size)
3243         *minimum_size = minimum_req.height;
3244       if (natural_size)
3245         *natural_size = natural_req.height;
3246     }
3247 }
3248
3249 static void     
3250 gtk_scrolled_window_get_preferred_width (GtkWidget *widget,
3251                                          gint      *minimum_size,
3252                                          gint      *natural_size)
3253 {
3254   gtk_scrolled_window_get_preferred_size (widget, GTK_ORIENTATION_HORIZONTAL, minimum_size, natural_size);
3255 }
3256
3257 static void
3258 gtk_scrolled_window_get_preferred_height (GtkWidget *widget,
3259                                           gint      *minimum_size,
3260                                           gint      *natural_size)
3261 {  
3262   gtk_scrolled_window_get_preferred_size (widget, GTK_ORIENTATION_VERTICAL, minimum_size, natural_size);
3263 }
3264
3265 static void
3266 gtk_scrolled_window_get_preferred_height_for_width (GtkWidget *widget,
3267                                                     gint       width,
3268                                                     gint      *minimum_height,
3269                                                     gint      *natural_height)
3270 {
3271   g_return_if_fail (GTK_IS_WIDGET (widget));
3272
3273   GTK_WIDGET_GET_CLASS (widget)->get_preferred_height (widget, minimum_height, natural_height);
3274 }
3275
3276 static void
3277 gtk_scrolled_window_get_preferred_width_for_height (GtkWidget *widget,
3278                                                     gint       height,
3279                                                     gint      *minimum_width,
3280                                                     gint      *natural_width)
3281 {
3282   g_return_if_fail (GTK_IS_WIDGET (widget));
3283
3284   GTK_WIDGET_GET_CLASS (widget)->get_preferred_width (widget, minimum_width, natural_width);
3285 }
3286
3287 static void
3288 gtk_scrolled_window_realize (GtkWidget *widget)
3289 {
3290   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3291   GtkAllocation allocation, relative_allocation;
3292   GdkWindowAttr attributes;
3293   GtkWidget *child_widget;
3294   gint attributes_mask;
3295
3296   gtk_widget_set_realized (widget, TRUE);
3297   gtk_widget_get_allocation (widget, &allocation);
3298   gtk_scrolled_window_relative_allocation (widget, &relative_allocation);
3299
3300   attributes.window_type = GDK_WINDOW_CHILD;
3301   attributes.x = allocation.x + relative_allocation.x;
3302   attributes.y = allocation.y + relative_allocation.y;
3303   attributes.width = allocation.width;
3304   attributes.height = allocation.height;
3305   attributes.wclass = GDK_INPUT_OUTPUT;
3306   attributes.visual = gtk_widget_get_visual (widget);
3307   attributes.event_mask = GDK_VISIBILITY_NOTIFY_MASK |
3308     GDK_BUTTON_MOTION_MASK | GDK_TOUCH_MASK;
3309
3310   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
3311
3312   scrolled_window->priv->overshoot_window =
3313     gdk_window_new (gtk_widget_get_parent_window (widget),
3314                     &attributes, attributes_mask);
3315
3316   gdk_window_set_user_data (scrolled_window->priv->overshoot_window, widget);
3317
3318   child_widget = gtk_bin_get_child (GTK_BIN (widget));
3319
3320   if (child_widget)
3321     gtk_widget_set_parent_window (child_widget,
3322                                   scrolled_window->priv->overshoot_window);
3323
3324   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->realize (widget);
3325 }
3326
3327 static void
3328 gtk_scrolled_window_unrealize (GtkWidget *widget)
3329 {
3330   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3331
3332   gdk_window_set_user_data (scrolled_window->priv->overshoot_window, NULL);
3333   gdk_window_destroy (scrolled_window->priv->overshoot_window);
3334   scrolled_window->priv->overshoot_window = NULL;
3335
3336   gtk_widget_set_realized (widget, FALSE);
3337
3338   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->unrealize (widget);
3339 }
3340
3341 static void
3342 gtk_scrolled_window_map (GtkWidget *widget)
3343 {
3344   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3345
3346   gdk_window_show (scrolled_window->priv->overshoot_window);
3347
3348   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->map (widget);
3349 }
3350
3351 static void
3352 gtk_scrolled_window_unmap (GtkWidget *widget)
3353 {
3354   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3355
3356   gdk_window_hide (scrolled_window->priv->overshoot_window);
3357
3358   GTK_WIDGET_CLASS (gtk_scrolled_window_parent_class)->unmap (widget);
3359 }
3360
3361 static void
3362 gtk_scrolled_window_grab_notify (GtkWidget *widget,
3363                                  gboolean   was_grabbed)
3364 {
3365   GtkScrolledWindow *scrolled_window = GTK_SCROLLED_WINDOW (widget);
3366   GtkScrolledWindowPrivate *priv = scrolled_window->priv;
3367
3368   if (priv->drag_device &&
3369       gtk_widget_device_is_shadowed (widget,
3370                                      priv->drag_device))
3371     {
3372       gdk_device_ungrab (priv->drag_device,
3373                          gtk_get_current_event_time ());
3374       priv->drag_device = NULL;
3375       priv->in_drag = FALSE;
3376
3377       if (priv->release_timeout_id)
3378         {
3379           g_source_remove (priv->release_timeout_id);
3380           priv->release_timeout_id = 0;
3381         }
3382
3383       if (_gtk_scrolled_window_get_overshoot (scrolled_window, NULL, NULL))
3384         gtk_scrolled_window_start_deceleration (scrolled_window);
3385       else
3386         gtk_scrolled_window_cancel_deceleration (scrolled_window);
3387
3388       priv->last_button_event_valid = FALSE;
3389     }
3390 }
3391
3392 /**
3393  * gtk_scrolled_window_get_min_content_width:
3394  * @scrolled_window: a #GtkScrolledWindow
3395  *
3396  * Gets the minimum content width of @scrolled_window, or -1 if not set.
3397  *
3398  * Returns: the minimum content width
3399  *
3400  * Since: 3.0
3401  */
3402 gint
3403 gtk_scrolled_window_get_min_content_width (GtkScrolledWindow *scrolled_window)
3404 {
3405   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), 0);
3406
3407   return scrolled_window->priv->min_content_width;
3408 }
3409
3410 /**
3411  * gtk_scrolled_window_set_min_content_width:
3412  * @scrolled_window: a #GtkScrolledWindow
3413  * @width: the minimal content width
3414  *
3415  * Sets the minimum width that @scrolled_window should keep visible.
3416  * Note that this can and (usually will) be smaller than the minimum
3417  * size of the content.
3418  *
3419  * Since: 3.0
3420  */
3421 void
3422 gtk_scrolled_window_set_min_content_width (GtkScrolledWindow *scrolled_window,
3423                                            gint               width)
3424 {
3425   GtkScrolledWindowPrivate *priv;
3426
3427   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
3428
3429   priv = scrolled_window->priv;
3430
3431   if (priv->min_content_width != width)
3432     {
3433       priv->min_content_width = width;
3434
3435       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
3436
3437       g_object_notify (G_OBJECT (scrolled_window), "min-content-width");
3438     }
3439 }
3440
3441 /**
3442  * gtk_scrolled_window_get_min_content_height:
3443  * @scrolled_window: a #GtkScrolledWindow
3444  *
3445  * Gets the minimal content height of @scrolled_window, or -1 if not set.
3446  *
3447  * Returns: the minimal content height
3448  *
3449  * Since: 3.0
3450  */
3451 gint
3452 gtk_scrolled_window_get_min_content_height (GtkScrolledWindow *scrolled_window)
3453 {
3454   g_return_val_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window), 0);
3455
3456   return scrolled_window->priv->min_content_height;
3457 }
3458
3459 /**
3460  * gtk_scrolled_window_set_min_content_height:
3461  * @scrolled_window: a #GtkScrolledWindow
3462  * @height: the minimal content height
3463  *
3464  * Sets the minimum height that @scrolled_window should keep visible.
3465  * Note that this can and (usually will) be smaller than the minimum
3466  * size of the content.
3467  *
3468  * Since: 3.0
3469  */
3470 void
3471 gtk_scrolled_window_set_min_content_height (GtkScrolledWindow *scrolled_window,
3472                                             gint               height)
3473 {
3474   GtkScrolledWindowPrivate *priv;
3475
3476   g_return_if_fail (GTK_IS_SCROLLED_WINDOW (scrolled_window));
3477
3478   priv = scrolled_window->priv;
3479
3480   if (priv->min_content_height != height)
3481     {
3482       priv->min_content_height = height;
3483
3484       gtk_widget_queue_resize (GTK_WIDGET (scrolled_window));
3485
3486       g_object_notify (G_OBJECT (scrolled_window), "min-content-height");
3487     }
3488 }