Pileus Git - ~andy/gtk/blob - gtk/gtkviewport.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, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19
  20 /*
  21  * Modified by the GTK+ Team and others 1997-2000.  See the AUTHORS
  22  * file for a list of people on the GTK+ Team.  See the ChangeLog
  23  * files for a list of changes.  These files are distributed with
  24  * GTK+ at ftp://ftp.gtk.org/pub/gtk/.
  25  */
  26
  27 #include "config.h"
  28 #include "gtkintl.h"
  29 #include "gtkmarshalers.h"
  30 #include "gtktypeutils.h"
  31 #include "gtkscrollable.h"
  32 #undef GTK_DISABLE_DEPRECATED
  33 #include "gtkviewport.h"
  34 #define GTK_DISABLE_DEPRECATED
  35 #include "gtkprivate.h"
  36
  37
  38 /**
  39  * SECTION:gtkviewport
  40  * @Short_description: An adapter which makes widgets scrollable
  41  * @Title: GtkViewport
  42  * @See_also:#GtkScrolledWindow, #GtkAdjustment
  43  *
  44  * The #GtkViewport widget acts as an adaptor class, implementing
  45  * scrollability for child widgets that lack their own scrolling
  46  * capabilities. Use #GtkViewport to scroll child widgets such as
  47  * #GtkTable, #GtkBox, and so on.
  48  *
  49  * If a widget has native scrolling abilities, such as #GtkTextView,
  50  * #GtkTreeView or #GtkIconview, it can be added to a #GtkScrolledWindow
  51  * with gtk_container_add(). If a widget does not, you must first add the
  52  * widget to a #GtkViewport, then add the viewport to the scrolled window.
  53  * The convenience function gtk_scrolled_window_add_with_viewport() does
  54  * exactly this, so you can ignore the presence of the viewport.
  55  *
  56  * The #GtkViewport will start scrolling content only if allocated less
  57  * than the child widget's minimum size in a given orientation.
  58  */
  59
  60 struct _GtkViewportPrivate
  61 {
  62   GtkAdjustment  *hadjustment;
  63   GtkAdjustment  *vadjustment;
  64   gint            min_display_width;
  65   gint            min_display_height;
  66   GtkShadowType   shadow_type;
  67
  68   GdkWindow      *bin_window;
  69   GdkWindow      *view_window;
  70 };
  71
  72 enum {
  73   PROP_0,
  74   PROP_HADJUSTMENT,
  75   PROP_VADJUSTMENT,
  76   PROP_MIN_DISPLAY_WIDTH,
  77   PROP_MIN_DISPLAY_HEIGHT,
  78   PROP_SHADOW_TYPE
  79 };
  80
  81
  82 static void gtk_viewport_finalize                 (GObject          *object);
  83 static void gtk_viewport_set_property             (GObject         *object,
  84                                                    guint            prop_id,
  85                                                    const GValue    *value,
  86                                                    GParamSpec      *pspec);
  87 static void gtk_viewport_get_property             (GObject         *object,
  88                                                    guint            prop_id,
  89                                                    GValue          *value,
  90                                                    GParamSpec      *pspec);
  91 static void gtk_viewport_destroy                  (GtkWidget        *widget);
  92 static void gtk_viewport_realize                  (GtkWidget        *widget);
  93 static void gtk_viewport_unrealize                (GtkWidget        *widget);
  94 static gint gtk_viewport_draw                     (GtkWidget        *widget,
  95                                                    cairo_t          *cr);
  96 static void gtk_viewport_add                      (GtkContainer     *container,
  97                                                    GtkWidget        *widget);
  98 static void gtk_viewport_size_allocate            (GtkWidget        *widget,
  99                                                    GtkAllocation    *allocation);
 100 static void gtk_viewport_adjustment_value_changed (GtkAdjustment    *adjustment,
 101                                                    gpointer          data);
 102 static void gtk_viewport_style_set                (GtkWidget        *widget,
 103                                                    GtkStyle         *previous_style);
 104
 105 static void gtk_viewport_get_preferred_width      (GtkWidget        *widget,
 106                                                    gint             *minimum_size,
 107                                                    gint             *natural_size);
 108 static void gtk_viewport_get_preferred_height     (GtkWidget        *widget,
 109                                                    gint             *minimum_size,
 110                                                    gint             *natural_size);
 111
 112
 113 G_DEFINE_TYPE_WITH_CODE (GtkViewport, gtk_viewport, GTK_TYPE_BIN,
 114                          G_IMPLEMENT_INTERFACE (GTK_TYPE_SCROLLABLE, NULL))
 115
 116 static void
 117 gtk_viewport_class_init (GtkViewportClass *class)
 118 {
 119   GObjectClass   *gobject_class;
 120   GtkWidgetClass *widget_class;
 121   GtkContainerClass *container_class;
 122
 123   gobject_class = G_OBJECT_CLASS (class);
 124   widget_class = (GtkWidgetClass*) class;
 125   container_class = (GtkContainerClass*) class;
 126
 127   gobject_class->finalize = gtk_viewport_finalize;
 128   gobject_class->set_property = gtk_viewport_set_property;
 129   gobject_class->get_property = gtk_viewport_get_property;
 130
 131   widget_class->destroy = gtk_viewport_destroy;
 132   widget_class->realize = gtk_viewport_realize;
 133   widget_class->unrealize = gtk_viewport_unrealize;
 134   widget_class->draw = gtk_viewport_draw;
 135   widget_class->size_allocate = gtk_viewport_size_allocate;
 136   widget_class->style_set = gtk_viewport_style_set;
 137   widget_class->get_preferred_width = gtk_viewport_get_preferred_width;
 138   widget_class->get_preferred_height = gtk_viewport_get_preferred_height;
 139
 140   container_class->add = gtk_viewport_add;
 141
 142   /* GtkScrollable implementation */
 143   g_object_class_override_property (gobject_class,
 144                                     PROP_HADJUSTMENT,
 145                                     "hadjustment");
 146   g_object_class_override_property (gobject_class,
 147                                     PROP_VADJUSTMENT,
 148                                     "vadjustment");
 149   g_object_class_override_property (gobject_class,
 150                                     PROP_MIN_DISPLAY_WIDTH,
 151                                     "min-display-width");
 152   g_object_class_override_property (gobject_class,
 153                                     PROP_MIN_DISPLAY_HEIGHT,
 154                                     "min-display-height");
 155
 156   g_object_class_install_property (gobject_class,
 157                                    PROP_SHADOW_TYPE,
 158                                    g_param_spec_enum ("shadow-type",
 159                                                       P_("Shadow type"),
 160                                                       P_("Determines how the shadowed box around the viewport is drawn"),
 161                                                       GTK_TYPE_SHADOW_TYPE,
 162                                                       GTK_SHADOW_IN,
 163                                                       GTK_PARAM_READWRITE));
 164
 165   g_type_class_add_private (class, sizeof (GtkViewportPrivate));
 166 }
 167
 168 static void
 169 gtk_viewport_set_property (GObject         *object,
 170                            guint            prop_id,
 171                            const GValue    *value,
 172                            GParamSpec      *pspec)
 173 {
 174   GtkViewport *viewport;
 175
 176   viewport = GTK_VIEWPORT (object);
 177
 178   switch (prop_id)
 179     {
 180     case PROP_HADJUSTMENT:
 181       gtk_viewport_set_hadjustment (viewport, g_value_get_object (value));
 182       break;
 183     case PROP_VADJUSTMENT:
 184       gtk_viewport_set_vadjustment (viewport, g_value_get_object (value));
 185       break;
 186     case PROP_MIN_DISPLAY_WIDTH:
 187       viewport->priv->min_display_width = g_value_get_int (value);
 188       break;
 189     case PROP_MIN_DISPLAY_HEIGHT:
 190       viewport->priv->min_display_height = g_value_get_int (value);
 191       break;
 192     case PROP_SHADOW_TYPE:
 193       gtk_viewport_set_shadow_type (viewport, g_value_get_enum (value));
 194       break;
 195     default:
 196       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 197       break;
 198     }
 199 }
 200
 201 static void
 202 gtk_viewport_get_property (GObject         *object,
 203                            guint            prop_id,
 204                            GValue          *value,
 205                            GParamSpec      *pspec)
 206 {
 207   GtkViewport *viewport = GTK_VIEWPORT (object);
 208   GtkViewportPrivate *priv = viewport->priv;
 209
 210   switch (prop_id)
 211     {
 212     case PROP_HADJUSTMENT:
 213       g_value_set_object (value, priv->hadjustment);
 214       break;
 215     case PROP_VADJUSTMENT:
 216       g_value_set_object (value, priv->vadjustment);
 217       break;
 218     case PROP_MIN_DISPLAY_WIDTH:
 219       g_value_set_int (value, priv->min_display_width);
 220       break;
 221     case PROP_MIN_DISPLAY_HEIGHT:
 222       g_value_set_int (value, priv->min_display_height);
 223       break;
 224     case PROP_SHADOW_TYPE:
 225       g_value_set_enum (value, priv->shadow_type);
 226       break;
 227     default:
 228       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
 229       break;
 230     }
 231 }
 232
 233 static void
 234 gtk_viewport_init (GtkViewport *viewport)
 235 {
 236   GtkViewportPrivate *priv;
 237
 238   viewport->priv = G_TYPE_INSTANCE_GET_PRIVATE (viewport,
 239                                                 GTK_TYPE_VIEWPORT,
 240                                                 GtkViewportPrivate);
 241   priv = viewport->priv;
 242
 243   gtk_widget_set_has_window (GTK_WIDGET (viewport), TRUE);
 244
 245   gtk_widget_set_redraw_on_allocate (GTK_WIDGET (viewport), FALSE);
 246   gtk_container_set_resize_mode (GTK_CONTAINER (viewport), GTK_RESIZE_QUEUE);
 247
 248   priv->shadow_type = GTK_SHADOW_IN;
 249   priv->view_window = NULL;
 250   priv->bin_window = NULL;
 251   priv->hadjustment = NULL;
 252   priv->vadjustment = NULL;
 253   priv->min_display_width = -1;
 254   priv->min_display_height = -1;
 255 }
 256
 257 /**
 258  * gtk_viewport_new:
 259  * @hadjustment: horizontal adjustment.
 260  * @vadjustment: vertical adjustment.
 261  * @returns: a new #GtkViewport.
 262  *
 263  * Creates a new #GtkViewport with the given adjustments.
 264  *
 265  **/
 266 GtkWidget*
 267 gtk_viewport_new (GtkAdjustment *hadjustment,
 268                   GtkAdjustment *vadjustment)
 269 {
 270   GtkWidget *viewport;
 271
 272   viewport = g_object_new (GTK_TYPE_VIEWPORT,
 273                              "hadjustment", hadjustment,
 274                              "vadjustment", vadjustment,
 275                              NULL);
 276
 277   return viewport;
 278 }
 279
 280 #define ADJUSTMENT_POINTER(viewport, orientation)         \
 281   (((orientation) == GTK_ORIENTATION_HORIZONTAL) ?        \
 282      &(viewport)->priv->hadjustment : &(viewport)->priv->vadjustment)
 283
 284 static void
 285 viewport_disconnect_adjustment (GtkViewport    *viewport,
 286                                 GtkOrientation  orientation)
 287 {
 288   GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (viewport, orientation);
 289
 290   if (*adjustmentp)
 291     {
 292       g_signal_handlers_disconnect_by_func (*adjustmentp,
 293                                             gtk_viewport_adjustment_value_changed,
 294                                             viewport);
 295       g_object_unref (*adjustmentp);
 296       *adjustmentp = NULL;
 297     }
 298 }
 299
 300 static void
 301 gtk_viewport_finalize (GObject *object)
 302 {
 303   GtkViewport *viewport = GTK_VIEWPORT (object);
 304
 305   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL);
 306   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_VERTICAL);
 307
 308   G_OBJECT_CLASS (gtk_viewport_parent_class)->finalize (object);
 309 }
 310
 311 static void
 312 gtk_viewport_destroy (GtkWidget *widget)
 313 {
 314   GtkViewport *viewport = GTK_VIEWPORT (widget);
 315
 316   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL);
 317   viewport_disconnect_adjustment (viewport, GTK_ORIENTATION_VERTICAL);
 318
 319   GTK_WIDGET_CLASS (gtk_viewport_parent_class)->destroy (widget);
 320 }
 321
 322 /**
 323  * gtk_viewport_get_hadjustment:
 324  * @viewport: a #GtkViewport.
 325  *
 326  * Returns the horizontal adjustment of the viewport.
 327  *
 328  * Return value: (transfer none): the horizontal adjustment of @viewport.
 329  *
 330  * Deprecated: 3.0: Use gtk_scrollable_get_hadjustment()
 331  **/
 332 GtkAdjustment*
 333 gtk_viewport_get_hadjustment (GtkViewport *viewport)
 334 {
 335   GtkViewportPrivate *priv;
 336
 337   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 338
 339   priv = viewport->priv;
 340
 341   if (!priv->hadjustment)
 342     gtk_viewport_set_hadjustment (viewport, NULL);
 343
 344   return priv->hadjustment;
 345 }
 346
 347 /**
 348  * gtk_viewport_get_vadjustment:
 349  * @viewport: a #GtkViewport.
 350  *
 351  * Returns the vertical adjustment of the viewport.
 352  *
 353  * Return value: (transfer none): the vertical adjustment of @viewport.
 354  *
 355  * Deprecated: 3.0: Use gtk_scrollable_get_vadjustment()
 356  **/
 357 GtkAdjustment*
 358 gtk_viewport_get_vadjustment (GtkViewport *viewport)
 359 {
 360   GtkViewportPrivate *priv;
 361
 362   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 363
 364   priv = viewport->priv;
 365
 366   if (!priv->vadjustment)
 367     gtk_viewport_set_vadjustment (viewport, NULL);
 368
 369   return priv->vadjustment;
 370 }
 371
 372 static void
 373 viewport_get_view_allocation (GtkViewport   *viewport,
 374                               GtkAllocation *view_allocation)
 375 {
 376   GtkViewportPrivate *priv = viewport->priv;
 377   GtkStyle *style;
 378   GtkWidget *widget = GTK_WIDGET (viewport);
 379   GtkAllocation allocation;
 380   guint border_width;
 381
 382   gtk_widget_get_allocation (widget, &allocation);
 383   border_width = gtk_container_get_border_width (GTK_CONTAINER (viewport));
 384
 385   view_allocation->x = 0;
 386   view_allocation->y = 0;
 387
 388   if (priv->shadow_type != GTK_SHADOW_NONE)
 389     {
 390       style = gtk_widget_get_style (widget);
 391       view_allocation->x = style->xthickness;
 392       view_allocation->y = style->ythickness;
 393     }
 394
 395   view_allocation->width = MAX (1, allocation.width - view_allocation->x * 2 - border_width * 2);
 396   view_allocation->height = MAX (1, allocation.height - view_allocation->y * 2 - border_width * 2);
 397 }
 398
 399 static void
 400 viewport_reclamp_adjustment (GtkAdjustment *adjustment,
 401                              gboolean      *value_changed)
 402 {
 403   gdouble value = adjustment->value;
 404
 405   value = CLAMP (value, 0, adjustment->upper - adjustment->page_size);
 406   if (value != adjustment->value)
 407     {
 408       adjustment->value = value;
 409       if (value_changed)
 410         *value_changed = TRUE;
 411     }
 412   else if (value_changed)
 413     *value_changed = FALSE;
 414 }
 415
 416 static void
 417 viewport_set_hadjustment_values (GtkViewport *viewport,
 418                                  gboolean    *value_changed)
 419 {
 420   GtkBin *bin = GTK_BIN (viewport);
 421   GtkAllocation view_allocation;
 422   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 423   GtkWidget *child;
 424   gdouble old_page_size;
 425   gdouble old_upper;
 426   gdouble old_value;
 427
 428   viewport_get_view_allocation (viewport, &view_allocation);
 429
 430   old_page_size = hadjustment->page_size;
 431   old_upper = hadjustment->upper;
 432   old_value = hadjustment->value;
 433   hadjustment->page_size = view_allocation.width;
 434   hadjustment->step_increment = view_allocation.width * 0.1;
 435   hadjustment->page_increment = view_allocation.width * 0.9;
 436
 437   hadjustment->lower = 0;
 438
 439   child = gtk_bin_get_child (bin);
 440   if (child && gtk_widget_get_visible (child))
 441     {
 442       gint minimum_width;
 443
 444       gtk_widget_get_preferred_width_for_height (child,
 445                                                  view_allocation.height,
 446                                                  &minimum_width,
 447                                                  NULL);
 448       hadjustment->upper = MAX (minimum_width, view_allocation.width);
 449     }
 450   else
 451     hadjustment->upper = view_allocation.width;
 452
 453   if (gtk_widget_get_direction (GTK_WIDGET (viewport)) == GTK_TEXT_DIR_RTL)
 454     {
 455       gdouble dist = old_upper - (old_value + old_page_size);
 456       hadjustment->value = hadjustment->upper - dist - hadjustment->page_size;
 457       viewport_reclamp_adjustment (hadjustment, value_changed);
 458       *value_changed = (old_value != hadjustment->value);
 459     }
 460   else
 461     viewport_reclamp_adjustment (hadjustment, value_changed);
 462 }
 463
 464 static void
 465 viewport_set_vadjustment_values (GtkViewport *viewport,
 466                                  gboolean    *value_changed)
 467 {
 468   GtkBin *bin = GTK_BIN (viewport);
 469   GtkAllocation view_allocation;
 470   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 471   GtkWidget *child;
 472
 473   viewport_get_view_allocation (viewport, &view_allocation);
 474
 475   vadjustment->page_size = view_allocation.height;
 476   vadjustment->step_increment = view_allocation.height * 0.1;
 477   vadjustment->page_increment = view_allocation.height * 0.9;
 478
 479   vadjustment->lower = 0;
 480
 481   child = gtk_bin_get_child (bin);
 482   if (child && gtk_widget_get_visible (child))
 483     {
 484       gint minimum_height;
 485
 486       gtk_widget_get_preferred_height_for_width (child,
 487                                                  view_allocation.width,
 488                                                  &minimum_height,
 489                                                  NULL);
 490
 491       vadjustment->upper = MAX (minimum_height, view_allocation.height);
 492     }
 493   else
 494     vadjustment->upper = view_allocation.height;
 495
 496   viewport_reclamp_adjustment (vadjustment, value_changed);
 497 }
 498
 499 static void
 500 viewport_set_adjustment (GtkViewport    *viewport,
 501                          GtkOrientation  orientation,
 502                          GtkAdjustment  *adjustment)
 503 {
 504   GtkAdjustment **adjustmentp = ADJUSTMENT_POINTER (viewport, orientation);
 505   gboolean value_changed;
 506
 507   if (adjustment && adjustment == *adjustmentp)
 508     return;
 509
 510   if (!adjustment)
 511     adjustment = gtk_adjustment_new (0.0, 0.0, 0.0, 0.0, 0.0, 0.0);
 512   viewport_disconnect_adjustment (viewport, orientation);
 513   *adjustmentp = adjustment;
 514   g_object_ref_sink (adjustment);
 515
 516   if (orientation == GTK_ORIENTATION_HORIZONTAL)
 517     viewport_set_hadjustment_values (viewport, &value_changed);
 518   else
 519     viewport_set_vadjustment_values (viewport, &value_changed);
 520
 521   g_signal_connect (adjustment, "value-changed",
 522                     G_CALLBACK (gtk_viewport_adjustment_value_changed),
 523                     viewport);
 524
 525   gtk_adjustment_changed (adjustment);
 526
 527   if (value_changed)
 528     gtk_adjustment_value_changed (adjustment);
 529   else
 530     gtk_viewport_adjustment_value_changed (adjustment, viewport);
 531 }
 532
 533 /**
 534  * gtk_viewport_set_hadjustment:
 535  * @viewport: a #GtkViewport.
 536  * @adjustment: (allow-none): a #GtkAdjustment.
 537  *
 538  * Sets the horizontal adjustment of the viewport.
 539  *
 540  * Deprecated: 3.0: Use gtk_scrollable_set_hadjustment()
 541  **/
 542 void
 543 gtk_viewport_set_hadjustment (GtkViewport   *viewport,
 544                               GtkAdjustment *adjustment)
 545 {
 546   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 547   if (adjustment)
 548     g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 549
 550   viewport_set_adjustment (viewport, GTK_ORIENTATION_HORIZONTAL, adjustment);
 551
 552   g_object_notify (G_OBJECT (viewport), "hadjustment");
 553 }
 554
 555 /**
 556  * gtk_viewport_set_vadjustment:
 557  * @viewport: a #GtkViewport.
 558  * @adjustment: (allow-none): a #GtkAdjustment.
 559  *
 560  * Sets the vertical adjustment of the viewport.
 561  *
 562  * Deprecated: 3.0: Use gtk_scrollable_set_vadjustment()
 563  **/
 564 void
 565 gtk_viewport_set_vadjustment (GtkViewport   *viewport,
 566                               GtkAdjustment *adjustment)
 567 {
 568   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 569   if (adjustment)
 570     g_return_if_fail (GTK_IS_ADJUSTMENT (adjustment));
 571
 572   viewport_set_adjustment (viewport, GTK_ORIENTATION_VERTICAL, adjustment);
 573
 574   g_object_notify (G_OBJECT (viewport), "vadjustment");
 575 }
 576
 577 /**
 578  * gtk_viewport_set_shadow_type:
 579  * @viewport: a #GtkViewport.
 580  * @type: the new shadow type.
 581  *
 582  * Sets the shadow type of the viewport.
 583  **/
 584 void
 585 gtk_viewport_set_shadow_type (GtkViewport   *viewport,
 586                               GtkShadowType  type)
 587 {
 588   GtkViewportPrivate *priv;
 589   GtkAllocation allocation;
 590   GtkWidget *widget;
 591
 592   g_return_if_fail (GTK_IS_VIEWPORT (viewport));
 593
 594   widget = GTK_WIDGET (viewport);
 595   priv = viewport->priv;
 596
 597   if ((GtkShadowType) priv->shadow_type != type)
 598     {
 599       priv->shadow_type = type;
 600
 601       if (gtk_widget_get_visible (widget))
 602         {
 603           gtk_widget_get_allocation (widget, &allocation);
 604           gtk_widget_size_allocate (widget, &allocation);
 605           gtk_widget_set_allocation (widget, &allocation);
 606           gtk_widget_queue_draw (widget);
 607         }
 608
 609       g_object_notify (G_OBJECT (viewport), "shadow-type");
 610     }
 611 }
 612
 613 /**
 614  * gtk_viewport_get_shadow_type:
 615  * @viewport: a #GtkViewport
 616  *
 617  * Gets the shadow type of the #GtkViewport. See
 618  * gtk_viewport_set_shadow_type().
 619  *
 620  * Return value: the shadow type
 621  **/
 622 GtkShadowType
 623 gtk_viewport_get_shadow_type (GtkViewport *viewport)
 624 {
 625   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), GTK_SHADOW_NONE);
 626
 627   return viewport->priv->shadow_type;
 628 }
 629
 630 /**
 631  * gtk_viewport_get_bin_window:
 632  * @viewport: a #GtkViewport
 633  *
 634  * Gets the bin window of the #GtkViewport.
 635  *
 636  * Return value: (transfer none): a #GdkWindow
 637  *
 638  * Since: 2.20
 639  **/
 640 GdkWindow*
 641 gtk_viewport_get_bin_window (GtkViewport *viewport)
 642 {
 643   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 644
 645   return viewport->priv->bin_window;
 646 }
 647
 648 /**
 649  * gtk_viewport_get_view_window:
 650  * @viewport: a #GtkViewport
 651  *
 652  * Gets the view window of the #GtkViewport.
 653  *
 654  * Return value: (transfer none): a #GdkWindow
 655  *
 656  * Since: 2.22
 657  **/
 658 GdkWindow*
 659 gtk_viewport_get_view_window (GtkViewport *viewport)
 660 {
 661   g_return_val_if_fail (GTK_IS_VIEWPORT (viewport), NULL);
 662
 663   return viewport->priv->view_window;
 664 }
 665
 666 static void
 667 gtk_viewport_realize (GtkWidget *widget)
 668 {
 669   GtkViewport *viewport = GTK_VIEWPORT (widget);
 670   GtkViewportPrivate *priv = viewport->priv;
 671   GtkBin *bin = GTK_BIN (widget);
 672   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 673   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 674   GtkAllocation allocation;
 675   GtkAllocation view_allocation;
 676   GtkStyle *style;
 677   GtkWidget *child;
 678   GdkWindow *window;
 679   GdkWindowAttr attributes;
 680   gint attributes_mask;
 681   gint event_mask;
 682   guint border_width;
 683
 684   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 685
 686   gtk_widget_set_realized (widget, TRUE);
 687
 688   gtk_widget_get_allocation (widget, &allocation);
 689
 690   attributes.x = allocation.x + border_width;
 691   attributes.y = allocation.y + border_width;
 692   attributes.width = allocation.width - border_width * 2;
 693   attributes.height = allocation.height - border_width * 2;
 694   attributes.window_type = GDK_WINDOW_CHILD;
 695   attributes.wclass = GDK_INPUT_OUTPUT;
 696   attributes.visual = gtk_widget_get_visual (widget);
 697
 698   event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
 699   /* We select on button_press_mask so that button 4-5 scrolls are trapped.
 700    */
 701   attributes.event_mask = event_mask | GDK_BUTTON_PRESS_MASK;
 702
 703   attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
 704
 705   window = gdk_window_new (gtk_widget_get_parent_window (widget),
 706                            &attributes, attributes_mask);
 707   gtk_widget_set_window (widget, window);
 708   gdk_window_set_user_data (window, viewport);
 709
 710   viewport_get_view_allocation (viewport, &view_allocation);
 711
 712   attributes.x = view_allocation.x;
 713   attributes.y = view_allocation.y;
 714   attributes.width = view_allocation.width;
 715   attributes.height = view_allocation.height;
 716   attributes.event_mask = 0;
 717
 718   priv->view_window = gdk_window_new (window,
 719                                       &attributes, attributes_mask);
 720   gdk_window_set_user_data (priv->view_window, viewport);
 721
 722   attributes.x = - hadjustment->value;
 723   attributes.y = - vadjustment->value;
 724   attributes.width = hadjustment->upper;
 725   attributes.height = vadjustment->upper;
 726
 727   attributes.event_mask = event_mask;
 728
 729   priv->bin_window = gdk_window_new (priv->view_window, &attributes, attributes_mask);
 730   gdk_window_set_user_data (priv->bin_window, viewport);
 731
 732   child = gtk_bin_get_child (bin);
 733   if (child)
 734     gtk_widget_set_parent_window (child, priv->bin_window);
 735
 736   gtk_widget_style_attach (widget);
 737   style = gtk_widget_get_style (widget);
 738   gtk_style_set_background (style, window, GTK_STATE_NORMAL);
 739   gtk_style_set_background (style, priv->bin_window, GTK_STATE_NORMAL);
 740
 741   gdk_window_show (priv->bin_window);
 742   gdk_window_show (priv->view_window);
 743 }
 744
 745 static void
 746 gtk_viewport_unrealize (GtkWidget *widget)
 747 {
 748   GtkViewport *viewport = GTK_VIEWPORT (widget);
 749   GtkViewportPrivate *priv = viewport->priv;
 750
 751   gdk_window_set_user_data (priv->view_window, NULL);
 752   gdk_window_destroy (priv->view_window);
 753   priv->view_window = NULL;
 754
 755   gdk_window_set_user_data (priv->bin_window, NULL);
 756   gdk_window_destroy (priv->bin_window);
 757   priv->bin_window = NULL;
 758
 759   GTK_WIDGET_CLASS (gtk_viewport_parent_class)->unrealize (widget);
 760 }
 761
 762 static gint
 763 gtk_viewport_draw (GtkWidget *widget,
 764                    cairo_t   *cr)
 765 {
 766   GtkViewport *viewport = GTK_VIEWPORT (widget);
 767   GtkViewportPrivate *priv = viewport->priv;
 768   int x, y;
 769
 770   if (gtk_cairo_should_draw_window (cr, gtk_widget_get_window (widget)))
 771     {
 772       gtk_paint_shadow (gtk_widget_get_style (widget),
 773                         cr,
 774                         GTK_STATE_NORMAL, priv->shadow_type,
 775                         widget, "viewport",
 776                         0, 0,
 777                         gdk_window_get_width (gtk_widget_get_window (widget)),
 778                         gdk_window_get_height (gtk_widget_get_window (widget)));
 779     }
 780
 781   if (gtk_cairo_should_draw_window (cr, priv->view_window))
 782     {
 783       /* This is a cute hack to ensure the contents of bin_window are
 784        * restricted to where they are visible. We only need to do this
 785        * clipping when called via gtk_widget_draw() and not in expose
 786        * events. And when that happens every window (including this one)
 787        * should be drawn.
 788        */
 789       gdk_window_get_position (priv->view_window, &x, &y);
 790       cairo_rectangle (cr, x, y,
 791                        gdk_window_get_width (priv->view_window),
 792                        gdk_window_get_height (priv->view_window));
 793       cairo_clip (cr);
 794     }
 795
 796   if (gtk_cairo_should_draw_window (cr, priv->bin_window))
 797     {
 798       gdk_window_get_position (priv->bin_window, &x, &y);
 799       gtk_paint_flat_box (gtk_widget_get_style (widget), cr,
 800                           GTK_STATE_NORMAL, GTK_SHADOW_NONE,
 801                           widget, "viewportbin",
 802                           x, y,
 803                           gdk_window_get_width (priv->bin_window),
 804                           gdk_window_get_height (priv->bin_window));
 805
 806       GTK_WIDGET_CLASS (gtk_viewport_parent_class)->draw (widget, cr);
 807     }
 808
 809   return FALSE;
 810 }
 811
 812 static void
 813 gtk_viewport_add (GtkContainer *container,
 814                   GtkWidget    *child)
 815 {
 816   GtkBin *bin = GTK_BIN (container);
 817   GtkViewport *viewport = GTK_VIEWPORT (bin);
 818   GtkViewportPrivate *priv = viewport->priv;
 819
 820   g_return_if_fail (gtk_bin_get_child (bin) == NULL);
 821
 822   gtk_widget_set_parent_window (child, priv->bin_window);
 823
 824   GTK_CONTAINER_CLASS (gtk_viewport_parent_class)->add (container, child);
 825 }
 826
 827 static void
 828 gtk_viewport_size_allocate (GtkWidget     *widget,
 829                             GtkAllocation *allocation)
 830 {
 831   GtkAllocation widget_allocation;
 832   GtkViewport *viewport = GTK_VIEWPORT (widget);
 833   GtkViewportPrivate *priv = viewport->priv;
 834   GtkBin *bin = GTK_BIN (widget);
 835   guint border_width;
 836   gboolean hadjustment_value_changed, vadjustment_value_changed;
 837   GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 838   GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 839   GtkAllocation child_allocation;
 840   GtkWidget *child;
 841
 842   border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
 843
 844   /* If our size changed, and we have a shadow, queue a redraw on widget->window to
 845    * redraw the shadow correctly.
 846    */
 847   gtk_widget_get_allocation (widget, &widget_allocation);
 848   if (gtk_widget_get_mapped (widget) &&
 849       priv->shadow_type != GTK_SHADOW_NONE &&
 850       (widget_allocation.width != allocation->width ||
 851        widget_allocation.height != allocation->height))
 852     gdk_window_invalidate_rect (gtk_widget_get_window (widget), NULL, FALSE);
 853
 854   gtk_widget_set_allocation (widget, allocation);
 855
 856   viewport_set_hadjustment_values (viewport, &hadjustment_value_changed);
 857   viewport_set_vadjustment_values (viewport, &vadjustment_value_changed);
 858
 859   child_allocation.x = 0;
 860   child_allocation.y = 0;
 861   child_allocation.width = hadjustment->upper;
 862   child_allocation.height = vadjustment->upper;
 863   if (gtk_widget_get_realized (widget))
 864     {
 865       GtkAllocation view_allocation;
 866
 867       gdk_window_move_resize (gtk_widget_get_window (widget),
 868                               allocation->x + border_width,
 869                               allocation->y + border_width,
 870                               allocation->width - border_width * 2,
 871                               allocation->height - border_width * 2);
 872
 873       viewport_get_view_allocation (viewport, &view_allocation);
 874       gdk_window_move_resize (priv->view_window,
 875                               view_allocation.x,
 876                               view_allocation.y,
 877                               view_allocation.width,
 878                               view_allocation.height);
 879       gdk_window_move_resize (priv->bin_window,
 880                               - hadjustment->value,
 881                               - vadjustment->value,
 882                               child_allocation.width,
 883                               child_allocation.height);
 884     }
 885
 886   child = gtk_bin_get_child (bin);
 887   if (child && gtk_widget_get_visible (child))
 888     gtk_widget_size_allocate (child, &child_allocation);
 889
 890   gtk_adjustment_changed (hadjustment);
 891   gtk_adjustment_changed (vadjustment);
 892   if (hadjustment_value_changed)
 893     gtk_adjustment_value_changed (hadjustment);
 894   if (vadjustment_value_changed)
 895     gtk_adjustment_value_changed (vadjustment);
 896 }
 897
 898 static void
 899 gtk_viewport_adjustment_value_changed (GtkAdjustment *adjustment,
 900                                        gpointer       data)
 901 {
 902   GtkViewport *viewport = GTK_VIEWPORT (data);
 903   GtkViewportPrivate *priv = viewport->priv;
 904   GtkBin *bin = GTK_BIN (data);
 905   GtkWidget *child;
 906
 907   child = gtk_bin_get_child (bin);
 908   if (child && gtk_widget_get_visible (child) &&
 909       gtk_widget_get_realized (GTK_WIDGET (viewport)))
 910     {
 911       GtkAdjustment *hadjustment = gtk_viewport_get_hadjustment (viewport);
 912       GtkAdjustment *vadjustment = gtk_viewport_get_vadjustment (viewport);
 913       gint old_x, old_y;
 914       gint new_x, new_y;
 915
 916       gdk_window_get_position (priv->bin_window, &old_x, &old_y);
 917       new_x = - hadjustment->value;
 918       new_y = - vadjustment->value;
 919
 920       if (new_x != old_x || new_y != old_y)
 921         {
 922           gdk_window_move (priv->bin_window, new_x, new_y);
 923           gdk_window_process_updates (priv->bin_window, TRUE);
 924         }
 925     }
 926 }
 927
 928 static void
 929 gtk_viewport_style_set (GtkWidget *widget,
 930                         GtkStyle  *previous_style)
 931 {
 932    if (gtk_widget_get_realized (widget) &&
 933        gtk_widget_get_has_window (widget))
 934      {
 935         GtkStyle *style;
 936         GtkViewport *viewport = GTK_VIEWPORT (widget);
 937         GtkViewportPrivate *priv = viewport->priv;
 938
 939         style = gtk_widget_get_style (widget);
 940         gtk_style_set_background (style, priv->bin_window, GTK_STATE_NORMAL);
 941         gtk_style_set_background (style,
 942                                   gtk_widget_get_window (widget),
 943                                   gtk_widget_get_state (widget));
 944      }
 945 }
 946
 947
 948 static void
 949 gtk_viewport_get_preferred_size (GtkWidget      *widget,
 950                                  GtkOrientation  orientation,
 951                                  gint           *minimum_size,
 952                                  gint           *natural_size)
 953 {
 954   GtkViewport *viewport = GTK_VIEWPORT (widget);
 955   GtkViewportPrivate *priv = viewport->priv;
 956   GtkStyle  *style;
 957   GtkWidget *child;
 958   gint       child_min, child_nat;
 959   gint       minimum, natural;
 960
 961   child = gtk_bin_get_child (GTK_BIN (widget));
 962
 963   /* XXX This should probably be (border_width * 2); but GTK+ has
 964    * been doing this with a single border for a while now...
 965    */
 966   minimum = gtk_container_get_border_width (GTK_CONTAINER (widget));
 967
 968   if (priv->shadow_type != GTK_SHADOW_NONE)
 969     {
 970       style = gtk_widget_get_style (GTK_WIDGET (widget));
 971       if (orientation == GTK_ORIENTATION_HORIZONTAL)
 972           minimum += 2 * style->xthickness;
 973       else
 974           minimum += 2 * style->ythickness;
 975     }
 976
 977   natural = minimum;
 978
 979   if (child && gtk_widget_get_visible (child))
 980     {
 981       if (orientation == GTK_ORIENTATION_HORIZONTAL)
 982         gtk_widget_get_preferred_width (child, &child_min, &child_nat);
 983       else
 984         gtk_widget_get_preferred_height (child, &child_min, &child_nat);
 985
 986       minimum += child_min;
 987       natural += child_nat;
 988     }
 989
 990   if (minimum_size)
 991     *minimum_size = minimum;
 992
 993   if (natural_size)
 994     *natural_size = natural;
 995 }
 996
 997 static void
 998 gtk_viewport_get_preferred_width (GtkWidget *widget,
 999                                   gint      *minimum_size,
1000                                   gint      *natural_size)
1001 {
1002   gtk_viewport_get_preferred_size (widget, GTK_ORIENTATION_HORIZONTAL, minimum_size, natural_size);
1003 }
1004
1005 static void
1006 gtk_viewport_get_preferred_height (GtkWidget *widget,
1007                                    gint      *minimum_size,
1008                                    gint      *natural_size)
1009 {
1010   gtk_viewport_get_preferred_size (widget, GTK_ORIENTATION_VERTICAL, minimum_size, natural_size);
1011 }