2 * This library is free software; you can redistribute it and/or
3 * modify it under the terms of the GNU Lesser General Public
4 * License as published by the Free Software Foundation; either
5 * version 2 of the License, or (at your option) any later version.
7 * This library is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
10 * Lesser General Public License for more details.
12 * You should have received a copy of the GNU Lesser General Public
13 * License along with this library; if not, write to the
14 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
15 * Boston, MA 02111-1307, USA.
17 * Authors: Cody Russell <crussell@canonical.com>
18 * Alexander Larsson <alexl@redhat.com>
23 #include "gtkoffscreenwindow.h"
24 #include "gtkwidgetprivate.h"
25 #include "gtkprivate.h"
28 * SECTION:gtkoffscreenwindow
29 * @short_description: A toplevel to manage offscreen rendering of child widgets
30 * @title: GtkOffscreenWindow
32 * GtkOffscreenWindow is strictly intended to be used for obtaining
33 * snapshots of widgets that are not part of a normal widget hierarchy.
34 * Since #GtkOffscreenWindow is a toplevel widget you cannot obtain
35 * snapshots of a full window with it since you cannot pack a toplevel
36 * widget in another toplevel.
38 * The idea is to take a widget and manually set the state of it,
39 * add it to a GtkOffscreenWindow and then retrieve the snapshot
40 * as a #cairo_surface_t or #GdkPixbuf.
42 * GtkOffscreenWindow derives from #GtkWindow only as an implementation
43 * detail. Applications should not use any API specific to #GtkWindow
44 * to operate on this object. It should be treated as a #GtkBin that
45 * has no parent widget.
47 * When contained offscreen widgets are redrawn, GtkOffscreenWindow
48 * will emit a #GtkWidget::damage-event signal.
51 G_DEFINE_TYPE (GtkOffscreenWindow, gtk_offscreen_window, GTK_TYPE_WINDOW);
54 gtk_offscreen_window_get_preferred_width (GtkWidget *widget,
58 GtkBin *bin = GTK_BIN (widget);
63 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
65 *minimum = border_width * 2;
66 *natural = border_width * 2;
68 child = gtk_bin_get_child (bin);
70 if (child != NULL && gtk_widget_get_visible (child))
72 gint child_min, child_nat;
74 gtk_widget_get_preferred_width (child, &child_min, &child_nat);
76 *minimum += child_min;
77 *natural += child_nat;
80 gtk_window_get_default_size (GTK_WINDOW (widget),
81 &default_width, NULL);
83 *minimum = MAX (*minimum, default_width);
84 *natural = MAX (*natural, default_width);
88 gtk_offscreen_window_get_preferred_height (GtkWidget *widget,
92 GtkBin *bin = GTK_BIN (widget);
97 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
99 *minimum = border_width * 2;
100 *natural = border_width * 2;
102 child = gtk_bin_get_child (bin);
104 if (child != NULL && gtk_widget_get_visible (child))
106 gint child_min, child_nat;
108 gtk_widget_get_preferred_height (child, &child_min, &child_nat);
110 *minimum += child_min;
111 *natural += child_nat;
114 gtk_window_get_default_size (GTK_WINDOW (widget),
115 NULL, &default_height);
117 *minimum = MAX (*minimum, default_height);
118 *natural = MAX (*natural, default_height);
122 gtk_offscreen_window_size_allocate (GtkWidget *widget,
123 GtkAllocation *allocation)
125 GtkBin *bin = GTK_BIN (widget);
129 gtk_widget_set_allocation (widget, allocation);
131 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
133 if (gtk_widget_get_realized (widget))
134 gdk_window_move_resize (gtk_widget_get_window (widget),
140 child = gtk_bin_get_child (bin);
142 if (child != NULL && gtk_widget_get_visible (child))
144 GtkAllocation child_alloc;
146 child_alloc.x = border_width;
147 child_alloc.y = border_width;
148 child_alloc.width = allocation->width - 2 * border_width;
149 child_alloc.height = allocation->height - 2 * border_width;
151 gtk_widget_size_allocate (child, &child_alloc);
154 gtk_widget_queue_draw (widget);
158 gtk_offscreen_window_realize (GtkWidget *widget)
160 GtkAllocation allocation;
164 GdkWindowAttr attributes;
165 gint attributes_mask;
168 bin = GTK_BIN (widget);
170 gtk_widget_set_realized (widget, TRUE);
172 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
174 gtk_widget_get_allocation (widget, &allocation);
176 attributes.x = allocation.x;
177 attributes.y = allocation.y;
178 attributes.width = allocation.width;
179 attributes.height = allocation.height;
180 attributes.window_type = GDK_WINDOW_OFFSCREEN;
181 attributes.event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
182 attributes.visual = gtk_widget_get_visual (widget);
183 attributes.wclass = GDK_INPUT_OUTPUT;
185 attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
187 window = gdk_window_new (gtk_widget_get_parent_window (widget),
188 &attributes, attributes_mask);
189 gtk_widget_set_window (widget, window);
190 gdk_window_set_user_data (window, widget);
192 child = gtk_bin_get_child (bin);
194 gtk_widget_set_parent_window (child, window);
196 gtk_widget_style_attach (widget);
197 gtk_style_set_background (gtk_widget_get_style (widget),
198 window, GTK_STATE_NORMAL);
202 gtk_offscreen_window_resize (GtkWidget *widget)
204 GtkAllocation allocation = { 0, 0 };
205 GtkRequisition requisition;
207 gtk_widget_get_preferred_size (widget, &requisition, NULL);
209 allocation.width = requisition.width;
210 allocation.height = requisition.height;
211 gtk_widget_size_allocate (widget, &allocation);
215 move_focus (GtkWidget *widget,
216 GtkDirectionType dir)
218 gtk_widget_child_focus (widget, dir);
220 if (!gtk_container_get_focus_child (GTK_CONTAINER (widget)))
221 gtk_window_set_focus (GTK_WINDOW (widget), NULL);
225 gtk_offscreen_window_show (GtkWidget *widget)
227 gboolean need_resize;
228 GtkContainer *container;
230 _gtk_widget_set_visible_flag (widget, TRUE);
232 container = GTK_CONTAINER (widget);
233 need_resize = _gtk_container_get_need_resize (container) || !gtk_widget_get_realized (widget);
234 _gtk_container_set_need_resize (container, FALSE);
237 gtk_offscreen_window_resize (widget);
239 gtk_widget_map (widget);
241 /* Try to make sure that we have some focused widget */
242 if (!gtk_window_get_focus (GTK_WINDOW (widget)))
243 move_focus (widget, GTK_DIR_TAB_FORWARD);
247 gtk_offscreen_window_hide (GtkWidget *widget)
249 _gtk_widget_set_visible_flag (widget, FALSE);
250 gtk_widget_unmap (widget);
254 gtk_offscreen_window_check_resize (GtkContainer *container)
256 GtkWidget *widget = GTK_WIDGET (container);
258 if (gtk_widget_get_visible (widget))
259 gtk_offscreen_window_resize (widget);
263 gtk_offscreen_window_class_init (GtkOffscreenWindowClass *class)
265 GtkWidgetClass *widget_class;
266 GtkContainerClass *container_class;
268 widget_class = GTK_WIDGET_CLASS (class);
269 container_class = GTK_CONTAINER_CLASS (class);
271 widget_class->realize = gtk_offscreen_window_realize;
272 widget_class->show = gtk_offscreen_window_show;
273 widget_class->hide = gtk_offscreen_window_hide;
274 widget_class->get_preferred_width = gtk_offscreen_window_get_preferred_width;
275 widget_class->get_preferred_height = gtk_offscreen_window_get_preferred_height;
276 widget_class->size_allocate = gtk_offscreen_window_size_allocate;
278 container_class->check_resize = gtk_offscreen_window_check_resize;
282 gtk_offscreen_window_init (GtkOffscreenWindow *window)
286 /* --- functions --- */
288 * gtk_offscreen_window_new:
290 * Creates a toplevel container widget that is used to retrieve
291 * snapshots of widgets without showing them on the screen.
293 * Return value: A pointer to a #GtkWidget
298 gtk_offscreen_window_new (void)
300 return g_object_new (gtk_offscreen_window_get_type (), NULL);
304 * gtk_offscreen_window_get_surface:
305 * @offscreen: the #GtkOffscreenWindow contained widget.
307 * Retrieves a snapshot of the contained widget in the form of
308 * a #cairo_surface_t. If you need to keep this around over window
309 * resizes then you should add a reference to it.
311 * Returns: (transfer none): A #cairo_surface_t pointer to the offscreen
317 gtk_offscreen_window_get_surface (GtkOffscreenWindow *offscreen)
319 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
321 return gdk_offscreen_window_get_surface (gtk_widget_get_window (GTK_WIDGET (offscreen)));
325 * gtk_offscreen_window_get_pixbuf:
326 * @offscreen: the #GtkOffscreenWindow contained widget.
328 * Retrieves a snapshot of the contained widget in the form of
329 * a #GdkPixbuf. This is a new pixbuf with a reference count of 1,
330 * and the application should unreference it once it is no longer
333 * Returns: (transfer full): A #GdkPixbuf pointer, or %NULL.
338 gtk_offscreen_window_get_pixbuf (GtkOffscreenWindow *offscreen)
340 cairo_surface_t *surface;
341 GdkPixbuf *pixbuf = NULL;
344 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
346 window = gtk_widget_get_window (GTK_WIDGET (offscreen));
347 surface = gdk_offscreen_window_get_surface (window);
351 pixbuf = gdk_pixbuf_get_from_surface (surface,
353 gdk_window_get_width (window),
354 gdk_window_get_height (window));