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"
25 #include "gtksizerequest.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 * It differs from gtk_widget_get_snapshot() in that the widget you
35 * want to get a snapshot of need not be displayed on the user's screen
36 * as a part of a widget hierarchy. However, since GtkOffscreenWindow
37 * is a toplevel widget you cannot obtain snapshots of a full window
38 * with it since you cannot pack a toplevel widget in another toplevel.
40 * The idea is to take a widget and manually set the state of it,
41 * add it to a GtkOffscreenWindow and then retrieve the snapshot
42 * as a #GdkPixmap or #GdkPixbuf.
44 * GtkOffscreenWindow derives from #GtkWindow only as an implementation
45 * detail. Applications should not use any API specific to #GtkWindow
46 * to operate on this object. It should be treated as a #GtkBin that
47 * has no parent widget.
49 * When contained offscreen widgets are redrawn, GtkOffscreenWindow
50 * will emit a #GtkWidget::damage-event signal.
53 G_DEFINE_TYPE (GtkOffscreenWindow, gtk_offscreen_window, GTK_TYPE_WINDOW);
56 gtk_offscreen_window_size_request (GtkWidget *widget,
57 GtkRequisition *requisition)
59 GtkBin *bin = GTK_BIN (widget);
62 gint default_width, default_height;
64 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
66 requisition->width = border_width * 2;
67 requisition->height = border_width * 2;
69 child = gtk_bin_get_child (bin);
71 if (child != NULL && gtk_widget_get_visible (child))
73 GtkRequisition child_req;
75 gtk_size_request_get_size (GTK_SIZE_REQUEST (child),
78 requisition->width += child_req.width;
79 requisition->height += child_req.height;
82 gtk_window_get_default_size (GTK_WINDOW (widget),
83 &default_width, &default_height);
84 if (default_width > 0)
85 requisition->width = default_width;
87 if (default_height > 0)
88 requisition->height = default_height;
92 gtk_offscreen_window_size_allocate (GtkWidget *widget,
93 GtkAllocation *allocation)
95 GtkBin *bin = GTK_BIN (widget);
99 gtk_widget_set_allocation (widget, allocation);
101 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
103 if (gtk_widget_get_realized (widget))
104 gdk_window_move_resize (gtk_widget_get_window (widget),
110 child = gtk_bin_get_child (bin);
112 if (child != NULL && gtk_widget_get_visible (child))
114 GtkAllocation child_alloc;
116 child_alloc.x = border_width;
117 child_alloc.y = border_width;
118 child_alloc.width = allocation->width - 2 * border_width;
119 child_alloc.height = allocation->height - 2 * border_width;
121 gtk_widget_size_allocate (child, &child_alloc);
124 gtk_widget_queue_draw (widget);
128 gtk_offscreen_window_realize (GtkWidget *widget)
130 GtkAllocation allocation;
134 GdkWindowAttr attributes;
135 gint attributes_mask;
138 bin = GTK_BIN (widget);
140 gtk_widget_set_realized (widget, TRUE);
142 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
144 gtk_widget_get_allocation (widget, &allocation);
146 attributes.x = allocation.x;
147 attributes.y = allocation.y;
148 attributes.width = allocation.width;
149 attributes.height = allocation.height;
150 attributes.window_type = GDK_WINDOW_OFFSCREEN;
151 attributes.event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
152 attributes.visual = gtk_widget_get_visual (widget);
153 attributes.colormap = gtk_widget_get_colormap (widget);
154 attributes.wclass = GDK_INPUT_OUTPUT;
156 attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL | GDK_WA_COLORMAP;
158 window = gdk_window_new (gtk_widget_get_parent_window (widget),
159 &attributes, attributes_mask);
160 gtk_widget_set_window (widget, window);
161 gdk_window_set_user_data (window, widget);
163 child = gtk_bin_get_child (bin);
165 gtk_widget_set_parent_window (child, window);
167 gtk_widget_style_attach (widget);
168 gtk_style_set_background (gtk_widget_get_style (widget),
169 window, GTK_STATE_NORMAL);
173 gtk_offscreen_window_resize (GtkWidget *widget)
175 GtkAllocation allocation = { 0, 0 };
176 GtkRequisition requisition;
178 gtk_size_request_get_size (GTK_SIZE_REQUEST (widget),
181 allocation.width = requisition.width;
182 allocation.height = requisition.height;
183 gtk_widget_size_allocate (widget, &allocation);
187 move_focus (GtkWidget *widget,
188 GtkDirectionType dir)
190 gtk_widget_child_focus (widget, dir);
192 if (!gtk_container_get_focus_child (GTK_CONTAINER (widget)))
193 gtk_window_set_focus (GTK_WINDOW (widget), NULL);
197 gtk_offscreen_window_show (GtkWidget *widget)
199 gboolean need_resize;
200 GtkContainer *container;
202 GTK_WIDGET_SET_FLAGS (widget, GTK_VISIBLE);
204 container = GTK_CONTAINER (widget);
205 need_resize = _gtk_container_get_need_resize (container) || !gtk_widget_get_realized (widget);
206 _gtk_container_set_need_resize (container, FALSE);
209 gtk_offscreen_window_resize (widget);
211 gtk_widget_map (widget);
213 /* Try to make sure that we have some focused widget */
214 if (!gtk_window_get_focus (GTK_WINDOW (widget)))
215 move_focus (widget, GTK_DIR_TAB_FORWARD);
219 gtk_offscreen_window_hide (GtkWidget *widget)
221 GTK_WIDGET_UNSET_FLAGS (widget, GTK_VISIBLE);
222 gtk_widget_unmap (widget);
226 gtk_offscreen_window_check_resize (GtkContainer *container)
228 GtkWidget *widget = GTK_WIDGET (container);
230 if (gtk_widget_get_visible (widget))
231 gtk_offscreen_window_resize (widget);
235 gtk_offscreen_window_class_init (GtkOffscreenWindowClass *class)
237 GtkWidgetClass *widget_class;
238 GtkContainerClass *container_class;
240 widget_class = GTK_WIDGET_CLASS (class);
241 container_class = GTK_CONTAINER_CLASS (class);
243 widget_class->realize = gtk_offscreen_window_realize;
244 widget_class->show = gtk_offscreen_window_show;
245 widget_class->hide = gtk_offscreen_window_hide;
246 widget_class->size_request = gtk_offscreen_window_size_request;
247 widget_class->size_allocate = gtk_offscreen_window_size_allocate;
249 container_class->check_resize = gtk_offscreen_window_check_resize;
253 gtk_offscreen_window_init (GtkOffscreenWindow *window)
257 /* --- functions --- */
259 * gtk_offscreen_window_new:
261 * Creates a toplevel container widget that is used to retrieve
262 * snapshots of widgets without showing them on the screen. For
263 * widgets that are on the screen and part of a normal widget
264 * hierarchy, gtk_widget_get_snapshot() can be used instead.
266 * Return value: A pointer to a #GtkWidget
271 gtk_offscreen_window_new (void)
273 return g_object_new (gtk_offscreen_window_get_type (), NULL);
277 * gtk_offscreen_window_get_pixmap:
278 * @offscreen: the #GtkOffscreenWindow contained widget.
280 * Retrieves a snapshot of the contained widget in the form of
281 * a #GdkPixmap. If you need to keep this around over window
282 * resizes then you should add a reference to it.
284 * Returns: (transfer none): A #GdkPixmap pointer to the offscreen pixmap,
290 gtk_offscreen_window_get_pixmap (GtkOffscreenWindow *offscreen)
292 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
294 return gdk_offscreen_window_get_pixmap (gtk_widget_get_window (GTK_WIDGET (offscreen)));
298 * gtk_offscreen_window_get_pixbuf:
299 * @offscreen: the #GtkOffscreenWindow contained widget.
301 * Retrieves a snapshot of the contained widget in the form of
302 * a #GdkPixbuf. This is a new pixbuf with a reference count of 1,
303 * and the application should unreference it once it is no longer
306 * Returns: (transfer full): A #GdkPixbuf pointer, or %NULL.
311 gtk_offscreen_window_get_pixbuf (GtkOffscreenWindow *offscreen)
313 GdkPixmap *pixmap = NULL;
314 GdkPixbuf *pixbuf = NULL;
316 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
318 pixmap = gdk_offscreen_window_get_pixmap (gtk_widget_get_window (GTK_WIDGET (offscreen)));
324 gdk_drawable_get_size (pixmap, &width, &height);
326 pixbuf = gdk_pixbuf_get_from_drawable (NULL, pixmap, NULL,