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 "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_size_request (GtkWidget *widget,
55 GtkRequisition *requisition)
57 GtkBin *bin = GTK_BIN (widget);
60 gint default_width, default_height;
62 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
64 requisition->width = border_width * 2;
65 requisition->height = border_width * 2;
67 child = gtk_bin_get_child (bin);
69 if (child != NULL && gtk_widget_get_visible (child))
71 GtkRequisition child_req;
73 gtk_widget_get_preferred_size (child, &child_req, NULL);
75 requisition->width += child_req.width;
76 requisition->height += child_req.height;
79 gtk_window_get_default_size (GTK_WINDOW (widget),
80 &default_width, &default_height);
81 if (default_width > 0)
82 requisition->width = default_width;
84 if (default_height > 0)
85 requisition->height = default_height;
89 gtk_offscreen_window_size_allocate (GtkWidget *widget,
90 GtkAllocation *allocation)
92 GtkBin *bin = GTK_BIN (widget);
96 gtk_widget_set_allocation (widget, allocation);
98 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
100 if (gtk_widget_get_realized (widget))
101 gdk_window_move_resize (gtk_widget_get_window (widget),
107 child = gtk_bin_get_child (bin);
109 if (child != NULL && gtk_widget_get_visible (child))
111 GtkAllocation child_alloc;
113 child_alloc.x = border_width;
114 child_alloc.y = border_width;
115 child_alloc.width = allocation->width - 2 * border_width;
116 child_alloc.height = allocation->height - 2 * border_width;
118 gtk_widget_size_allocate (child, &child_alloc);
121 gtk_widget_queue_draw (widget);
125 gtk_offscreen_window_realize (GtkWidget *widget)
127 GtkAllocation allocation;
131 GdkWindowAttr attributes;
132 gint attributes_mask;
135 bin = GTK_BIN (widget);
137 gtk_widget_set_realized (widget, TRUE);
139 border_width = gtk_container_get_border_width (GTK_CONTAINER (widget));
141 gtk_widget_get_allocation (widget, &allocation);
143 attributes.x = allocation.x;
144 attributes.y = allocation.y;
145 attributes.width = allocation.width;
146 attributes.height = allocation.height;
147 attributes.window_type = GDK_WINDOW_OFFSCREEN;
148 attributes.event_mask = gtk_widget_get_events (widget) | GDK_EXPOSURE_MASK;
149 attributes.visual = gtk_widget_get_visual (widget);
150 attributes.wclass = GDK_INPUT_OUTPUT;
152 attributes_mask = GDK_WA_X | GDK_WA_Y | GDK_WA_VISUAL;
154 window = gdk_window_new (gtk_widget_get_parent_window (widget),
155 &attributes, attributes_mask);
156 gtk_widget_set_window (widget, window);
157 gdk_window_set_user_data (window, widget);
159 child = gtk_bin_get_child (bin);
161 gtk_widget_set_parent_window (child, window);
163 gtk_widget_style_attach (widget);
164 gtk_style_set_background (gtk_widget_get_style (widget),
165 window, GTK_STATE_NORMAL);
169 gtk_offscreen_window_resize (GtkWidget *widget)
171 GtkAllocation allocation = { 0, 0 };
172 GtkRequisition requisition;
174 gtk_widget_get_preferred_size (widget, &requisition, NULL);
176 allocation.width = requisition.width;
177 allocation.height = requisition.height;
178 gtk_widget_size_allocate (widget, &allocation);
182 move_focus (GtkWidget *widget,
183 GtkDirectionType dir)
185 gtk_widget_child_focus (widget, dir);
187 if (!gtk_container_get_focus_child (GTK_CONTAINER (widget)))
188 gtk_window_set_focus (GTK_WINDOW (widget), NULL);
192 gtk_offscreen_window_show (GtkWidget *widget)
194 gboolean need_resize;
195 GtkContainer *container;
197 _gtk_widget_set_visible_flag (widget, TRUE);
199 container = GTK_CONTAINER (widget);
200 need_resize = _gtk_container_get_need_resize (container) || !gtk_widget_get_realized (widget);
201 _gtk_container_set_need_resize (container, FALSE);
204 gtk_offscreen_window_resize (widget);
206 gtk_widget_map (widget);
208 /* Try to make sure that we have some focused widget */
209 if (!gtk_window_get_focus (GTK_WINDOW (widget)))
210 move_focus (widget, GTK_DIR_TAB_FORWARD);
214 gtk_offscreen_window_hide (GtkWidget *widget)
216 _gtk_widget_set_visible_flag (widget, FALSE);
217 gtk_widget_unmap (widget);
221 gtk_offscreen_window_check_resize (GtkContainer *container)
223 GtkWidget *widget = GTK_WIDGET (container);
225 if (gtk_widget_get_visible (widget))
226 gtk_offscreen_window_resize (widget);
230 gtk_offscreen_window_class_init (GtkOffscreenWindowClass *class)
232 GtkWidgetClass *widget_class;
233 GtkContainerClass *container_class;
235 widget_class = GTK_WIDGET_CLASS (class);
236 container_class = GTK_CONTAINER_CLASS (class);
238 widget_class->realize = gtk_offscreen_window_realize;
239 widget_class->show = gtk_offscreen_window_show;
240 widget_class->hide = gtk_offscreen_window_hide;
241 widget_class->size_request = gtk_offscreen_window_size_request;
242 widget_class->size_allocate = gtk_offscreen_window_size_allocate;
244 container_class->check_resize = gtk_offscreen_window_check_resize;
248 gtk_offscreen_window_init (GtkOffscreenWindow *window)
252 /* --- functions --- */
254 * gtk_offscreen_window_new:
256 * Creates a toplevel container widget that is used to retrieve
257 * snapshots of widgets without showing them on the screen.
259 * Return value: A pointer to a #GtkWidget
264 gtk_offscreen_window_new (void)
266 return g_object_new (gtk_offscreen_window_get_type (), NULL);
270 * gtk_offscreen_window_get_surface:
271 * @offscreen: the #GtkOffscreenWindow contained widget.
273 * Retrieves a snapshot of the contained widget in the form of
274 * a #cairo_surface_t. If you need to keep this around over window
275 * resizes then you should add a reference to it.
277 * Returns: (transfer none): A #cairo_surface_t pointer to the offscreen
283 gtk_offscreen_window_get_surface (GtkOffscreenWindow *offscreen)
285 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
287 return gdk_offscreen_window_get_surface (gtk_widget_get_window (GTK_WIDGET (offscreen)));
291 * gtk_offscreen_window_get_pixbuf:
292 * @offscreen: the #GtkOffscreenWindow contained widget.
294 * Retrieves a snapshot of the contained widget in the form of
295 * a #GdkPixbuf. This is a new pixbuf with a reference count of 1,
296 * and the application should unreference it once it is no longer
299 * Returns: (transfer full): A #GdkPixbuf pointer, or %NULL.
304 gtk_offscreen_window_get_pixbuf (GtkOffscreenWindow *offscreen)
306 cairo_surface_t *surface;
307 GdkPixbuf *pixbuf = NULL;
310 g_return_val_if_fail (GTK_IS_OFFSCREEN_WINDOW (offscreen), NULL);
312 window = gtk_widget_get_window (GTK_WIDGET (offscreen));
313 surface = gdk_offscreen_window_get_surface (window);
317 pixbuf = gdk_pixbuf_get_from_surface (NULL, surface,
319 gdk_window_get_width (window),
320 gdk_window_get_height (window));