use offscreen windows for previews

gtk 2.20+ provides offscreen window. use them for previews

note by @monsta: commit is patched to leave the current GTK+2 code as is
because offscreen windows don't work properly there for some reason...

1 files changed, 46 insertions, 25 deletions

diff --git a/capplets/common/theme-thumbnail.c b/capplets/common/theme-thumbnail.c
index 4376ef0f..f66a05ec 100644
--- a/capplets/common/theme-thumbnail.c
+++ b/capplets/common/theme-thumbnail.c
@@ -94,16 +94,12 @@ static int pipe_from_factory_fd[2];
 
 /* This draw the thumbnail of gtk
  */
-#if GTK_CHECK_VERSION (3, 0, 0)
-static void draw_window_on_pixbuf(GtkWidget* widget, GdkPixbuf* pixbuf)
-#else
-static GdkPixmap* draw_window_on_pixbuf(GtkWidget* widget)
-#endif
-{
 #if !GTK_CHECK_VERSION (3, 0, 0)
+static GdkPixmap *
+draw_window_on_pixbuf(GtkWidget* widget)
+{
 	GdkVisual* visual;
 	GdkPixmap* pixmap;
-#endif
 	GtkStyle* style;
 	GdkScreen* screen = gdk_screen_get_default();
 	GdkWindow* window;
@@ -118,41 +114,32 @@ static GdkPixmap* draw_window_on_pixbuf(GtkWidget* widget)
 
 	gtk_window_get_size(GTK_WINDOW(widget), &width, &height);
 
-#if !GTK_CHECK_VERSION (3, 0, 0)
 	visual = gtk_widget_get_visual(widget);
 	pixmap = gdk_pixmap_new(NULL, width, height, gdk_visual_get_depth (visual));
 	gdk_drawable_set_colormap(GDK_DRAWABLE(pixmap), gtk_widget_get_colormap(widget));
-#endif
 
 	window = gtk_widget_get_window(widget);
 
 	/* This is a hack for the default resize grip on Ubuntu.
 	 * We need to add a --enable-ubuntu for this.
-   * Resize grip is also default with GTK3.
+	 * Resize grip is also default with GTK3.
 	 */
-#if defined(UBUNTU) || GTK_CHECK_VERSION (3, 0, 0)
+#if defined(UBUNTU)
 	gtk_window_set_has_resize_grip(GTK_WINDOW(widget), FALSE);
 #endif
 
-#if !GTK_CHECK_VERSION (3, 0, 0)
 	gdk_window_redirect_to_drawable(window, pixmap, 0, 0, 0, 0, width, height);
-#endif
 	gdk_window_set_override_redirect(window, TRUE);
 	gtk_window_move(GTK_WINDOW(widget), gdk_screen_get_width(screen), gdk_screen_get_height(screen));
 	gtk_widget_show(widget);
 
 	gdk_window_process_updates(window, TRUE);
 
-#if GTK_CHECK_VERSION (3, 0, 0)
-	pixbuf = gdk_pixbuf_get_from_window (window, 0, 0, width, height);
-#endif
-
 	gtk_widget_hide(widget);
 
-#if !GTK_CHECK_VERSION (3, 0, 0)
 	return pixmap;
-#endif
 }
+#endif
 
 static void pixbuf_apply_mask_region(GdkPixbuf* pixbuf, GdkRegion* region)
 {
@@ -288,11 +275,20 @@ create_meta_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
           META_FRAME_ALLOWS_SHADE |
           META_FRAME_ALLOWS_MOVE;
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+  window = gtk_offscreen_window_new ();
+#else
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+#endif
   preview = meta_preview_new ();
   gtk_container_add (GTK_CONTAINER (window), preview);
+#if GTK_CHECK_VERSION (3, 0, 0)
+  gtk_widget_show_all (window);
+#else
   gtk_widget_realize (window);
   gtk_widget_realize (preview);
+#endif
+
 #if GTK_CHECK_VERSION (3, 0, 0)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
 #else
@@ -333,8 +329,11 @@ create_meta_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   gtk_widget_get_preferred_size (window, &requisition, NULL);
 
 #if GTK_CHECK_VERSION (3, 0, 0)
-  pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, META_THUMBNAIL_SIZE, META_THUMBNAIL_SIZE);
-  draw_window_on_pixbuf (window, pixbuf);
+  gtk_widget_queue_draw (window);
+  while (gtk_events_pending ())
+    gtk_main_iteration ();
+
+  pixbuf = gtk_offscreen_window_get_pixbuf (GTK_OFFSCREEN_WINDOW (window));
 #else
   pixmap = draw_window_on_pixbuf (window);
 
@@ -385,7 +384,11 @@ create_gtk_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
 			  "gtk-color-scheme", (char *) theme_thumbnail_data->gtk_color_scheme->data,
  			  NULL);
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+  window = gtk_offscreen_window_new ();
+#else
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+#endif
 
 #if GTK_CHECK_VERSION (3, 0, 0)
   vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 0);
@@ -408,6 +411,9 @@ create_gtk_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   radio = gtk_radio_button_new_from_widget (NULL);
   gtk_box_pack_start (GTK_BOX (box), radio, FALSE, FALSE, 0);
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+  gtk_widget_show_all (window);
+#else
   gtk_widget_show_all (vbox);
   gtk_widget_realize (stock_button);
   gtk_widget_realize (gtk_bin_get_child (GTK_BIN (stock_button)));
@@ -417,6 +423,7 @@ create_gtk_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   gtk_widget_map (gtk_bin_get_child (GTK_BIN (stock_button)));
   gtk_widget_map (checkbox);
   gtk_widget_map (radio);
+#endif
 
   gtk_widget_get_preferred_size (window, &requisition, NULL);
   allocation.x = 0;
@@ -429,8 +436,11 @@ create_gtk_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   gtk_window_get_size (GTK_WINDOW (window), &width, &height);
 
 #if GTK_CHECK_VERSION (3, 0, 0)
-  pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, width, height);
-  draw_window_on_pixbuf (window, pixbuf);
+  gtk_widget_queue_draw (window);
+  while (gtk_events_pending ())
+    gtk_main_iteration ();
+
+  pixbuf = gtk_offscreen_window_get_pixbuf (GTK_OFFSCREEN_WINDOW (window));
 #else
   pixmap = draw_window_on_pixbuf (window);
 
@@ -479,7 +489,11 @@ create_marco_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
           META_FRAME_ALLOWS_SHADE |
           META_FRAME_ALLOWS_MOVE;
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+  window = gtk_offscreen_window_new ();
+#else
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+#endif
   gtk_window_set_default_size (GTK_WINDOW (window), (int) MARCO_THUMBNAIL_WIDTH * 1.2, (int) MARCO_THUMBNAIL_HEIGHT * 1.2);
 
   preview = meta_preview_new ();
@@ -491,11 +505,15 @@ create_marco_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   dummy = gtk_label_new ("");
   gtk_container_add (GTK_CONTAINER (preview), dummy);
 
+#if GTK_CHECK_VERSION (3, 0, 0)
+  gtk_widget_show_all (window);
+#else
   gtk_widget_realize (window);
   gtk_widget_realize (preview);
   gtk_widget_realize (dummy);
   gtk_widget_show_all (preview);
   gtk_widget_map (dummy);
+#endif
 
   gtk_widget_get_preferred_size (window, &requisition, NULL);
   allocation.x = 0;
@@ -506,8 +524,11 @@ create_marco_theme_pixbuf (ThemeThumbnailData *theme_thumbnail_data)
   gtk_widget_get_preferred_size (window, &requisition, NULL);
 
 #if GTK_CHECK_VERSION (3, 0, 0)
-  pixbuf = gdk_pixbuf_new (GDK_COLORSPACE_RGB, TRUE, 8, (int) MARCO_THUMBNAIL_WIDTH * 1.2, (int) MARCO_THUMBNAIL_HEIGHT * 1.2);
-  draw_window_on_pixbuf (window, pixbuf);
+  gtk_widget_queue_draw (window);
+  while (gtk_events_pending ())
+    gtk_main_iteration ();
+
+  pixbuf = gtk_offscreen_window_get_pixbuf (GTK_OFFSCREEN_WINDOW (window));
 #else
   pixmap = draw_window_on_pixbuf (window);