Introduce MetaPixmap compatibility wrapper

Similar to the region compatibility shim, we will soon need a
compatibility shim around GdkPixmap/cairo_surface_t. For now, the patch
just introduces the compatibility layer.

This patch also does not include the function
meta_gdk_pixbuf_get_from_pixmap() as that function will need special
treatment in GTK3 anyway.

https://bugzilla.gnome.org/show_bug.cgi?id=630203

src/gdk2-drawing-utils.h

@@ -24,6 +24,13 @@
 
 #include <gtk/gtk.h>
 
+#define MetaPixmap GdkPixmap
+
+#define meta_pixmap_new(window, w, h) gdk_pixmap_new (window, w, h, -1)
+#define meta_pixmap_free(pixmap) g_object_unref (pixmap)
+#define meta_pixmap_cairo_create(pixmap) meta_cairo_create (pixmap)
+#define meta_cairo_set_source_pixmap(cr, pixmap, x, y) gdk_cairo_set_source_pixmap (cr, pixmap, x, y)
+
 /* This function only exists for GTK2 code. */
 cairo_t *     meta_cairo_create            (GdkDrawable        *drawable);
 

src/ui/frames.c

@@ -276,7 +276,7 @@ meta_frames_finalize (GObject *object)
 typedef struct
 {
   GdkRectangle rect;
-  GdkPixmap *pixmap;
+  MetaPixmap *pixmap;
 } CachedFramePiece;
 
 typedef struct
@@ -313,7 +313,7 @@ invalidate_cache (MetaFrames *frames,
   
   for (i = 0; i < 4; i++)
     if (pixels->piece[i].pixmap)
-      g_object_unref (pixels->piece[i].pixmap);
+      meta_pixmap_free (pixels->piece[i].pixmap);
   
   g_free (pixels);
   g_hash_table_remove (frames->cache, frame);
@@ -2084,22 +2084,22 @@ setup_bg_cr (cairo_t *cr, GdkWindow *window, int x_offset, int y_offset)
 /* Returns a pixmap with a piece of the windows frame painted on it.
 */
 
-static GdkPixmap *
+static MetaPixmap *
 generate_pixmap (MetaFrames *frames,
                  MetaUIFrame *frame,
                  GdkRectangle *rect)
 {
-  GdkPixmap *result;
+  MetaPixmap *result;
   cairo_t *cr;
 
   /* do not create a pixmap for nonexisting areas */
   if (rect->width <= 0 || rect->height <= 0)
     return NULL;
 
-  result = gdk_pixmap_new (frame->window,
+  result = meta_pixmap_new (frame->window,
-                           rect->width, rect->height, -1);
+                            rect->width, rect->height);
   
-  cr = meta_cairo_create (result);
+  cr = meta_pixmap_cairo_create (result);
 
   setup_bg_cr (cr, frame->window, rect->x, rect->y);
   cairo_paint (cr);
@@ -2270,7 +2270,7 @@ cached_pixels_draw (CachedPixels *pixels,
       
       if (piece->pixmap)
         {
-          gdk_cairo_set_source_pixmap (cr, piece->pixmap,
+          meta_cairo_set_source_pixmap (cr, piece->pixmap,
                                         piece->rect.x, piece->rect.y);
           cairo_paint (cr);
           

src/ui/theme-viewer.c

@@ -943,7 +943,7 @@ static void
 run_theme_benchmark (void)
 {
   GtkWidget* widget;
-  GdkPixmap *pixmap;
+  MetaPixmap *pixmap;
   int top_height, bottom_height, left_width, right_width;
   MetaButtonState button_states[META_BUTTON_TYPE_LAST] =
   {
@@ -1007,12 +1007,11 @@ run_theme_benchmark (void)
       /* Creating the pixmap in the loop is right, since
        * GDK does the same with its double buffering.
        */
-      pixmap = gdk_pixmap_new (gtk_widget_get_window (widget),
+      pixmap = meta_pixmap_new (gtk_widget_get_window (widget),
                                 client_width + left_width + right_width,
-                               client_height + top_height + bottom_height,
+                                client_height + top_height + bottom_height);
-                               -1);
 
-      cr = meta_cairo_create (pixmap);
+      cr = meta_pixmap_cairo_create (pixmap);
 
       meta_theme_draw_frame (global_theme,
                              widget,
@@ -1029,7 +1028,7 @@ run_theme_benchmark (void)
                              meta_preview_get_icon ());
 
       cairo_destroy (cr);
-      g_object_unref (G_OBJECT (pixmap));
+      meta_pixmap_free (pixmap);
       
       ++i;
       client_width += inc;