Move default paint volume computation into a function

This should reduce the amount of copy and paste for actor sub-classes
that use the default paint volume from the allocation.

clutter/clutter-cairo-texture.c

@@ -370,25 +370,9 @@ static gboolean
 clutter_cairo_texture_get_paint_volume (ClutterActor       *self,
                                         ClutterPaintVolume *volume)
 {
-  ClutterGeometry allocation;
+  return _clutter_actor_set_default_paint_volume (self,
-
+                                                  CLUTTER_TYPE_CAIRO_TEXTURE,
-  /* XXX: we are being conservative here and not making assumptions
+                                                  volume);
-   * that sub-classes won't paint outside their allocation. */
-  if (G_OBJECT_TYPE (self) != CLUTTER_TYPE_CAIRO_TEXTURE)
-    return FALSE;
-
-  /* XXX: clutter_actor_get_allocation can potentially be very
-   * expensive to call if called while the actor doesn't have a valid
-   * allocation since it will trigger a synchronous relayout of the
-   * scenegraph. We explicitly check we have a valid allocation
-   * to avoid hitting that codepath. */
-  if (!clutter_actor_has_allocation (self))
-    return FALSE;
-
-  clutter_actor_get_allocation_geometry (self, &allocation);
-  clutter_paint_volume_set_width (volume, allocation.width);
-  clutter_paint_volume_set_height (volume, allocation.height);
-  return TRUE;
 }
 
 static void

clutter/clutter-paint-volume.c

@@ -812,4 +812,50 @@ _clutter_paint_volume_axis_align (ClutterPaintVolume *pv)
     pv->is_2d = FALSE;
 }
 
+/*<private>
+ * _clutter_actor_set_default_paint_volume:
+ * @self: a #ClutterActor
+ * @check_gtype: if not %G_TYPE_INVALID, match the type of @self against
+ *   this type
+ * @volume: the #ClutterPaintVolume to set
+ *
+ * Sets the default paint volume for @self.
+ *
+ * This function should be called by #ClutterActor sub-classes that follow
+ * the default assumption that their paint volume is defined by their
+ * allocation.
+ *
+ * If @check_gtype is not %G_TYPE_INVALID, this function will check the
+ * type of @self and only compute the paint volume if the type matches;
+ * this can be used to avoid computing the paint volume for sub-classes
+ * of an actor class
+ *
+ * Return value: %TRUE if the paint volume was set, and %FALSE otherwise
+ */
+gboolean
+_clutter_actor_set_default_paint_volume (ClutterActor       *self,
+                                         GType               check_gtype,
+                                         ClutterPaintVolume *volume)
+{
+  ClutterGeometry geometry = { 0, };
 
+  if (check_gtype != G_TYPE_INVALID)
+    {
+      if (G_OBJECT_TYPE (self) != check_gtype)
+        return FALSE;
+    }
+
+  /* calling clutter_actor_get_allocation_* can potentially be very
+   * expensive, as it can result in a synchronous full stage relayout
+   * and redraw
+   */
+  if (!clutter_actor_has_allocation (self))
+    return FALSE;
+
+  clutter_actor_get_allocation_geometry (self, &geometry);
+
+  clutter_paint_volume_set_width (volume, geometry.width);
+  clutter_paint_volume_set_height (volume, geometry.height);
+
+  return TRUE;
+}

clutter/clutter-private.h

@@ -530,6 +530,10 @@ void                _clutter_util_fully_transform_vertices (const CoglMatrix *mo
                                                             ClutterVertex *vertices_out,
                                                             int n_vertices);
 
+gboolean           _clutter_actor_set_default_paint_volume (ClutterActor *self,
+                                                            GType         check_gtype,
+                                                            ClutterPaintVolume *volume);
+
 G_END_DECLS
 
 #endif /* _HAVE_CLUTTER_PRIVATE_H */

clutter/clutter-rectangle.c

@@ -156,25 +156,9 @@ static gboolean
 clutter_rectangle_get_paint_volume (ClutterActor       *self,
                                     ClutterPaintVolume *volume)
 {
-  ClutterGeometry allocation;
+  return _clutter_actor_set_default_paint_volume (self,
-
+                                                  CLUTTER_TYPE_RECTANGLE,
-  /* XXX: we are being conservative here and not making assumptions
+                                                  volume);
-   * that sub-classes won't paint outside their allocation. */
-  if (G_OBJECT_TYPE (self) != CLUTTER_TYPE_RECTANGLE)
-    return FALSE;
-
-  /* XXX: clutter_actor_get_allocation can potentially be very
-   * expensive to call if called while the actor doesn't have a valid
-   * allocation since it will trigger a synchronous relayout of the
-   * scenegraph. We explicitly check we have a valid allocation
-   * to avoid hitting that codepath. */
-  if (!clutter_actor_has_allocation (self))
-    return FALSE;
-
-  clutter_actor_get_allocation_geometry (self, &allocation);
-  clutter_paint_volume_set_width (volume, allocation.width);
-  clutter_paint_volume_set_height (volume, allocation.height);
-  return TRUE;
 }
 
 static void

clutter/clutter-texture.c

@@ -689,25 +689,9 @@ static gboolean
 clutter_texture_get_paint_volume (ClutterActor       *self,
                                   ClutterPaintVolume *volume)
 {
-  ClutterGeometry allocation;
+  return _clutter_actor_set_default_paint_volume (self,
-
+                                                  CLUTTER_TYPE_TEXTURE,
-  /* XXX: we are being conservative here and not making assumptions
+                                                  volume);
-   * that sub-classes won't paint outside their allocation. */
-  if (G_OBJECT_TYPE (self) != CLUTTER_TYPE_TEXTURE)
-    return FALSE;
-
-  /* XXX: clutter_actor_get_allocation can potentially be very
-   * expensive to call if called while the actor doesn't have a valid
-   * allocation since it will trigger a synchronous relayout of the
-   * scenegraph. We explicitly check we have a valid allocation
-   * to avoid hitting that codepath. */
-  if (!clutter_actor_has_allocation (self))
-    return FALSE;
-
-  clutter_actor_get_allocation_geometry (self, &allocation);
-  clutter_paint_volume_set_width (volume, allocation.width);
-  clutter_paint_volume_set_height (volume, allocation.height);
-  return TRUE;
 }
 
 static void