gdk: Add gdk_draw_context_get_frame_region()

This does the same as gdk_drawing_context_get_clip().

4 files changed, 36 insertions, 20 deletions

diff --git a/gdk/gdkdrawcontext.c b/gdk/gdkdrawcontext.c
index 33324f44e3..45a353b086 100644
--- a/gdk/gdkdrawcontext.c
+++ b/gdk/gdkdrawcontext.c
@@ -303,3 +303,26 @@ gdk_draw_context_get_surface (GdkDrawContext *context)
   return priv->surface;
 }
 
+/**
+ * gdk_draw_context_get_frame_region:
+ * @context: a #GdkDrawContext
+ *
+ * Retrieves the region that is currently in the process of being repainted.
+ *
+ * After a call to gdk_draw_context_begin_frame() this function will return
+ * a union of the region passed to that function and the area of the surface
+ * that the @context determined needs to be repainted.
+ *
+ * If @context is not inbetween calls to gdk_draw_context_begin_frame() and
+ * gdk_draw_context_end_frame(), %NULL will be returned.
+ *
+ * Returns: (transfer none) (nullable): a Cairo region or %NULL if not drawing
+ *     a frame.
+ */
+const cairo_region_t *
+gdk_draw_context_get_frame_region (GdkDrawContext *context)
+{
+  g_return_val_if_fail (GDK_IS_DRAW_CONTEXT (context), NULL);
+
+  return context->frame_region;
+}
diff --git a/gdk/gdkdrawcontext.h b/gdk/gdkdrawcontext.h
index 70bc802c4a..5b542667cd 100644
--- a/gdk/gdkdrawcontext.h
+++ b/gdk/gdkdrawcontext.h
@@ -40,7 +40,10 @@ GType gdk_draw_context_get_type (void) G_GNUC_CONST;
 GDK_AVAILABLE_IN_ALL
 GdkDisplay *            gdk_draw_context_get_display              (GdkDrawContext  *context);
 GDK_AVAILABLE_IN_ALL
-GdkSurface *             gdk_draw_context_get_surface               (GdkDrawContext  *context);
+GdkSurface *            gdk_draw_context_get_surface              (GdkDrawContext  *context);
+
+GDK_AVAILABLE_IN_ALL
+const cairo_region_t *  gdk_draw_context_get_frame_region         (GdkDrawContext  *context);
 
 G_END_DECLS
 
diff --git a/gdk/gdkdrawcontextprivate.h b/gdk/gdkdrawcontextprivate.h
index 33c4b72546..242919698f 100644
--- a/gdk/gdkdrawcontextprivate.h
+++ b/gdk/gdkdrawcontextprivate.h
@@ -34,6 +34,8 @@ typedef struct _GdkDrawContextClass GdkDrawContextClass;
 struct _GdkDrawContext
 {
   GObject parent_instance;
+
+  cairo_region_t *frame_region;
 };
 
 struct _GdkDrawContextClass
diff --git a/gdk/gdksurface.c b/gdk/gdksurface.c
index 6e7f125896..90486c4ed8 100644
--- a/gdk/gdksurface.c
+++ b/gdk/gdksurface.c
@@ -1586,7 +1586,6 @@ gdk_surface_begin_draw_frame (GdkSurface           *surface,
                               const cairo_region_t *region)
 {
   GdkDrawingContext *context;
-  cairo_region_t *real_region;
 
   g_return_val_if_fail (GDK_IS_SURFACE (surface), NULL);
   g_return_val_if_fail (gdk_surface_has_native (surface), NULL);
@@ -1606,21 +1605,19 @@ gdk_surface_begin_draw_frame (GdkSurface           *surface,
       return NULL;
     }
 
-  real_region = cairo_region_copy (region);
+  draw_context->frame_region = cairo_region_copy (region);
 
-  gdk_draw_context_begin_frame (draw_context, real_region);
+  gdk_draw_context_begin_frame (draw_context, draw_context->frame_region);
 
   context = g_object_new (GDK_TYPE_DRAWING_CONTEXT,
                           "surface", surface,
                           "paint-context", draw_context,
-                          "clip", real_region,
+                          "clip", draw_context->frame_region,
                           NULL);
 
   /* Do not take a reference, to avoid creating cycles */
   surface->drawing_context = context;
 
-  cairo_region_destroy (real_region);
-
   return context;
 }
 
@@ -1659,22 +1656,13 @@ gdk_surface_end_draw_frame (GdkSurface         *surface,
   g_return_if_fail (surface->drawing_context == context);
 
   paint_context = gdk_drawing_context_get_paint_context (context);
-  if (paint_context)
-    {
-      cairo_region_t *clip = gdk_drawing_context_get_clip (context);
-
-      gdk_draw_context_end_frame (paint_context,
-                                  clip,
-                                  surface->active_update_area);
-
-      cairo_region_destroy (clip);
-    }
-  else
-    {
-    }
+  gdk_draw_context_end_frame (paint_context,
+                              paint_context->frame_region,
+                              surface->active_update_area);
 
   surface->drawing_context = NULL;
 
+  g_clear_pointer (&paint_context->frame_region, cairo_region_destroy);
   g_object_unref (context);
 }