Allow partial CairoWidget exposure

2 files changed, 7 insertions, 3 deletions

diff --git a/libs/gtkmm2ext/cairo_widget.cc b/libs/gtkmm2ext/cairo_widget.cc
index a597a7e29d..0f34a3ffdb 100644
--- a/libs/gtkmm2ext/cairo_widget.cc
+++ b/libs/gtkmm2ext/cairo_widget.cc
@@ -230,10 +230,14 @@ CairoWidget::on_expose_event (GdkEventExpose *ev)
  */
 
 void
-CairoWidget::set_dirty ()
+CairoWidget::set_dirty (cairo_rectangle_t *area)
 {
 	ENSURE_GUI_THREAD (*this, &CairoWidget::set_dirty);
-	queue_draw ();
+	if (!area) {
+		queue_draw ();
+	} else {
+		queue_draw_area (area->x, area->y, area->width, area->height);
+	}
 }
 
 /** Handle a size allocation.
diff --git a/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h b/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
index f6db0dbe94..2a483840f9 100644
--- a/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
+++ b/libs/gtkmm2ext/gtkmm2ext/cairo_widget.h
@@ -35,7 +35,7 @@ public:
 	CairoWidget ();
 	virtual ~CairoWidget ();
 
-	void set_dirty ();
+	void set_dirty (cairo_rectangle_t *area = 0);
 
 	Gtkmm2ext::ActiveState active_state() const { return _active_state; }
 	Gtkmm2ext::VisualState visual_state() const { return _visual_state; }