[gthumb: 38/40] the image selector is slow at activation time if the image is big

[Paolo Bacchilega <paobac src gnome org>]

commit f34a08c2bf44bf089a10f370bab227c54763a4cc
Author: Paolo Bacchilega <paobac src gnome org>
Date:   Fri Sep 10 13:08:17 2010 +0200

    the image selector is slow at activation time if the image is big
    
    Do not copy the original pixbuf to make the non selected part
    darker.  The darker effect is now done painting a
    semi-transparent surface on top of the original image.

 gthumb/gth-image-selector.c |   42 ++++++++++++++++++++++++++----------------
 1 files changed, 26 insertions(+), 16 deletions(-)
---
diff --git a/gthumb/gth-image-selector.c b/gthumb/gth-image-selector.c
index 9011c48..7161941 100644
--- a/gthumb/gth-image-selector.c
+++ b/gthumb/gth-image-selector.c
@@ -196,7 +196,6 @@ struct _GthImageSelectorPrivate {
 	GthSelectorType  type;
 
 	GdkPixbuf       *pixbuf;
-	GdkPixbuf       *background;
 	GdkRectangle     pixbuf_area;
 
 	gboolean         use_ratio;
@@ -580,12 +579,37 @@ paint_background (GthImageSelector *self,
 {
 	gth_image_viewer_paint_region (self->priv->viewer,
 				       cr,
-				       self->priv->background,
+				       self->priv->pixbuf,
 				       self->priv->viewer->x_offset - self->priv->viewer->image_area.x,
 				       self->priv->viewer->y_offset - self->priv->viewer->image_area.y,
 				       &self->priv->viewer->image_area,
 				       event->region,
 				       GDK_INTERP_TILES);
+
+	/* make the background darker */
+	{
+		GdkRectangle *rects;
+		int           n_rects;
+		int           i;
+
+		cairo_save (cr);
+		gdk_cairo_region (cr, event->region);
+		cairo_clip (cr);
+		gdk_cairo_rectangle (cr, &self->priv->viewer->image_area);
+		cairo_clip (cr);
+		cairo_set_source_rgba (cr, 0.0, 0.0, 0.0, 0.5);
+		gdk_region_get_rectangles (event->region, &rects, &n_rects);
+		for (i = 0; i < n_rects; i++) {
+			GdkRectangle paint_area;
+
+			if (gdk_rectangle_intersect (&self->priv->viewer->image_area, &rects[i], &paint_area))
+				cairo_rectangle (cr, paint_area.x, paint_area.y, paint_area.width, paint_area.height);
+		}
+		cairo_fill (cr);
+		cairo_restore (cr);
+
+		g_free (rects);
+	}
 }
 
 
@@ -1277,9 +1301,6 @@ gth_image_selector_image_changed (GthImageViewerTool *base)
 	_g_object_unref (self->priv->pixbuf);
 	self->priv->pixbuf = gth_image_viewer_get_current_pixbuf (self->priv->viewer);
 
-	_g_object_unref (self->priv->background);
-	self->priv->background = NULL;
-
 	if (self->priv->pixbuf == NULL) {
 		self->priv->pixbuf_area.width = 0;
 		self->priv->pixbuf_area.height = 0;
@@ -1290,15 +1311,6 @@ gth_image_selector_image_changed (GthImageViewerTool *base)
 	self->priv->pixbuf_area.width = gdk_pixbuf_get_width (self->priv->pixbuf);
 	self->priv->pixbuf_area.height = gdk_pixbuf_get_height (self->priv->pixbuf);
 
-	self->priv->background = gdk_pixbuf_composite_color_simple (
-					self->priv->pixbuf,
-					gdk_pixbuf_get_width (self->priv->pixbuf),
-					gdk_pixbuf_get_height (self->priv->pixbuf),
-					GDK_INTERP_TILES,
-					128,
-					10,
-					0x00000000,
-					0x00000000);
 	init_selection (self);
 }
 
@@ -1337,9 +1349,7 @@ gth_image_selector_finalize (GObject *object)
 	g_return_if_fail (GTH_IS_IMAGE_SELECTOR (object));
 
 	self = (GthImageSelector *) object;
-
 	_g_object_unref (self->priv->pixbuf);
-	_g_object_unref (self->priv->background);
 
 	/* Chain up */
 	G_OBJECT_CLASS (parent_class)->finalize (object);