Journal detail view: draw the thumbnail without using a Gdk.Pixmap

Code based on the one in get_preview in toolkit-gtk3 and the
one in Browse for the linkbutton.

1 files changed, 20 insertions, 5 deletions

diff --git a/src/jarabe/journal/expandedentry.py b/src/jarabe/journal/expandedentry.py
index f1ad35a..e6bbbdc 100644
--- a/src/jarabe/journal/expandedentry.py
+++ b/src/jarabe/journal/expandedentry.py
@@ -218,16 +218,31 @@ class ExpandedEntry(Gtk.EventBox):
             png_file = StringIO.StringIO(preview_data)
             try:
                 # Load image and scale to dimensions
+                im = Gtk.Image()
                 surface = cairo.ImageSurface.create_from_png(png_file)
                 png_width = surface.get_width()
                 png_height = surface.get_height()
-                pixmap = Gdk.Pixmap(None, png_width, png_height, 24)
-                cr = pixmap.cairo_create()
-                cr.set_source_surface(surface, 0, 0)
-                cr.scale(width / png_width, height / png_height)
+
+                preview_surface = cairo.ImageSurface(cairo.FORMAT_ARGB32,
+                                                     width, height)
+                cr = cairo.Context(preview_surface)
+
+                scale_w = width * 1.0 / png_width
+                scale_h = height * 1.0 / png_height
+                scale = min(scale_w, scale_h)
+
+                cr.scale(scale, scale)
+
+                cr.set_source_rgba(1, 1, 1, 0)
+                cr.set_operator(cairo.OPERATOR_SOURCE)
+                cr.paint()
+                cr.set_source_surface(surface)
                 cr.paint()
 
-                im = Gtk.image_new_from_pixmap(pixmap, None)
+                pixbuf_bg = Gdk.pixbuf_get_from_surface(preview_surface, 0, 0,
+                                                        width, height)
+                im.set_from_pixbuf(pixbuf_bg)
+
                 has_preview = True
             except Exception:
                 logging.exception('Error while loading the preview')