theme: Render window control buttons and icons as surfaces

When loading window control buttons and icon as pixbufs, we just set
them as the source for the cairo context used to paint them. Instead, we
now convert them to cairo surfaces and scale them to the correct display
density before painting them.

This allows us to load higher resolution assets (i.e. at twice the size)
and by explicitly setting the intended size in the theme draw_ops, we
can then scale them down to fit lower resolution displays, or render
them at full density for HiDPI displays.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/ui/theme.h b/src/ui/theme.h
index 34b98935..9dfb8d89 100644
--- a/src/ui/theme.h
+++ b/src/ui/theme.h
@@ -964,6 +964,7 @@ gboolean          meta_gradient_spec_validate (MetaGradientSpec     *spec,
 MetaAlphaGradientSpec* meta_alpha_gradient_spec_new  (MetaGradientType       type,
                                                       int                    n_alphas);
 void                   meta_alpha_gradient_spec_free (MetaAlphaGradientSpec *spec);
+cairo_pattern_t *      meta_alpha_gradient_spec_get_mask (const MetaAlphaGradientSpec *spec);
 
 
 MetaFrameStyle* meta_frame_style_new   (MetaFrameStyle *parent);