pixbuf: handle creating pixbufs for HiDPI resolutions

Under certain HiDPI situations, 1x icons were loaded and rendered with
the scale factor applied. As expected, this resulted in blurry icons.

Of note, were blurry icons in the GtkSourceGutterRendererPixbuf.

This is not the most efficient, but is not terribly different from what
is happening today. We create a new cairo_surface_t for the pixbuf
manually, with the scale applied. gdk_cairo_set_source_pixbuf() also
does this, but without the scale.

We could optimize this in the future by making our pixbuf helper return
cairo_surface_t* rather than GdkPixbuf*.

2 files changed, 30 insertions, 5 deletions

diff --git a/gtksourceview/gtksourcegutterrendererpixbuf.c b/gtksourceview/gtksourcegutterrendererpixbuf.c
index 47e5636e..f737c489 100644
--- a/gtksourceview/gtksourcegutterrendererpixbuf.c
+++ b/gtksourceview/gtksourcegutterrendererpixbuf.c
@@ -87,9 +87,11 @@ gutter_renderer_pixbuf_draw (GtkSourceGutterRenderer      *renderer,
 	gfloat yalign;
 	GtkSourceGutterRendererAlignmentMode mode;
 	GtkTextView *view;
+	gint scale;
 	gint x = 0;
 	gint y = 0;
 	GdkPixbuf *pixbuf;
+	cairo_surface_t *surface;
 
 	/* Chain up to draw background */
 	if (GTK_SOURCE_GUTTER_RENDERER_CLASS (gtk_source_gutter_renderer_pixbuf_parent_class)->draw != NULL)
@@ -117,6 +119,22 @@ gutter_renderer_pixbuf_draw (GtkSourceGutterRenderer      *renderer,
 	width = gdk_pixbuf_get_width (pixbuf);
 	height = gdk_pixbuf_get_height (pixbuf);
 
+	/*
+	 * We might have gotten a pixbuf back from the helper that will allow
+	 * us to render for HiDPI. If we detect this, we pretend that we got a
+	 * different size back and then gdk_cairo_surface_create_from_pixbuf()
+	 * will take care of the rest.
+	 */
+	scale = gtk_widget_get_scale_factor (GTK_WIDGET (view));
+	if ((scale > 1) &&
+	    ((width > cell_area->width) || (height > cell_area->height)) &&
+	    (width <= (cell_area->width * scale)) &&
+	    (height <= (cell_area->height * scale)))
+	{
+		width = width / scale;
+		height = height / scale;
+	}
+
 	gtk_source_gutter_renderer_get_alignment (renderer,
 	                                          &xalign,
 	                                          &yalign);
@@ -155,8 +173,12 @@ gutter_renderer_pixbuf_draw (GtkSourceGutterRenderer      *renderer,
 			g_assert_not_reached ();
 	}
 
-	gdk_cairo_set_source_pixbuf (cr, pixbuf, x, y);
+	surface = gdk_cairo_surface_create_from_pixbuf (pixbuf, scale, NULL);
+	cairo_set_source_surface (cr, surface, x, y);
+
 	cairo_paint (cr);
+
+	cairo_surface_destroy (surface);
 }
 
 static void
diff --git a/gtksourceview/gtksourcepixbufhelper.c b/gtksourceview/gtksourcepixbufhelper.c
index 6a10b7f4..99dd6b21 100644
--- a/gtksourceview/gtksourcepixbufhelper.c
+++ b/gtksourceview/gtksourcepixbufhelper.c
@@ -279,16 +279,19 @@ from_name (GtkSourcePixbufHelper *helper,
 	GtkIconTheme *icon_theme;
 	GtkIconInfo *info;
 	GtkIconLookupFlags flags;
+	gint scale;
 
 	screen = gtk_widget_get_screen (widget);
 	icon_theme = gtk_icon_theme_get_for_screen (screen);
 
 	flags = GTK_ICON_LOOKUP_USE_BUILTIN;
+        scale = gtk_widget_get_scale_factor (widget);
 
-	info = gtk_icon_theme_lookup_icon (icon_theme,
-	                                   helper->icon_name,
-	                                   size,
-	                                   flags);
+	info = gtk_icon_theme_lookup_icon_for_scale (icon_theme,
+	                                             helper->icon_name,
+	                                             size,
+	                                             scale,
+	                                             flags);
 
 	if (info)
 	{