[meld] misc, emblemcellrenderer: Fix 3.20 API break in colour parsing

[Kai Willadsen <kaiw src gnome org>]

commit 5b0d31d2799550ad9af1c8ac6349f7b8823af20b
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Jan 30 09:28:49 2016 +1000

    misc, emblemcellrenderer: Fix 3.20 API break in colour parsing

 meld/misc.py                  |   15 ++++++++++++---
 meld/ui/emblemcellrenderer.py |    5 +++--
 2 files changed, 15 insertions(+), 5 deletions(-)
---
diff --git a/meld/misc.py b/meld/misc.py
index ad323ef..8580139 100644
--- a/meld/misc.py
+++ b/meld/misc.py
@@ -147,6 +147,17 @@ def make_tool_button_widget(label):
 MELD_STYLE_SCHEME = "meld-base"
 
 
+def parse_rgba(string):
+    """Parse a string to a Gdk.RGBA across different GTK+ APIs
+
+    Introspection changes broke this API in GTK+ 3.20; this function
+    is just a backwards-compatiblity workaround.
+    """
+    colour = Gdk.RGBA()
+    result = colour.parse(string)
+    return result[1] if isinstance(result, tuple) else colour
+
+
 def colour_lookup_with_fallback(name, attribute):
     from meld.settings import meldsettings
     source_style = meldsettings.style_scheme
@@ -169,9 +180,7 @@ def colour_lookup_with_fallback(name, attribute):
             "this is a bad install") % (name, attribute)
         sys.exit(1)
 
-    colour = Gdk.RGBA()
-    colour.parse(style_attr)
-    return colour
+    return parse_rgba(style_attr)
 
 
 def get_common_theme():
diff --git a/meld/ui/emblemcellrenderer.py b/meld/ui/emblemcellrenderer.py
index a924aae..e1e528d 100644
--- a/meld/ui/emblemcellrenderer.py
+++ b/meld/ui/emblemcellrenderer.py
@@ -19,6 +19,8 @@ from gi.repository import GObject
 from gi.repository import Gdk
 from gi.repository import Gtk
 
+from meld.misc import parse_rgba
+
 
 class EmblemCellRenderer(Gtk.CellRenderer):
 
@@ -57,8 +59,7 @@ class EmblemCellRenderer(Gtk.CellRenderer):
         elif pspec.name == "icon-tint":
             self._icon_tint = value
             if self._icon_tint:
-                self._tint_color = Gdk.RGBA()
-                self._tint_color.parse(value)
+                self._tint_color = parse_rgba(value)
             else:
                 self._tint_color = None
         else: