[gnome-tweak-tool] startup: Force a pixel icon size

[Rui Matos <rtcm src gnome org>]

commit 696b127c97fecc4bb950acd13def961afbf6d48f
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Aug 18 15:29:24 2015 +0200

    startup: Force a pixel icon size
    
    If we don't set a pixel size gtk+ doesn't scale the resulting pixbuf
    unless the source icon is in a scalable format such as SVG.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=742947

 gtweak/tweaks/tweak_group_startup.py |   10 ++++++++--
 1 files changed, 8 insertions(+), 2 deletions(-)
---
diff --git a/gtweak/tweaks/tweak_group_startup.py b/gtweak/tweaks/tweak_group_startup.py
index 3c84460..ea60e24 100644
--- a/gtweak/tweaks/tweak_group_startup.py
+++ b/gtweak/tweaks/tweak_group_startup.py
@@ -26,6 +26,12 @@ from gtweak.tweakmodel import Tweak
 from gtweak.widgets import ListBoxTweakGroup, UI_BOX_SPACING
 from gtweak.utils import AutostartManager, AutostartFile
 
+def _image_from_gicon(gicon):
+    image = Gtk.Image.new_from_gicon(gicon, Gtk.IconSize.DIALOG)
+    (_, _, h) = Gtk.IconSize.lookup(Gtk.IconSize.DIALOG)
+    image.set_pixel_size(h)
+    return image
+
 def _list_header_func(row, before, user_data):
     if before and not row.get_header():
         row.set_header (Gtk.Separator(orientation=Gtk.Orientation.HORIZONTAL))
@@ -127,7 +133,7 @@ class _AppChooser(Gtk.Dialog):
             return None
         icn = a.get_icon()
         if icn:
-            img = Gtk.Image.new_from_gicon(a.get_icon(),Gtk.IconSize.DIALOG)
+            img = _image_from_gicon(icn)
             g.attach(img, 0, 0, 1, 1)
             img.props.hexpand = False
         else:
@@ -210,7 +216,7 @@ class _StartupTweak(Gtk.ListBoxRow, Tweak):
 
         icn = df.get_icon()
         if icn:
-            img = Gtk.Image.new_from_gicon(icn,Gtk.IconSize.DIALOG)
+            img = _image_from_gicon(icn)
             grid.attach(img, 0, 0, 1, 1)
         else:
             img = None #attach_next_to treats this correctly