add a 'force' option to the 'css_add' wrapper

-enforce css overrides by loading as USER priority when absolutely
necessary (e.g. when a user override would compromise the resizing/
positioning calculations). doing this is no different to enforcing
styling via use of widget properties (e.g. margin) or style properties,
for which users obviously have zero influence upon

quodlibet/quodlibet/qltk/__init__.py

@@ -352,7 +352,7 @@ def is_accel(event, *accels):
     return False
 
 
-def add_css(widget, css):
+def add_css(widget, css, force=False):
     """Add css for the widget, overriding the theme.
 
     Can raise GLib.GError in case the css is invalid
@@ -364,7 +364,9 @@ def add_css(widget, css):
     provider = Gtk.CssProvider()
     provider.load_from_data(css)
     context = widget.get_style_context()
-    context.add_provider(provider, Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
+    context.add_provider(provider,
+        Gtk.STYLE_PROVIDER_PRIORITY_USER if force else
+        Gtk.STYLE_PROVIDER_PRIORITY_APPLICATION)
 
 
 def remove_padding(widget):

quodlibet/quodlibet/qltk/paned.py

@@ -34,7 +34,7 @@ def ensure_wide_handle(self):
                 paned {
                     padding: 0px;
                 }
-            """)
+            """, True)
             return
 
         if hasattr(self.props, "wide_handle"):
@@ -46,7 +46,7 @@ def ensure_wide_handle(self):
                     border-width: 0;
                     background: none;
                 }
-            """)
+            """, True)
             return
 
         # gtk 3.14
@@ -57,7 +57,7 @@ def ensure_wide_handle(self):
                 margin: 0;
                 border-width: 0;
             }
-        """)
+        """, True)
 
     @property
     def handle_size(self):
@@ -235,12 +235,12 @@ def __expander_widget(cls, xpaned, widget, allocated=False):
                 }
                 expander arrow {
                     padding: """ + str(__expander_spacing) + """px;
-                }""")
+                }""", True)
         else:
             add_css(widget, """
                 GtkExpander, expander {
                     -GtkExpander-expander-size: """ +
-                        str(__expander_size) + "; }")
+                        str(__expander_size) + "; }", True)
 
         # common
         add_css(widget, """
@@ -256,7 +256,7 @@ def __expander_widget(cls, xpaned, widget, allocated=False):
                 background-image: none;
                 margin: 0px;
                 padding: """ + str(__label_padding) + """px;
-            }""")
+            }""", True)
 
         widget.title_size = title_size