styleprovider: Make all implementors emit the new signal

... and listen to it in the cases where they use other style providers.

gtk/gtkcssprovider.c

@@ -2537,6 +2537,8 @@ gtk_css_provider_load_from_data (GtkCssProvider  *css_provider,
 
   g_free (free_data);
 
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (css_provider));
+
   return ret;
 }
 
@@ -2556,12 +2558,18 @@ gtk_css_provider_load_from_file (GtkCssProvider  *css_provider,
                                  GFile           *file,
                                  GError         **error)
 {
+  gboolean success;
+
   g_return_val_if_fail (GTK_IS_CSS_PROVIDER (css_provider), FALSE);
   g_return_val_if_fail (G_IS_FILE (file), FALSE);
 
   gtk_css_provider_reset (css_provider);
 
-  return gtk_css_provider_load_internal (css_provider, NULL, file, NULL, error);
+  success = gtk_css_provider_load_internal (css_provider, NULL, file, NULL, error);
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (css_provider));
+
+  return success;
 }
 
 /**

gtk/gtkmodifierstyle.c

@@ -210,6 +210,7 @@ modifier_style_set_color (GtkModifierStyle *style,
     gtk_style_properties_unset_property (priv->style, prop, state);
 
   g_signal_emit (style, signals[CHANGED], 0);
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (style));
 }
 
 void
@@ -250,6 +251,7 @@ _gtk_modifier_style_set_font (GtkModifierStyle           *style,
     gtk_style_properties_unset_property (priv->style, "font", 0);
 
   g_signal_emit (style, signals[CHANGED], 0);
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (style));
 }
 
 void
@@ -272,6 +274,7 @@ _gtk_modifier_style_map_color (GtkModifierStyle *style,
                                   name, symbolic_color);
 
   g_signal_emit (style, signals[CHANGED], 0);
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (style));
 }
 
 void
@@ -312,4 +315,5 @@ _gtk_modifier_style_set_color_property (GtkModifierStyle *style,
     }
 
   g_signal_emit (style, signals[CHANGED], 0);
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (style));
 }

gtk/gtksettings.c

@@ -1738,6 +1738,8 @@ settings_invalidate_style (GtkSettings *settings)
       g_object_unref (priv->style);
       priv->style = NULL;
     }
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (settings));
 }
 
 static void

gtk/gtkstylecascade.c

@@ -34,6 +34,7 @@ struct _GtkStyleProviderData
 {
   GtkStyleProvider *provider;
   guint priority;
+  guint changed_signal_id;
 };
 
 static GtkStyleProvider *
@@ -263,6 +264,7 @@ style_provider_data_clear (gpointer data_)
 {
   GtkStyleProviderData *data = data_;
 
+  g_signal_handler_disconnect (data->provider, data->changed_signal_id);
   g_object_unref (data->provider);
 }
 
@@ -313,10 +315,21 @@ _gtk_style_cascade_set_parent (GtkStyleCascade *cascade,
     return;
 
   if (parent)
+    {
       g_object_ref (parent);
+      g_signal_connect_swapped (parent,
+                                "-gtk-private-changed",
+                                G_CALLBACK (_gtk_style_provider_private_changed),
+                                cascade);
+    }
 
   if (cascade->parent)
+    {
+      g_signal_handlers_disconnect_by_func (cascade->parent, 
+                                            _gtk_style_provider_private_changed,
+                                            cascade);
       g_object_unref (cascade->parent);
+    }
 
   cascade->parent = parent;
 }
@@ -335,6 +348,10 @@ _gtk_style_cascade_add_provider (GtkStyleCascade  *cascade,
 
   data.provider = g_object_ref (provider);
   data.priority = priority;
+  data.changed_signal_id = g_signal_connect_swapped (provider,
+                                                     "-gtk-private-changed",
+                                                     G_CALLBACK (_gtk_style_provider_private_changed),
+                                                     cascade);
 
   /* ensure it gets removed first */
   _gtk_style_cascade_remove_provider (cascade, provider);
@@ -345,6 +362,8 @@ _gtk_style_cascade_add_provider (GtkStyleCascade  *cascade,
         break;
     }
   g_array_insert_val (cascade->providers, i, data);
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (cascade));
 }
 
 void
@@ -363,6 +382,8 @@ _gtk_style_cascade_remove_provider (GtkStyleCascade  *cascade,
       if (data->provider == provider)
         {
           g_array_remove_index (cascade->providers, i);
+  
+          _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (cascade));
           break;
         }
     }

gtk/gtkstyleproperties.c

@@ -399,6 +399,8 @@ gtk_style_properties_map_color (GtkStyleProperties *props,
   g_hash_table_replace (priv->color_map,
                         g_strdup (name),
                         gtk_symbolic_color_ref (color));
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (props));
 }
 
 /**
@@ -453,6 +455,8 @@ _gtk_style_properties_set_property_by_property (GtkStyleProperties  *props,
 
   _gtk_css_value_unref (val->value);
   val->value = _gtk_css_value_ref (value);
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (props));
 }
 
 /**
@@ -797,6 +801,8 @@ gtk_style_properties_unset_property (GtkStyleProperties *props,
       data->value = NULL;
 
       g_array_remove_index (prop->values, pos);
+
+      _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (props));
     }
 }
 
@@ -815,6 +821,8 @@ gtk_style_properties_clear (GtkStyleProperties *props)
 
   priv = props->priv;
   g_hash_table_remove_all (priv->properties);
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (props));
 }
 
 /**
@@ -935,4 +943,6 @@ gtk_style_properties_merge (GtkStyleProperties       *props,
             }
         }
     }
+
+  _gtk_style_provider_private_changed (GTK_STYLE_PROVIDER_PRIVATE (props));
 }