[gtk/fix-icontheme-invalidation] widget: Add a system_setting_changed vfunc

[Matthias Clasen <matthiasc src gnome org>]

commit a204c624828b59587e8f1faaa9e4390c9471de62
Author: Matthias Clasen <mclasen redhat com>
Date:   Tue Apr 21 12:05:45 2020 -0400

    widget: Add a system_setting_changed vfunc
    
    This is going to be a better replacement for
    gtk_style_context_reset_widgets().

 gtk/gtkenums.h         | 10 ++++++++++
 gtk/gtkwidget.c        | 24 ++++++++++++++++++++++++
 gtk/gtkwidget.h        |  4 ++++
 gtk/gtkwidgetprivate.h |  2 ++
 4 files changed, 40 insertions(+)
---
diff --git a/gtk/gtkenums.h b/gtk/gtkenums.h
index 3069183f61..1f19f64ba9 100644
--- a/gtk/gtkenums.h
+++ b/gtk/gtkenums.h
@@ -1088,4 +1088,14 @@ typedef enum {
   GTK_CONSTRAINT_VFL_PARSER_ERROR_INVALID_RELATION
 } GtkConstraintVflParserError;
 
+typedef enum {
+  GTK_SYSTEM_SETTING_DPI,
+  GTK_SYSTEM_SETTING_FONT_NAME,
+  GTK_SYSTEM_SETTING_FONT_CONFIG,
+  GTK_SYSTEM_SETTING_DISPLAY,
+  GTK_SYSTEM_SETTING_ICON_THEME,
+  GTK_SYSTEM_SETTING_THEME,
+  GTK_SYSTEM_SETTING_ANIMATIONS
+} GtkSystemSetting;
+
 #endif /* __GTK_ENUMS_H__ */
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index b1c9bea8bd..7735d78c68 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -592,6 +592,8 @@ static gboolean gtk_widget_real_query_tooltip    (GtkWidget         *widget,
                                                  GtkTooltip        *tooltip);
 static void     gtk_widget_real_css_changed      (GtkWidget         *widget,
                                                   GtkCssStyleChange *change);
+static void     gtk_widget_real_system_setting_changed (GtkWidget         *widget,
+                                                        GtkSystemSetting   setting);
 
 static void             gtk_widget_real_set_focus_child         (GtkWidget        *widget,
                                                                  GtkWidget        *child);
@@ -911,6 +913,7 @@ gtk_widget_class_init (GtkWidgetClass *klass)
   klass->keynav_failed = gtk_widget_real_keynav_failed;
   klass->query_tooltip = gtk_widget_real_query_tooltip;
   klass->css_changed = gtk_widget_real_css_changed;
+  klass->system_setting_changed = gtk_widget_real_system_setting_changed;
 
   /* Accessibility support */
   klass->priv->accessible_type = GTK_TYPE_ACCESSIBLE;
@@ -4865,6 +4868,20 @@ gtk_widget_real_css_changed (GtkWidget         *widget,
     }
 }
 
+static void
+gtk_widget_real_system_setting_changed (GtkWidget        *widget,
+                                        GtkSystemSetting  setting)
+{
+  GtkWidget *child;
+
+  for (child = _gtk_widget_get_first_child (widget);
+       child != NULL;
+       child = _gtk_widget_get_next_sibling (child))
+    {
+      gtk_widget_system_setting_changed (child, setting);
+    }
+}
+
 static gboolean
 direction_is_forward (GtkDirectionType direction)
 {
@@ -10627,6 +10644,13 @@ gtk_widget_css_changed (GtkWidget         *widget,
   GTK_WIDGET_GET_CLASS (widget)->css_changed (widget, change);
 }
 
+void
+gtk_widget_system_setting_changed (GtkWidget        *widget,
+                                   GtkSystemSetting  setting)
+{
+  GTK_WIDGET_GET_CLASS (widget)->system_setting_changed (widget, setting);
+}
+
 GtkCssNode *
 gtk_widget_get_css_node (GtkWidget *widget)
 {
diff --git a/gtk/gtkwidget.h b/gtk/gtkwidget.h
index a08309efb8..021a96c604 100644
--- a/gtk/gtkwidget.h
+++ b/gtk/gtkwidget.h
@@ -201,6 +201,7 @@ struct _GtkWidget
  *   should then discard their caches that depend on CSS and queue resizes or
  *   redraws accordingly. The default implementation will take care of this for
  *   all the default CSS properties, so implementations must chain up.
+ * @system_setting_changed: Emitted when a system setting was changed. Must chain up.
  * @snapshot: Vfunc for gtk_widget_snapshot().
  * @contains: Vfunc for gtk_widget_contains().
  */
@@ -277,6 +278,9 @@ struct _GtkWidgetClass
   void         (* css_changed)                 (GtkWidget            *widget,
                                                 GtkCssStyleChange    *change);
 
+  void         (* system_setting_changed)      (GtkWidget            *widget,
+                                                GtkSystemSetting      settings);
+
   void         (* snapshot)                    (GtkWidget            *widget,
                                                 GtkSnapshot          *snapshot);
 
diff --git a/gtk/gtkwidgetprivate.h b/gtk/gtkwidgetprivate.h
index db969f4cb2..9157d7e796 100644
--- a/gtk/gtkwidgetprivate.h
+++ b/gtk/gtkwidgetprivate.h
@@ -282,6 +282,8 @@ gboolean          _gtk_widget_captured_event               (GtkWidget *widget,
 
 void              gtk_widget_css_changed                   (GtkWidget           *widget,
                                                             GtkCssStyleChange   *change);
+void              gtk_widget_system_setting_changed        (GtkWidget           *widget,
+                                                            GtkSystemSetting     setting);
 
 void              _gtk_widget_update_parent_muxer          (GtkWidget    *widget);
 GtkActionMuxer *  _gtk_widget_get_action_muxer             (GtkWidget    *widget,