actionmuxer: add test for action parent

This tests that the infrastructure for action muxer parents is working
by activating an action on a widget for which the action is defined on
a widget not in the ancestry.

gtk/gtkactionmuxer.c

@@ -991,13 +991,15 @@ gtk_action_muxer_unregister_observer (GtkActionObservable *observable,
                                       GtkActionObserver   *observer)
 {
   GtkActionMuxer *muxer = GTK_ACTION_MUXER (observable);
-  Action *action;
+  Action *action = find_observers (muxer, name);
 
-  action = find_observers (muxer, name);
   if (action)
     {
-      g_object_weak_unref (G_OBJECT (observer), gtk_action_muxer_weak_notify, action);
+      if (g_slist_find (action->watchers, observer) != NULL)
-      gtk_action_muxer_unregister_internal (action, observer);
+        {
+          g_object_weak_unref (G_OBJECT (observer), gtk_action_muxer_weak_notify, action);
+          gtk_action_muxer_unregister_internal (action, observer);
+        }
     }
 }
 
@@ -1269,7 +1271,7 @@ gtk_action_muxer_insert (GtkActionMuxer *muxer,
   if (!muxer->groups)
     muxer->groups = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, gtk_action_muxer_free_group);
 
-  group = g_slice_new (Group);
+  group = g_slice_new0 (Group);
   group->muxer = muxer;
   group->group = g_object_ref (action_group);
   group->prefix = g_strdup (prefix);
@@ -1356,6 +1358,23 @@ gtk_action_muxer_get_parent (GtkActionMuxer *muxer)
   return muxer->parent;
 }
 
+static gboolean
+muxer_will_cycle (GtkActionMuxer *muxer,
+                  GtkActionMuxer *parent)
+{
+  GtkActionMuxer *ancestor;
+
+  for (ancestor = parent;
+       ancestor != NULL;
+       ancestor = gtk_action_muxer_get_parent (ancestor))
+    {
+      if (ancestor == muxer)
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
 /*< private >
  * gtk_action_muxer_set_parent:
  * @muxer: a `GtkActionMuxer`
@@ -1369,6 +1388,7 @@ gtk_action_muxer_set_parent (GtkActionMuxer *muxer,
 {
   g_return_if_fail (GTK_IS_ACTION_MUXER (muxer));
   g_return_if_fail (parent == NULL || GTK_IS_ACTION_MUXER (parent));
+  g_return_if_fail (parent == NULL || !muxer_will_cycle (muxer, parent));
 
   if (muxer->parent == parent)
     return;

gtk/gtkwidget.c

@@ -7390,6 +7390,8 @@ gtk_widget_dispose (GObject *object)
   GSList *sizegroups;
   GtkATContext *at_context;
 
+  g_clear_object (&priv->action_parent);
+
   if (priv->muxer != NULL)
     g_object_run_dispose (G_OBJECT (priv->muxer));
 
@@ -10808,13 +10810,20 @@ void
 _gtk_widget_update_parent_muxer (GtkWidget *widget)
 {
   GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+  GtkActionMuxer *parent_muxer;
   GtkWidget *child;
 
   if (priv->muxer == NULL)
     return;
 
-  gtk_action_muxer_set_parent (priv->muxer,
+  if (priv->action_parent != NULL &&
-                               gtk_widget_get_parent_muxer (widget, FALSE));
+      !gtk_widget_is_ancestor (priv->action_parent, widget))
+    parent_muxer = _gtk_widget_get_action_muxer (priv->action_parent, FALSE);
+  else
+    parent_muxer = gtk_widget_get_parent_muxer (widget, FALSE);
+
+  gtk_action_muxer_set_parent (priv->muxer, parent_muxer);
+
   for (child = gtk_widget_get_first_child (widget);
        child != NULL;
        child = gtk_widget_get_next_sibling (child))
@@ -12934,3 +12943,59 @@ gtk_widget_set_active_state (GtkWidget *widget,
         gtk_widget_unset_state_flags (widget, GTK_STATE_FLAG_ACTIVE);
     }
 }
+
+/**
+ * gtk_widget_set_action_parent:
+ * @widget: a [class@Gtk.Widget]
+ * @action_parent: (nullable): a [class@Gtk.Widget]
+ *
+ * Sets the action parent for @widget.
+ *
+ * Actions will resolve through @action_parent for @widget and all of
+ * it's descendants unless otherwise specified with
+ * [method@Gtk.Widget.set_action_parent].
+ *
+ * Setting an action parent can be useful when you want actions within
+ * a menu or toolbar to resolve through a document widget.
+ *
+ * To unset an action parent, use `NULL` for @action_parent and the widget
+ * will resume using the parent widget as the action parent.
+ *
+ * It is a programming error to set an action parent which will cause a
+ * cycle to occur.
+ *
+ * Since: 4.8
+ */
+void
+gtk_widget_set_action_parent (GtkWidget *widget,
+                              GtkWidget *action_parent)
+{
+  GtkWidgetPrivate *priv = gtk_widget_get_instance_private (widget);
+  GtkActionMuxer *muxer;
+  GtkActionMuxer *parent_muxer;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (action_parent != widget);
+  g_return_if_fail (!action_parent || GTK_IS_WIDGET (action_parent));
+  g_return_if_fail (!action_parent || !gtk_widget_is_ancestor (action_parent, widget));
+
+  muxer = _gtk_widget_get_action_muxer (widget, FALSE);
+
+  if (action_parent == NULL)
+    {
+      if (muxer != NULL)
+        {
+          parent_muxer = gtk_widget_get_parent_muxer (widget, FALSE);
+          gtk_action_muxer_set_parent (muxer, parent_muxer);
+        }
+    }
+  else
+    {
+      if (muxer == NULL)
+        muxer = _gtk_widget_get_action_muxer (widget, TRUE);
+      parent_muxer = _gtk_widget_get_action_muxer (action_parent, TRUE);
+      gtk_action_muxer_set_parent (muxer, parent_muxer);
+    }
+
+  g_set_object (&priv->action_parent, action_parent);
+}

gtk/gtkwidget.h

@@ -924,6 +924,9 @@ char **                 gtk_widget_get_css_classes      (GtkWidget   *widget);
 GDK_AVAILABLE_IN_ALL
 void                    gtk_widget_set_css_classes      (GtkWidget   *widget,
                                                          const char **classes);
+GDK_AVAILABLE_IN_4_8
+void                    gtk_widget_set_action_parent    (GtkWidget   *widget,
+                                                         GtkWidget   *action_parent);
 
 
 

gtk/gtkwidgetprivate.h

@@ -185,6 +185,7 @@ struct _GtkWidgetPrivate
   GtkListListModel *children_observer;
   GtkListListModel *controller_observer;
   GtkActionMuxer *muxer;
+  GtkWidget *action_parent;
 
   GtkWidget *focus_child;
 

testsuite/gtk/action.c

@@ -15,6 +15,8 @@
  */
 #include <gtk/gtk.h>
 
+#include "gtkwidgetprivate.h"
+
 static void
 activate (GSimpleAction *action,
           GVariant      *parameter,
@@ -717,6 +719,109 @@ test_enabled (void)
   g_object_unref (g_object_ref_sink (text));
 }
 
+static void
+test_action_parent_action1 (GSimpleAction *action,
+                            GVariant      *param,
+                            gpointer       user_data)
+{
+  guint *count = user_data;
+  (*count)++;
+}
+
+static void
+test_action_parent_action2 (GSimpleAction *action,
+                            GVariant      *param,
+                            gpointer       user_data)
+{
+  g_simple_action_set_state (action, param);
+}
+
+static void
+test_action_parent (void)
+{
+  static const GActionEntry test_actions[] = {
+    { "action1", test_action_parent_action1 },
+    { "action2", test_action_parent_action2, "s", "'initial'", test_action_parent_action2 },
+  };
+  GSimpleActionGroup *group;
+  GAction *action2;
+  GtkWidget *window;
+  GtkWidget *header;
+  GtkWidget *content;
+  GtkWidget *label1;
+  GtkWidget *label2;
+  GVariant *state = NULL;
+  const GVariantType *state_type = NULL;
+  GtkActionMuxer *muxer;
+  guint count = 0;
+
+  window = g_object_new (GTK_TYPE_WINDOW, NULL);
+  g_object_ref_sink (window);
+
+  header = g_object_new (GTK_TYPE_BUTTON, NULL);
+  content = g_object_new (GTK_TYPE_BOX, NULL);
+  label1 = g_object_new (GTK_TYPE_LABEL, NULL);
+  label2 = g_object_new (GTK_TYPE_LABEL, NULL);
+  gtk_box_append (GTK_BOX (content), label1);
+  gtk_box_append (GTK_BOX (content), label2);
+  gtk_window_set_titlebar (GTK_WINDOW (window), header);
+  gtk_window_set_child (GTK_WINDOW (window), content);
+  group = g_simple_action_group_new ();
+  g_action_map_add_action_entries (G_ACTION_MAP (group),
+                                   test_actions,
+                                   G_N_ELEMENTS (test_actions),
+                                   &count);
+  action2 = g_action_map_lookup_action (G_ACTION_MAP (group), "action2");
+
+  gtk_widget_insert_action_group (content, "test", G_ACTION_GROUP (group));
+  gtk_widget_activate_action (label1, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 1);
+
+  gtk_widget_activate_action (header, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 1);
+
+  gtk_widget_set_action_parent (header, label1);
+  gtk_widget_activate_action (header, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 2);
+
+  gtk_widget_activate_action (header, "test.action2", "s", "changed");
+  g_assert_cmpstr ("changed", ==, g_variant_get_string (g_action_get_state (action2), NULL));
+  muxer = _gtk_widget_get_action_muxer (header, FALSE);
+  gtk_action_muxer_query_action (muxer, "test.action2", NULL, NULL, &state_type, NULL, &state);
+  g_assert_nonnull (state_type);
+  g_assert_nonnull (state);
+  g_assert_cmpstr ((const char *)state_type, ==, "s");
+  g_assert_cmpstr ("changed", ==, g_variant_get_string (state, NULL));
+  g_variant_unref (state);
+
+  gtk_widget_set_action_parent (header, label2);
+  gtk_widget_activate_action (header, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 3);
+
+  gtk_widget_set_action_parent (header, NULL);
+  gtk_widget_activate_action (header, "test.action1", NULL);
+  gtk_widget_activate_action (header, "test.action2", "s", "third");
+  g_assert_cmpint (count, ==, 3);
+  g_assert_cmpstr ("changed", ==, g_variant_get_string (g_action_get_state (action2), NULL));
+
+  gtk_widget_set_action_parent (label2, header);
+  gtk_widget_activate_action (label2, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 3);
+
+  gtk_widget_insert_action_group (content, "test", NULL);
+  gtk_widget_activate_action (label1, "test.action1", NULL);
+  gtk_widget_activate_action (header, "test.action1", NULL);
+  g_assert_cmpint (count, ==, 3);
+
+  gtk_widget_activate_action (label2, "test.action2", "s", "third");
+  g_assert_cmpstr ("changed", ==, g_variant_get_string (g_action_get_state (action2), NULL));
+
+  gtk_window_destroy (GTK_WINDOW (window));
+
+  g_assert_finalize_object (group);
+  g_assert_finalize_object (window);
+}
+
 int
 main (int   argc,
       char *argv[])
@@ -732,6 +837,7 @@ main (int   argc,
   g_test_add_func ("/action/overlap2", test_overlap2);
   g_test_add_func ("/action/introspection", test_introspection);
   g_test_add_func ("/action/enabled", test_enabled);
+  g_test_add_func ("/action/action_parent", test_action_parent);
 
   return g_test_run();
 }

testsuite/gtk/meson.build

@@ -23,7 +23,6 @@ tests = [
   { 'name': 'accel' },
 # sadly, mesons xfail support seems busted
 #  { 'name': 'accessor-apis' },
-  { 'name': 'action' },
   { 'name': 'adjustment' },
   { 'name': 'bitset' },
   {
@@ -105,6 +104,7 @@ tests = [
 
 # Tests that test private apis and therefore are linked against libgtk-4.a
 internal_tests = [
+  { 'name': 'action' },
   { 'name': 'bitmask' },
   {
     'name': 'composetable',