[libdazzle] util: add helper to find parents or relatives

[Christian Hergert <chergert src gnome org>]

commit 1270ce3ddb01a41c0cd6b32bccdd852846612336
Author: Christian Hergert <chergert redhat com>
Date:   Sat Jul 8 03:17:46 2017 -0700

    util: add helper to find parents or relatives
    
    This checks a few known types of relative widgets which can be
    useful when doing state tracking.

 src/util/dzl-gtk.c |   54 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/util/dzl-gtk.h |    2 +
 2 files changed, 56 insertions(+), 0 deletions(-)
---
diff --git a/src/util/dzl-gtk.c b/src/util/dzl-gtk.c
index ff49b7f..107861d 100644
--- a/src/util/dzl-gtk.c
+++ b/src/util/dzl-gtk.c
@@ -594,3 +594,57 @@ dzl_gtk_list_store_insert_sorted (GtkListStore     *store,
   else
     gtk_list_store_insert_after (store, iter, &middle);
 }
+
+static GtkWidget *
+get_parent_or_relative (GtkWidget *widget)
+{
+  GtkWidget *parent = NULL;
+
+  g_assert (GTK_IS_WIDGET (widget));
+
+  if (GTK_IS_POPOVER (widget))
+    parent = gtk_popover_get_relative_to (GTK_POPOVER (widget));
+  else if (GTK_IS_WINDOW (widget))
+    parent = (GtkWidget *)gtk_window_get_transient_for (GTK_WINDOW (widget));
+  else if (GTK_IS_MENU (widget))
+    parent = gtk_menu_get_attach_widget (GTK_MENU (widget));
+
+  if (parent == NULL)
+    parent = gtk_widget_get_parent (widget);
+
+  return parent;
+}
+
+/**
+ * dzl_gtk_widget_is_ancestor_or_relative:
+ * @widget: a #GtkWidget
+ * @ancestor: a #GtkWidget that might be an ancestor
+ *
+ * This function is like gtk_widget_is_ancestor() except that it checks
+ * various relative widgets that are not in the direct hierarchy of
+ * widgets. That includes #GtkMenu:attach-widget,
+ * #GtkPopover:relative-to, and #GtkWindow:transient-for.
+ *
+ * Returns: %TRUE if @ancestor is an ancestor or relative for @widget.
+ *
+ * Since: 3.26
+ */
+gboolean
+dzl_gtk_widget_is_ancestor_or_relative (GtkWidget *widget,
+                                        GtkWidget *ancestor)
+{
+  g_return_val_if_fail (!widget || GTK_IS_WIDGET (widget), FALSE);
+  g_return_val_if_fail (!ancestor || GTK_IS_WIDGET (ancestor), FALSE);
+
+  if (widget == NULL || ancestor == NULL)
+    return FALSE;
+
+  do
+    {
+      if (widget == ancestor)
+        return TRUE;
+    }
+  while (NULL != (widget = get_parent_or_relative (widget)));
+
+  return FALSE;
+}
diff --git a/src/util/dzl-gtk.h b/src/util/dzl-gtk.h
index 13a8dd8..df32855 100644
--- a/src/util/dzl-gtk.h
+++ b/src/util/dzl-gtk.h
@@ -56,6 +56,8 @@ void          dzl_gtk_list_store_insert_sorted   (GtkListStore            *store
                                                   guint                    compare_column,
                                                   GCompareDataFunc         compare_func,
                                                   gpointer                 compare_data);
+gboolean      dzl_gtk_widget_is_ancestor_or_relative (GtkWidget               *widget,
+                                                      GtkWidget               *ancestor);
 
 G_END_DECLS