[libpanel] grid: add foreach_frame() callback helper

[Christian Hergert <chergert src gnome org>]

commit f823550b5ab7c8a542c3b0c41648128c4b0caef5
Author: Christian Hergert <chergert redhat com>
Date:   Thu Sep 15 20:03:27 2022 -0700

    grid: add foreach_frame() callback helper

 src/panel-grid.c | 28 ++++++++++++++++++++++++++++
 src/panel-grid.h |  4 ++++
 2 files changed, 32 insertions(+)
---
diff --git a/src/panel-grid.c b/src/panel-grid.c
index dac2b4b..17f693e 100644
--- a/src/panel-grid.c
+++ b/src/panel-grid.c
@@ -732,3 +732,31 @@ panel_grid_agree_to_close_finish (PanelGrid     *self,
 
   return g_task_propagate_boolean (G_TASK (result), error);
 }
+
+/**
+ * panel_grid_foreach_frame:
+ * @self: a #PanelGrid
+ * @callback: (scope call): a #PanelFrameCallback
+ * @user_data: closure data for @callback
+ *
+ * Calls @callback for each #PanelFrame within @grid.
+ */
+void
+panel_grid_foreach_frame (PanelGrid          *self,
+                          PanelFrameCallback  callback,
+                          gpointer            user_data)
+{
+  guint n_columns;
+
+  g_return_if_fail (PANEL_IS_GRID (self));
+  g_return_if_fail (callback != NULL);
+
+  n_columns = panel_grid_get_n_columns (self);
+
+  for (guint i = 0; i < n_columns; i++)
+    {
+      PanelGridColumn *column = panel_grid_get_column (self, i);
+
+      panel_grid_column_foreach_frame (column, callback, user_data);
+    }
+}
diff --git a/src/panel-grid.h b/src/panel-grid.h
index 5f6ff9c..c7eefb2 100644
--- a/src/panel-grid.h
+++ b/src/panel-grid.h
@@ -48,6 +48,10 @@ PanelGridColumn *panel_grid_get_most_recent_column (PanelGrid            *self);
 PANEL_AVAILABLE_IN_ALL
 PanelFrame      *panel_grid_get_most_recent_frame  (PanelGrid            *self);
 PANEL_AVAILABLE_IN_ALL
+void             panel_grid_foreach_frame          (PanelGrid            *self,
+                                                    PanelFrameCallback    callback,
+                                                    gpointer              user_data);
+PANEL_AVAILABLE_IN_ALL
 void             panel_grid_add                    (PanelGrid            *self,
                                                     PanelWidget          *widget);
 PANEL_AVAILABLE_IN_ALL