[gnome-text-editor] menu: add joined menu helper

[Christian Hergert <chergert src gnome org>]

commit 140901bd1975c12065f3699183edfc9717911b90
Author: Christian Hergert <chergert redhat com>
Date:   Fri Jun 25 14:33:40 2021 -0700

    menu: add joined menu helper

 src/editor-joined-menu-private.h |  42 +++++
 src/editor-joined-menu.c         | 325 +++++++++++++++++++++++++++++++++++++++
 2 files changed, 367 insertions(+)
---
diff --git a/src/editor-joined-menu-private.h b/src/editor-joined-menu-private.h
new file mode 100644
index 0000000..a1ff0ff
--- /dev/null
+++ b/src/editor-joined-menu-private.h
@@ -0,0 +1,42 @@
+/* editor-joined-menu-private.h
+ *
+ * Copyright 2017-2021 Christian Hergert <chergert redhat com>
+ *
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+#pragma once
+
+#include <gio/gio.h>
+
+G_BEGIN_DECLS
+
+#define EDITOR_TYPE_JOINED_MENU (editor_joined_menu_get_type())
+
+G_DECLARE_FINAL_TYPE (EditorJoinedMenu, editor_joined_menu, EDITOR, JOINED_MENU, GMenuModel)
+
+EditorJoinedMenu *editor_joined_menu_new          (void);
+guint             editor_joined_menu_get_n_joined (EditorJoinedMenu *self);
+void              editor_joined_menu_append_menu  (EditorJoinedMenu *self,
+                                                   GMenuModel      *model);
+void              editor_joined_menu_prepend_menu (EditorJoinedMenu *self,
+                                                   GMenuModel      *model);
+void              editor_joined_menu_remove_menu  (EditorJoinedMenu *self,
+                                                   GMenuModel      *model);
+void              editor_joined_menu_remove_index (EditorJoinedMenu *self,
+                                                   guint            index);
+
+G_END_DECLS
diff --git a/src/editor-joined-menu.c b/src/editor-joined-menu.c
new file mode 100644
index 0000000..8e9d674
--- /dev/null
+++ b/src/editor-joined-menu.c
@@ -0,0 +1,325 @@
+/* editor-joined-menu.c
+ *
+ * Copyright 2017-2021 Christian Hergert <chergert redhat com>
+ *
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option)
+ * any later version.
+ *
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * SPDX-License-Identifier: LGPL-3.0-or-later
+ */
+
+#include "config.h"
+
+#include "editor-joined-menu-private.h"
+
+typedef struct
+{
+  GMenuModel *model;
+  gulong      items_changed_handler;
+} Menu;
+
+struct _EditorJoinedMenu
+{
+  GMenuModel  parent_instance;
+  GArray     *menus;
+};
+
+G_DEFINE_TYPE (EditorJoinedMenu, editor_joined_menu, G_TYPE_MENU_MODEL)
+
+static void
+clear_menu (gpointer data)
+{
+  Menu *menu = data;
+
+  g_signal_handler_disconnect (menu->model, menu->items_changed_handler);
+  menu->items_changed_handler = 0;
+  g_clear_object (&menu->model);
+}
+
+static gint
+editor_joined_menu_get_offset_at_index (EditorJoinedMenu *self,
+                                        gint              index)
+{
+  gint offset = 0;
+
+  for (guint i = 0; i < index; i++)
+    offset += g_menu_model_get_n_items (g_array_index (self->menus, Menu, i).model);
+
+  return offset;
+}
+
+static gint
+editor_joined_menu_get_offset_at_model (EditorJoinedMenu *self,
+                                        GMenuModel       *model)
+{
+  gint offset = 0;
+
+  for (guint i = 0; i < self->menus->len; i++)
+    {
+      const Menu *menu = &g_array_index (self->menus, Menu, i);
+
+      if (menu->model == model)
+        break;
+
+      offset += g_menu_model_get_n_items (menu->model);
+    }
+
+  return offset;
+}
+
+static gboolean
+editor_joined_menu_is_mutable (GMenuModel *model)
+{
+  return TRUE;
+}
+
+static gint
+editor_joined_menu_get_n_items (GMenuModel *model)
+{
+  EditorJoinedMenu *self = (EditorJoinedMenu *)model;
+
+  if (self->menus->len == 0)
+    return 0;
+
+  return editor_joined_menu_get_offset_at_index (self, self->menus->len);
+}
+
+static const Menu *
+editor_joined_menu_get_item (EditorJoinedMenu *self,
+                             gint             *item_index)
+{
+  g_assert (EDITOR_IS_JOINED_MENU (self));
+
+  for (guint i = 0; i < self->menus->len; i++)
+    {
+      const Menu *menu = &g_array_index (self->menus, Menu, i);
+      gint n_items = g_menu_model_get_n_items (menu->model);
+
+      if (n_items > *item_index)
+        return menu;
+
+      (*item_index) -= n_items;
+    }
+
+  g_assert_not_reached ();
+
+  return NULL;
+}
+
+static void
+editor_joined_menu_get_item_attributes (GMenuModel  *model,
+                                        gint         item_index,
+                                        GHashTable **attributes)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  G_MENU_MODEL_GET_CLASS (menu->model)->get_item_attributes (menu->model, item_index, attributes);
+}
+
+static GMenuAttributeIter *
+editor_joined_menu_iterate_item_attributes (GMenuModel *model,
+                                            gint        item_index)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  return G_MENU_MODEL_GET_CLASS (menu->model)->iterate_item_attributes (menu->model, item_index);
+}
+
+static GVariant *
+editor_joined_menu_get_item_attribute_value (GMenuModel         *model,
+                                             gint                item_index,
+                                             const gchar        *attribute,
+                                             const GVariantType *expected_type)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  return G_MENU_MODEL_GET_CLASS (menu->model)->get_item_attribute_value (menu->model, item_index, attribute, 
expected_type);
+}
+
+static void
+editor_joined_menu_get_item_links (GMenuModel  *model,
+                                   gint         item_index,
+                                   GHashTable **links)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  G_MENU_MODEL_GET_CLASS (menu->model)->get_item_links (menu->model, item_index, links);
+}
+
+static GMenuLinkIter *
+editor_joined_menu_iterate_item_links (GMenuModel *model,
+                                       gint        item_index)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  return G_MENU_MODEL_GET_CLASS (menu->model)->iterate_item_links (menu->model, item_index);
+}
+
+static GMenuModel *
+editor_joined_menu_get_item_link (GMenuModel  *model,
+                                  gint         item_index,
+                                  const gchar *link)
+{
+  const Menu *menu = editor_joined_menu_get_item (EDITOR_JOINED_MENU (model), &item_index);
+  return G_MENU_MODEL_GET_CLASS (menu->model)->get_item_link (menu->model, item_index, link);
+}
+
+static void
+editor_joined_menu_finalize (GObject *object)
+{
+  EditorJoinedMenu *self = (EditorJoinedMenu *)object;
+
+  g_clear_pointer (&self->menus, g_array_unref);
+
+  G_OBJECT_CLASS (editor_joined_menu_parent_class)->finalize (object);
+}
+
+static void
+editor_joined_menu_class_init (EditorJoinedMenuClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+  GMenuModelClass *menu_model_class = G_MENU_MODEL_CLASS (klass);
+
+  object_class->finalize = editor_joined_menu_finalize;
+
+  menu_model_class->is_mutable = editor_joined_menu_is_mutable;
+  menu_model_class->get_n_items = editor_joined_menu_get_n_items;
+  menu_model_class->get_item_attributes = editor_joined_menu_get_item_attributes;
+  menu_model_class->iterate_item_attributes = editor_joined_menu_iterate_item_attributes;
+  menu_model_class->get_item_attribute_value = editor_joined_menu_get_item_attribute_value;
+  menu_model_class->get_item_links = editor_joined_menu_get_item_links;
+  menu_model_class->iterate_item_links = editor_joined_menu_iterate_item_links;
+  menu_model_class->get_item_link = editor_joined_menu_get_item_link;
+}
+
+static void
+editor_joined_menu_init (EditorJoinedMenu *self)
+{
+  self->menus = g_array_new (FALSE, FALSE, sizeof (Menu));
+  g_array_set_clear_func (self->menus, clear_menu);
+}
+
+static void
+editor_joined_menu_on_items_changed (EditorJoinedMenu *self,
+                                     guint             offset,
+                                     guint             removed,
+                                     guint             added,
+                                     GMenuModel       *model)
+{
+  g_assert (EDITOR_IS_JOINED_MENU (self));
+  g_assert (G_IS_MENU_MODEL (model));
+
+  offset += editor_joined_menu_get_offset_at_model (self, model);
+  g_menu_model_items_changed (G_MENU_MODEL (self), offset, removed, added);
+}
+
+EditorJoinedMenu *
+editor_joined_menu_new (void)
+{
+  return g_object_new (EDITOR_TYPE_JOINED_MENU, NULL);
+}
+
+static void
+editor_joined_menu_insert (EditorJoinedMenu *self,
+                           GMenuModel       *model,
+                           gint              index)
+{
+  Menu menu = { 0 };
+  gint offset;
+  gint n_items;
+
+  g_assert (EDITOR_IS_JOINED_MENU (self));
+  g_assert (G_IS_MENU_MODEL (model));
+  g_assert (index >= 0);
+  g_assert (index <= self->menus->len);
+
+  menu.model = g_object_ref (model);
+  menu.items_changed_handler =
+    g_signal_connect_swapped (menu.model,
+                              "items-changed",
+                              G_CALLBACK (editor_joined_menu_on_items_changed),
+                              self);
+  g_array_insert_val (self->menus, index, menu);
+
+  n_items = g_menu_model_get_n_items (model);
+  offset = editor_joined_menu_get_offset_at_index (self, index);
+  g_menu_model_items_changed (G_MENU_MODEL (self), offset, 0, n_items);
+}
+
+void
+editor_joined_menu_append_menu (EditorJoinedMenu *self,
+                                GMenuModel       *model)
+{
+
+  g_return_if_fail (EDITOR_IS_JOINED_MENU (self));
+  g_return_if_fail (G_MENU_MODEL (model));
+
+  editor_joined_menu_insert (self, model, self->menus->len);
+}
+
+void
+editor_joined_menu_prepend_menu (EditorJoinedMenu *self,
+                                 GMenuModel       *model)
+{
+  g_return_if_fail (EDITOR_IS_JOINED_MENU (self));
+  g_return_if_fail (G_MENU_MODEL (model));
+
+  editor_joined_menu_insert (self, model, 0);
+}
+
+void
+editor_joined_menu_remove_index (EditorJoinedMenu *self,
+                                 guint             index)
+{
+  const Menu *menu;
+  gint n_items;
+  gint offset;
+
+  g_return_if_fail (EDITOR_IS_JOINED_MENU (self));
+  g_return_if_fail (index < self->menus->len);
+
+  menu = &g_array_index (self->menus, Menu, index);
+
+  offset = editor_joined_menu_get_offset_at_index (self, index);
+  n_items = g_menu_model_get_n_items (menu->model);
+
+  g_array_remove_index (self->menus, index);
+
+  g_menu_model_items_changed (G_MENU_MODEL (self), offset, n_items, 0);
+}
+
+void
+editor_joined_menu_remove_menu (EditorJoinedMenu *self,
+                                GMenuModel       *model)
+{
+  g_return_if_fail (EDITOR_IS_JOINED_MENU (self));
+  g_return_if_fail (G_IS_MENU_MODEL (model));
+
+  for (guint i = 0; i < self->menus->len; i++)
+    {
+      if (g_array_index (self->menus, Menu, i).model == model)
+        {
+          editor_joined_menu_remove_index (self, i);
+          break;
+        }
+    }
+}
+
+/**
+ * editor_joined_menu_get_n_joined:
+ * @self: a #EditorJoinedMenu
+ *
+ * Gets the number of joined menus.
+ */
+guint
+editor_joined_menu_get_n_joined (EditorJoinedMenu *self)
+{
+  g_return_val_if_fail (EDITOR_IS_JOINED_MENU (self), 0);
+
+  return self->menus->len;
+}