// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CHROME_BROWSER_UI_GTK_GLOBAL_MENU_BAR_H_
#define CHROME_BROWSER_UI_GTK_GLOBAL_MENU_BAR_H_

#include <map>

#include "base/compiler_specific.h"
#include "base/prefs/pref_change_registrar.h"
#include "chrome/browser/command_observer.h"
#include "chrome/browser/ui/gtk/global_history_menu.h"
#include "ui/base/gtk/gtk_signal.h"
#include "ui/base/gtk/owned_widget_gtk.h"

class Browser;
struct GlobalMenuBarCommand;
class GlobalMenuOwner;

typedef struct _GtkAccelGroup GtkAccelGroup;
typedef struct _GtkWidget GtkWidget;

// Controls the Mac style menu bar on Linux.
//
// Unity and some configurations of GNOME have a Apple-like menu bar at the top
// of the screen that changes depending on the active window. These mainly work
// by inspecting the application's widget hierarchy, and intercepting any
// GtkMenuBar found. Thankfully, these systems don't check to see if the menu
// bar itself is visible, so we insert a GtkMenuBar into the window hierarchy
// and set it to be invisible.
class GlobalMenuBar : public CommandObserver {
 public:
  static const int TAG_NORMAL = 0;
  static const int TAG_MOST_VISITED = 1;
  static const int TAG_RECENTLY_CLOSED = 2;
  static const int TAG_MOST_VISITED_HEADER = 3;
  static const int TAG_RECENTLY_CLOSED_HEADER = 4;
  static const int TAG_BOOKMARK_CLEARABLE = 5;

  explicit GlobalMenuBar(Browser* browser);
  virtual ~GlobalMenuBar();

  // Use this method to remove the GlobalMenuBar from any further notifications
  // and command updates but not destroy the widgets.
  virtual void Disable();

  GtkWidget* widget() { return menu_bar_.get(); }

 private:
  typedef std::map<int, GtkWidget*> CommandIDMenuItemMap;

  // Helper function that builds the data.
  void BuildGtkMenuFrom(int menu_str_id,
                        std::map<int, GtkWidget*>* id_to_menu_item,
                        GlobalMenuBarCommand* commands,
                        GlobalMenuOwner* owner);

  // Builds an individual menu item.
  GtkWidget* BuildMenuItem(int string_id,
                           int command_id,
                           int tag_id,
                           std::map<int, GtkWidget*>* id_to_menu_item,
                           GtkWidget* menu_to_add_to);

  // CommandObserver:
  virtual void EnabledStateChangedForCommand(int id, bool enabled) OVERRIDE;

  // Updates the visibility of the bookmark bar on pref changes.
  void OnBookmarkBarVisibilityChanged();

  CHROMEGTK_CALLBACK_0(GlobalMenuBar, void, OnItemActivated);

  Browser* browser_;

  // Tracks value of the kShowBookmarkBar preference.
  PrefChangeRegistrar pref_change_registrar_;

  // Our menu bar widget.
  ui::OwnedWidgetGtk menu_bar_;

  // Listens to the TabRestoreService and the HistoryService and keeps the
  // history menu fresh.
  GlobalHistoryMenu history_menu_;

  // For some menu items, we want to show the accelerator, but not actually
  // explicitly handle it. To this end we connect those menu items' accelerators
  // to this group, but don't attach this group to any top level window.
  GtkAccelGroup* dummy_accel_group_;

  // A mapping from command ids to GtkMenuItem objects. We use this to update
  // the command enable state.
  CommandIDMenuItemMap id_to_menu_item_;

  // gtk_check_menu_item_set_active() will call the "activate" signal. We need
  // to block this activation while we change the checked state.
  bool block_activation_;
};

#endif  // CHROME_BROWSER_UI_GTK_GLOBAL_MENU_BAR_H_