ui/views/controls/menu/native_menu_win.h

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_
   6 #define UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_
   7
   8 #include <vector>
   9
  10 #include "base/basictypes.h"
  11 #include "base/compiler_specific.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "base/observer_list.h"
  15 #include "base/strings/string16.h"
  16 #include "ui/views/controls/menu/menu_wrapper.h"
  17 #include "ui/views/views_export.h"
  18
  19 namespace ui {
  20 class MenuModel;
  21 }
  22
  23 namespace views {
  24
  25 // A Windows implementation of MenuWrapper.
  26 // TODO(beng): rename to MenuWin once the old class is dead.
  27 class VIEWS_EXPORT NativeMenuWin : public MenuWrapper {
  28  public:
  29   // Construct a NativeMenuWin, with a model and delegate. If |system_menu_for|
  30   // is non-NULL, the NativeMenuWin wraps the system menu for that window.
  31   // The caller owns the model and the delegate.
  32   NativeMenuWin(ui::MenuModel* model, HWND system_menu_for);
  33   virtual ~NativeMenuWin();
  34
  35   // Overridden from MenuWrapper:
  36   virtual void RunMenuAt(const gfx::Point& point, int alignment) override;
  37   virtual void CancelMenu() override;
  38   virtual void Rebuild(MenuInsertionDelegateWin* delegate) override;
  39   virtual void UpdateStates() override;
  40   virtual HMENU GetNativeMenu() const override;
  41   virtual MenuAction GetMenuAction() const override;
  42   virtual void AddMenuListener(MenuListener* listener) override;
  43   virtual void RemoveMenuListener(MenuListener* listener) override;
  44   virtual void SetMinimumWidth(int width) override;
  45
  46  private:
  47   // IMPORTANT: Note about indices.
  48   //            Functions in this class deal in two index spaces:
  49   //            1. menu_index - the index of an item within the actual Windows
  50   //               native menu.
  51   //            2. model_index - the index of the item within our model.
  52   //            These two are most often but not always the same value! The
  53   //            notable exception is when this object is used to wrap the
  54   //            Windows System Menu. In this instance, the model indices start
  55   //            at 0, but the insertion index into the existing menu is not.
  56   //            It is important to take this into consideration when editing the
  57   //            code in the functions in this class.
  58
  59   struct HighlightedMenuItemInfo;
  60
  61   // Returns true if the item at the specified index is a separator.
  62   bool IsSeparatorItemAt(int menu_index) const;
  63
  64   // Add items. See note above about indices.
  65   void AddMenuItemAt(int menu_index, int model_index);
  66   void AddSeparatorItemAt(int menu_index, int model_index);
  67
  68   // Sets the state of the item at the specified index.
  69   void SetMenuItemState(int menu_index,
  70                         bool enabled,
  71                         bool checked,
  72                         bool is_default);
  73
  74   // Sets the label of the item at the specified index.
  75   void SetMenuItemLabel(int menu_index,
  76                         int model_index,
  77                         const base::string16& label);
  78
  79   // Updates the local data structure with the correctly formatted version of
  80   // |label| at the specified model_index, and adds string data to |mii| if
  81   // the menu is not owner-draw. That's a mouthful. This function exists because
  82   // of the peculiarities of the Windows menu API.
  83   void UpdateMenuItemInfoForString(MENUITEMINFO* mii,
  84                                    int model_index,
  85                                    const base::string16& label);
  86
  87   // Returns the alignment flags to be passed to TrackPopupMenuEx, based on the
  88   // supplied alignment and the UI text direction.
  89   UINT GetAlignmentFlags(int alignment) const;
  90
  91   // Resets the native menu stored in |menu_| by destroying any old menu then
  92   // creating a new empty one.
  93   void ResetNativeMenu();
  94
  95   // Creates the host window that receives notifications from the menu.
  96   void CreateHostWindow();
  97
  98   // Callback from task to notify menu it was selected.
  99   void DelayedSelect();
 100
 101   // Given a menu that's currently popped-up, find the currently highlighted
 102   // item. Returns true if a highlighted item was found.
 103   static bool GetHighlightedMenuItemInfo(HMENU menu,
 104                                          HighlightedMenuItemInfo* info);
 105
 106   // Hook to receive keyboard events while the menu is open.
 107   static LRESULT CALLBACK MenuMessageHook(
 108       int n_code, WPARAM w_param, LPARAM l_param);
 109
 110   // Our attached model and delegate.
 111   ui::MenuModel* model_;
 112
 113   HMENU menu_;
 114
 115   // True if the contents of menu items in this menu are drawn by the menu host
 116   // window, rather than Windows.
 117   bool owner_draw_;
 118
 119   // An object that collects all of the data associated with an individual menu
 120   // item.
 121   struct ItemData;
 122   std::vector<ItemData*> items_;
 123
 124   // The window that receives notifications from the menu.
 125   class MenuHostWindow;
 126   friend MenuHostWindow;
 127   scoped_ptr<MenuHostWindow> host_window_;
 128
 129   // The HWND this menu is the system menu for, or NULL if the menu is not a
 130   // system menu.
 131   HWND system_menu_for_;
 132
 133   // The index of the first item in the model in the menu.
 134   int first_item_index_;
 135
 136   // The action that took place during the call to RunMenuAt.
 137   MenuAction menu_action_;
 138
 139   // A list of listeners to call when the menu opens.
 140   ObserverList<MenuListener> listeners_;
 141
 142   // Keep track of whether the listeners have already been called at least
 143   // once.
 144   bool listeners_called_;
 145
 146   // See comment in MenuMessageHook for details on these.
 147   NativeMenuWin* menu_to_select_;
 148   int position_to_select_;
 149   base::WeakPtrFactory<NativeMenuWin> menu_to_select_factory_;
 150
 151   // If we're a submenu, this is our parent.
 152   NativeMenuWin* parent_;
 153
 154   // If non-null the destructor sets this to true. This is set to non-null while
 155   // the menu is showing. It is used to detect if the menu was deleted while
 156   // running.
 157   bool* destroyed_flag_;
 158
 159   // Ugly: a static pointer to the instance of this class that currently
 160   // has a menu open, because our hook function that receives keyboard
 161   // events doesn't have a mechanism to get a user data pointer.
 162   static NativeMenuWin* open_native_menu_win_;
 163
 164   DISALLOW_COPY_AND_ASSIGN(NativeMenuWin);
 165 };
 166
 167 }  // namespace views
 168
 169 #endif  // UI_VIEWS_CONTROLS_MENU_NATIVE_MENU_WIN_H_