root/ui/views/controls/menu/native_menu_win.cc

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DEFINITIONS

This source file includes following definitions.
  1. GetNativeMenuWinFromHMENU
  2. MenuHostWindow
  3. MenuHostWindow
  4. hwnd
  5. RegisterClass
  6. GetMenuItemIndexFromWPARAM
  7. GetItemData
  8. OnMenuCommand
  9. OnMenuSelect
  10. OnMeasureItem
  11. OnDrawItem
  12. ProcessWindowMessage
  13. MenuHostWindowProc
  14. destroyed_flag_
  15. RunMenuAt
  16. CancelMenu
  17. Rebuild
  18. UpdateStates
  19. GetNativeMenu
  20. GetMenuAction
  21. AddMenuListener
  22. RemoveMenuListener
  23. SetMinimumWidth
  24. DelayedSelect
  25. GetHighlightedMenuItemInfo
  26. MenuMessageHook
  27. IsSeparatorItemAt
  28. AddMenuItemAt
  29. AddSeparatorItemAt
  30. SetMenuItemState
  31. SetMenuItemLabel
  32. UpdateMenuItemInfoForString
  33. GetAlignmentFlags
  34. ResetNativeMenu
  35. CreateHostWindow
  36. CreateWrapper

// 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.

#include "ui/views/controls/menu/native_menu_win.h"

#include <Windowsx.h>

#include "base/bind.h"
#include "base/logging.h"
#include "base/message_loop/message_loop.h"
#include "base/stl_util.h"
#include "base/strings/string_util.h"
#include "base/win/wrapped_window_proc.h"
#include "ui/base/accelerators/accelerator.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/l10n/l10n_util_win.h"
#include "ui/base/models/menu_model.h"
#include "ui/events/keycodes/keyboard_codes.h"
#include "ui/gfx/canvas.h"
#include "ui/gfx/font_list.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/image/image.h"
#include "ui/gfx/image/image_skia.h"
#include "ui/gfx/text_utils.h"
#include "ui/gfx/win/hwnd_util.h"
#include "ui/native_theme/native_theme.h"
#include "ui/native_theme/native_theme_win.h"
#include "ui/views/controls/menu/menu_2.h"
#include "ui/views/controls/menu/menu_config.h"
#include "ui/views/controls/menu/menu_insertion_delegate_win.h"
#include "ui/views/controls/menu/menu_listener.h"
#include "ui/views/layout/layout_constants.h"

using ui::NativeTheme;

namespace views {

// The width of an icon, including the pixels between the icon and
// the item label.
static const int kIconWidth = 23;
// Margins between the top of the item and the label.
static const int kItemTopMargin = 3;
// Margins between the bottom of the item and the label.
static const int kItemBottomMargin = 4;
// Margins between the left of the item and the icon.
static const int kItemLeftMargin = 4;
// The width for displaying the sub-menu arrow.
static const int kArrowWidth = 10;

struct NativeMenuWin::ItemData {
  // The Windows API requires that whoever creates the menus must own the
  // strings used for labels, and keep them around for the lifetime of the
  // created menu. So be it.
  base::string16 label;

  // Someone needs to own submenus, it may as well be us.
  scoped_ptr<Menu2> submenu;

  // We need a pointer back to the containing menu in various circumstances.
  NativeMenuWin* native_menu_win;

  // The index of the item within the menu's model.
  int model_index;
};

// Returns the NativeMenuWin for a particular HMENU.
static NativeMenuWin* GetNativeMenuWinFromHMENU(HMENU hmenu) {
  MENUINFO mi = {0};
  mi.cbSize = sizeof(mi);
  mi.fMask = MIM_MENUDATA | MIM_STYLE;
  GetMenuInfo(hmenu, &mi);
  return reinterpret_cast<NativeMenuWin*>(mi.dwMenuData);
}

// A window that receives messages from Windows relevant to the native menu
// structure we have constructed in NativeMenuWin.
class NativeMenuWin::MenuHostWindow {
 public:
  explicit MenuHostWindow(NativeMenuWin* parent) : parent_(parent) {
    RegisterClass();
    hwnd_ = CreateWindowEx(l10n_util::GetExtendedStyles(), kWindowClassName,
                           L"", 0, 0, 0, 0, 0, HWND_MESSAGE, NULL, NULL, NULL);
    gfx::CheckWindowCreated(hwnd_);
    gfx::SetWindowUserData(hwnd_, this);
  }

  ~MenuHostWindow() {
    DestroyWindow(hwnd_);
  }

  HWND hwnd() const { return hwnd_; }

 private:
  static const wchar_t* kWindowClassName;

  void RegisterClass() {
    static bool registered = false;
    if (registered)
      return;

    WNDCLASSEX window_class;
    base::win::InitializeWindowClass(
        kWindowClassName,
        &base::win::WrappedWindowProc<MenuHostWindowProc>,
        CS_DBLCLKS,
        0,
        0,
        NULL,
        reinterpret_cast<HBRUSH>(COLOR_WINDOW+1),
        NULL,
        NULL,
        NULL,
        &window_class);
    ATOM clazz = RegisterClassEx(&window_class);
    CHECK(clazz);
    registered = true;
  }

  // Converts the WPARAM value passed to WM_MENUSELECT into an index
  // corresponding to the menu item that was selected.
  int GetMenuItemIndexFromWPARAM(HMENU menu, WPARAM w_param) const {
    int count = GetMenuItemCount(menu);
    // For normal command menu items, Windows passes a command id as the LOWORD
    // of WPARAM for WM_MENUSELECT. We need to walk forward through the menu
    // items to find an item with a matching ID. Ugh!
    for (int i = 0; i < count; ++i) {
      MENUITEMINFO mii = {0};
      mii.cbSize = sizeof(mii);
      mii.fMask = MIIM_ID;
      GetMenuItemInfo(menu, i, MF_BYPOSITION, &mii);
      if (mii.wID == w_param)
        return i;
    }
    // If we didn't find a matching command ID, this means a submenu has been
    // selected instead, and rather than passing a command ID in
    // LOWORD(w_param), Windows has actually passed us a position, so we just
    // return it.
    return w_param;
  }

  NativeMenuWin::ItemData* GetItemData(ULONG_PTR item_data) {
    return reinterpret_cast<NativeMenuWin::ItemData*>(item_data);
  }

  // Called when the user selects a specific item.
  void OnMenuCommand(int position, HMENU menu) {
    NativeMenuWin* menu_win = GetNativeMenuWinFromHMENU(menu);
    ui::MenuModel* model = menu_win->model_;
    NativeMenuWin* root_menu = menu_win;
    while (root_menu->parent_)
      root_menu = root_menu->parent_;

    // Only notify the model if it didn't already send out notification.
    // See comment in MenuMessageHook for details.
    if (root_menu->menu_action_ == MenuWrapper::MENU_ACTION_NONE)
      model->ActivatedAt(position);
  }

  // Called as the user moves their mouse or arrows through the contents of the
  // menu.
  void OnMenuSelect(WPARAM w_param, HMENU menu) {
    if (!menu)
      return;  // menu is null when closing on XP.

    int position = GetMenuItemIndexFromWPARAM(menu, w_param);
    if (position >= 0)
      GetNativeMenuWinFromHMENU(menu)->model_->HighlightChangedTo(position);
  }

  // Called by Windows to measure the size of an owner-drawn menu item.
  void OnMeasureItem(WPARAM w_param, MEASUREITEMSTRUCT* measure_item_struct) {
    NativeMenuWin::ItemData* data = GetItemData(measure_item_struct->itemData);
    if (data) {
      gfx::FontList font_list;
      measure_item_struct->itemWidth =
          gfx::GetStringWidth(data->label, font_list) +
          kIconWidth + kItemLeftMargin + views::kItemLabelSpacing -
          GetSystemMetrics(SM_CXMENUCHECK);
      if (data->submenu.get())
        measure_item_struct->itemWidth += kArrowWidth;
      // If the label contains an accelerator, make room for tab.
      if (data->label.find(L'\t') != base::string16::npos)
        measure_item_struct->itemWidth += gfx::GetStringWidth(L" ", font_list);
      measure_item_struct->itemHeight =
          font_list.GetHeight() + kItemBottomMargin + kItemTopMargin;
    } else {
      // Measure separator size.
      measure_item_struct->itemHeight = GetSystemMetrics(SM_CYMENU) / 2;
      measure_item_struct->itemWidth = 0;
    }
  }

  // Called by Windows to paint an owner-drawn menu item.
  void OnDrawItem(UINT w_param, DRAWITEMSTRUCT* draw_item_struct) {
    HDC dc = draw_item_struct->hDC;
    COLORREF prev_bg_color, prev_text_color;

    // Set background color and text color
    if (draw_item_struct->itemState & ODS_SELECTED) {
      prev_bg_color = SetBkColor(dc, GetSysColor(COLOR_HIGHLIGHT));
      prev_text_color = SetTextColor(dc, GetSysColor(COLOR_HIGHLIGHTTEXT));
    } else {
      prev_bg_color = SetBkColor(dc, GetSysColor(COLOR_MENU));
      if (draw_item_struct->itemState & ODS_DISABLED)
        prev_text_color = SetTextColor(dc, GetSysColor(COLOR_GRAYTEXT));
      else
        prev_text_color = SetTextColor(dc, GetSysColor(COLOR_MENUTEXT));
    }

    if (draw_item_struct->itemData) {
      NativeMenuWin::ItemData* data = GetItemData(draw_item_struct->itemData);
      // Draw the background.
      HBRUSH hbr = CreateSolidBrush(GetBkColor(dc));
      FillRect(dc, &draw_item_struct->rcItem, hbr);
      DeleteObject(hbr);

      // Draw the label.
      RECT rect = draw_item_struct->rcItem;
      rect.top += kItemTopMargin;
      // Should we add kIconWidth only when icon.width() != 0 ?
      rect.left += kItemLeftMargin + kIconWidth;
      rect.right -= views::kItemLabelSpacing;
      UINT format = DT_TOP | DT_SINGLELINE;
      // Check whether the mnemonics should be underlined.
      BOOL underline_mnemonics;
      SystemParametersInfo(SPI_GETKEYBOARDCUES, 0, &underline_mnemonics, 0);
      if (!underline_mnemonics)
        format |= DT_HIDEPREFIX;
      gfx::FontList font_list;
      HGDIOBJ old_font = static_cast<HFONT>(
          SelectObject(dc, font_list.GetPrimaryFont().GetNativeFont()));

      // If an accelerator is specified (with a tab delimiting the rest of the
      // label from the accelerator), we have to justify the fist part on the
      // left and the accelerator on the right.
      // TODO(jungshik): This will break in RTL UI. Currently, he/ar use the
      //                 window system UI font and will not hit here.
      base::string16 label = data->label;
      base::string16 accel;
      base::string16::size_type tab_pos = label.find(L'\t');
      if (tab_pos != base::string16::npos) {
        accel = label.substr(tab_pos);
        label = label.substr(0, tab_pos);
      }
      DrawTextEx(dc, const_cast<wchar_t*>(label.data()),
                 static_cast<int>(label.size()), &rect, format | DT_LEFT, NULL);
      if (!accel.empty())
        DrawTextEx(dc, const_cast<wchar_t*>(accel.data()),
                   static_cast<int>(accel.size()), &rect,
                   format | DT_RIGHT, NULL);
      SelectObject(dc, old_font);

      ui::MenuModel::ItemType type =
          data->native_menu_win->model_->GetTypeAt(data->model_index);

      // Draw the icon after the label, otherwise it would be covered
      // by the label.
      gfx::Image icon;
      if (data->native_menu_win->model_->GetIconAt(data->model_index, &icon)) {
        // We currently don't support items with both icons and checkboxes.
        const gfx::ImageSkia* skia_icon = icon.ToImageSkia();
        DCHECK(type != ui::MenuModel::TYPE_CHECK);
        gfx::Canvas canvas(
            skia_icon->GetRepresentation(1.0f),
            false);
        skia::DrawToNativeContext(
            canvas.sk_canvas(), dc,
            draw_item_struct->rcItem.left + kItemLeftMargin,
            draw_item_struct->rcItem.top + (draw_item_struct->rcItem.bottom -
                draw_item_struct->rcItem.top - skia_icon->height()) / 2, NULL);
      } else if (type == ui::MenuModel::TYPE_CHECK &&
                 data->native_menu_win->model_->IsItemCheckedAt(
                     data->model_index)) {
        // Manually render a checkbox.
        ui::NativeThemeWin* native_theme = ui::NativeThemeWin::instance();
        const MenuConfig& config = MenuConfig::instance(native_theme);
        NativeTheme::State state;
        if (draw_item_struct->itemState & ODS_DISABLED) {
          state = NativeTheme::kDisabled;
        } else {
          state = draw_item_struct->itemState & ODS_SELECTED ?
              NativeTheme::kHovered : NativeTheme::kNormal;
        }
        int height =
            draw_item_struct->rcItem.bottom - draw_item_struct->rcItem.top;
        int icon_y = kItemTopMargin +
            (height - kItemTopMargin - kItemBottomMargin -
             config.check_height) / 2;
        gfx::Canvas canvas(gfx::Size(config.check_width, config.check_height),
                           1.0f,
                           false);
        NativeTheme::ExtraParams extra;
        extra.menu_check.is_radio = false;
        gfx::Rect bounds(0, 0, config.check_width, config.check_height);

        // Draw the background and the check.
        native_theme->Paint(
            canvas.sk_canvas(), NativeTheme::kMenuCheckBackground,
            state, bounds, extra);
        native_theme->Paint(
            canvas.sk_canvas(), NativeTheme::kMenuCheck, state, bounds, extra);

        // Draw checkbox to menu.
        skia::DrawToNativeContext(canvas.sk_canvas(), dc,
            draw_item_struct->rcItem.left + kItemLeftMargin,
            draw_item_struct->rcItem.top + (draw_item_struct->rcItem.bottom -
                draw_item_struct->rcItem.top - config.check_height) / 2, NULL);
      }

    } else {
      // Draw the separator
      draw_item_struct->rcItem.top +=
          (draw_item_struct->rcItem.bottom - draw_item_struct->rcItem.top) / 3;
      DrawEdge(dc, &draw_item_struct->rcItem, EDGE_ETCHED, BF_TOP);
    }

    SetBkColor(dc, prev_bg_color);
    SetTextColor(dc, prev_text_color);
  }

  bool ProcessWindowMessage(HWND window,
                            UINT message,
                            WPARAM w_param,
                            LPARAM l_param,
                            LRESULT* l_result) {
    switch (message) {
      case WM_MENUCOMMAND:
        OnMenuCommand(w_param, reinterpret_cast<HMENU>(l_param));
        *l_result = 0;
        return true;
      case WM_MENUSELECT:
        OnMenuSelect(LOWORD(w_param), reinterpret_cast<HMENU>(l_param));
        *l_result = 0;
        return true;
      case WM_MEASUREITEM:
        OnMeasureItem(w_param, reinterpret_cast<MEASUREITEMSTRUCT*>(l_param));
        *l_result = 0;
        return true;
      case WM_DRAWITEM:
        OnDrawItem(w_param, reinterpret_cast<DRAWITEMSTRUCT*>(l_param));
        *l_result = 0;
        return true;
      // TODO(beng): bring over owner draw from old menu system.
    }
    return false;
  }

  static LRESULT CALLBACK MenuHostWindowProc(HWND window,
                                             UINT message,
                                             WPARAM w_param,
                                             LPARAM l_param) {
    MenuHostWindow* host =
        reinterpret_cast<MenuHostWindow*>(gfx::GetWindowUserData(window));
    // host is null during initial construction.
    LRESULT l_result = 0;
    if (!host || !host->ProcessWindowMessage(window, message, w_param, l_param,
                                             &l_result)) {
      return DefWindowProc(window, message, w_param, l_param);
    }
    return l_result;
  }

  HWND hwnd_;
  NativeMenuWin* parent_;

  DISALLOW_COPY_AND_ASSIGN(MenuHostWindow);
};

struct NativeMenuWin::HighlightedMenuItemInfo {
  HighlightedMenuItemInfo()
      : has_parent(false),
        has_submenu(false),
        menu(NULL),
        position(-1) {
  }

  bool has_parent;
  bool has_submenu;

  // The menu and position. These are only set for non-disabled menu items.
  NativeMenuWin* menu;
  int position;
};

// static
const wchar_t* NativeMenuWin::MenuHostWindow::kWindowClassName =
    L"ViewsMenuHostWindow";

////////////////////////////////////////////////////////////////////////////////
// NativeMenuWin, public:

NativeMenuWin::NativeMenuWin(ui::MenuModel* model, HWND system_menu_for)
    : model_(model),
      menu_(NULL),
      owner_draw_(l10n_util::NeedOverrideDefaultUIFont(NULL, NULL) &&
                  !system_menu_for),
      system_menu_for_(system_menu_for),
      first_item_index_(0),
      menu_action_(MENU_ACTION_NONE),
      menu_to_select_(NULL),
      position_to_select_(-1),
      menu_to_select_factory_(this),
      parent_(NULL),
      destroyed_flag_(NULL) {
}

NativeMenuWin::~NativeMenuWin() {
  if (destroyed_flag_)
    *destroyed_flag_ = true;
  STLDeleteContainerPointers(items_.begin(), items_.end());
  DestroyMenu(menu_);
}

////////////////////////////////////////////////////////////////////////////////
// NativeMenuWin, MenuWrapper implementation:

void NativeMenuWin::RunMenuAt(const gfx::Point& point, int alignment) {
  CreateHostWindow();
  UpdateStates();
  UINT flags = TPM_LEFTBUTTON | TPM_RIGHTBUTTON | TPM_RECURSE;
  flags |= GetAlignmentFlags(alignment);
  menu_action_ = MENU_ACTION_NONE;

  // Set a hook function so we can listen for keyboard events while the
  // menu is open, and store a pointer to this object in a static
  // variable so the hook has access to it (ugly, but it's the
  // only way).
  open_native_menu_win_ = this;
  HHOOK hhook = SetWindowsHookEx(WH_MSGFILTER, MenuMessageHook,
                                 GetModuleHandle(NULL), ::GetCurrentThreadId());

  // Mark that any registered listeners have not been called for this particular
  // opening of the menu.
  listeners_called_ = false;

  // Command dispatch is done through WM_MENUCOMMAND, handled by the host
  // window.
  HWND hwnd = host_window_->hwnd();
  menu_to_select_ = NULL;
  position_to_select_ = -1;
  menu_to_select_factory_.InvalidateWeakPtrs();
  bool destroyed = false;
  destroyed_flag_ = &destroyed;
  model_->MenuWillShow();
  TrackPopupMenu(menu_, flags, point.x(), point.y(), 0, host_window_->hwnd(),
                 NULL);
  UnhookWindowsHookEx(hhook);
  open_native_menu_win_ = NULL;
  if (destroyed)
    return;
  destroyed_flag_ = NULL;
  if (menu_to_select_) {
    // Folks aren't too happy if we notify immediately. In particular, notifying
    // the delegate can cause destruction leaving the stack in a weird
    // state. Instead post a task, then notify. This mirrors what WM_MENUCOMMAND
    // does.
    menu_to_select_factory_.InvalidateWeakPtrs();
    base::MessageLoop::current()->PostTask(
        FROM_HERE,
        base::Bind(&NativeMenuWin::DelayedSelect,
                   menu_to_select_factory_.GetWeakPtr()));
    menu_action_ = MENU_ACTION_SELECTED;
  }
  // Send MenuClosed after we schedule the select, otherwise MenuClosed is
  // processed after the select (MenuClosed posts a delayed task too).
  model_->MenuClosed();
}

void NativeMenuWin::CancelMenu() {
  EndMenu();
}

void NativeMenuWin::Rebuild(MenuInsertionDelegateWin* delegate) {
  ResetNativeMenu();
  items_.clear();

  owner_draw_ = model_->HasIcons() || owner_draw_;
  first_item_index_ = delegate ? delegate->GetInsertionIndex(menu_) : 0;
  for (int menu_index = first_item_index_;
        menu_index < first_item_index_ + model_->GetItemCount(); ++menu_index) {
    int model_index = menu_index - first_item_index_;
    if (model_->GetTypeAt(model_index) == ui::MenuModel::TYPE_SEPARATOR)
      AddSeparatorItemAt(menu_index, model_index);
    else
      AddMenuItemAt(menu_index, model_index);
  }
}

void NativeMenuWin::UpdateStates() {
  // A depth-first walk of the menu items, updating states.
  int model_index = 0;
  std::vector<ItemData*>::const_iterator it;
  for (it = items_.begin(); it != items_.end(); ++it, ++model_index) {
    int menu_index = model_index + first_item_index_;
    SetMenuItemState(menu_index, model_->IsEnabledAt(model_index),
                     model_->IsItemCheckedAt(model_index), false);
    if (model_->IsItemDynamicAt(model_index)) {
      // TODO(atwilson): Update the icon as well (http://crbug.com/66508).
      SetMenuItemLabel(menu_index, model_index,
                       model_->GetLabelAt(model_index));
    }
    Menu2* submenu = (*it)->submenu.get();
    if (submenu)
      submenu->UpdateStates();
  }
}

HMENU NativeMenuWin::GetNativeMenu() const {
  return menu_;
}

NativeMenuWin::MenuAction NativeMenuWin::GetMenuAction() const {
  return menu_action_;
}

void NativeMenuWin::AddMenuListener(MenuListener* listener) {
  listeners_.AddObserver(listener);
}

void NativeMenuWin::RemoveMenuListener(MenuListener* listener) {
  listeners_.RemoveObserver(listener);
}

void NativeMenuWin::SetMinimumWidth(int width) {
  NOTIMPLEMENTED();
}

////////////////////////////////////////////////////////////////////////////////
// NativeMenuWin, private:

// static
NativeMenuWin* NativeMenuWin::open_native_menu_win_ = NULL;

void NativeMenuWin::DelayedSelect() {
  if (menu_to_select_)
    menu_to_select_->model_->ActivatedAt(position_to_select_);
}

// static
bool NativeMenuWin::GetHighlightedMenuItemInfo(
    HMENU menu,
    HighlightedMenuItemInfo* info) {
  for (int i = 0; i < ::GetMenuItemCount(menu); i++) {
    UINT state = ::GetMenuState(menu, i, MF_BYPOSITION);
    if (state & MF_HILITE) {
      if (state & MF_POPUP) {
        HMENU submenu = GetSubMenu(menu, i);
        if (GetHighlightedMenuItemInfo(submenu, info))
          info->has_parent = true;
        else
          info->has_submenu = true;
      } else if (!(state & MF_SEPARATOR) && !(state & MF_DISABLED)) {
        info->menu = GetNativeMenuWinFromHMENU(menu);
        info->position = i;
      }
      return true;
    }
  }
  return false;
}

// static
LRESULT CALLBACK NativeMenuWin::MenuMessageHook(
    int n_code, WPARAM w_param, LPARAM l_param) {
  LRESULT result = CallNextHookEx(NULL, n_code, w_param, l_param);

  NativeMenuWin* this_ptr = open_native_menu_win_;
  if (!this_ptr)
    return result;

  // The first time this hook is called, that means the menu has successfully
  // opened, so call the callback function on all of our listeners.
  if (!this_ptr->listeners_called_) {
    FOR_EACH_OBSERVER(MenuListener, this_ptr->listeners_, OnMenuOpened());
    this_ptr->listeners_called_ = true;
  }

  MSG* msg = reinterpret_cast<MSG*>(l_param);
  if (msg->message == WM_LBUTTONUP || msg->message == WM_RBUTTONUP) {
    HighlightedMenuItemInfo info;
    if (GetHighlightedMenuItemInfo(this_ptr->menu_, &info) && info.menu) {
      // It appears that when running a menu by way of TrackPopupMenu(Ex) win32
      // gets confused if the underlying window paints itself. As its very easy
      // for the underlying window to repaint itself (especially since some menu
      // items trigger painting of the tabstrip on mouse over) we have this
      // workaround. When the mouse is released on a menu item we remember the
      // menu item and end the menu. When the nested message loop returns we
      // schedule a task to notify the model. It's still possible to get a
      // WM_MENUCOMMAND, so we have to be careful that we don't notify the model
      // twice.
      this_ptr->menu_to_select_ = info.menu;
      this_ptr->position_to_select_ = info.position;
      EndMenu();
    }
  } else if (msg->message == WM_KEYDOWN) {
    HighlightedMenuItemInfo info;
    if (GetHighlightedMenuItemInfo(this_ptr->menu_, &info)) {
      if (msg->wParam == VK_LEFT && !info.has_parent) {
        this_ptr->menu_action_ = MENU_ACTION_PREVIOUS;
        ::EndMenu();
      } else if (msg->wParam == VK_RIGHT && !info.has_parent &&
                 !info.has_submenu) {
        this_ptr->menu_action_ = MENU_ACTION_NEXT;
        ::EndMenu();
      }
    }
  }

  return result;
}

bool NativeMenuWin::IsSeparatorItemAt(int menu_index) const {
  MENUITEMINFO mii = {0};
  mii.cbSize = sizeof(mii);
  mii.fMask = MIIM_FTYPE;
  GetMenuItemInfo(menu_, menu_index, MF_BYPOSITION, &mii);
  return !!(mii.fType & MF_SEPARATOR);
}

void NativeMenuWin::AddMenuItemAt(int menu_index, int model_index) {
  MENUITEMINFO mii = {0};
  mii.cbSize = sizeof(mii);
  mii.fMask = MIIM_FTYPE | MIIM_ID | MIIM_DATA;
  if (!owner_draw_)
    mii.fType = MFT_STRING;
  else
    mii.fType = MFT_OWNERDRAW;

  ItemData* item_data = new ItemData;
  item_data->label = base::string16();
  ui::MenuModel::ItemType type = model_->GetTypeAt(model_index);
  if (type == ui::MenuModel::TYPE_SUBMENU) {
    item_data->submenu.reset(new Menu2(model_->GetSubmenuModelAt(model_index)));
    mii.fMask |= MIIM_SUBMENU;
    mii.hSubMenu = item_data->submenu->GetNativeMenu();
    GetNativeMenuWinFromHMENU(mii.hSubMenu)->parent_ = this;
  } else {
    if (type == ui::MenuModel::TYPE_RADIO)
      mii.fType |= MFT_RADIOCHECK;
    mii.wID = model_->GetCommandIdAt(model_index);
  }
  item_data->native_menu_win = this;
  item_data->model_index = model_index;
  items_.insert(items_.begin() + model_index, item_data);
  mii.dwItemData = reinterpret_cast<ULONG_PTR>(item_data);
  UpdateMenuItemInfoForString(&mii, model_index,
                              model_->GetLabelAt(model_index));
  InsertMenuItem(menu_, menu_index, TRUE, &mii);
}

void NativeMenuWin::AddSeparatorItemAt(int menu_index, int model_index) {
  MENUITEMINFO mii = {0};
  mii.cbSize = sizeof(mii);
  mii.fMask = MIIM_FTYPE;
  mii.fType = MFT_SEPARATOR;
  // Insert a dummy entry into our label list so we can index directly into it
  // using item indices if need be.
  items_.insert(items_.begin() + model_index, new ItemData);
  InsertMenuItem(menu_, menu_index, TRUE, &mii);
}

void NativeMenuWin::SetMenuItemState(int menu_index, bool enabled, bool checked,
                                     bool is_default) {
  if (IsSeparatorItemAt(menu_index))
    return;

  UINT state = enabled ? MFS_ENABLED : MFS_DISABLED;
  if (checked)
    state |= MFS_CHECKED;
  if (is_default)
    state |= MFS_DEFAULT;

  MENUITEMINFO mii = {0};
  mii.cbSize = sizeof(mii);
  mii.fMask = MIIM_STATE;
  mii.fState = state;
  SetMenuItemInfo(menu_, menu_index, MF_BYPOSITION, &mii);
}

void NativeMenuWin::SetMenuItemLabel(int menu_index,
                                     int model_index,
                                     const base::string16& label) {
  if (IsSeparatorItemAt(menu_index))
    return;

  MENUITEMINFO mii = {0};
  mii.cbSize = sizeof(mii);
  UpdateMenuItemInfoForString(&mii, model_index, label);
  SetMenuItemInfo(menu_, menu_index, MF_BYPOSITION, &mii);
}

void NativeMenuWin::UpdateMenuItemInfoForString(MENUITEMINFO* mii,
                                                int model_index,
                                                const base::string16& label) {
  base::string16 formatted = label;
  ui::MenuModel::ItemType type = model_->GetTypeAt(model_index);
  // Strip out any tabs, otherwise they get interpreted as accelerators and can
  // lead to weird behavior.
  ReplaceSubstringsAfterOffset(&formatted, 0, L"\t", L" ");
  if (type != ui::MenuModel::TYPE_SUBMENU) {
    // Add accelerator details to the label if provided.
    ui::Accelerator accelerator(ui::VKEY_UNKNOWN, ui::EF_NONE);
    if (model_->GetAcceleratorAt(model_index, &accelerator)) {
      formatted += L"\t";
      formatted += accelerator.GetShortcutText();
    }
  }

  // Update the owned string, since Windows will want us to keep this new
  // version around.
  items_[model_index]->label = formatted;

  // Give Windows a pointer to the label string.
  mii->fMask |= MIIM_STRING;
  mii->dwTypeData =
      const_cast<wchar_t*>(items_[model_index]->label.c_str());
}

UINT NativeMenuWin::GetAlignmentFlags(int alignment) const {
  UINT alignment_flags = TPM_TOPALIGN;
  if (alignment == Menu2::ALIGN_TOPLEFT)
    alignment_flags |= TPM_LEFTALIGN;
  else if (alignment == Menu2::ALIGN_TOPRIGHT)
    alignment_flags |= TPM_RIGHTALIGN;
  return alignment_flags;
}

void NativeMenuWin::ResetNativeMenu() {
  if (IsWindow(system_menu_for_)) {
    if (menu_)
      GetSystemMenu(system_menu_for_, TRUE);
    menu_ = GetSystemMenu(system_menu_for_, FALSE);
  } else {
    if (menu_)
      DestroyMenu(menu_);
    menu_ = CreatePopupMenu();
    // Rather than relying on the return value of TrackPopupMenuEx, which is
    // always a command identifier, instead we tell the menu to notify us via
    // our host window and the WM_MENUCOMMAND message.
    MENUINFO mi = {0};
    mi.cbSize = sizeof(mi);
    mi.fMask = MIM_STYLE | MIM_MENUDATA;
    mi.dwStyle = MNS_NOTIFYBYPOS;
    mi.dwMenuData = reinterpret_cast<ULONG_PTR>(this);
    SetMenuInfo(menu_, &mi);
  }
}

void NativeMenuWin::CreateHostWindow() {
  // This only gets called from RunMenuAt, and as such there is only ever one
  // host window per menu hierarchy, no matter how many NativeMenuWin objects
  // exist wrapping submenus.
  if (!host_window_.get())
    host_window_.reset(new MenuHostWindow(this));
}

////////////////////////////////////////////////////////////////////////////////
// MenuWrapper, public:

// static
MenuWrapper* MenuWrapper::CreateWrapper(ui::MenuModel* model) {
  return new NativeMenuWin(model, NULL);
}

}  // namespace views

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