ui/views/controls/button/menu_button.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_BUTTON_MENU_BUTTON_H_
   6 #define UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_
   7
   8 #include <string>
   9
  10 #include "base/strings/string16.h"
  11 #include "base/time/time.h"
  12 #include "ui/views/background.h"
  13 #include "ui/views/controls/button/label_button.h"
  14
  15 namespace views {
  16
  17 class MenuButtonListener;
  18
  19 ////////////////////////////////////////////////////////////////////////////////
  20 //
  21 // MenuButton
  22 //
  23 //  A button that shows a menu when the left mouse button is pushed
  24 //
  25 ////////////////////////////////////////////////////////////////////////////////
  26 class VIEWS_EXPORT MenuButton : public LabelButton {
  27  public:
  28   static const char kViewClassName[];
  29
  30   // How much padding to put on the left and right of the menu marker.
  31   static const int kMenuMarkerPaddingLeft;
  32   static const int kMenuMarkerPaddingRight;
  33
  34   // Create a Button.
  35   MenuButton(ButtonListener* listener,
  36              const base::string16& text,
  37              MenuButtonListener* menu_button_listener,
  38              bool show_menu_marker);
  39   virtual ~MenuButton();
  40
  41   bool show_menu_marker() const { return show_menu_marker_; }
  42   void set_menu_marker(const gfx::ImageSkia* menu_marker) {
  43     menu_marker_ = menu_marker;
  44   }
  45   const gfx::ImageSkia* menu_marker() const { return menu_marker_; }
  46
  47   const gfx::Point& menu_offset() const { return menu_offset_; }
  48   void set_menu_offset(int x, int y) { menu_offset_.SetPoint(x, y); }
  49
  50   // Activate the button (called when the button is pressed).
  51   virtual bool Activate();
  52
  53   // Overridden from View:
  54   virtual gfx::Size GetPreferredSize() const OVERRIDE;
  55   virtual const char* GetClassName() const OVERRIDE;
  56   virtual void OnPaint(gfx::Canvas* canvas) OVERRIDE;
  57   virtual bool OnMousePressed(const ui::MouseEvent& event) OVERRIDE;
  58   virtual void OnMouseReleased(const ui::MouseEvent& event) OVERRIDE;
  59   virtual void OnMouseExited(const ui::MouseEvent& event) OVERRIDE;
  60   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
  61   virtual bool OnKeyPressed(const ui::KeyEvent& event) OVERRIDE;
  62   virtual bool OnKeyReleased(const ui::KeyEvent& event) OVERRIDE;
  63   virtual void GetAccessibleState(ui::AXViewState* state) OVERRIDE;
  64
  65  protected:
  66   // Paint the menu marker image.
  67   void PaintMenuMarker(gfx::Canvas* canvas);
  68
  69   // Overridden from LabelButton:
  70   virtual gfx::Rect GetChildAreaBounds() OVERRIDE;
  71
  72   // True if the menu is currently visible.
  73   bool menu_visible_;
  74
  75   // Offset of the associated menu position.
  76   gfx::Point menu_offset_;
  77
  78  private:
  79   // Compute the maximum X coordinate for the current screen. MenuButtons
  80   // use this to make sure a menu is never shown off screen.
  81   int GetMaximumScreenXCoordinate();
  82
  83   // We use a time object in order to keep track of when the menu was closed.
  84   // The time is used for simulating menu behavior for the menu button; that
  85   // is, if the menu is shown and the button is pressed, we need to close the
  86   // menu. There is no clean way to get the second click event because the
  87   // menu is displayed using a modal loop and, unlike regular menus in Windows,
  88   // the button is not part of the displayed menu.
  89   base::TimeTicks menu_closed_time_;
  90
  91   // Our listener. Not owned.
  92   MenuButtonListener* listener_;
  93
  94   // Whether or not we're showing a drop marker.
  95   bool show_menu_marker_;
  96
  97   // The down arrow used to differentiate the menu button from normal buttons.
  98   const gfx::ImageSkia* menu_marker_;
  99
 100   // If non-null the destuctor sets this to true. This is set while the menu is
 101   // showing and used to detect if the menu was deleted while running.
 102   bool* destroyed_flag_;
 103
 104   DISALLOW_COPY_AND_ASSIGN(MenuButton);
 105 };
 106
 107 }  // namespace views
 108
 109 #endif  // UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_