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/memory/weak_ptr.h"
  11 #include "base/strings/string16.h"
  12 #include "base/time/time.h"
  13 #include "ui/views/background.h"
  14 #include "ui/views/controls/button/label_button.h"
  15
  16 namespace views {
  17
  18 class MenuButtonListener;
  19
  20 ////////////////////////////////////////////////////////////////////////////////
  21 //
  22 // MenuButton
  23 //
  24 //  A button that shows a menu when the left mouse button is pushed
  25 //
  26 ////////////////////////////////////////////////////////////////////////////////
  27 class VIEWS_EXPORT MenuButton : public LabelButton {
  28  public:
  29   // A scoped lock for keeping the MenuButton in STATE_PRESSED e.g., while a
  30   // menu is running. These are cumulative.
  31   class VIEWS_EXPORT PressedLock {
  32    public:
  33     explicit PressedLock(MenuButton* menu_button);
  34     ~PressedLock();
  35
  36    private:
  37     base::WeakPtr<MenuButton> menu_button_;
  38
  39     DISALLOW_COPY_AND_ASSIGN(PressedLock);
  40   };
  41
  42   static const char kViewClassName[];
  43
  44   // How much padding to put on the left and right of the menu marker.
  45   static const int kMenuMarkerPaddingLeft;
  46   static const int kMenuMarkerPaddingRight;
  47
  48   // Create a Button.
  49   MenuButton(ButtonListener* listener,
  50              const base::string16& text,
  51              MenuButtonListener* menu_button_listener,
  52              bool show_menu_marker);
  53   ~MenuButton() override;
  54
  55   bool show_menu_marker() const { return show_menu_marker_; }
  56   void set_menu_marker(const gfx::ImageSkia* menu_marker) {
  57     menu_marker_ = menu_marker;
  58   }
  59   const gfx::ImageSkia* menu_marker() const { return menu_marker_; }
  60
  61   const gfx::Point& menu_offset() const { return menu_offset_; }
  62   void set_menu_offset(int x, int y) { menu_offset_.SetPoint(x, y); }
  63
  64   // Activate the button (called when the button is pressed).
  65   virtual bool Activate();
  66
  67   // Overridden from View:
  68   gfx::Size GetPreferredSize() const override;
  69   const char* GetClassName() const override;
  70   void OnPaint(gfx::Canvas* canvas) override;
  71   bool OnMousePressed(const ui::MouseEvent& event) override;
  72   void OnMouseReleased(const ui::MouseEvent& event) override;
  73   void OnMouseEntered(const ui::MouseEvent& event) override;
  74   void OnMouseExited(const ui::MouseEvent& event) override;
  75   void OnMouseMoved(const ui::MouseEvent& event) override;
  76   void OnGestureEvent(ui::GestureEvent* event) override;
  77   bool OnKeyPressed(const ui::KeyEvent& event) override;
  78   bool OnKeyReleased(const ui::KeyEvent& event) override;
  79   void GetAccessibleState(ui::AXViewState* state) override;
  80
  81  protected:
  82   // Paint the menu marker image.
  83   void PaintMenuMarker(gfx::Canvas* canvas);
  84
  85   // Overridden from LabelButton:
  86   gfx::Rect GetChildAreaBounds() override;
  87
  88   // Overridden from CustomButton:
  89   bool ShouldEnterPushedState(const ui::Event& event) override;
  90   void StateChanged() override;
  91
  92   // Offset of the associated menu position.
  93   gfx::Point menu_offset_;
  94
  95  private:
  96   friend class PressedLock;
  97
  98   // Increment/decrement the number of "pressed" locks this button has, and
  99   // set the state accordingly.
 100   void IncrementPressedLocked();
 101   void DecrementPressedLocked();
 102
 103   // Compute the maximum X coordinate for the current screen. MenuButtons
 104   // use this to make sure a menu is never shown off screen.
 105   int GetMaximumScreenXCoordinate();
 106
 107   // We use a time object in order to keep track of when the menu was closed.
 108   // The time is used for simulating menu behavior for the menu button; that
 109   // is, if the menu is shown and the button is pressed, we need to close the
 110   // menu. There is no clean way to get the second click event because the
 111   // menu is displayed using a modal loop and, unlike regular menus in Windows,
 112   // the button is not part of the displayed menu.
 113   base::TimeTicks menu_closed_time_;
 114
 115   // Our listener. Not owned.
 116   MenuButtonListener* listener_;
 117
 118   // Whether or not we're showing a drop marker.
 119   bool show_menu_marker_;
 120
 121   // The down arrow used to differentiate the menu button from normal buttons.
 122   const gfx::ImageSkia* menu_marker_;
 123
 124   // If non-null the destuctor sets this to true. This is set while the menu is
 125   // showing and used to detect if the menu was deleted while running.
 126   bool* destroyed_flag_;
 127
 128   // The current number of "pressed" locks this button has.
 129   int pressed_lock_count_;
 130
 131   // True if the button was in a disabled state when a menu was run, and should
 132   // return to it once the press is complete. This can happen if, e.g., we
 133   // programmatically show a menu on a disabled button.
 134   bool should_disable_after_press_;
 135
 136   base::WeakPtrFactory<MenuButton> weak_factory_;
 137
 138   DISALLOW_COPY_AND_ASSIGN(MenuButton);
 139 };
 140
 141 }  // namespace views
 142
 143 #endif  // UI_VIEWS_CONTROLS_BUTTON_MENU_BUTTON_H_