chrome/browser/ui/cocoa/wrench_menu/menu_tracked_button.h

   1 // Copyright (c) 2010 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 CHROME_BROWSER_UI_COCOA_WRENCH_MENU_MENU_TRACKED_BUTTON_H_
   6 #define CHROME_BROWSER_UI_COCOA_WRENCH_MENU_MENU_TRACKED_BUTTON_H_
   7
   8 #import <Cocoa/Cocoa.h>
   9
  10 // A MenuTrackedButton is meant to be used whenever a button is placed inside
  11 // the custom view of an NSMenuItem. If the user opens the menu in a non-sticky
  12 // fashion (i.e. clicks, holds, and drags) and then releases the mouse over
  13 // a MenuTrackedButton, it will |-performClick:| itself.
  14 //
  15 // To create the hover state effects, there are two code paths.  When the menu
  16 // is opened sticky, a tracking rect produces mouse entered/exit events that
  17 // allow for setting the cell's highlight property.  When in a drag cycle,
  18 // however, the only event received is |-mouseDragged:|.  Therefore, a
  19 // delayed selector is scheduled to poll the mouse location after each drag
  20 // event.  This checks if the user is still over the button after the drag
  21 // events stop being sent, indicating either the user is hovering without
  22 // movement or that the mouse is no longer over the receiver.
  23 @interface MenuTrackedButton : NSButton {
  24  @private
  25   // If the button received a |-mouseEntered:| event. This short-circuits the
  26   // custom drag tracking logic.
  27   BOOL didEnter_;
  28
  29   // Whether or not the user is in a click-drag-release event sequence. If so
  30   // and this receives a |-mouseUp:|, then this will click itself.
  31   BOOL tracking_;
  32
  33   // In order to get hover effects when the menu is sticky-opened, a tracking
  34   // rect needs to be installed on the button.
  35   NSTrackingRectTag trackingTag_;
  36 }
  37
  38 @property(nonatomic, readonly, getter=isTracking) BOOL tracking;
  39
  40 @end
  41
  42 #endif  // CHROME_BROWSER_UI_COCOA_WRENCH_MENU_MENU_TRACKED_BUTTON_H_