ui/views/cocoa/cocoa_mouse_capture.h

   1 // Copyright 2014 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_COCOA_COCOA_MOUSE_CAPTURE_H_
   6 #define UI_VIEWS_COCOA_COCOA_MOUSE_CAPTURE_H_
   7
   8 #include "base/macros.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "ui/views/views_export.h"
  11
  12 namespace views {
  13
  14 class CocoaMouseCaptureDelegate;
  15
  16 // Basic mouse capture to simulate ::SetCapture() from Windows. This is used to
  17 // support menu widgets (e.g. on Combo boxes). Clicking anywhere other than the
  18 // menu should dismiss the menu and "swallow" the mouse event. All events are
  19 // forwarded, but only events to the same application are "swallowed", which is
  20 // consistent with how native NSMenus behave.
  21 class VIEWS_EXPORT CocoaMouseCapture {
  22  public:
  23   explicit CocoaMouseCapture(CocoaMouseCaptureDelegate* delegate);
  24   ~CocoaMouseCapture();
  25
  26   // True if the event tap is active (i.e. not stolen by a later instance).
  27   bool IsActive() const { return active_handle_; }
  28
  29  private:
  30   class ActiveEventTap;
  31
  32   // Deactivates the event tap if still active.
  33   void OnOtherClientGotCapture();
  34
  35   CocoaMouseCaptureDelegate* delegate_;  // Weak. Owns this.
  36
  37   // The active event tap for this capture. Owned by this, but can be cleared
  38   // out early if another instance of CocoaMouseCapture is created.
  39   scoped_ptr<ActiveEventTap> active_handle_;
  40
  41   DISALLOW_COPY_AND_ASSIGN(CocoaMouseCapture);
  42 };
  43
  44 }  // namespace views
  45
  46 #endif  // UI_VIEWS_COCOA_COCOA_MOUSE_CAPTURE_H_