content/renderer/mouse_lock_dispatcher.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 CONTENT_RENDERER_MOUSE_LOCK_DISPATCHER_H_
   6 #define CONTENT_RENDERER_MOUSE_LOCK_DISPATCHER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "content/common/content_export.h"
  10
  11 namespace WebKit {
  12 class WebMouseEvent;
  13 }  // namespace WebKit
  14
  15 namespace content {
  16
  17 class CONTENT_EXPORT MouseLockDispatcher {
  18  public:
  19   MouseLockDispatcher();
  20   virtual ~MouseLockDispatcher();
  21
  22   class LockTarget {
  23    public:
  24     virtual ~LockTarget() {}
  25     // A mouse lock request was pending and this reports success or failure.
  26     virtual void OnLockMouseACK(bool succeeded) = 0;
  27     // A mouse lock was in place, but has been lost.
  28     virtual void OnMouseLockLost() = 0;
  29     // A mouse lock is enabled and mouse events are being delievered.
  30     virtual bool HandleMouseLockedInputEvent(
  31         const WebKit::WebMouseEvent& event) = 0;
  32   };
  33
  34   // Locks the mouse to the |target|. If true is returned, an asynchronous
  35   // response to target->OnLockMouseACK() will follow.
  36   bool LockMouse(LockTarget* target);
  37   // Request to unlock the mouse. An asynchronous response to
  38   // target->OnMouseLockLost() will follow.
  39   void UnlockMouse(LockTarget* target);
  40   // Clears out the reference to the |target| because it has or is being
  41   // destroyed. Unlocks if locked. The pointer will not be accessed.
  42   void OnLockTargetDestroyed(LockTarget* target);
  43   bool IsMouseLockedTo(LockTarget* target);
  44
  45   // Allow lock target to consumed a mouse event, if it does return true.
  46   bool WillHandleMouseEvent(const WebKit::WebMouseEvent& event);
  47
  48   // Subclasses or users have to call these methods to report mouse lock events
  49   // from the browser.
  50   void OnLockMouseACK(bool succeeded);
  51   void OnMouseLockLost();
  52
  53  protected:
  54   // Subclasses must implement these methods to send mouse lock requests to the
  55   // browser.
  56   virtual void SendLockMouseRequest(bool unlocked_by_target) = 0;
  57   virtual void SendUnlockMouseRequest() = 0;
  58
  59  private:
  60   bool MouseLockedOrPendingAction() const {
  61     return mouse_locked_ || pending_lock_request_ || pending_unlock_request_;
  62   }
  63
  64   bool mouse_locked_;
  65   // If both |pending_lock_request_| and |pending_unlock_request_| are true,
  66   // it means a lock request was sent before an unlock request and we haven't
  67   // received responses for them. The logic in LockMouse() makes sure that a
  68   // lock request won't be sent when there is a pending unlock request.
  69   bool pending_lock_request_;
  70   bool pending_unlock_request_;
  71
  72   // Used when locking to indicate when a target application has voluntarily
  73   // unlocked and desires to relock the mouse. If the mouse is unlocked due
  74   // to ESC being pressed by the user, this will be false
  75   bool unlocked_by_target_;
  76
  77   // |target_| is the pending or current owner of mouse lock. We retain a non
  78   // owning reference here that must be cleared by |OnLockTargetDestroyed|
  79   // when it is destroyed.
  80   LockTarget* target_;
  81
  82   DISALLOW_COPY_AND_ASSIGN(MouseLockDispatcher);
  83 };
  84
  85 }  // namespace content
  86
  87 #endif  // CONTENT_RENDERER_MOUSE_LOCK_DISPATCHER_H_