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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef PPAPI_CPP_MOUSE_LOCK_H_
#define PPAPI_CPP_MOUSE_LOCK_H_
#include "ppapi/c/pp_stdint.h"
#include "ppapi/cpp/instance_handle.h"
/// @file
/// This file defines the API for locking the target of mouse events to a
/// specific module instance.
namespace pp {
class CompletionCallback;
class Instance;
/// This class allows you to associate the <code>PPP_MouseLock</code> and
/// <code>PPB_MouseLock</code> C-based interfaces with an object. It associates
/// itself with the given instance, and registers as the global handler for
/// handling the <code>PPP_MouseLock</code> interface that the browser calls.
///
/// You would typically use this class by inheritance on your instance or by
/// composition.
///
/// <strong>Example (inheritance):</strong>
/// @code
/// class MyInstance : public pp::Instance, public pp::MouseLock {
/// class MyInstance() : pp::MouseLock(this) {
/// }
/// ...
/// };
/// @endcode
///
/// <strong>Example (composition):</strong>
/// @code
/// class MyMouseLock : public pp::MouseLock {
/// ...
/// };
///
/// class MyInstance : public pp::Instance {
/// MyInstance() : mouse_lock_(this) {
/// }
///
/// MyMouseLock mouse_lock_;
/// };
/// @endcode
class MouseLock {
public:
/// A constructor for creating a <code>MouseLock</code>.
///
/// @param[in] instance The instance with which this resource will be
/// associated.
explicit MouseLock(Instance* instance);
/// Destructor.
virtual ~MouseLock();
/// PPP_MouseLock functions exposed as virtual functions for you to override.
virtual void MouseLockLost() = 0;
/// LockMouse() requests the mouse to be locked.
///
/// While the mouse is locked, the cursor is implicitly hidden from the user.
/// Any movement of the mouse will generate a
/// <code>PP_INPUTEVENT_TYPE_MOUSEMOVE</code> event. The
/// <code>GetPosition()</code> function in <code>InputEvent()</code>
/// reports the last known mouse position just as mouse lock was
/// entered. The <code>GetMovement()</code> function provides relative
/// movement information indicating what the change in position of the mouse
/// would be had it not been locked.
///
/// The browser may revoke the mouse lock for reasons including (but not
/// limited to) the user pressing the ESC key, the user activating another
/// program using a reserved keystroke (e.g. ALT+TAB), or some other system
/// event.
///
/// @param[in] cc A <code>CompletionCallback</code> to be called upon
/// completion.
///
/// @return An int32_t containing an error code from <code>pp_errors.h</code>.
int32_t LockMouse(const CompletionCallback& cc);
/// UnlockMouse causes the mouse to be unlocked, allowing it to track user
/// movement again. This is an asynchronous operation. The module instance
/// will be notified using the <code>PPP_MouseLock</code> interface when it
/// has lost the mouse lock.
void UnlockMouse();
private:
InstanceHandle associated_instance_;
};
} // namespace pp
#endif // PPAPI_CPP_MOUSE_LOCK_H_