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 PPAPI_CPP_MOUSE_LOCK_H_
6#define PPAPI_CPP_MOUSE_LOCK_H_
7
8#include "ppapi/c/pp_stdint.h"
9#include "ppapi/cpp/instance_handle.h"
10
11/// @file
12/// This file defines the API for locking the target of mouse events to a
13/// specific module instance.
14
15namespace pp {
16
17class CompletionCallback;
18class Instance;
19
20/// This class allows you to associate the <code>PPP_MouseLock</code> and
21/// <code>PPB_MouseLock</code> C-based interfaces with an object. It associates
22/// itself with the given instance, and registers as the global handler for
23/// handling the <code>PPP_MouseLock</code> interface that the browser calls.
24///
25/// You would typically use this class by inheritance on your instance or by
26/// composition.
27///
28/// <strong>Example (inheritance):</strong>
29/// @code
30///   class MyInstance : public pp::Instance, public pp::MouseLock {
31///     class MyInstance() : pp::MouseLock(this) {
32///     }
33///     ...
34///   };
35/// @endcode
36///
37/// <strong>Example (composition):</strong>
38/// @code
39///   class MyMouseLock : public pp::MouseLock {
40///     ...
41///   };
42///
43///   class MyInstance : public pp::Instance {
44///     MyInstance() : mouse_lock_(this) {
45///     }
46///
47///     MyMouseLock mouse_lock_;
48///   };
49/// @endcode
50class MouseLock {
51 public:
52  /// A constructor for creating a <code>MouseLock</code>.
53  ///
54  /// @param[in] instance The instance with which this resource will be
55  /// associated.
56  explicit MouseLock(Instance* instance);
57
58  /// Destructor.
59  virtual ~MouseLock();
60
61  /// PPP_MouseLock functions exposed as virtual functions for you to override.
62  virtual void MouseLockLost() = 0;
63
64  /// LockMouse() requests the mouse to be locked.
65  ///
66  /// While the mouse is locked, the cursor is implicitly hidden from the user.
67  /// Any movement of the mouse will generate a
68  /// <code>PP_INPUTEVENT_TYPE_MOUSEMOVE</code> event. The
69  /// <code>GetPosition()</code> function in <code>InputEvent()</code>
70  /// reports the last known mouse position just as mouse lock was
71  /// entered. The <code>GetMovement()</code> function provides relative
72  /// movement information indicating what the change in position of the mouse
73  /// would be had it not been locked.
74  ///
75  /// The browser may revoke the mouse lock for reasons including (but not
76  /// limited to) the user pressing the ESC key, the user activating another
77  /// program using a reserved keystroke (e.g. ALT+TAB), or some other system
78  /// event.
79  ///
80  /// @param[in] cc A <code>CompletionCallback</code> to be called upon
81  /// completion.
82  ///
83  /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
84  int32_t LockMouse(const CompletionCallback& cc);
85
86  /// UnlockMouse causes the mouse to be unlocked, allowing it to track user
87  /// movement again. This is an asynchronous operation. The module instance
88  /// will be notified using the <code>PPP_MouseLock</code> interface when it
89  /// has lost the mouse lock.
90  void UnlockMouse();
91
92 private:
93  InstanceHandle associated_instance_;
94};
95
96}  // namespace pp
97
98#endif  // PPAPI_CPP_MOUSE_LOCK_H_
99