remoting/host/touch_injector_win.h

   1 // Copyright 2015 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 REMOTING_HOST_TOUCH_INJECTOR_WIN_H_
   6 #define REMOTING_HOST_TOUCH_INJECTOR_WIN_H_
   7
   8 #include <windows.h>
   9 #include <map>
  10 #include <vector>
  11
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/scoped_native_library.h"
  14
  15 namespace remoting {
  16
  17 namespace protocol {
  18
  19 class TouchEvent;
  20
  21 }  // namespace protocol
  22
  23 // This class calls InitializeTouchInjection() and InjectTouchInput() functions.
  24 // The methods are virtual for mocking.
  25 class TouchInjectorWinDelegate {
  26  public:
  27   virtual ~TouchInjectorWinDelegate();
  28
  29   // Determines whether Windows touch injection functions can be used.
  30   // Returns a non-null TouchInjectorWinDelegate on success.
  31   static scoped_ptr<TouchInjectorWinDelegate> Create();
  32
  33   // These match the functions in MSDN.
  34   virtual BOOL InitializeTouchInjection(UINT32 max_count, DWORD dw_mode);
  35   virtual DWORD InjectTouchInput(UINT32 count,
  36                                  const POINTER_TOUCH_INFO* contacts);
  37
  38  protected:
  39   // Ctor in protected scope for mocking.
  40   // This object takes ownership of the |library|.
  41   TouchInjectorWinDelegate(
  42       base::NativeLibrary library,
  43       BOOL(NTAPI* initialize_touch_injection_func)(UINT32, DWORD),
  44       BOOL(NTAPI* inject_touch_input_func)(UINT32, const POINTER_TOUCH_INFO*));
  45
  46  private:
  47   base::ScopedNativeLibrary library_module_;
  48
  49   // Pointers to Windows touch injection functions.
  50   BOOL(NTAPI* initialize_touch_injection_func_)(UINT32, DWORD);
  51   BOOL(NTAPI* inject_touch_input_func_)(UINT32, const POINTER_TOUCH_INFO*);
  52
  53   DISALLOW_COPY_AND_ASSIGN(TouchInjectorWinDelegate);
  54 };
  55
  56 // This class converts TouchEvent objects to POINTER_TOUCH_INFO so that it can
  57 // be injected using the Windows touch injection API, and calls the injection
  58 // functions.
  59 // This class expects good inputs and does not sanity check the inputs.
  60 // This class just converts the object and hands it off to the Windows API.
  61 class TouchInjectorWin {
  62  public:
  63   TouchInjectorWin();
  64   ~TouchInjectorWin();
  65
  66   // Returns false if initialization of touch injection APIs fails.
  67   bool Init();
  68
  69   // Deinitializes the object so that it can be reinitialized.
  70   void Deinitialize();
  71
  72   // Inject touch events.
  73   void InjectTouchEvent(const protocol::TouchEvent& event);
  74
  75   void SetInjectorDelegateForTest(
  76       scoped_ptr<TouchInjectorWinDelegate> functions);
  77
  78  private:
  79   // Helper methods called from InjectTouchEvent().
  80   // These helpers adapt Chromoting touch events, which convey changes to touch
  81   // points, to Windows touch descriptions, which must include descriptions for
  82   // all currently-active touch points, not just the changed ones.
  83   void AddNewTouchPoints(const protocol::TouchEvent& event);
  84   void MoveTouchPoints(const protocol::TouchEvent& event);
  85   void EndTouchPoints(const protocol::TouchEvent& event);
  86   void CancelTouchPoints(const protocol::TouchEvent& event);
  87
  88   // Set to null if touch injection is not available from the OS.
  89   scoped_ptr<TouchInjectorWinDelegate> delegate_;
  90
  91   // TODO(rkuroiwa): crbug.com/470203
  92   // This is a naive implementation. Check if we can achieve
  93   // better performance by reducing the number of copies.
  94   // To reduce the number of copies, we can have a vector of
  95   // POINTER_TOUCH_INFO and a map from touch ID to index in the vector.
  96   // When removing points from the vector, just swap it with the last element
  97   // and resize the vector.
  98   // All the POINTER_TOUCH_INFOs are stored as "move" points.
  99   std::map<uint32_t, POINTER_TOUCH_INFO> touches_in_contact_;
 100
 101   DISALLOW_COPY_AND_ASSIGN(TouchInjectorWin);
 102 };
 103
 104 }  // namespace remoting
 105
 106 #endif  // REMOTING_HOST_TOUCH_INJECTOR_WIN_H_