ui/base/win/window_event_target.h

   1 // Copyright (c) 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_BASE_WIN_WINDOW_EVENT_TARGET_H_
   6 #define UI_BASE_WIN_WINDOW_EVENT_TARGET_H_
   7
   8 #include <windows.h>
   9
  10 #include "base/basictypes.h"
  11 #include "ui/base/ui_base_export.h"
  12
  13 namespace ui {
  14
  15 // This interface is implemented by classes who get input events forwarded to
  16 // them from others. E.g. would be a win32 parent child relationship where the
  17 // child forwards input events to the parent after doing minimal processing.
  18 class UI_BASE_EXPORT WindowEventTarget {
  19  public:
  20   static const char kWin32InputEventTarget[];
  21
  22   // Handles mouse events like WM_MOUSEMOVE, WM_LBUTTONDOWN, etc.
  23   // The |message| parameter identifies the message.
  24   // The |w_param| and |l_param| values are dependent on the type of the
  25   // message.
  26   // Returns the result of processing the message.
  27   virtual LRESULT HandleMouseMessage(unsigned int message,
  28                                      WPARAM w_param,
  29                                      LPARAM l_param) = 0;
  30
  31   // Handles keyboard events like WM_KEYDOWN/WM_KEYUP, etc.
  32   // The |message| parameter identifies the message.
  33   // The |w_param| and |l_param| values are dependent on the type of the
  34   // message.
  35   // Returns the result of processing the message.
  36   virtual LRESULT HandleKeyboardMessage(unsigned int message,
  37                                         WPARAM w_param,
  38                                         LPARAM l_param) = 0;
  39
  40   // Handles WM_TOUCH events.
  41   // The |message| parameter identifies the message.
  42   // The |w_param| and |l_param| values are as per MSDN docs.
  43   // Returns the result of processing the message.
  44   virtual LRESULT HandleTouchMessage(unsigned int message,
  45                                      WPARAM w_param,
  46                                      LPARAM l_param) = 0;
  47
  48   // Handles scroll messages like WM_VSCROLL and WM_HSCROLL.
  49   // The |message| parameter identifies the scroll message.
  50   // The |w_param| and |l_param| values are dependent on the type of scroll.
  51   virtual LRESULT HandleScrollMessage(unsigned int message,
  52                                       WPARAM w_param,
  53                                       LPARAM l_param) = 0;
  54
  55   // Handles the WM_NCHITTEST message
  56   // The |message| parameter identifies the message.
  57   // The |w_param| and |l_param| values are as per MSDN docs.
  58   // Returns the result of processing the message.
  59   virtual LRESULT HandleNcHitTestMessage(unsigned int message,
  60                                          WPARAM w_param,
  61                                          LPARAM l_param) = 0;
  62  protected:
  63   WindowEventTarget();
  64   virtual ~WindowEventTarget();
  65 };
  66
  67 }  // namespace ui
  68
  69 #endif  // UI_BASE_WIN_WINDOW_EVENT_TARGET_H_
  70
  71