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   // The |handled| parameter is an output parameter which when set to false
  27   // indicates that the message should be DefProc'ed.
  28   // Returns the result of processing the message.
  29   virtual LRESULT HandleMouseMessage(unsigned int message,
  30                                      WPARAM w_param,
  31                                      LPARAM l_param,
  32                                      bool* handled) = 0;
  33
  34   // Handles keyboard events like WM_KEYDOWN/WM_KEYUP, etc.
  35   // The |message| parameter identifies the message.
  36   // The |w_param| and |l_param| values are dependent on the type of the
  37   // message.
  38   // The |handled| parameter is an output parameter which when set to false
  39   // indicates that the message should be DefProc'ed.
  40   // Returns the result of processing the message.
  41   virtual LRESULT HandleKeyboardMessage(unsigned int message,
  42                                         WPARAM w_param,
  43                                         LPARAM l_param,
  44                                         bool* handled) = 0;
  45
  46   // Handles WM_TOUCH events.
  47   // The |message| parameter identifies the message.
  48   // The |w_param| and |l_param| values are as per MSDN docs.
  49   // The |handled| parameter is an output parameter which when set to false
  50   // indicates that the message should be DefProc'ed.
  51   // Returns the result of processing the message.
  52   virtual LRESULT HandleTouchMessage(unsigned int message,
  53                                      WPARAM w_param,
  54                                      LPARAM l_param,
  55                                      bool* handled) = 0;
  56
  57   // Handles scroll messages like WM_VSCROLL and WM_HSCROLL.
  58   // The |message| parameter identifies the scroll message.
  59   // The |w_param| and |l_param| values are dependent on the type of scroll.
  60   // The |handled| parameter is an output parameter which when set to false
  61   // indicates that the message should be DefProc'ed.
  62   virtual LRESULT HandleScrollMessage(unsigned int message,
  63                                       WPARAM w_param,
  64                                       LPARAM l_param,
  65                                       bool* handled) = 0;
  66
  67   // Handles the WM_NCHITTEST message
  68   // The |message| parameter identifies the message.
  69   // The |w_param| and |l_param| values are as per MSDN docs.
  70   // The |handled| parameter is an output parameter which when set to false
  71   // indicates that the message should be DefProc'ed.
  72   // Returns the result of processing the message.
  73   virtual LRESULT HandleNcHitTestMessage(unsigned int message,
  74                                          WPARAM w_param,
  75                                          LPARAM l_param,
  76                                          bool* handled) = 0;
  77  protected:
  78   WindowEventTarget();
  79   virtual ~WindowEventTarget();
  80 };
  81
  82 }  // namespace ui
  83
  84 #endif  // UI_BASE_WIN_WINDOW_EVENT_TARGET_H_
  85
  86