ash/display/event_transformation_handler.h

   1 // Copyright (c) 2013 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 ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
   6 #define ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_
   7
   8 #include "ash/ash_export.h"
   9 #include "base/compiler_specific.h"
  10 #include "ui/events/event_handler.h"
  11
  12 namespace ash {
  13
  14 // An event filter that transforms input event properties in extended desktop
  15 // environment.
  16 class ASH_EXPORT EventTransformationHandler : public ui::EventHandler {
  17  public:
  18   enum TransformationMode {
  19     TRANSFORM_AUTO,   // Transform events by the default amount.
  20                       // 1. Linear scaling w.r.t. the device scale factor.
  21                       // 2. Add 20% more for non-integrated displays.
  22     TRANSFORM_NONE,   // No transformation.
  23   };
  24
  25   EventTransformationHandler();
  26   ~EventTransformationHandler() override;
  27
  28   void set_transformation_mode(TransformationMode transformation_mode) {
  29     transformation_mode_ = transformation_mode;
  30   }
  31
  32   // Overridden from ui::EventHandler.
  33   void OnScrollEvent(ui::ScrollEvent* event) override;
  34
  35  private:
  36   TransformationMode transformation_mode_;
  37
  38   DISALLOW_COPY_AND_ASSIGN(EventTransformationHandler);
  39 };
  40
  41 }  // namespace ash
  42
  43 #endif  // ASH_DISPLAY_EVENT_TRANSFORMATION_HANDLER_H_