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 virtual ~EventTransformationHandler(); 27 set_transformation_mode(TransformationMode transformation_mode)28 void set_transformation_mode(TransformationMode transformation_mode) { 29 transformation_mode_ = transformation_mode; 30 } 31 32 // Overridden from ui::EventHandler. 33 virtual 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_ 44