ash/display/event_transformation_handler.cc

   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 #include "ash/display/event_transformation_handler.h"
   6
   7 #include <cmath>
   8
   9 #include "ash/display/display_info.h"
  10 #include "ash/display/display_manager.h"
  11 #include "ash/shell.h"
  12 #include "ash/wm/window_util.h"
  13 #include "ui/aura/window.h"
  14 #include "ui/aura/window_event_dispatcher.h"
  15 #include "ui/compositor/dip_util.h"
  16 #include "ui/events/event.h"
  17 #include "ui/gfx/display.h"
  18 #include "ui/gfx/screen.h"
  19 #include "ui/wm/core/coordinate_conversion.h"
  20
  21 namespace ash {
  22 namespace {
  23
  24 // Boost factor for non-integrated displays.
  25 const float kBoostForNonIntegrated = 1.20f;
  26
  27 }  // namespace
  28
  29 EventTransformationHandler::EventTransformationHandler()
  30     : transformation_mode_(TRANSFORM_AUTO) {
  31 }
  32
  33 EventTransformationHandler::~EventTransformationHandler() {
  34 }
  35
  36 void EventTransformationHandler::OnScrollEvent(ui::ScrollEvent* event) {
  37   if (transformation_mode_ == TRANSFORM_NONE)
  38     return;
  39
  40   // It is unnecessary to scale the event for the device scale factor since
  41   // the event locations etc. are already in DIP.
  42   gfx::Point point_in_screen(event->location());
  43   aura::Window* target = static_cast<aura::Window*>(event->target());
  44   ::wm::ConvertPointToScreen(target, &point_in_screen);
  45   const gfx::Display& display =
  46       Shell::GetScreen()->GetDisplayNearestPoint(point_in_screen);
  47
  48   // Apply some additional scaling if the display is non-integrated.
  49   if (!display.IsInternal())
  50     event->Scale(kBoostForNonIntegrated);
  51 }
  52
  53 }  // namespace ash