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/screen_ash.h"
  10 #include "ash/shell.h"
  11 #include "ash/wm/coordinate_conversion.h"
  12 #include "ash/wm/window_util.h"
  13 #include "ui/aura/root_window.h"
  14 #include "ui/aura/window.h"
  15 #include "ui/base/events/event.h"
  16 #include "ui/compositor/dip_util.h"
  17 #include "ui/gfx/display.h"
  18 #include "ui/gfx/screen.h"
  19
  20 #if defined(OS_CHROMEOS)
  21 #include "chromeos/display/output_configurator.h"
  22 #endif  // defined(OS_CHROMEOS)
  23
  24 namespace ash {
  25 namespace internal {
  26 namespace {
  27
  28 // Boost factor for non-integrated displays.
  29 const float kBoostForNonIntegrated = 1.20f;
  30 }
  31
  32 EventTransformationHandler::EventTransformationHandler()
  33     : transformation_mode_(TRANSFORM_AUTO) {
  34 }
  35
  36 EventTransformationHandler::~EventTransformationHandler() {
  37 }
  38
  39 void EventTransformationHandler::OnScrollEvent(ui::ScrollEvent* event) {
  40   if (transformation_mode_ == TRANSFORM_NONE)
  41     return;
  42
  43   // Get the device scale factor and stack it on the final scale factor.
  44   gfx::Point point_in_screen(event->location());
  45   aura::Window* target = static_cast<aura::Window*>(event->target());
  46   const float scale_at_target = ui::GetDeviceScaleFactor(target->layer());
  47   float scale = scale_at_target;
  48
  49   // Apply some additional scaling if the display is non-integrated.
  50   wm::ConvertPointToScreen(target, &point_in_screen);
  51   const gfx::Display& display =
  52       Shell::GetScreen()->GetDisplayNearestPoint(point_in_screen);
  53   if (!display.IsInternal())
  54     scale *= kBoostForNonIntegrated;
  55
  56   event->Scale(scale);
  57 }
  58
  59 #if defined(OS_CHROMEOS)
  60 // This is to scale the TouchEvent's radius when the touch display is in
  61 // mirror mode. TouchEvent's radius is often reported in the touchscreen's
  62 // native resolution. In mirror mode, the touch display could be configured
  63 // at a lower resolution. We scale down the radius using the ratio defined as
  64 // the sqrt of
  65 // (mirror_width * mirror_height) / (native_width * native_height)
  66 void EventTransformationHandler::OnTouchEvent(ui::TouchEvent* event) {
  67   using chromeos::OutputConfigurator;
  68   OutputConfigurator* output_configurator =
  69       ash::Shell::GetInstance()->output_configurator();
  70
  71   // Check output_configurator's output_state instead of checking
  72   // DisplayManager::IsMirrored() because the compositor based mirroring
  73   // won't cause the scaling issue.
  74   if (output_configurator->output_state() != chromeos::STATE_DUAL_MIRROR)
  75     return;
  76
  77   const std::map<int, float>& area_ratio_map =
  78       output_configurator->GetMirroredDisplayAreaRatioMap();
  79
  80   // TODO(miletus): When there are more than 1 touchscreen (e.g. Link connected
  81   // to an external touchscreen), the correct way to do is to have a way
  82   // to find out which touchscreen is the event originating from and use the
  83   // area ratio of that touchscreen to scale the event's radius.
  84   // Tracked here crbug.com/233245
  85   if (area_ratio_map.size() != 1) {
  86     LOG(ERROR) << "Mirroring mode with " << area_ratio_map.size()
  87                << " touch display found";
  88     return;
  89   }
  90
  91   float area_ratio_sqrt = std::sqrt(area_ratio_map.begin()->second);
  92   event->set_radius_x(event->radius_x() * area_ratio_sqrt);
  93   event->set_radius_y(event->radius_y() * area_ratio_sqrt);
  94 }
  95 #endif  // defined(OS_CHROMEOS)
  96
  97 }  // namespace internal
  98 }  // namespace ash