ash/touch/touchscreen_util.cc

   1 // Copyright 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 #include "ash/touch/touchscreen_util.h"
   6
   7 #include <set>
   8
   9 #include "base/logging.h"
  10 #include "ui/events/devices/input_device.h"
  11
  12 namespace ash {
  13
  14 void AssociateTouchscreens(std::vector<DisplayInfo>* displays,
  15                            const std::vector<ui::TouchscreenDevice>& devices) {
  16   DisplayInfo* internal_state = NULL;
  17   for (size_t i = 0; i < displays->size(); ++i) {
  18     DisplayInfo* state = &(*displays)[i];
  19     if (gfx::Display::IsInternalDisplayId(state->id()) &&
  20         !state->GetNativeModeSize().IsEmpty() &&
  21         state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  22       DCHECK(!internal_state);
  23       internal_state = state;
  24     }
  25     state->ClearInputDevices();
  26   }
  27
  28   std::set<int> no_match_touchscreen;
  29   for (size_t i = 0; i < devices.size(); ++i) {
  30     if (devices[i].type == ui::InputDeviceType::INPUT_DEVICE_INTERNAL) {
  31       VLOG(2) << "Found internal device for display " << internal_state->id()
  32               << " with device id " << devices[i].id << " size "
  33               << devices[i].size.ToString();
  34       internal_state->AddInputDevice(devices[i].id);
  35       internal_state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  36       continue;
  37     }
  38
  39     bool found_mapping = false;
  40     for (size_t j = 0; j < displays->size(); ++j) {
  41       DisplayInfo* state = &(*displays)[j];
  42       if (state == internal_state)
  43         continue;
  44
  45       const gfx::Size native_size = state->GetNativeModeSize();
  46       if (state->touch_support() == gfx::Display::TOUCH_SUPPORT_AVAILABLE ||
  47           native_size.IsEmpty())
  48         continue;
  49
  50       // Allow 1 pixel difference between screen and touchscreen
  51       // resolutions. Because in some cases for monitor resolution
  52       // 1024x768 touchscreen's resolution would be 1024x768, but for
  53       // some 1023x767. It really depends on touchscreen's firmware
  54       // configuration.
  55       if (std::abs(native_size.width() - devices[i].size.width()) <= 1 &&
  56           std::abs(native_size.height() - devices[i].size.height()) <= 1) {
  57         state->AddInputDevice(devices[i].id);
  58         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  59
  60         VLOG(2) << "Found touchscreen for display " << state->id()
  61                 << " with device id " << devices[i].id << " size "
  62                 << devices[i].size.ToString();
  63         found_mapping = true;
  64         break;
  65       }
  66     }
  67
  68     if (!found_mapping) {
  69       no_match_touchscreen.insert(devices[i].id);
  70       VLOG(2) << "No matching display for device id " << devices[i].id
  71               << " size " << devices[i].size.ToString();
  72     }
  73   }
  74
  75   // Sometimes we can't find a matching screen for the touchscreen, e.g.
  76   // due to the touchscreen's reporting range having no correlation with the
  77   // screen's resolution. In this case, we arbitrarily assign unmatched
  78   // touchscreens to unmatched screens.
  79   for (std::set<int>::iterator it = no_match_touchscreen.begin();
  80        it != no_match_touchscreen.end();
  81        ++it) {
  82     for (size_t i = 0; i < displays->size(); ++i) {
  83       DisplayInfo* state = &(*displays)[i];
  84       if (!gfx::Display::IsInternalDisplayId(state->id()) &&
  85           !state->GetNativeModeSize().IsEmpty() &&
  86           state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  87         state->AddInputDevice(*it);
  88         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  89         VLOG(2) << "Arbitrarily matching touchscreen " << *it << " to display "
  90                 << state->id();
  91         break;
  92       }
  93     }
  94   }
  95 }
  96
  97 }  // namespace ash