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       // Don't try and map internal touchscreens to external displays.
  32       if (!internal_state)
  33         continue;
  34       VLOG(2) << "Found internal device for display " << internal_state->id()
  35               << " with device id " << devices[i].id << " size "
  36               << devices[i].size.ToString();
  37       internal_state->AddInputDevice(devices[i].id);
  38       internal_state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  39       continue;
  40     }
  41
  42     bool found_mapping = false;
  43     for (size_t j = 0; j < displays->size(); ++j) {
  44       DisplayInfo* state = &(*displays)[j];
  45       if (state == internal_state)
  46         continue;
  47
  48       const gfx::Size native_size = state->GetNativeModeSize();
  49       if (state->touch_support() == gfx::Display::TOUCH_SUPPORT_AVAILABLE ||
  50           native_size.IsEmpty())
  51         continue;
  52
  53       // Allow 1 pixel difference between screen and touchscreen
  54       // resolutions. Because in some cases for monitor resolution
  55       // 1024x768 touchscreen's resolution would be 1024x768, but for
  56       // some 1023x767. It really depends on touchscreen's firmware
  57       // configuration.
  58       if (std::abs(native_size.width() - devices[i].size.width()) <= 1 &&
  59           std::abs(native_size.height() - devices[i].size.height()) <= 1) {
  60         state->AddInputDevice(devices[i].id);
  61         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  62
  63         VLOG(2) << "Found touchscreen for display " << state->id()
  64                 << " with device id " << devices[i].id << " size "
  65                 << devices[i].size.ToString();
  66         found_mapping = true;
  67         break;
  68       }
  69     }
  70
  71     if (!found_mapping) {
  72       no_match_touchscreen.insert(devices[i].id);
  73       VLOG(2) << "No matching display for device id " << devices[i].id
  74               << " size " << devices[i].size.ToString();
  75     }
  76   }
  77
  78   // Sometimes we can't find a matching screen for the touchscreen, e.g.
  79   // due to the touchscreen's reporting range having no correlation with the
  80   // screen's resolution. In this case, we arbitrarily assign unmatched
  81   // touchscreens to unmatched screens.
  82   for (std::set<int>::iterator it = no_match_touchscreen.begin();
  83        it != no_match_touchscreen.end();
  84        ++it) {
  85     for (size_t i = 0; i < displays->size(); ++i) {
  86       DisplayInfo* state = &(*displays)[i];
  87       if (!gfx::Display::IsInternalDisplayId(state->id()) &&
  88           !state->GetNativeModeSize().IsEmpty() &&
  89           state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  90         state->AddInputDevice(*it);
  91         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  92         VLOG(2) << "Arbitrarily matching touchscreen " << *it << " to display "
  93                 << state->id();
  94         break;
  95       }
  96     }
  97   }
  98 }
  99
 100 }  // namespace ash