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   std::set<int> no_match_touchscreen;
  17   int internal_touchscreen = -1;
  18   for (size_t i = 0; i < devices.size(); ++i) {
  19     if (devices[i].type == ui::InputDeviceType::INPUT_DEVICE_INTERNAL) {
  20       internal_touchscreen = i;
  21       break;
  22     }
  23   }
  24
  25   DisplayInfo* internal_state = NULL;
  26   for (size_t i = 0; i < displays->size(); ++i) {
  27     DisplayInfo* state = &(*displays)[i];
  28     if (state->id() == gfx::Display::InternalDisplayId() &&
  29         !state->GetNativeModeSize().IsEmpty() &&
  30         state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  31       internal_state = state;
  32       break;
  33     }
  34   }
  35
  36   if (internal_state && internal_touchscreen >= 0) {
  37     internal_state->set_touch_device_id(devices[internal_touchscreen].id);
  38     internal_state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  39     VLOG(2) << "Found internal touchscreen for internal display "
  40             << internal_state->id() << " touch_device_id "
  41             << internal_state->touch_device_id() << " size "
  42             << devices[internal_touchscreen].size.ToString();
  43   }
  44
  45   for (size_t i = 0; i < devices.size(); ++i) {
  46     if (internal_state && internal_state->touch_device_id() == devices[i].id)
  47       continue;
  48
  49     bool found_mapping = false;
  50     for (size_t j = 0; j < displays->size(); ++j) {
  51       DisplayInfo* state = &(*displays)[j];
  52       const gfx::Size native_size = state->GetNativeModeSize();
  53       if (state->touch_support() == gfx::Display::TOUCH_SUPPORT_AVAILABLE ||
  54           native_size.IsEmpty())
  55         continue;
  56
  57       // Allow 1 pixel difference between screen and touchscreen
  58       // resolutions. Because in some cases for monitor resolution
  59       // 1024x768 touchscreen's resolution would be 1024x768, but for
  60       // some 1023x767. It really depends on touchscreen's firmware
  61       // configuration.
  62       if (std::abs(native_size.width() - devices[i].size.width()) <= 1 &&
  63           std::abs(native_size.height() - devices[i].size.height()) <= 1) {
  64         state->set_touch_device_id(devices[i].id);
  65         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  66
  67         VLOG(2) << "Found touchscreen for display " << state->id()
  68                 << " touch_device_id " << state->touch_device_id() << " size "
  69                 << devices[i].size.ToString();
  70         found_mapping = true;
  71         break;
  72       }
  73     }
  74
  75     if (!found_mapping) {
  76       no_match_touchscreen.insert(devices[i].id);
  77       VLOG(2) << "No matching display for touch_device_id " << devices[i].id
  78               << " size " << devices[i].size.ToString();
  79     }
  80   }
  81
  82   // Sometimes we can't find a matching screen for the touchscreen, e.g.
  83   // due to the touchscreen's reporting range having no correlation with the
  84   // screen's resolution. In this case, we arbitrarily assign unmatched
  85   // touchscreens to unmatched screens.
  86   for (std::set<int>::iterator it = no_match_touchscreen.begin();
  87        it != no_match_touchscreen.end();
  88        ++it) {
  89     for (size_t i = 0; i < displays->size(); ++i) {
  90       DisplayInfo* state = &(*displays)[i];
  91       if (state->id() != gfx::Display::InternalDisplayId() &&
  92           !state->GetNativeModeSize().IsEmpty() &&
  93           state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  94         state->set_touch_device_id(*it);
  95         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  96         VLOG(2) << "Arbitrarily matching touchscreen "
  97                 << state->touch_device_id() << " to display " << state->id();
  98         break;
  99       }
 100     }
 101   }
 102 }
 103
 104 }  // namespace ash