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
  11 namespace ash {
  12
  13 void AssociateTouchscreens(std::vector<DisplayInfo>* displays,
  14                            const std::vector<ui::TouchscreenDevice>& devices) {
  15   std::set<int> no_match_touchscreen;
  16   int internal_touchscreen = -1;
  17   for (size_t i = 0; i < devices.size(); ++i) {
  18     if (devices[i].is_internal) {
  19       internal_touchscreen = i;
  20       break;
  21     }
  22   }
  23
  24   DisplayInfo* internal_state = NULL;
  25   for (size_t i = 0; i < displays->size(); ++i) {
  26     DisplayInfo* state = &(*displays)[i];
  27     if (state->id() == gfx::Display::InternalDisplayId() &&
  28         !state->GetNativeModeSize().IsEmpty() &&
  29         state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  30       internal_state = state;
  31       break;
  32     }
  33   }
  34
  35   if (internal_state && internal_touchscreen >= 0) {
  36     internal_state->set_touch_device_id(devices[internal_touchscreen].id);
  37     internal_state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  38     VLOG(2) << "Found internal touchscreen for internal display "
  39             << internal_state->id() << " touch_device_id "
  40             << internal_state->touch_device_id() << " size "
  41             << devices[internal_touchscreen].size.ToString();
  42   }
  43
  44   for (size_t i = 0; i < devices.size(); ++i) {
  45     if (internal_state && internal_state->touch_device_id() == devices[i].id)
  46       continue;
  47
  48     bool found_mapping = false;
  49     for (size_t j = 0; j < displays->size(); ++j) {
  50       DisplayInfo* state = &(*displays)[j];
  51       const gfx::Size native_size = state->GetNativeModeSize();
  52       if (state->touch_support() == gfx::Display::TOUCH_SUPPORT_AVAILABLE ||
  53           native_size.IsEmpty())
  54         continue;
  55
  56       // Allow 1 pixel difference between screen and touchscreen
  57       // resolutions. Because in some cases for monitor resolution
  58       // 1024x768 touchscreen's resolution would be 1024x768, but for
  59       // some 1023x767. It really depends on touchscreen's firmware
  60       // configuration.
  61       if (std::abs(native_size.width() - devices[i].size.width()) <= 1 &&
  62           std::abs(native_size.height() - devices[i].size.height()) <= 1) {
  63         state->set_touch_device_id(devices[i].id);
  64         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  65
  66         VLOG(2) << "Found touchscreen for display " << state->id()
  67                 << " touch_device_id " << state->touch_device_id() << " size "
  68                 << devices[i].size.ToString();
  69         found_mapping = true;
  70         break;
  71       }
  72     }
  73
  74     if (!found_mapping) {
  75       no_match_touchscreen.insert(devices[i].id);
  76       VLOG(2) << "No matching display for touch_device_id " << devices[i].id
  77               << " size " << devices[i].size.ToString();
  78     }
  79   }
  80
  81   // Sometimes we can't find a matching screen for the touchscreen, e.g.
  82   // due to the touchscreen's reporting range having no correlation with the
  83   // screen's resolution. In this case, we arbitrarily assign unmatched
  84   // touchscreens to unmatched screens.
  85   for (std::set<int>::iterator it = no_match_touchscreen.begin();
  86        it != no_match_touchscreen.end();
  87        ++it) {
  88     for (size_t i = 0; i < displays->size(); ++i) {
  89       DisplayInfo* state = &(*displays)[i];
  90       if (state->id() != gfx::Display::InternalDisplayId() &&
  91           !state->GetNativeModeSize().IsEmpty() &&
  92           state->touch_support() == gfx::Display::TOUCH_SUPPORT_UNKNOWN) {
  93         state->set_touch_device_id(*it);
  94         state->set_touch_support(gfx::Display::TOUCH_SUPPORT_AVAILABLE);
  95         VLOG(2) << "Arbitrarily matching touchscreen "
  96                 << state->touch_device_id() << " to display " << state->id();
  97         break;
  98       }
  99     }
 100   }
 101 }
 102
 103 }  // namespace ash