Fix touch screen on Linux with or without flag --touch-devices

ui/events/devices/x11/touch_factory_x11.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/devices/x11/touch_factory_x11.h"
 
 #include <X11/Xatom.h>
 #include <X11/cursorfont.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 85 matching lines @@
   // not delivered to the client. So we select for slave devices instead.
   // If the touch device has 'GrabDevice' set and 'SendCoreEvents' unset (which
   // is possible), then the device is detected as a floating device, and a
   // floating device is not connected to a master device. So it is necessary to
   // also select on the floating devices.
   pointer_device_lookup_.reset();
   const XIDeviceList& xi_dev_list =
       DeviceListCacheX11::GetInstance()->GetXI2DeviceList(display);
   for (int i = 0; i < xi_dev_list.count; i++) {
     const XIDeviceInfo& devinfo = xi_dev_list[i];
+    device_master_id_list_[devinfo.deviceid] = devinfo.attachment;

[sadrul, 2015/06/17 03:33:52]

We should do this only for XISlavePointer device?

[lanwei, 2015/06/17 17:59:15]

Done.

     if (devinfo.use == XIFloatingSlave || devinfo.use == XIMasterPointer) {
       for (int k = 0; k < devinfo.num_classes; ++k) {
         XIAnyClassInfo* xiclassinfo = devinfo.classes[k];
         if (xiclassinfo->type == XITouchClass) {
           XITouchClassInfo* tci =
               reinterpret_cast<XITouchClassInfo*>(xiclassinfo);
           // Only care direct touch device (such as touch screen) right now
           if (tci->mode == XIDirectTouch) {
             touch_device_lookup_[devinfo.deviceid] = true;
             touch_device_list_[devinfo.deviceid] = true;
           }
         }
       }
       pointer_device_lookup_[devinfo.deviceid] = true;
     } else if (devinfo.use == XIMasterKeyboard) {
       virtual_core_keyboard_device_ = devinfo.deviceid;
     }
 
     if (devinfo.use == XIFloatingSlave || devinfo.use == XISlavePointer) {
       for (int k = 0; k < devinfo.num_classes; ++k) {
         XIAnyClassInfo* xiclassinfo = devinfo.classes[k];
         if (xiclassinfo->type == XITouchClass) {
           XITouchClassInfo* tci =
               reinterpret_cast<XITouchClassInfo*>(xiclassinfo);
           // Only care direct touch device (such as touch screen) right now
           if (tci->mode == XIDirectTouch)
             CacheTouchscreenIds(devinfo.deviceid);
+            // If the device is direct touch device, we also set its master
+            // device to be touch device.
+            touch_device_lookup_[device_master_id_list_[devinfo.deviceid]] =
+                true;
+            touch_device_list_[device_master_id_list_[devinfo.deviceid]] = true;

[sadrul, 2015/06/17 03:33:52]

We should do this only for XISlavePointer?

Also, can this directly use |devinfo.attachment|, instead of going through
|device_master_id_list_|?

[lanwei, 2015/06/17 17:59:15]

Done.

         }
       }
     }
   }
 }
 
 bool TouchFactory::ShouldProcessXI2Event(XEvent* xev) {
   DCHECK_EQ(GenericEvent, xev->type);
   XIEvent* event = static_cast<XIEvent*>(xev->xcookie.data);
   XIDeviceEvent* xiev = reinterpret_cast<XIDeviceEvent*>(event);
@@ skipping 69 matching lines @@
   evmask.deviceid = XIAllDevices;
   evmask.mask_len = sizeof(mask);
   evmask.mask = mask;
   XISelectEvents(display, window, &evmask, 1);
   XFlush(display);
 }
 
 void TouchFactory::SetTouchDeviceList(const std::vector<int>& devices) {
   touch_device_lookup_.reset();
   touch_device_list_.clear();
   for (std::vector<int>::const_iterator iter = devices.begin();

[sadrul, 2015/06/17 03:33:52]

Since you are here: can you change this to:

  for (int deviceid : devices) { ... }

[lanwei, 2015/06/17 17:59:15]

Done.

        iter != devices.end(); ++iter) {
     DCHECK(IsValidDevice(*iter));
     touch_device_lookup_[*iter] = true;
     touch_device_list_[*iter] = false;
+    // When we set the device through the "--touch-devices" flag to touch
+    // device, we also set its master device to be touch device.
+    touch_device_lookup_[device_master_id_list_[*iter]] = true;

[sadrul, 2015/06/17 03:33:52]

Check to see if |*iter| exists in |device_master_id_list_| first?

[lanwei, 2015/06/17 17:59:15]

Done.

+    touch_device_list_[device_master_id_list_[*iter]] = false;
   }
 }
 
 bool TouchFactory::IsValidDevice(int deviceid) const {
   return (deviceid >= 0) &&
          (static_cast<size_t>(deviceid) < touch_device_lookup_.size());
 }
 
 bool TouchFactory::IsTouchDevice(int deviceid) const {
   return IsValidDevice(deviceid) ? touch_device_lookup_[deviceid] : false;
@@ skipping 64 matching lines @@
       std::find_if(touchscreens.begin(), touchscreens.end(),
                    [device_id](const TouchscreenDevice& touchscreen) {
                      return touchscreen.id == device_id;
                    });
   // Internal displays will have a vid and pid of 0. Ignore them.
   if (it != touchscreens.end() && it->vendor_id && it->product_id)
     touchscreen_ids_.insert(std::make_pair(it->vendor_id, it->product_id));
 }
 
 }  // namespace ui