root/ui/events/x/touch_factory_x11.cc

DEFINITIONS

1. id_generator_
2. GetInstance
3. SetTouchDeviceListFromCommandLine
4. UpdateDeviceList
5. ShouldProcessXI2Event
6. SetupXI2ForXWindow
7. SetTouchDeviceList
8. IsTouchDevice
9. IsMultiTouchDevice
10. QuerySlotForTrackingID
11. GetSlotForTrackingID
12. ReleaseSlotForTrackingID
13. IsTouchDevicePresent
14. GetMaxTouchPoints
15. SetTouchDeviceForTest
16. SetPointerDeviceForTest
17. CacheTouchscreenIds

// 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/x/touch_factory_x11.h"

#include <X11/Xatom.h>
#include <X11/cursorfont.h>
#include <X11/extensions/XInput.h>
#include <X11/extensions/XInput2.h>
#include <X11/extensions/XIproto.h>

#include "base/basictypes.h"
#include "base/command_line.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/memory/singleton.h"
#include "base/message_loop/message_loop.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_split.h"
#include "ui/events/event_switches.h"
#include "ui/events/x/device_data_manager.h"
#include "ui/events/x/device_list_cache_x.h"
#include "ui/gfx/x/x11_types.h"

namespace ui {

TouchFactory::TouchFactory()
    : pointer_device_lookup_(),
      touch_device_available_(false),
      touch_events_disabled_(false),
      touch_device_list_(),
      max_touch_points_(-1),
      id_generator_(0) {
  if (!DeviceDataManager::GetInstance()->IsXInput2Available())
    return;

  XDisplay* display = gfx::GetXDisplay();
  UpdateDeviceList(display);

  CommandLine* cmdline = CommandLine::ForCurrentProcess();
  touch_events_disabled_ = cmdline->HasSwitch(switches::kTouchEvents) &&
      cmdline->GetSwitchValueASCII(switches::kTouchEvents) ==
          switches::kTouchEventsDisabled;
}

TouchFactory::~TouchFactory() {
}

// static
TouchFactory* TouchFactory::GetInstance() {
  return Singleton<TouchFactory>::get();
}

// static
void TouchFactory::SetTouchDeviceListFromCommandLine() {
  // Get a list of pointer-devices that should be treated as touch-devices.
  // This is primarily used for testing/debugging touch-event processing when a
  // touch-device isn't available.
  std::string touch_devices =
      CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
          switches::kTouchDevices);

  if (!touch_devices.empty()) {
    std::vector<std::string> devs;
    std::vector<unsigned int> device_ids;
    unsigned int devid;
    base::SplitString(touch_devices, ',', &devs);
    for (std::vector<std::string>::iterator iter = devs.begin();
        iter != devs.end(); ++iter) {
      if (base::StringToInt(*iter, reinterpret_cast<int*>(&devid)))
        device_ids.push_back(devid);
      else
        DLOG(WARNING) << "Invalid touch-device id: " << *iter;
    }
    ui::TouchFactory::GetInstance()->SetTouchDeviceList(device_ids);
  }
}

void TouchFactory::UpdateDeviceList(Display* display) {
  // Detect touch devices.
  touch_device_available_ = false;
  touch_device_lookup_.reset();
  touch_device_list_.clear();
  touchscreen_ids_.clear();
  max_touch_points_ = -1;

#if !defined(USE_XI2_MT)
  // NOTE: The new API for retrieving the list of devices (XIQueryDevice) does
  // not provide enough information to detect a touch device. As a result, the
  // old version of query function (XListInputDevices) is used instead.
  // If XInput2 is not supported, this will return null (with count of -1) so
  // we assume there cannot be any touch devices.
  // With XI2.1 or older, we allow only single touch devices.
  XDeviceList dev_list =
      DeviceListCacheX::GetInstance()->GetXDeviceList(display);
  Atom xi_touchscreen = XInternAtom(display, XI_TOUCHSCREEN, false);
  for (int i = 0; i < dev_list.count; i++) {
    if (dev_list[i].type == xi_touchscreen) {
      touch_device_lookup_[dev_list[i].id] = true;
      touch_device_list_[dev_list[i].id] = false;
      touch_device_available_ = true;
    }
  }
#endif

  if (!DeviceDataManager::GetInstance()->IsXInput2Available())
    return;

  // Instead of asking X for the list of devices all the time, let's maintain a
  // list of pointer devices we care about.
  // It should not be necessary to select for slave devices. XInput2 provides
  // enough information to the event callback to decide which slave device
  // triggered the event, thus decide whether the 'pointer event' is a
  // 'mouse event' or a 'touch event'.
  // However, on some desktops, some events from a master pointer are
  // 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();
  XIDeviceList xi_dev_list =
      DeviceListCacheX::GetInstance()->GetXI2DeviceList(display);
  for (int i = 0; i < xi_dev_list.count; i++) {
    XIDeviceInfo* devinfo = xi_dev_list.devices + i;
    if (devinfo->use == XIFloatingSlave || devinfo->use == XIMasterPointer) {
#if defined(USE_XI2_MT)
      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;
            touch_device_available_ = true;
            if (tci->num_touches > 0 && tci->num_touches > max_touch_points_)
              max_touch_points_ = tci->num_touches;
          }
        }
      }
#endif
      pointer_device_lookup_[devinfo->deviceid] = true;
    }

#if defined(USE_XI2_MT)
    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(display, devinfo->deviceid);
        }
      }
    }
#endif
  }
}

bool TouchFactory::ShouldProcessXI2Event(XEvent* xev) {
  DCHECK_EQ(GenericEvent, xev->type);
  XIEvent* event = static_cast<XIEvent*>(xev->xcookie.data);
  XIDeviceEvent* xiev = reinterpret_cast<XIDeviceEvent*>(event);

#if defined(USE_XI2_MT)
  if (event->evtype == XI_TouchBegin ||
      event->evtype == XI_TouchUpdate ||
      event->evtype == XI_TouchEnd) {
    return !touch_events_disabled_ && IsTouchDevice(xiev->deviceid);
  }
#endif
  if (event->evtype != XI_ButtonPress &&
      event->evtype != XI_ButtonRelease &&
      event->evtype != XI_Motion)
    return true;

  if (!pointer_device_lookup_[xiev->deviceid])
    return false;

  return IsTouchDevice(xiev->deviceid) ? !touch_events_disabled_ : true;
}

void TouchFactory::SetupXI2ForXWindow(Window window) {
  // Setup mask for mouse events. It is possible that a device is loaded/plugged
  // in after we have setup XInput2 on a window. In such cases, we need to
  // either resetup XInput2 for the window, so that we get events from the new
  // device, or we need to listen to events from all devices, and then filter
  // the events from uninteresting devices. We do the latter because that's
  // simpler.

  XDisplay* display = gfx::GetXDisplay();

  unsigned char mask[XIMaskLen(XI_LASTEVENT)];
  memset(mask, 0, sizeof(mask));

#if defined(USE_XI2_MT)
  XISetMask(mask, XI_TouchBegin);
  XISetMask(mask, XI_TouchUpdate);
  XISetMask(mask, XI_TouchEnd);
#endif
  XISetMask(mask, XI_ButtonPress);
  XISetMask(mask, XI_ButtonRelease);
  XISetMask(mask, XI_Motion);

  XIEventMask evmask;
  evmask.deviceid = XIAllDevices;
  evmask.mask_len = sizeof(mask);
  evmask.mask = mask;
  XISelectEvents(display, window, &evmask, 1);
  XFlush(display);
}

void TouchFactory::SetTouchDeviceList(
    const std::vector<unsigned int>& devices) {
  touch_device_lookup_.reset();
  touch_device_list_.clear();
  for (std::vector<unsigned int>::const_iterator iter = devices.begin();
       iter != devices.end(); ++iter) {
    DCHECK(*iter < touch_device_lookup_.size());
    touch_device_lookup_[*iter] = true;
    touch_device_list_[*iter] = false;
  }
}

bool TouchFactory::IsTouchDevice(unsigned deviceid) const {
  return deviceid < touch_device_lookup_.size() ?
      touch_device_lookup_[deviceid] : false;
}

bool TouchFactory::IsMultiTouchDevice(unsigned int deviceid) const {
  return (deviceid < touch_device_lookup_.size() &&
          touch_device_lookup_[deviceid]) ?
          touch_device_list_.find(deviceid)->second :
          false;
}

bool TouchFactory::QuerySlotForTrackingID(uint32 tracking_id, int* slot) {
  if (!id_generator_.HasGeneratedIDFor(tracking_id))
    return false;
  *slot = static_cast<int>(id_generator_.GetGeneratedID(tracking_id));
  return true;
}

int TouchFactory::GetSlotForTrackingID(uint32 tracking_id) {
  return id_generator_.GetGeneratedID(tracking_id);
}

void TouchFactory::ReleaseSlotForTrackingID(uint32 tracking_id) {
  id_generator_.ReleaseNumber(tracking_id);
}

bool TouchFactory::IsTouchDevicePresent() {
  return !touch_events_disabled_ && touch_device_available_;
}

int TouchFactory::GetMaxTouchPoints() const {
  return max_touch_points_;
}

void TouchFactory::SetTouchDeviceForTest(
    const std::vector<unsigned int>& devices) {
  touch_device_lookup_.reset();
  touch_device_list_.clear();
  for (std::vector<unsigned int>::const_iterator iter = devices.begin();
       iter != devices.end(); ++iter) {
    DCHECK(*iter < touch_device_lookup_.size());
    touch_device_lookup_[*iter] = true;
    touch_device_list_[*iter] = true;
  }
  touch_device_available_ = true;
  touch_events_disabled_ = false;
}

void TouchFactory::SetPointerDeviceForTest(
    const std::vector<unsigned int>& devices) {
  pointer_device_lookup_.reset();
  for (std::vector<unsigned int>::const_iterator iter = devices.begin();
       iter != devices.end(); ++iter) {
    pointer_device_lookup_[*iter] = true;
  }
}

void TouchFactory::CacheTouchscreenIds(Display* display, int device_id) {
  XDevice* device = XOpenDevice(display, device_id);
  if (!device)
    return;

  Atom actual_type_return;
  int actual_format_return;
  unsigned long nitems_return;
  unsigned long bytes_after_return;
  unsigned char *prop_return;

  const char kDeviceProductIdString[] = "Device Product ID";
  Atom device_product_id_atom =
      XInternAtom(display, kDeviceProductIdString, false);

  if (device_product_id_atom != None &&
      XGetDeviceProperty(display, device, device_product_id_atom, 0, 2,
                         False, XA_INTEGER, &actual_type_return,
                         &actual_format_return, &nitems_return,
                         &bytes_after_return, &prop_return) == Success) {
    if (actual_type_return == XA_INTEGER &&
        actual_format_return == 32 &&
        nitems_return == 2) {
      // An actual_format_return of 32 implies that the returned data is an
      // array of longs. See the description of |prop_return| in `man
      // XGetDeviceProperty` for details.
      long* ptr = reinterpret_cast<long*>(prop_return);

      // Internal displays will have a vid and pid of 0. Ignore them.
      // ptr[0] is the vid, and ptr[1] is the pid.
      if (ptr[0] || ptr[1])
        touchscreen_ids_.insert(std::make_pair(ptr[0], ptr[1]));
    }
    XFree(prop_return);
  }

  XCloseDevice(display, device);
}

}  // namespace ui