touch: Allow grabbing/ungrabbing touch devices for XInput2.

views/touchui/touch_factory.cc

+// Copyright (c) 2011 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 "views/touchui/touch_factory.h"
+
+#if defined(HAVE_XINPUT2)
+#include <gdk/gdkx.h>
+#include <X11/extensions/XInput2.h>
+
+#include "base/logging.h"
+
+namespace views {
+
+// static
+TouchFactory* TouchFactory::GetInstance() {
+  return Singleton<TouchFactory>::get();
+}
+
+TouchFactory::TouchFactory()
+    : touch_device_lookup_(),
+      touch_device_list_() {
+}
+
+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_.push_back(*iter);
+  }
+}
+
+bool TouchFactory::IsTouchDevice(unsigned deviceid) {
+  return deviceid < touch_device_lookup_.size() ?
+      touch_device_lookup_[deviceid] : false;
+}
+
+bool TouchFactory::GrabTouchDevices(Display* display, ::Window window) {
+  if (touch_device_list_.empty())
+    return true;
+
+  unsigned char mask[(XI_LASTEVENT + 7) / 8];
+  bool success = true;
+
+  memset(mask, 0, sizeof(mask));
+  XISetMask(mask, XI_ButtonPress);
+  XISetMask(mask, XI_ButtonRelease);
+  XISetMask(mask, XI_Motion);
+
+  XIEventMask evmask;
+  evmask.mask_len = sizeof(mask);
+  evmask.mask = mask;
+  for (std::vector<int>::const_iterator iter =
+       touch_device_list_.begin();
+       iter != touch_device_list_.end(); ++iter) {
+    evmask.deviceid = *iter;
+    Status status = XIGrabDevice(display, *iter, window, CurrentTime, None,
+                                 GrabModeAsync, GrabModeAsync, False, &evmask);
+    success = success && status == GrabSuccess;
+  }
+
+  return success;
+}
+
+bool TouchFactory::UngrabTouchDevices(Display* display) {
+  bool success = true;
+  for (std::vector<int>::const_iterator iter =
+       touch_device_list_.begin();
+       iter != touch_device_list_.end(); ++iter) {
+    Status status = XIUngrabDevice(display, *iter, CurrentTime);
+    success = success && status == GrabSuccess;
+  }
+  return success;
+}
+
+}  // namespace views
+
+#endif  // defined(HAVE_XINPUT2)

[sadrul, 2011/01/20 02:51:22]

I needed this '#if defined' to fix build failures on systems that don't have
XInput2. I tried to simply exclude this file from compiling if XInput2 is not
available, by excluding it in views/views.gyp, but there doesn't look to be a
[tolerable] way of doing this (conditionally including/excluding the file based
on a gyp-variable in build/linux/system.gyp:x11, where HAVE_XINPUT2 is defined,
didn't work).