Adds special support to the device manager for keyboards devices.

ui/events/x/hotplug_event_handler_x11.cc

 // Copyright 2014 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/hotplug_event_handler_x11.h"
 
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
 
+#include <algorithm>
 #include <cmath>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/file_enumerator.h"
 #include "base/logging.h"
 #include "base/process/launch.h"
 #include "base/strings/string_util.h"
 #include "base/sys_info.h"
 #include "ui/events/device_hotplug_event_observer.h"
+#include "ui/events/input_device.h"
+#include "ui/events/keyboard_device.h"
 #include "ui/events/touchscreen_device.h"
 #include "ui/gfx/x/x11_types.h"
 
 namespace ui {
 
 namespace {
 
+// The name of the xinput device corresponding to the internal keyboard.
+const char kInternalKeyboardName[] = "AT Translated Set 2 keyboard";
+
+// Filters out all devices that that are not known keyboards. This may return

[flackr, 2014/10/04 00:35:12]

nit: This function only determines devices that are not known keyboards for one
device, not all devices. Perhaps update comment to:

// Returns true if |name| is the name of a known keyboard device. Note, this may
return false negatives.

See also style guide on descriptive function comments:
http://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Function_Comm...

[rsadam, 2014/10/04 18:46:27]

Done.

+// false negatives.
+bool IsKnownKeyboard(const std::string& name) {
+  std::string lower(name);
+  std::transform(lower.begin(), lower.end(), lower.begin(), ::tolower);
+  return lower.find("keyboard") != std::string::npos;
+}
+
+// Filters out all devices that that are XTEST keyboards.

[flackr, 2014/10/04 00:35:12]

Ditto.

[rsadam, 2014/10/04 18:46:27]

Done.

+bool IsTestKeyboard(const std::string& name) {
+  return name.find("XTEST") != std::string::npos;
+}
+
 // We consider the touchscreen to be internal if it is an I2c device.
 // With the device id, we can query X to get the device's dev input
 // node eventXXX. Then we search all the dev input nodes registered
 // by I2C devices to see if we can find eventXXX.
 bool IsTouchscreenInternal(XDisplay* dpy, int device_id) {
   using base::FileEnumerator;
   using base::FilePath;
 
 #if !defined(CHROMEOS)
   return false;
@@ skipping 70 matching lines @@
     : delegate_(delegate) {
 }
 
 HotplugEventHandlerX11::~HotplugEventHandlerX11() {
 }
 
 void HotplugEventHandlerX11::OnHotplugEvent() {
   const XIDeviceList& device_list =
       DeviceListCacheX::GetInstance()->GetXI2DeviceList(gfx::GetXDisplay());
   HandleTouchscreenDevices(device_list);
+  HandleKeyboardDevices(device_list);
+}
+
+void HotplugEventHandlerX11::HandleKeyboardDevices(
+    const XIDeviceList& x11_devices) {
+  std::vector<KeyboardDevice> devices;
+
+  for (int i = 0; i < x11_devices.count; i++) {
+    if (!x11_devices[i].enabled || x11_devices[i].use != XISlaveKeyboard)
+      continue;  // Assume all keyboards are keyboard slaves
+    std::string device_name(x11_devices[i].name);
+    base::TrimWhitespaceASCII(device_name, base::TRIM_TRAILING,
+        &device_name);
+    InputDeviceType type;
+    if (IsTestKeyboard(device_name)) {
+        continue;

[flackr, 2014/10/04 00:35:12]

No need for else if after a continue. Perhaps put an empty line afterwards to
clearly separate from cases where device is added.

[rsadam, 2014/10/04 18:46:27]

Done.

+    } else if (device_name == kInternalKeyboardName) {
+        type = InputDeviceType::INTERNAL;
+    } else if (IsKnownKeyboard(device_name)) {
+        type = InputDeviceType::EXTERNAL;
+    } else {
+        type = InputDeviceType::UNKNOWN;
+    }
+    devices.push_back(KeyboardDevice(x11_devices[i].deviceid,
+        type, device_name));
+  }
+  delegate_->OnKeyboardDevicesUpdated(devices);
 }
 
 void HotplugEventHandlerX11::HandleTouchscreenDevices(
     const XIDeviceList& x11_devices) {
   std::vector<TouchscreenDevice> devices;
   Display* display = gfx::GetXDisplay();
   Atom valuator_x = XInternAtom(display, "Abs MT Position X", False);
   Atom valuator_y = XInternAtom(display, "Abs MT Position Y", False);
   if (valuator_x == None || valuator_y == None)
     return;
@@ skipping 33 matching lines @@
         XITouchClassInfo* touch_info =
             reinterpret_cast<XITouchClassInfo*>(class_info);
         is_direct_touch = touch_info->mode == XIDirectTouch;
       }
 #endif
     }
 
     // Touchscreens should have absolute X and Y axes, and be direct touch
     // devices.
     if (width > 0.0 && height > 0.0 && is_direct_touch) {
-      bool is_internal =
-          IsTouchscreenInternal(display, x11_devices[i].deviceid);
+      InputDeviceType type =
+          IsTouchscreenInternal(display, x11_devices[i].deviceid) ?
+          InputDeviceType::INTERNAL : InputDeviceType::EXTERNAL;
+      std::string name(x11_devices[i].name);
       devices.push_back(TouchscreenDevice(
-          x11_devices[i].deviceid, gfx::Size(width, height), is_internal));
+          x11_devices[i].deviceid, type, name, gfx::Size(width, height)));
     }
   }
 
   delegate_->OnTouchscreenDevicesUpdated(devices);
 }
 
 }  // namespace ui