evdev: Support device hotplug with udev

ui/events/ozone/evdev/event_factory.h

 // Copyright 2013 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.
 
 #ifndef UI_EVENTS_OZONE_EVENT_FACTORY_DELEGATE_EVDEV_H_
 #define UI_EVENTS_OZONE_EVENT_FACTORY_DELEGATE_EVDEV_H_
 
 #include "base/compiler_specific.h"
 #include "base/files/file_path.h"
+#include "base/message_loop/message_pump_libevent.h"
 #include "ui/events/events_export.h"
 #include "ui/events/ozone/evdev/event_converter.h"
 #include "ui/events/ozone/evdev/event_modifiers.h"
 #include "ui/events/ozone/event_factory_ozone.h"
 
 #if defined(USE_UDEV)
 #include "ui/events/ozone/evdev/scoped_udev.h"
 #endif
 
 namespace ui {
 
+#if defined(USE_UDEV)
+class UdevWatcher;
+#endif
+
 // Ozone events implementation for the Linux input subsystem ("evdev").
 class EVENTS_EXPORT EventFactoryEvdev : public EventFactoryOzone {
  public:
   EventFactoryEvdev();
   virtual ~EventFactoryEvdev();
 
   virtual void StartProcessingEvents() OVERRIDE;
 
  private:
   // Open device at path & starting processing events.
   void AttachInputDevice(const base::FilePath& file_path);
 
+  // Close device at path.
+  void DetachInputDevice(const base::FilePath& file_path);
+
   // Scan & open devices in /dev/input (without udev).
   void StartProcessingEventsManual();
 
 #if defined(USE_UDEV)
   // Scan & open devices using udev.
   void StartProcessingEventsUdev();
+
+  // Set up device monitor for hotplug.
+  bool StartMonitoringDevicesUdev();
 #endif
 
   // Owned per-device event converters (by path).
   std::map<base::FilePath, EventConverterEvdev*> converters_;
 
 #if defined(USE_UDEV)
   // Udev daemon connection.
   scoped_udev udev_;
+
+  // Udev device change monitor.
+  scoped_udev_monitor udev_monitor_;
+
+  // Watcher for uevent netlink socket.
+  scoped_ptr<UdevWatcher> watcher_;

[sadrul, 2014/01/30 22:10:36]

Can there a be single scoped_ptr<UdevController> that we use in this file, with
the rest of the udev-dependent code (including UdevController, which could be
friend to this class) moved into some _udev file that we exclude from gyp when
udev==0? That way, there will be very little USE_UDEV checks in the code, and it
will be a bit clearer.

[rjkroege, 2014/01/30 22:18:09]

+1

[spang, 2014/01/31 17:33:00]

Done.

 #endif
 
   EventModifiersEvdev modifiers_;
 
   DISALLOW_COPY_AND_ASSIGN(EventFactoryEvdev);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_OZONE_EVENT_FACTORY_DELEGATE_EVDEV_H_