chromeos: Add ArcInputBridge to components/arc

components/arc/input/arc_input_bridge_impl.h

Index: components/arc/input/arc_input_bridge_impl.h
diff --git a/components/arc/input/arc_input_bridge_impl.h b/components/arc/input/arc_input_bridge_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..7b52dcae381a321ed11c4d702029cec57b54bd0e
--- /dev/null
+++ b/components/arc/input/arc_input_bridge_impl.h
@@ -0,0 +1,123 @@
+// Copyright 2015 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 COMPONENTS_EXO_ARC_INPUT_ARC_INPUT_BRIDGE_IMPL_H_
+#define COMPONENTS_EXO_ARC_INPUT_ARC_INPUT_BRIDGE_IMPL_H_
+
+#include "base/files/scoped_file.h"
+#include "base/macros.h"
+#include "components/arc/input/arc_input_bridge.h"
+#include "ui/aura/env.h"
+#include "ui/aura/env_observer.h"
+#include "ui/aura/window_observer.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+
+namespace aura {
+class Window;
+}
+
+namespace arc {
+
+class ArcBridgeService;
+
+// Private implementation of ArcInputBridge
+class ArcInputBridgeImpl : public ArcInputBridge,
+                           public ArcBridgeService::Observer,
+                           public aura::EnvObserver,
+                           public ui::EventHandler {
+ public:
+  // The constructor will register an Observer with aura::Env and the
+  // ArcBridgeService. From then on, no further interaction with this class
+  // is needed.
+  ArcInputBridgeImpl(ArcBridgeService* arc_bridge_service);

[reveman, 2015/12/04 23:19:32]

nit: explicit

[denniskempin, 2015/12/05 00:05:19]

Done.

+  ~ArcInputBridgeImpl() override;
+
+  // Overridden from ui::EventHandler:
+  void OnEvent(ui::Event* event) override;
+
+  // Overridden from aura::EnvObserver:
+  void OnWindowInitialized(aura::Window* new_window) override;
+
+  // Overridden from ArcBridgeService::Observer:
+  void OnInstanceBootPhase(InstanceBootPhase phase) override;
+
+ private:
+  // Initialized the aura::EnvObserver on the ui message loop.
+  void InitializeAuraObserver();
+
+  // Specialized method to translate and send events to the right file
+  // descriptor.
+  void SendKeyEvent(ui::KeyEvent* event);
+  void SendTouchEvent(ui::TouchEvent* event);
+  void SendMouseEvent(ui::MouseEvent* event);
+
+  // Helper method to send a struct input_event to the file descriptor. This
+  // method is to be called on the ui thread and will post a request to send
+  // the event to the io thread.
+  // The parameters map directly to the members of input_event as
+  // defined by the evdev protocol.
+  // |type| is the type of event to sent, such as EV_SYN, EV_KEY, EV_ABS.
+  // |code| is either interpreted as axis (ABS_X, ABS_Y, ...) or as key-code
+  //        (KEY_A, KEY_B, ...).
+  // |value| is either the value of that axis or the boolean value of the key
+  //         as in 0 (released), 1 (pressed) or 2 (repeated press).
+  void SendKernelEvent(const base::ScopedFD& fd,
+                       base::TimeDelta timestamp,
+                       unsigned short type,
+                       unsigned short code,
+                       int value);
+
+  // Shorthand for sending EV_SYN/SYN_REPORT
+  void SendSynReport(const base::ScopedFD& fd, base::TimeDelta timestamp);
+
+  // Return existing or new slot for this event.
+  int AcquireTouchSlot(ui::TouchEvent* event);
+
+  // Return touch slot for tracking id.
+  int FindTouchSlot(int tracking_id);
+
+  // Setup bridge devices on the instance side. This needs to be called after
+  // the InstanceBootPhase::SYSTEM_SERVICES_READY has been reached.
+  void SetupBridgeDevices();
+
+  // Creates and registers file descriptor pair with the ARC bridge service,
+  // the write end is returned while the read end is sent through the bridge
+  // to the ARC instance.
+  // TODO(denniskempin): Make this interface more typesafe.
+  // |name| should be the displayable name of the emulated device (e.g. "Chrome
+  // OS Keyboard"), |device_type| the name of the device type (e.g. "keyboard")
+  // and |fd| a file descriptor that emulates the kernel events of the device.
+  // This can only be called on the thread that this class was created on.
+  base::ScopedFD CreateBridgeInputDevice(const std::string& name,
+                                         const std::string& device_type);
+
+  ArcBridgeService* arc_bridge_service_;

[Luis Héctor Chávez, 2015/12/04 22:52:08]

Just add a comment about lifetime and why it's safe to use this as-is.

[denniskempin, 2015/12/05 00:05:19]

Done.

+
+  // File descriptors for the different device types.
+  base::ScopedFD keyboard_fd_;
+  base::ScopedFD mouse_fd_;
+  base::ScopedFD touchscreen_fd_;
+
+  // Scroll accumlator.
+  float offset_x_acc_;
+  float offset_y_acc_;
+
+  // Currently selected slot for multi-touch events.
+  int current_slot_;
+
+  // List of touch tracking id to slot assignments.
+  std::vector<int> current_slot_tracking_ids_;
+
+  scoped_refptr<base::SequencedTaskRunner> origin_task_runner_;
+
+  // WeakPtrFactory to use for callbacks.
+  base::WeakPtrFactory<ArcInputBridgeImpl> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcInputBridgeImpl);
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_EXO_ARC_INPUT_ARC_INPUT_BRIDGE_IMPL_H_