chromeos: Add ArcInputBridge to components/arc

components/exo/arc/arc_input_bridge.h

+// 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_ARC_INPUT_BRIDGE_H_
+#define COMPONENTS_EXO_ARC_ARC_INPUT_BRIDGE_H_
+
+#include "base/macros.h"
+#include "components/arc/arc_bridge_service.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+
+namespace arc {
+
+class ArcBridgeService;
+
+// This class allows ui::Event's to be sent through the ArcBridgeService to be
+// received by the ARC instance.
+class ArcInputBridge : private ArcBridgeService::Observer {
+ public:
+  // Registers an observer with the ArcBridgeService. This must happen before
+  // the ArcBridgeService is started so we do not miss the InstanceBootPhase
+  // messages.
+  ArcInputBridge(base::WeakPtr<ArcBridgeService> arc_bridge_service);
+  virtual ~ArcInputBridge();
+
+  // Gets the global instance of the ARC Input Bridge.
+  static ArcInputBridge* Get();
+
+  // Translates and sends a ui::Event to the appropriate bridge device of the
+  // ARC instance. If the devices have not yet been initialized, the event
+  // will be ignored.
+  void SendInputEvent(ui::Event* event);
+
+ private:
+  // 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
+  // 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);
+
+  // ArcBridgeService::Observer:
+  void OnInstanceBootPhase(InstanceBootPhase phase) override;
+
+  // Setup bridge devices on the instance side. This needs to be called after
+  // the InstanceBootPhase::SYSTEM_SERVICES_READY has been reached.
+  void SetupBridgeDevices();
+
+  // Return existing or new slot for this event.
+  int AcquireTouchSlot(ui::TouchEvent* event);
+
+  // Return touch slot for tracking id.
+  int FindTouchSlot(int tracking_id);
+
+  // 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);
+
+  base::WeakPtr<ArcBridgeService> arc_bridge_service_;
+
+  // File descriptors for the different device types.
+  base::ScopedFD keyboard_fd_;
+  base::ScopedFD mouse_fd_;
+  base::ScopedFD touchscreen_fd_;
+
+  // 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_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcInputBridge);
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_EXO_ARC_ARC_INPUT_BRIDGE_H_