chromeos: Add ArcInputBridge to components/arc

components/arc/input/arc_input_bridge.h

Index: components/arc/input/arc_input_bridge.h
diff --git a/components/arc/input/arc_input_bridge.h b/components/arc/input/arc_input_bridge.h
new file mode 100644
index 0000000000000000000000000000000000000000..f61e7a8b6c8c6abf23e68c230b084bfd6af525e4
--- /dev/null
+++ b/components/arc/input/arc_input_bridge.h
@@ -0,0 +1,140 @@
+// 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_

[reveman, 2015/12/04 03:21:24]

should be COMPONENTS_ARC_INPUT_ARC_INPUT_BRIDGE_H_

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+#include "base/macros.h"
+#include "components/arc/arc_bridge_service.h"
+#include "ui/aura/window_observer.h"
+#include "ui/aura/env.h"
+#include "ui/aura/env_observer.h"
+#include "ui/events/event.h"
+#include "ui/events/event_handler.h"
+
+namespace aura {
+
+class Window;
+
+}  // namespace aura

[reveman, 2015/12/04 03:21:24]

fyi, typically just

namespace aura {
class Window;
}

for simple forward declarations like this but current code is of course fine too

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+namespace arc {
+
+class ArcBridgeService;
+
+// The ArcInputBridge is responsible for sending input events from ARC windows
+// to the ARC instance.
+// It hooks into aura::Env to watch for ExoSurface windows that are running ARC
+// applications. On those windows the input bridge will attach an EventPreTarget
+// to capture all input events.
+// To send those events to the ARC instance it will create bridge input devices
+// through the ArcBridgeService, which will provide a file descriptor to which
+// we can send linux input_event's.
+// ui::Events to the ARC windows are translated to linux input_event's, which
+// are then sent through the respective file descriptor.
+class 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.
+  ArcInputBridge(
+      ArcBridgeService* arc_bridge_service,
+      const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner);
+  ~ArcInputBridge() override;
+
+ protected:
+  // 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 OnEvent(ui::Event* event) override;

[reveman, 2015/12/04 03:21:24]

nit: I don't recommend inheriting a public function as protected.

also when overriding functions we typically but a comments such as:

// Overridden from ui::EventHandler:

and other comments are not supposed to be needed as it should be properly
documented as part of the interface. I'd move the comment above to the
definition in the .cc file.

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // Attaches the input bridge to the window if it is marked as an ARC window.
+  void OnWindowInitialized(aura::Window* new_window) override;

[reveman, 2015/12/04 03:21:24]

ditto

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+ private:
+  // Initialized the aura::EnvObserver on the ui message loop.
+  void InitializeAuraObserver();
+
+  void SendInputEventIO(scoped_ptr<ui::Event> event);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // Specialized method to translate and send events to the right file
+  // descriptor

[reveman, 2015/12/04 03:21:24]

nit: missing punctuation. also, does this comment fit on one line?

[denniskempin, 2015/12/04 22:35:30]

close. 82. Added dot.

+  void SendKeyEventIO(ui::KeyEvent* event);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+  void SendTouchEventIO(ui::TouchEvent* event);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+  void SendMouseEventIO(ui::MouseEvent* event);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // 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 SendKernelEventIO(const base::ScopedFD& fd,

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+                         base::TimeDelta timestamp,
+                         unsigned short type,
+                         unsigned short code,
+                         int value);
+
+  // Shorthand for sending EV_SYN/SYN_REPORT
+  void SendSynReportIO(const base::ScopedFD& fd, base::TimeDelta timestamp);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // Return existing or new slot for this event.
+  int AcquireTouchSlotIO(ui::TouchEvent* event);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // Return touch slot for tracking id.
+  int FindTouchSlotIO(int tracking_id);

[reveman, 2015/12/04 03:21:24]

nit: s/IO/OnIO/

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // ArcBridgeService::Observer:
+  void OnInstanceBootPhase(InstanceBootPhase phase) override;

[reveman, 2015/12/04 03:21:24]

nit: avoid inheriting a public function as private

[denniskempin, 2015/12/04 22:35:30]

Done.

+
+  // 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_;

[reveman, 2015/12/04 03:21:24]

it's not clear what members below are used on what thread. can this be
documented? I'm assuming they are never accessed from more than one thread as
there's no mutex here to protect them..

[denniskempin, 2015/12/04 22:35:30]

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;

[jochen (gone - plz use gerrit), 2015/12/04 14:18:12]

should end in _

[denniskempin, 2015/12/04 22:35:30]

Done.

+  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_;
+  scoped_refptr<base::SequencedTaskRunner> io_task_runner_;
+
+  // WeakPtrFactory to use callbacks.
+  base::WeakPtrFactory<ArcInputBridge> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcInputBridge);
+};
+
+}  // namespace arc
+
+#endif  // COMPONENTS_EXO_ARC_ARC_INPUT_BRIDGE_H_

[reveman, 2015/12/04 03:21:24]

COMPONENTS_ARC_INPUT_ARC_INPUT_BRIDGE_H_

[denniskempin, 2015/12/04 22:35:30]

Done.