arc-bridge: Introduce the ArcService class

components/arc/input/arc_input_bridge_impl.cc

Index: components/arc/input/arc_input_bridge_impl.cc
diff --git a/components/arc/input/arc_input_bridge_impl.cc b/components/arc/input/arc_input_bridge_impl.cc
deleted file mode 100644
index e24aeb866a3364df9fdb6f71be737cf6c328fe64..0000000000000000000000000000000000000000
--- a/components/arc/input/arc_input_bridge_impl.cc
+++ /dev/null
@@ -1,387 +0,0 @@
-// 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.
-
-#include "components/arc/input/arc_input_bridge_impl.h"
-
-#include <linux/input.h>
-#include <fcntl.h>
-#include <stddef.h>
-
-#include <string>
-
-#include "base/logging.h"
-#include "base/posix/eintr_wrapper.h"
-#include "base/thread_task_runner_handle.h"
-#include "base/time/time.h"
-#include "components/arc/arc_bridge_service.h"
-#include "third_party/mojo/src/mojo/edk/embedder/embedder.h"
-#include "ui/aura/env.h"
-#include "ui/aura/env_observer.h"
-#include "ui/aura/window.h"
-#include "ui/aura/window_observer.h"
-#include "ui/events/event.h"
-#include "ui/events/event_handler.h"
-#include "ui/events/event_utils.h"
-#include "ui/events/keycodes/dom/keycode_converter.h"
-
-namespace {
-
-// ARC runs as 32-bit in all platforms, so we need to make sure to send a
-// struct input_event that is the same size it expects.
-struct timeval32 {
-  int32_t tv_sec;
-  int32_t tv_usec;
-};
-
-struct input_event32 {
-  struct timeval32 time;
-  uint16_t type;
-  uint16_t code;
-  int32_t value;
-};
-
-// input_event values for keyboard events.
-const int kKeyReleased = 0;
-const int kKeyPressed = 1;
-const int kKeyRepeated = 2;
-
-// maximum number of supported multi-touch slots (simultaneous fingers).
-const int kMaxSlots = 64;
-
-// tracking id of an empty slot.
-const int kEmptySlot = -1;
-
-// maximum possible pressure as defined in EventHubARC.
-// TODO(denniskempin): communicate maximum during initialization.
-const int kMaxPressure = 65536;
-
-// speed of the scroll emulation. Scroll events are reported at about 100 times
-// the speed of a scroll wheel.
-const float kScrollEmulationSpeed = 100.0f;
-
-struct MouseButtonMapping {
-  int ui_flag;
-  int evdev_code;
-} kMouseButtonMap[] = {
-    {ui::EF_LEFT_MOUSE_BUTTON, BTN_LEFT},
-    {ui::EF_RIGHT_MOUSE_BUTTON, BTN_RIGHT},
-    {ui::EF_MIDDLE_MOUSE_BUTTON, BTN_MIDDLE},
-};
-
-// Offset between evdev key codes and chrome native key codes
-const int kXkbKeycodeOffset = 8;
-
-}  // namespace
-
-namespace arc {
-
-ArcInputBridgeImpl::ArcInputBridgeImpl(ArcBridgeService* arc_bridge_service)
-    : arc_bridge_service_(arc_bridge_service),
-      offset_x_acc_(0.5f),
-      offset_y_acc_(0.5f),
-      current_slot_(-1),
-      current_slot_tracking_ids_(kMaxSlots, kEmptySlot),
-      origin_task_runner_(base::ThreadTaskRunnerHandle::Get()),
-      weak_factory_(this) {
-  arc_bridge_service->AddObserver(this);
-  if (arc_bridge_service->input_instance())
-    OnInputInstanceReady();
-
-  aura::Env* env = aura::Env::GetInstanceDontCreate();
-  if (env)
-    env->AddObserver(this);
-}
-
-ArcInputBridgeImpl::~ArcInputBridgeImpl() {
-  DCHECK(origin_task_runner_->RunsTasksOnCurrentThread());
-  arc_bridge_service_->RemoveObserver(this);
-
-  aura::Env* env = aura::Env::GetInstanceDontCreate();
-  if (env)
-    env->RemoveObserver(this);
-
-  for (aura::Window* window : arc_windows_.windows()) {
-    window->RemovePreTargetHandler(this);
-  }
-}
-
-void ArcInputBridgeImpl::OnInputInstanceReady() {
-  DCHECK(origin_task_runner_->RunsTasksOnCurrentThread());
-
-  keyboard_fd_ = CreateBridgeInputDevice("ChromeOS Keyboard", "keyboard");
-  mouse_fd_ = CreateBridgeInputDevice("ChromeOS Mouse", "mouse");
-  touchscreen_fd_ =
-      CreateBridgeInputDevice("ChromeOS Touchscreen", "touchscreen");
-}
-
-// 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 ArcInputBridgeImpl::OnEvent(ui::Event* event) {
-  DCHECK(origin_task_runner_->RunsTasksOnCurrentThread());
-  if (event->IsKeyEvent()) {
-    SendKeyEvent(static_cast<ui::KeyEvent*>(event));
-  } else if (event->IsMouseEvent() || event->IsScrollEvent()) {
-    SendMouseEvent(static_cast<ui::MouseEvent*>(event));
-  } else if (event->IsTouchEvent()) {
-    SendTouchEvent(static_cast<ui::TouchEvent*>(event));
-  }
-}
-
-// Attaches the input bridge to the window if it is marked as an ARC window.
-void ArcInputBridgeImpl::OnWindowInitialized(aura::Window* new_window) {
-  if (new_window->name() == "ExoSurface") {
-    arc_windows_.Add(new_window);
-    new_window->AddPreTargetHandler(this);
-  }
-}
-
-void ArcInputBridgeImpl::SendKeyEvent(ui::KeyEvent* event) {
-  if (keyboard_fd_.get() < 0) {
-    VLOG(2) << "No keyboard bridge device available.";
-    return;
-  }
-
-  uint16_t evdev_code = DomCodeToEvdevCode(event->code());
-  int evdev_value = 0;
-  if (event->type() == ui::ET_KEY_PRESSED) {
-    if (event->flags() & ui::EF_IS_REPEAT) {
-      evdev_value = kKeyRepeated;
-    } else {
-      evdev_value = kKeyPressed;
-    }
-  } else if (event->type() == ui::ET_KEY_RELEASED) {
-    evdev_value = kKeyReleased;
-  } else {
-    NOTREACHED() << "Key should be either PRESSED or RELEASED.";
-  }
-
-  base::TimeDelta time_stamp = event->time_stamp();
-  SendKernelEvent(keyboard_fd_, time_stamp, EV_KEY, evdev_code, evdev_value);
-  SendSynReport(keyboard_fd_, time_stamp);
-}
-
-void ArcInputBridgeImpl::SendTouchEvent(ui::TouchEvent* event) {
-  if (touchscreen_fd_.get() < 0) {
-    VLOG(2) << "No touchscreen bridge device available.";
-    return;
-  }
-
-  ui::PointerDetails details = event->pointer_details();
-  base::TimeDelta time_stamp = event->time_stamp();
-
-  // find or assing a slot for this tracking id
-  int slot_id = AcquireTouchSlot(event);
-  if (slot_id < 0) {
-    VLOG(1) << "Ran out of slot IDs.";
-    return;
-  }
-
-  // we only need to send the slot ID when it has changed.
-  if (slot_id != current_slot_) {
-    current_slot_ = slot_id;
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_SLOT,
-                    current_slot_);
-  }
-
-  // update tracking id
-  if (event->type() == ui::ET_TOUCH_PRESSED) {
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_TRACKING_ID,
-                    event->touch_id());
-  } else if (event->type() == ui::ET_TOUCH_RELEASED) {
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_TRACKING_ID,
-                    kEmptySlot);
-  }
-
-  // update touch information
-  if (event->type() == ui::ET_TOUCH_MOVED ||
-      event->type() == ui::ET_TOUCH_PRESSED) {
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_POSITION_X,
-                    event->x());
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_POSITION_Y,
-                    event->y());
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_TOUCH_MAJOR,
-                    details.radius_x());
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_TOUCH_MINOR,
-                    details.radius_y());
-    SendKernelEvent(touchscreen_fd_, time_stamp, EV_ABS, ABS_MT_PRESSURE,
-                    details.force() * kMaxPressure);
-  }
-  SendSynReport(touchscreen_fd_, time_stamp);
-}
-
-void ArcInputBridgeImpl::SendMouseEvent(ui::MouseEvent* event) {
-  if (mouse_fd_.get() < 0) {
-    VLOG(2) << "No mouse bridge device available.";
-    return;
-  }
-
-  base::TimeDelta time_stamp = event->time_stamp();
-
-  // update location
-  if (event->type() == ui::ET_MOUSE_MOVED ||
-      event->type() == ui::ET_MOUSE_DRAGGED) {
-    SendKernelEvent(mouse_fd_, time_stamp, EV_ABS, ABS_X, event->x());
-    SendKernelEvent(mouse_fd_, time_stamp, EV_ABS, ABS_Y, event->y());
-  }
-
-  // update buttons
-  if (event->type() == ui::ET_MOUSE_PRESSED ||
-      event->type() == ui::ET_MOUSE_RELEASED) {
-    int evdev_value = static_cast<int>(event->type() == ui::ET_MOUSE_PRESSED);
-    for (MouseButtonMapping mapping : kMouseButtonMap) {
-      if (event->changed_button_flags() & mapping.ui_flag) {
-        SendKernelEvent(mouse_fd_, time_stamp, EV_KEY, mapping.evdev_code,
-                        evdev_value);
-      }
-    }
-  }
-
-  // update scroll wheel
-  if (event->type() == ui::ET_SCROLL) {
-    ui::ScrollEvent* scroll_event = static_cast<ui::ScrollEvent*>(event);
-    // accumulate floating point scroll offset since we can only send full
-    // integer
-    // wheel events.
-    offset_x_acc_ += scroll_event->x_offset_ordinal() / kScrollEmulationSpeed;
-    offset_y_acc_ += scroll_event->y_offset_ordinal() / kScrollEmulationSpeed;
-
-    int wheel = floor(offset_y_acc_);
-    if (wheel != 0) {
-      SendKernelEvent(mouse_fd_, time_stamp, EV_REL, REL_WHEEL, wheel);
-      offset_y_acc_ -= static_cast<float>(wheel);
-    }
-
-    int hwheel = floor(offset_x_acc_);
-    if (hwheel != 0) {
-      SendKernelEvent(mouse_fd_, time_stamp, EV_REL, REL_HWHEEL, hwheel);
-      offset_x_acc_ -= static_cast<float>(hwheel);
-    }
-  }
-
-  SendSynReport(mouse_fd_, time_stamp);
-}
-
-void ArcInputBridgeImpl::SendKernelEvent(const base::ScopedFD& fd,
-                                         base::TimeDelta time_stamp,
-                                         uint16_t type,
-                                         uint16_t code,
-                                         int value) {
-  DCHECK(fd.is_valid());
-
-  struct input_event32 event;
-  event.time.tv_sec = time_stamp.InSeconds();
-  base::TimeDelta remainder =
-      time_stamp - base::TimeDelta::FromSeconds(event.time.tv_sec);
-  event.time.tv_usec = remainder.InMicroseconds();
-  event.type = type;
-  event.code = code;
-  event.value = value;
-
-  // Write event to file descriptor
-  size_t num_written = write(fd.get(), reinterpret_cast<void*>(&event),
-                             sizeof(struct input_event32));
-  DCHECK_EQ(num_written, sizeof(struct input_event32));
-}
-
-void ArcInputBridgeImpl::SendSynReport(const base::ScopedFD& fd,
-                                       base::TimeDelta time) {
-  DCHECK(origin_task_runner_->RunsTasksOnCurrentThread());
-
-  SendKernelEvent(fd, time, EV_SYN, SYN_REPORT, 0);
-}
-
-int ArcInputBridgeImpl::AcquireTouchSlot(ui::TouchEvent* event) {
-  int slot_id;
-  if (event->type() == ui::ET_TOUCH_PRESSED) {
-    slot_id = FindTouchSlot(kEmptySlot);
-  } else {
-    slot_id = FindTouchSlot(event->touch_id());
-  }
-  if (slot_id < 0) {
-    return -1;
-  }
-
-  if (event->type() == ui::ET_TOUCH_RELEASED) {
-    current_slot_tracking_ids_[slot_id] = kEmptySlot;
-  } else if (event->type() == ui::ET_TOUCH_PRESSED) {
-    current_slot_tracking_ids_[slot_id] = event->touch_id();
-  }
-  return slot_id;
-}
-
-int ArcInputBridgeImpl::FindTouchSlot(int tracking_id) {
-  for (int i = 0; i < kMaxSlots; ++i) {
-    if (current_slot_tracking_ids_[i] == tracking_id) {
-      return i;
-    }
-  }
-  return -1;
-}
-
-uint16_t ArcInputBridgeImpl::DomCodeToEvdevCode(ui::DomCode dom_code) {
-  int native_code = ui::KeycodeConverter::DomCodeToNativeKeycode(dom_code);
-  if (native_code == ui::KeycodeConverter::InvalidNativeKeycode())
-    return KEY_RESERVED;
-
-  return native_code - kXkbKeycodeOffset;
-}
-
-base::ScopedFD ArcInputBridgeImpl::CreateBridgeInputDevice(
-    const std::string& name,
-    const std::string& device_type) {
-  if (!arc_bridge_service_) {
-    VLOG(1) << "ArcBridgeService disappeared.";
-    return base::ScopedFD();
-  }
-
-  // Create file descriptor pair for communication
-  int fd[2];
-  int res = HANDLE_EINTR(pipe(fd));
-  if (res < 0) {
-    VPLOG(1) << "Cannot create pipe";
-    return base::ScopedFD();
-  }
-  base::ScopedFD read_fd(fd[0]);
-  base::ScopedFD write_fd(fd[1]);
-
-  // The read end is sent to the instance, ownership of fd transfers.
-  InputInstance* input_instance = arc_bridge_service_->input_instance();
-  if (!input_instance) {
-    VLOG(1) << "ArcBridgeService InputInstance disappeared.";
-    return base::ScopedFD();
-  }
-  MojoHandle wrapped_handle;
-  MojoResult wrap_result = mojo::embedder::CreatePlatformHandleWrapper(
-      mojo::embedder::ScopedPlatformHandle(
-          mojo::embedder::PlatformHandle(read_fd.release())),
-      &wrapped_handle);
-  if (wrap_result != MOJO_RESULT_OK) {
-    LOG(WARNING) << "Pipe failed to wrap handles. Closing: " << wrap_result;
-    return base::ScopedFD();
-  }
-  input_instance->RegisterInputDevice(
-      name, device_type, mojo::ScopedHandle(mojo::Handle(wrapped_handle)));
-
-  // setup write end as non blocking
-  int flags = HANDLE_EINTR(fcntl(write_fd.get(), F_GETFL, 0));
-  if (res < 0) {
-    VPLOG(1) << "Cannot get file descriptor flags";
-    return base::ScopedFD();
-  }
-
-  res = HANDLE_EINTR(fcntl(write_fd.get(), F_SETFL, flags | O_NONBLOCK));
-  if (res < 0) {
-    VPLOG(1) << "Cannot set file descriptor flags";
-    return base::ScopedFD();
-  }
-  return write_fd;
-}
-
-scoped_ptr<ArcInputBridge> ArcInputBridge::Create(
-    ArcBridgeService* arc_bridge_service) {
-  return make_scoped_ptr(new ArcInputBridgeImpl(arc_bridge_service));
-}
-
-}  // namespace arc