Remote assistance on Chrome OS Part IX - Input injection on Ozone

remoting/host/input_injector_chromeos.cc

 // Copyright 2014 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 "remoting/host/input_injector_chromeos.h"
 
-#include "base/logging.h"
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/location.h"
+#include "remoting/host/clipboard.h"
 #include "remoting/proto/internal.pb.h"
+#include "ui/events/keycodes/dom3/dom_code.h"
+#include "ui/events/keycodes/dom4/keycode_converter.h"
+#include "ui/ozone/public/ozone_platform.h"
+#include "ui/ozone/public/system_input_injector.h"
 
 namespace remoting {
 
 using protocol::ClipboardEvent;
 using protocol::KeyEvent;
 using protocol::MouseEvent;
 using protocol::TextEvent;
 
-// TODO(kelvinp): Implement this class (See crbug.com/426716).
+namespace {
+
+ui::EventFlags MouseButtonToUIFlags(MouseEvent::MouseButton button) {
+  switch (button) {
+    case MouseEvent::BUTTON_LEFT:
+      return ui::EF_LEFT_MOUSE_BUTTON;
+    case MouseEvent::BUTTON_RIGHT:
+      return ui::EF_RIGHT_MOUSE_BUTTON;
+    case MouseEvent::BUTTON_MIDDLE:
+      return ui::EF_MIDDLE_MOUSE_BUTTON;
+    default:
+      NOTREACHED();
+      return ui::EF_NONE;
+  }
+}
+
+}  // namespace
+
+class InputInjectorChromeos::Core {
+ public:
+  explicit Core(scoped_ptr<ui::SystemInputInjector> delegate_);
+
+  // Mirrors the public InputInjectorChromeos interface.
+  void InjectClipboardEvent(const ClipboardEvent& event);
+  void InjectKeyEvent(const KeyEvent& event);
+  void InjectTextEvent(const TextEvent& event);
+  void InjectMouseEvent(const MouseEvent& event);
+  void Start(scoped_ptr<protocol::ClipboardStub> client_clipboard);
+
+ private:
+  scoped_ptr<ui::SystemInputInjector> delegate_;
+  scoped_ptr<Clipboard> clipboard_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+InputInjectorChromeos::Core::Core(scoped_ptr<ui::SystemInputInjector> delegate)
+    : delegate_(delegate.Pass()),
+      clipboard_(Clipboard::Create()) {
+  DCHECK(delegate);
+
+  // TODO(kelvinp): Disable AutoRepeat as long as keys are pressed on ChromeOS
+  // when the auto-repeat API is ready to avoid triggering the auto-repeat if
+  // network congestion delays the key-up event from the client
+  // (See crbug.com/425201).
+}
+
+void InputInjectorChromeos::Core::InjectClipboardEvent(
+    const ClipboardEvent& event) {
+  clipboard_->InjectClipboardEvent(event);
+}
+
+void InputInjectorChromeos::Core::InjectKeyEvent(const KeyEvent& event) {
+  if (!event.has_pressed() || !event.has_usb_keycode()) {
+    return;
+  }
+
+  ui::DomCode dom_code =
+      ui::KeycodeConverter::UsbKeycodeToDomCode(event.usb_keycode());
+
+  // Ignore events which can't be mapped.
+  if (dom_code != ui::DomCode::NONE) {
+    delegate_->InjectKeyPress(dom_code, event.pressed());
+  }
+}
+
+void InputInjectorChromeos::Core::InjectTextEvent(const TextEvent& event) {
+  // TextEvents are not supported on Chrome OS.
+  NOTIMPLEMENTED();
+}
+
+void InputInjectorChromeos::Core::InjectMouseEvent(const MouseEvent& event) {
+  if (event.has_button() && event.has_button_down()) {
+    delegate_->InjectMouseButton(MouseButtonToUIFlags(event.button()),
+                                 event.button_down());
+  } else if (event.has_wheel_delta_y() || event.has_wheel_delta_x()) {
+    delegate_->InjectMouseWheel(event.wheel_delta_x(), event.wheel_delta_y());
+  } else {
+    DCHECK(event.has_x() && event.has_y());

[spang, 2014/11/26 17:06:42]

I think just do:

aura::WindowTreeHost* host = ash::Shell::GetPrimaryRootWindow()->GetHost();
gfx::Point location(event.x(), event.y());

host->ConvertPointToHost(&location);
// after some pending ozone changes this will change to:
// host->ConvertPointToNativeScreen(&location);

delegate_->MoveCursorTo(location);

[kelvinp, 2014/12/02 00:12:26]

We need a class to handle the rotation for a few reasons:
1. Chromoting monitors local mouse movement such that when both the local and
the remote user moves the mouse in the same time, the local user will always
win.  The local mouse movement is obtained by subtracting all mouse movements by
the injected positions.  As a result, we need to apply the co-ordinate rotation
early in the pipeline such that the coordinates system of injected events
matches those returned by the monitor. 
2. Using a separate class allows us to remove the rotation during unittest and
on non chromeos platforms. 

[spang, 2014/12/02 21:00:19]

Those pending changes are now landed. You should use ConvertPointToNativeScreen
and inject a screen location (although since you only support one display, the
native screen coordinates are probably probably the same as the host coordinates
because the display origin is 0,0).
I don't completely follow. Can't you use the root window or ash screen
coordinates to implement that feature?
 
The host / native screen space is an implementation detail and is basically
nonsense to work in. If possible, I'd suggesting trying hard to avoid it, and
also to avoid reproducing ash's root transformer in the remoting code.

Why wouldn't the following work:

(1) Right before calling InjectMouseEvent, convert your (sensible) root window
coordinates to (nonsense) native screen coordinates using the aura API
(ConvertPointToNativeScreen).

(2) If you ever get host or native screen coordinates somewhere (where?),
immediately convert them to root window or ash screen so that they're in a
sensible space. Use the sensible space for any mouse-related logic.

The idea is to sweep these platform-dependent rotations under the rug. I don't
think it will affect your tests either way; the test won't set a rotation in the
first place.

+    delegate_->MoveCursorTo(gfx::PointF(event.x(), event.y()));
+  }
+}
+
+void InputInjectorChromeos::Core::Start(
+    scoped_ptr<protocol::ClipboardStub> client_clipboard) {
+  clipboard_->Start(client_clipboard.Pass());
+}
+
 InputInjectorChromeos::InputInjectorChromeos(
     scoped_refptr<base::SingleThreadTaskRunner> task_runner)
     : input_task_runner_(task_runner) {
-  NOTIMPLEMENTED();
+  ui::OzonePlatform* ozone_platform = ui::OzonePlatform::GetInstance();
+  core_.reset(new Core(ozone_platform->CreateSystemInputInjector()));
 }
 
 InputInjectorChromeos::~InputInjectorChromeos() {
-  NOTIMPLEMENTED();
+  input_task_runner_->DeleteSoon(FROM_HERE, core_.release());
 }
 
 void InputInjectorChromeos::InjectClipboardEvent(const ClipboardEvent& event) {
-  NOTIMPLEMENTED();
+  input_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&Core::InjectClipboardEvent,
+                            base::Unretained(core_.get()), event));
 }
 
 void InputInjectorChromeos::InjectKeyEvent(const KeyEvent& event) {
-  NOTIMPLEMENTED();
+  input_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&Core::InjectKeyEvent, base::Unretained(core_.get()), event));
 }
 
 void InputInjectorChromeos::InjectTextEvent(const TextEvent& event) {
-  NOTIMPLEMENTED();
+  input_task_runner_->PostTask(
+      FROM_HERE,
+      base::Bind(&Core::InjectTextEvent, base::Unretained(core_.get()), event));
 }
 
 void InputInjectorChromeos::InjectMouseEvent(const MouseEvent& event) {
-  NOTIMPLEMENTED();
+  input_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&Core::InjectMouseEvent,
+                            base::Unretained(core_.get()), event));
 }
 
 void InputInjectorChromeos::Start(
     scoped_ptr<protocol::ClipboardStub> client_clipboard) {
-  NOTIMPLEMENTED();
+  input_task_runner_->PostTask(
+      FROM_HERE, base::Bind(&Core::Start, base::Unretained(core_.get()),
+                            base::Passed(&client_clipboard)));
 }
 
 // static
 scoped_ptr<InputInjector> InputInjector::Create(
     scoped_refptr<base::SingleThreadTaskRunner> input_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner) {
-  scoped_ptr<InputInjectorChromeos> injector(new InputInjectorChromeos(
-      ui_task_runner));
-  return injector.Pass();
+  return make_scoped_ptr(new InputInjectorChromeos(ui_task_runner));
 }
 
 }  // namespace remoting