Input Injection API on Ozone

ui/ozone/public/system_input_injector.h

Index: ui/ozone/public/system_input_injector.h
diff --git a/ui/ozone/public/system_input_injector.h b/ui/ozone/public/system_input_injector.h
new file mode 100644
index 0000000000000000000000000000000000000000..5ce8db9ecaf90ad839d0d2375e9b3385f34934be
--- /dev/null
+++ b/ui/ozone/public/system_input_injector.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef UI_OZONE_PUBLIC_SYSTEM_INPUT_INJECTOR_H_
+#define UI_OZONE_PUBLIC_SYSTEM_INPUT_INJECTOR_H_
+
+#include "base/memory/scoped_ptr.h"
+#include "ui/events/event.h"
+#include "ui/events/keycodes/dom4/keycode_converter.h"
+#include "ui/gfx/geometry/point_f.h"
+#include "ui/ozone/ozone_export.h"
+
+namespace gfx {
+class PointF;
+}  // namespace gfx
+
+namespace ui {
+class Event;
+
+// Interface for converting input into ui::Events and injecting them to the
+// Ozone platform.
+class OZONE_EXPORT SystemInputInjector {
+ public:
+  SystemInputInjector() {};
+  virtual ~SystemInputInjector() {};
+
+  // Moves the cursor on the screen and generates the corresponding MouseMove or
+  // MouseDragged event.  |location| is in physical screen co-ordinates,
+  // independent of the scale factor and the display rotation settings.
+  virtual void MoveCursorTo(const gfx::PointF& location) = 0;

[kelvinp, 2014/11/25 04:43:08]

Why separate injection functions instead of one PostEvent?
I find the PostEvent(Event* event) signature too generic and can lead to
ambiguity like:
1. What event types are supported?
2. Should I inject a MouseMoved event or call MoveCursorTo?
3. What flags in the event are ignored?
4. Are the mouse location in device independent pixels or physical pixels.
Separating different event types into different function addresses those
ambiguity.
 

+
+  // Simulates a mouse button click.  |button| must be one of
+  // EF_LEFT_MOUSE_BUTTON, EF_RIGHT_MOUSE_BUTTON or EF_MIDDLE_MOUSE_BUTTON.
+  // SystemInputInjector will apply the correct modifiers (shift, ctrl, etc).
+  virtual void InjectMouseButton(EventFlags button, bool down) = 0;
+
+  // |delta_x| and |delta_y| are in physical pixels independent of the scale
+  // factor.
+  virtual void InjectMouseWheel(int delta_x, int delta_y) = 0;
+
+  // Simulates a key press.  SystemInputInjector maps |physical_key| to the
+  // correct logical key based on the current keyboard layout.
+  virtual void InjectKeyPress(DomKey physical_key, bool down) = 0;

[kpschoedel, 2014/11/25 15:39:24]

ui::DomCode for physical keys.
ui/events/keycodes/dom3/dom_code.h

Practically speaking dom_code == static_cast<DomCode>(usb_code) but it might be
desirable to hide that behind a KeycodeConverter::UsbKeycodeToDomCode()
function.

[kelvinp, 2014/11/25 21:16:49]

Good idea.  I will add the function
KeycodeConverter::UsbKeycodeToDomCode()
in a separate change

+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(SystemInputInjector);
+};
+
+}  // namespace ui
+
+#endif  // UI_OZONE_PUBLIC_SYSTEM_INPUT_INJECTOR_H_