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

remoting/host/chromeos/point_transformer.h

+// 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 REMOTING_HOST_CHROMEOS_POINT_TRANSFORMER_H_
+#define REMOTING_HOST_CHROMEOS_POINT_TRANSFORMER_H_
+
+#include "ui/aura/window_observer.h"
+#include "ui/gfx/geometry/point_f.h"
+#include "ui/gfx/transform.h"
+
+namespace aura {
+class Window;
+}  // namespace aura
+
+namespace remoting {
+
+// A class that performs coordinate transformations between the root window
+// coordinates and the native screen coordinates, according to the current
+// display rotation settings.
+//
+// Root window coordinates are expressed relative to the top left corner of the
+// root window whereas native screen coordinates are expressed relative to the
+// top left corner of the frame buffer, which may not match the root window
+// either in origin nor orientation.  Both coordinate systems are always in
+// device pixels.
+//
+// For example, when the display is rotated by 90 deg, the pixel at root window
+// coordinates (x, y) will have native screen coordinates (height - y, x).
+class PointTransformer : public aura::WindowObserver {
+ public:
+  PointTransformer();
+  ~PointTransformer() override;
+
+  // Converts from root window coordinates to native screen coordinates.
+  gfx::PointF ToScreenCoordinates(const gfx::PointF& window_location);
+
+  // Converts from native screen coordinates to root window coordinates.
+  gfx::PointF FromScreenCoordinates(const gfx::PointF& screen_location);
+
+ private:
+  // aura::WindowObserver interface.
+  void OnWindowTransformed(aura::Window* window) override;
+
+  aura::Window* root_window_;
+  gfx::Transform root_to_screen_;
+  gfx::Transform screen_to_root_;
+
+  DISALLOW_COPY_AND_ASSIGN(PointTransformer);
+};
+
+}  // namespace remoting
+
+#endif  // REMOTING_HOST_CHROMEOS_POINT_TRANSFORMER_H_