[Remoting iOS] Basic viewport manipulation support

remoting/client/gesture_interpreter.cc

+// Copyright 2017 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/client/gesture_interpreter.h"
+
+#include "base/logging.h"
+
+namespace remoting {
+
+GestureInterpreter::GestureInterpreter(
+    const DesktopViewport::TransformationCallback& on_transformation_changed) {
+  viewport_.RegisterOnTransformationChangedCallback(on_transformation_changed,
+                                                    true);
+}
+
+GestureInterpreter::~GestureInterpreter() {}
+
+void GestureInterpreter::Pinch(float pivot_x, float pivot_y, float scale) {
+  viewport_.ScaleDesktop(pivot_x, pivot_y, scale);
+}
+
+void GestureInterpreter::Pan(float translation_x, float translation_y) {
+  // TODO(yuweih): Handle trackpad mode where the viewport always focus on the
+  //     cursor.
+  viewport_.MoveDesktop(translation_x, translation_y);
+}
+
+void GestureInterpreter::Tap(float x, float y) {
+  NOTIMPLEMENTED();
+}
+
+void GestureInterpreter::LongPress(float x, float y) {
+  NOTIMPLEMENTED();
+}
+
+void GestureInterpreter::OnSurfaceSizeChanged(int width, int height) {
+  viewport_.SetSurfaceSize(width, height);
+}
+
+void GestureInterpreter::OnDesktopSizeChanged(int width, int height) {
+  viewport_.SetDesktopSize(width, height);
+}
+
+}  // namespace remoting