[CRD iOS] Trackpad Input Mode

remoting/client/ui/trackpad_input_strategy.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/ui/trackpad_input_strategy.h"
+
+#include "remoting/client/ui/desktop_viewport.h"
+
+namespace remoting {
+
+namespace {
+
+// Trackpad mode does not need tap feedback.
+const float kTapFeedbackRadius = 0.f;
+
+const float kDragFeedbackRadius = 8.f;
+
+}  // namespace
+
+TrackpadInputStrategy::TrackpadInputStrategy(const DesktopViewport& viewport)
+    : cursor_position_(viewport.GetViewportCenter()) {}
+
+TrackpadInputStrategy::~TrackpadInputStrategy() {}
+
+void TrackpadInputStrategy::HandleZoom(const ViewMatrix::Point& pivot,
+                                       float scale,
+                                       DesktopViewport* viewport) {
+  // The cursor position is the pivot point.
+  ViewMatrix::Point cursor_pivot =
+      viewport->GetTransformation().MapPoint(cursor_position_);
+  viewport->ScaleDesktop(cursor_pivot.x, cursor_pivot.y, scale);
+
+  // Keep the cursor on focus.
+  viewport->SetViewportCenter(cursor_position_.x, cursor_position_.y);
+}
+
+bool TrackpadInputStrategy::HandlePan(const ViewMatrix::Vector2D& translation,
+                                      Gesture simultaneous_gesture,
+                                      DesktopViewport* viewport) {
+  if (simultaneous_gesture == ZOOM) {
+    // Don't move the cursor if the user is scaling the viewport.
+    return false;
+  }
+  ViewMatrix::Vector2D translation_on_desktop =
+      viewport->GetTransformation().Invert().MapVector(translation);
+
+  cursor_position_.x += translation_on_desktop.x;
+  cursor_position_.y += translation_on_desktop.y;
+
+  cursor_position_ = viewport->ConstrainPointToDesktop(cursor_position_);
+
+  // Keep the cursor on focus.
+  viewport->SetViewportCenter(cursor_position_.x, cursor_position_.y);
+  return true;
+}
+
+void TrackpadInputStrategy::TrackTouchInput(
+    const ViewMatrix::Point& touch_point,
+    const DesktopViewport& viewport) {
+  // Do nothing. The cursor position is independent of the touch position.
+}
+
+ViewMatrix::Point TrackpadInputStrategy::GetCursorPosition() const {
+  return cursor_position_;
+}
+
+ViewMatrix::Vector2D TrackpadInputStrategy::MapScreenVectorToDesktop(
+    const ViewMatrix::Vector2D& delta,
+    const DesktopViewport& viewport) const {
+  // No conversion is needed for trackpad mode.
+  return delta;
+}
+
+float TrackpadInputStrategy::GetFeedbackRadius(InputFeedbackType type) const {
+  switch (type) {
+    case InputFeedbackType::TAP_FEEDBACK:
+      return kTapFeedbackRadius;
+    case InputFeedbackType::DRAG_FEEDBACK:
+      return kDragFeedbackRadius;
+  }
+  NOTREACHED();
+  return 0.f;
+}
+
+bool TrackpadInputStrategy::IsCursorVisible() const {
+  return true;
+}
+}  // namespace remoting