[Tracking Patch] Unified gesture detection

content/browser/renderer_host/input/gestures/motion_event.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 "content/browser/renderer_host/input/gestures/motion_event.h"
+
+#include "base/logging.h"
+
+using blink::WebInputEvent;
+using blink::WebTouchEvent;
+using blink::WebTouchPoint;
+
+namespace content {
+namespace {
+
+  bool AllTouchPointsHaveState(const WebTouchEvent& event,
+                             WebTouchPoint::State state) {
+  for (size_t i = 0; i < event.touchesLength; ++i)
+    if (event.touches[i].state != state)
+      return true;
+  return false;
+}
+
+}  // namespace
+
+MotionEvent::MotionEvent(const WebTouchEvent& event) : event(event) {
+  DCHECK_GT(GetPointerCount(), 0U);
+}
+
+MotionEvent::~MotionEvent() {}
+
+MotionEvent::Action MotionEvent::GetActionMasked() const {
+  switch (event.type) {
+    case WebInputEvent::TouchStart:
+      if (AllTouchPointsHaveState(event, WebTouchPoint::StatePressed))
+        return ACTION_DOWN;
+      else
+        return ACTION_POINTER_DOWN;
+    case WebInputEvent::TouchEnd:
+      if (AllTouchPointsHaveState(event, WebTouchPoint::StateReleased))
+        return ACTION_UP;
+      else
+        return ACTION_POINTER_UP;
+    case WebInputEvent::TouchCancel:
+      DCHECK(AllTouchPointsHaveState(event, WebTouchPoint::StateCancelled));
+      return ACTION_CANCEL;
+    case WebInputEvent::TouchMove:
+      return ACTION_MOVE;
+    default:
+      break;
+  };
+  NOTREACHED() << "Invalid masked MotionEvent action.";
+  return ACTION_CANCEL;
+}
+
+size_t MotionEvent::GetActionIndex() const {
+  for (size_t i = 0; i < GetPointerCount(); ++i) {
+    if (event.touches[i].state != WebTouchPoint::StateUndefined &&
+        event.touches[i].state != WebTouchPoint::StateStationary)
+      return i;
+  }
+  NOTREACHED() << "Invalid MotionEvent action index.";
+  return 0;
+}
+
+size_t MotionEvent::GetPointerCount() const {
+  return event.touchesLength;
+}
+
+int MotionEvent::GetPointerId(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+  return event.touches[pointer_index].id;
+}
+
+float MotionEvent::GetX(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+  return event.touches[pointer_index].position.x;
+}
+
+float MotionEvent::GetY(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+  return event.touches[pointer_index].position.y;
+}
+
+float MotionEvent::GetTouchMajor(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, GetPointerCount());
+  // TODO(jdduke): We should be a bit more careful about axes here.
+  return std::max(event.touches[pointer_index].radiusX,
+                  event.touches[pointer_index].radiusY);
+}
+
+base::TimeTicks MotionEvent::GetEventTime() const {
+  return base::TimeTicks() +
+         base::TimeDelta::FromMicroseconds(event.timeStampSeconds * 1000000);
+}
+
+base::TimeTicks MotionEvent::GetDownTime() const {
+  return base::TimeTicks() +
+         base::TimeDelta::FromMicroseconds(event.timeStampSeconds * 1000000);
+}
+
+size_t MotionEvent::GetHistorySize() const {
+  return 0;
+}
+
+base::TimeTicks MotionEvent::GetHistoricalEventTime(
+    size_t historical_index) const {
+  NOTIMPLEMENTED();
+  return base::TimeTicks();
+}
+
+float MotionEvent::GetHistoricalTouchMajor(size_t pointer_index,
+                                           size_t historical_index) const {
+  NOTIMPLEMENTED();
+  return 0.f;
+}
+
+float MotionEvent::GetHistoricalX(size_t pointer_index,
+                                  size_t historical_index) const {
+  NOTIMPLEMENTED();
+  return 0.f;
+}
+
+float MotionEvent::GetHistoricalY(size_t pointer_index,
+                                  size_t historical_index) const {
+  NOTIMPLEMENTED();
+  return 0.f;
+}
+
+}  // namespace content