1 files changed, 306 insertions, 0 deletions
diff --git a/dom/events/PointerEvent.cpp b/dom/events/PointerEvent.cpp
new file mode 100644
index 0000000000..eac8c54a75
--- /dev/null
+++ b/dom/events/PointerEvent.cpp
@@ -0,0 +1,306 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * Portions Copyright 2013 Microsoft Open Technologies, Inc. */
+
+#include "mozilla/dom/MouseEventBinding.h"
+#include "mozilla/dom/PointerEvent.h"
+#include "mozilla/dom/PointerEventBinding.h"
+#include "mozilla/dom/PointerEventHandler.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/StaticPrefs_dom.h"
+#include "nsContentUtils.h"
+#include "prtime.h"
+#include "jsfriendapi.h"
+
+namespace mozilla::dom {
+
+PointerEvent::PointerEvent(EventTarget* aOwner, nsPresContext* aPresContext,
+                           WidgetPointerEvent* aEvent)
+    : MouseEvent(aOwner, aPresContext,
+                 aEvent ? aEvent
+                        : new WidgetPointerEvent(false, eVoidEvent, nullptr)) {
+  NS_ASSERTION(mEvent->mClass == ePointerEventClass,
+               "event type mismatch ePointerEventClass");
+
+  WidgetMouseEvent* mouseEvent = mEvent->AsMouseEvent();
+  if (aEvent) {
+    mEventIsInternal = false;
+  } else {
+    mEventIsInternal = true;
+    mEvent->mRefPoint = LayoutDeviceIntPoint(0, 0);
+    mouseEvent->mInputSource = MouseEvent_Binding::MOZ_SOURCE_UNKNOWN;
+  }
+  // 5.2 Pointer Event types, for all pointer events, |detail| attribute SHOULD
+  // be 0.
+  mDetail = 0;
+}
+
+JSObject* PointerEvent::WrapObjectInternal(JSContext* aCx,
+                                           JS::Handle<JSObject*> aGivenProto) {
+  return PointerEvent_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+static uint16_t ConvertStringToPointerType(const nsAString& aPointerTypeArg) {
+  if (aPointerTypeArg.EqualsLiteral("mouse")) {
+    return MouseEvent_Binding::MOZ_SOURCE_MOUSE;
+  }
+  if (aPointerTypeArg.EqualsLiteral("pen")) {
+    return MouseEvent_Binding::MOZ_SOURCE_PEN;
+  }
+  if (aPointerTypeArg.EqualsLiteral("touch")) {
+    return MouseEvent_Binding::MOZ_SOURCE_TOUCH;
+  }
+
+  return MouseEvent_Binding::MOZ_SOURCE_UNKNOWN;
+}
+
+void ConvertPointerTypeToString(uint16_t aPointerTypeSrc,
+                                nsAString& aPointerTypeDest) {
+  switch (aPointerTypeSrc) {
+    case MouseEvent_Binding::MOZ_SOURCE_MOUSE:
+      aPointerTypeDest.AssignLiteral("mouse");
+      break;
+    case MouseEvent_Binding::MOZ_SOURCE_PEN:
+      aPointerTypeDest.AssignLiteral("pen");
+      break;
+    case MouseEvent_Binding::MOZ_SOURCE_TOUCH:
+      aPointerTypeDest.AssignLiteral("touch");
+      break;
+    default:
+      aPointerTypeDest.Truncate();
+      break;
+  }
+}
+
+// static
+already_AddRefed<PointerEvent> PointerEvent::Constructor(
+    EventTarget* aOwner, const nsAString& aType,
+    const PointerEventInit& aParam) {
+  RefPtr<PointerEvent> e = new PointerEvent(aOwner, nullptr, nullptr);
+  bool trusted = e->Init(aOwner);
+
+  e->InitMouseEvent(aType, aParam.mBubbles, aParam.mCancelable, aParam.mView,
+                    aParam.mDetail, aParam.mScreenX, aParam.mScreenY,
+                    aParam.mClientX, aParam.mClientY, false, false, false,
+                    false, aParam.mButton, aParam.mRelatedTarget);
+  e->InitializeExtraMouseEventDictionaryMembers(aParam);
+  e->mPointerType = Some(aParam.mPointerType);
+
+  WidgetPointerEvent* widgetEvent = e->mEvent->AsPointerEvent();
+  widgetEvent->pointerId = aParam.mPointerId;
+  widgetEvent->mWidth = aParam.mWidth;
+  widgetEvent->mHeight = aParam.mHeight;
+  widgetEvent->mPressure = aParam.mPressure;
+  widgetEvent->tangentialPressure = aParam.mTangentialPressure;
+  widgetEvent->tiltX = aParam.mTiltX;
+  widgetEvent->tiltY = aParam.mTiltY;
+  widgetEvent->twist = aParam.mTwist;
+  widgetEvent->mInputSource = ConvertStringToPointerType(aParam.mPointerType);
+  widgetEvent->mIsPrimary = aParam.mIsPrimary;
+  widgetEvent->mButtons = aParam.mButtons;
+
+  if (!aParam.mCoalescedEvents.IsEmpty()) {
+    e->mCoalescedEvents.AppendElements(aParam.mCoalescedEvents);
+  }
+  if (!aParam.mPredictedEvents.IsEmpty()) {
+    e->mPredictedEvents.AppendElements(aParam.mPredictedEvents);
+  }
+  e->SetTrusted(trusted);
+  e->SetComposed(aParam.mComposed);
+  return e.forget();
+}
+
+// static
+already_AddRefed<PointerEvent> PointerEvent::Constructor(
+    const GlobalObject& aGlobal, const nsAString& aType,
+    const PointerEventInit& aParam) {
+  nsCOMPtr<EventTarget> owner = do_QueryInterface(aGlobal.GetAsSupports());
+  return Constructor(owner, aType, aParam);
+}
+
+NS_IMPL_CYCLE_COLLECTION_CLASS(PointerEvent)
+
+NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(PointerEvent, MouseEvent)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mCoalescedEvents)
+  NS_IMPL_CYCLE_COLLECTION_UNLINK(mPredictedEvents)
+NS_IMPL_CYCLE_COLLECTION_UNLINK_END
+
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(PointerEvent, MouseEvent)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mCoalescedEvents)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPredictedEvents)
+NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
+
+NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PointerEvent)
+NS_INTERFACE_MAP_END_INHERITING(MouseEvent)
+
+NS_IMPL_ADDREF_INHERITED(PointerEvent, MouseEvent)
+NS_IMPL_RELEASE_INHERITED(PointerEvent, MouseEvent)
+
+void PointerEvent::GetPointerType(nsAString& aPointerType) {
+  if (mPointerType.isSome()) {
+    aPointerType = mPointerType.value();
+    return;
+  }
+
+  if (ShouldResistFingerprinting()) {
+    aPointerType.AssignLiteral("mouse");
+    return;
+  }
+
+  ConvertPointerTypeToString(mEvent->AsPointerEvent()->mInputSource,
+                             aPointerType);
+}
+
+int32_t PointerEvent::PointerId() {
+  return ShouldResistFingerprinting()
+             ? PointerEventHandler::GetSpoofedPointerIdForRFP()
+             : mEvent->AsPointerEvent()->pointerId;
+}
+
+int32_t PointerEvent::Width() {
+  return ShouldResistFingerprinting() ? 1 : mEvent->AsPointerEvent()->mWidth;
+}
+
+int32_t PointerEvent::Height() {
+  return ShouldResistFingerprinting() ? 1 : mEvent->AsPointerEvent()->mHeight;
+}
+
+float PointerEvent::Pressure() {
+  if (mEvent->mMessage == ePointerUp || !ShouldResistFingerprinting()) {
+    return mEvent->AsPointerEvent()->mPressure;
+  }
+
+  // According to [1], we should use 0.5 when it is in active buttons state and
+  // 0 otherwise for devices that don't support pressure. And a pointerup event
+  // always reports 0, so we don't need to spoof that.
+  //
+  // [1] https://www.w3.org/TR/pointerevents/#dom-pointerevent-pressure
+  float spoofedPressure = 0.0;
+  if (mEvent->AsPointerEvent()->mButtons) {
+    spoofedPressure = 0.5;
+  }
+
+  return spoofedPressure;
+}
+
+float PointerEvent::TangentialPressure() {
+  return ShouldResistFingerprinting()
+             ? 0
+             : mEvent->AsPointerEvent()->tangentialPressure;
+}
+
+int32_t PointerEvent::TiltX() {
+  return ShouldResistFingerprinting() ? 0 : mEvent->AsPointerEvent()->tiltX;
+}
+
+int32_t PointerEvent::TiltY() {
+  return ShouldResistFingerprinting() ? 0 : mEvent->AsPointerEvent()->tiltY;
+}
+
+int32_t PointerEvent::Twist() {
+  return ShouldResistFingerprinting() ? 0 : mEvent->AsPointerEvent()->twist;
+}
+
+bool PointerEvent::IsPrimary() { return mEvent->AsPointerEvent()->mIsPrimary; }
+
+bool PointerEvent::EnableGetCoalescedEvents(JSContext* aCx, JSObject* aGlobal) {
+  return !StaticPrefs::
+             dom_w3c_pointer_events_getcoalescedevents_only_in_securecontext() ||
+         nsContentUtils::IsSecureContextOrWebExtension(aCx, aGlobal);
+}
+
+void PointerEvent::GetCoalescedEvents(
+    nsTArray<RefPtr<PointerEvent>>& aPointerEvents) {
+  WidgetPointerEvent* widgetEvent = mEvent->AsPointerEvent();
+  if (mCoalescedEvents.IsEmpty() && widgetEvent &&
+      widgetEvent->mCoalescedWidgetEvents &&
+      !widgetEvent->mCoalescedWidgetEvents->mEvents.IsEmpty()) {
+    nsCOMPtr<EventTarget> owner = do_QueryInterface(mOwner);
+    for (WidgetPointerEvent& event :
+         widgetEvent->mCoalescedWidgetEvents->mEvents) {
+      RefPtr<PointerEvent> domEvent =
+          NS_NewDOMPointerEvent(owner, nullptr, &event);
+
+      // The dom event is derived from an OS generated widget event. Setup
+      // mWidget and mPresContext since they are necessary to calculate
+      // offsetX / offsetY.
+      domEvent->mEvent->AsGUIEvent()->mWidget = widgetEvent->mWidget;
+      domEvent->mPresContext = mPresContext;
+
+      // The coalesced widget mouse events shouldn't have been dispatched.
+      MOZ_ASSERT(!domEvent->mEvent->mTarget);
+      // The event target should be the same as the dispatched event's target.
+      domEvent->mEvent->mTarget = mEvent->mTarget;
+
+      // JS could hold reference to dom events. We have to ask dom event to
+      // duplicate its private data to avoid the widget event is destroyed.
+      domEvent->DuplicatePrivateData();
+
+      // Setup mPresContext again after DuplicatePrivateData since it clears
+      // mPresContext.
+      domEvent->mPresContext = mPresContext;
+      mCoalescedEvents.AppendElement(domEvent);
+    }
+  }
+  if (mEvent->IsTrusted() && mEvent->mTarget) {
+    for (RefPtr<PointerEvent>& pointerEvent : mCoalescedEvents) {
+      // Only set event target when it's null.
+      if (!pointerEvent->mEvent->mTarget) {
+        pointerEvent->mEvent->mTarget = mEvent->mTarget;
+      }
+    }
+  }
+  aPointerEvents.AppendElements(mCoalescedEvents);
+}
+
+void PointerEvent::GetPredictedEvents(
+    nsTArray<RefPtr<PointerEvent>>& aPointerEvents) {
+  // XXX Add support for native predicted events, bug 1550461
+  if (mEvent->IsTrusted() && mEvent->mTarget) {
+    for (RefPtr<PointerEvent>& pointerEvent : mPredictedEvents) {
+      // Only set event target when it's null.
+      if (!pointerEvent->mEvent->mTarget) {
+        pointerEvent->mEvent->mTarget = mEvent->mTarget;
+      }
+    }
+  }
+  aPointerEvents.AppendElements(mPredictedEvents);
+}
+
+bool PointerEvent::ShouldResistFingerprinting() {
+  // There are three simple situations we don't need to spoof this pointer
+  // event.
+  //   1. The pref privcy.resistFingerprinting' is false, we fast return here
+  //      since we don't need to do any QI of following codes.
+  //   2. This event is generated by scripts.
+  //   3. This event is a mouse pointer event.
+  //  We don't need to check for the system group since pointer events won't be
+  //  dispatched to the system group.
+  if (!nsContentUtils::ShouldResistFingerprinting("Efficiency Check",
+                                                  RFPTarget::PointerEvents) ||
+      !mEvent->IsTrusted() ||
+      mEvent->AsPointerEvent()->mInputSource ==
+          MouseEvent_Binding::MOZ_SOURCE_MOUSE) {
+    return false;
+  }
+
+  // Pref is checked above, so use true as fallback.
+  nsCOMPtr<Document> doc = GetDocument();
+  return doc ? doc->ShouldResistFingerprinting(RFPTarget::PointerEvents) : true;
+}
+
+}  // namespace mozilla::dom
+
+using namespace mozilla;
+using namespace mozilla::dom;
+
+already_AddRefed<PointerEvent> NS_NewDOMPointerEvent(
+    EventTarget* aOwner, nsPresContext* aPresContext,
+    WidgetPointerEvent* aEvent) {
+  RefPtr<PointerEvent> it = new PointerEvent(aOwner, aPresContext, aEvent);
+  return it.forget();
+}