1 files changed, 235 insertions, 0 deletions
diff --git a/dom/events/PointerEventHandler.h b/dom/events/PointerEventHandler.h
new file mode 100644
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+++ b/dom/events/PointerEventHandler.h
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+/* -*- 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/. */
+
+#ifndef mozilla_PointerEventHandler_h
+#define mozilla_PointerEventHandler_h
+
+#include "mozilla/EventForwards.h"
+#include "mozilla/MouseEvents.h"
+#include "mozilla/TouchEvents.h"
+#include "mozilla/WeakPtr.h"
+
+// XXX Avoid including this here by moving function bodies to the cpp file
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/Element.h"
+
+class nsIFrame;
+class nsIContent;
+class nsPresContext;
+
+namespace mozilla {
+
+class PresShell;
+
+namespace dom {
+class BrowserParent;
+class Document;
+class Element;
+};  // namespace dom
+
+class PointerCaptureInfo final {
+ public:
+  RefPtr<dom::Element> mPendingElement;
+  RefPtr<dom::Element> mOverrideElement;
+
+  explicit PointerCaptureInfo(dom::Element* aPendingElement)
+      : mPendingElement(aPendingElement) {
+    MOZ_COUNT_CTOR(PointerCaptureInfo);
+  }
+
+  MOZ_COUNTED_DTOR(PointerCaptureInfo)
+
+  bool Empty() { return !(mPendingElement || mOverrideElement); }
+};
+
+class PointerInfo final {
+ public:
+  uint16_t mPointerType;
+  bool mActiveState;
+  bool mPrimaryState;
+  bool mPreventMouseEventByContent;
+  WeakPtr<dom::Document> mActiveDocument;
+  explicit PointerInfo(bool aActiveState, uint16_t aPointerType,
+                       bool aPrimaryState, dom::Document* aActiveDocument)
+      : mPointerType(aPointerType),
+        mActiveState(aActiveState),
+        mPrimaryState(aPrimaryState),
+        mPreventMouseEventByContent(false),
+        mActiveDocument(aActiveDocument) {}
+};
+
+class PointerEventHandler final {
+ public:
+  // Called in nsLayoutStatics::Initialize/Shutdown to initialize pointer event
+  // related static variables.
+  static void InitializeStatics();
+  static void ReleaseStatics();
+
+  // Return the preference value of implicit capture.
+  static bool IsPointerEventImplicitCaptureForTouchEnabled();
+
+  // Called in ESM::PreHandleEvent to update current active pointers in a hash
+  // table.
+  static void UpdateActivePointerState(WidgetMouseEvent* aEvent,
+                                       nsIContent* aTargetContent = nullptr);
+
+  // Request/release pointer capture of the specified pointer by the element.
+  static void RequestPointerCaptureById(uint32_t aPointerId,
+                                        dom::Element* aElement);
+  static void ReleasePointerCaptureById(uint32_t aPointerId);
+  static void ReleaseAllPointerCapture();
+
+  // Set/release pointer capture of the specified pointer by the remote target.
+  // Should only be called in parent process.
+  static bool SetPointerCaptureRemoteTarget(uint32_t aPointerId,
+                                            dom::BrowserParent* aBrowserParent);
+  static void ReleasePointerCaptureRemoteTarget(
+      dom::BrowserParent* aBrowserParent);
+  static void ReleasePointerCaptureRemoteTarget(uint32_t aPointerId);
+  static void ReleaseAllPointerCaptureRemoteTarget();
+
+  // Get the pointer capturing remote target of the specified pointer.
+  static dom::BrowserParent* GetPointerCapturingRemoteTarget(
+      uint32_t aPointerId);
+
+  // Get the pointer captured info of the specified pointer.
+  static PointerCaptureInfo* GetPointerCaptureInfo(uint32_t aPointerId);
+
+  // Return the PointerInfo if the pointer with aPointerId is situated in device
+  // , nullptr otherwise.
+  static const PointerInfo* GetPointerInfo(uint32_t aPointerId);
+
+  // CheckPointerCaptureState checks cases, when got/lostpointercapture events
+  // should be fired.
+  MOZ_CAN_RUN_SCRIPT
+  static void MaybeProcessPointerCapture(WidgetGUIEvent* aEvent);
+  MOZ_CAN_RUN_SCRIPT
+  static void ProcessPointerCaptureForMouse(WidgetMouseEvent* aEvent);
+  MOZ_CAN_RUN_SCRIPT
+  static void ProcessPointerCaptureForTouch(WidgetTouchEvent* aEvent);
+  MOZ_CAN_RUN_SCRIPT
+  static void CheckPointerCaptureState(WidgetPointerEvent* aEvent);
+
+  // Implicitly get and release capture of current pointer for touch.
+  static void ImplicitlyCapturePointer(nsIFrame* aFrame, WidgetEvent* aEvent);
+  MOZ_CAN_RUN_SCRIPT
+  static void ImplicitlyReleasePointerCapture(WidgetEvent* aEvent);
+
+  /**
+   * GetPointerCapturingContent returns a target element which captures the
+   * pointer. It's applied to mouse or pointer event (except mousedown and
+   * pointerdown). When capturing, return the element. Otherwise, nullptr.
+   *
+   * @param aEvent               A mouse event or pointer event which may be
+   *                             captured.
+   *
+   * @return                     Target element for aEvent.
+   */
+  static dom::Element* GetPointerCapturingElement(WidgetGUIEvent* aEvent);
+
+  static dom::Element* GetPointerCapturingElement(uint32_t aPointerId);
+
+  // Release pointer capture if captured by the specified content or it's
+  // descendant. This is called to handle the case that the pointer capturing
+  // content or it's parent is removed from the document.
+  static void ReleaseIfCaptureByDescendant(nsIContent* aContent);
+
+  /*
+   * This function handles the case when content had called preventDefault on
+   * the active pointer. In that case we have to prevent firing subsequent mouse
+   * to content. We check the flag PointerInfo::mPreventMouseEventByContent and
+   * call PreventDefault(false) to stop default behaviors and stop firing mouse
+   * events to content and chrome.
+   *
+   * note: mouse transition events are excluded
+   * note: we have to clean mPreventMouseEventByContent on pointerup for those
+   *       devices support hover
+   * note: we don't suppress firing mouse events to chrome and system group
+   *       handlers because they may implement default behaviors
+   */
+  static void PreHandlePointerEventsPreventDefault(
+      WidgetPointerEvent* aPointerEvent, WidgetGUIEvent* aMouseOrTouchEvent);
+
+  /*
+   * This function handles the preventDefault behavior of pointerdown. When user
+   * preventDefault on pointerdown, We have to mark the active pointer to
+   * prevent sebsequent mouse events (except mouse transition events) and
+   * default behaviors.
+   *
+   * We add mPreventMouseEventByContent flag in PointerInfo to represent the
+   * active pointer won't firing compatible mouse events. It's set to true when
+   * content preventDefault on pointerdown
+   */
+  static void PostHandlePointerEventsPreventDefault(
+      WidgetPointerEvent* aPointerEvent, WidgetGUIEvent* aMouseOrTouchEvent);
+
+  MOZ_CAN_RUN_SCRIPT
+  static void DispatchPointerFromMouseOrTouch(
+      PresShell* aShell, nsIFrame* aFrame, nsIContent* aContent,
+      WidgetGUIEvent* aEvent, bool aDontRetargetEvents, nsEventStatus* aStatus,
+      nsIContent** aTargetContent);
+
+  static void InitPointerEventFromMouse(WidgetPointerEvent* aPointerEvent,
+                                        WidgetMouseEvent* aMouseEvent,
+                                        EventMessage aMessage);
+
+  static void InitPointerEventFromTouch(WidgetPointerEvent* aPointerEvent,
+                                        WidgetTouchEvent* aTouchEvent,
+                                        mozilla::dom::Touch* aTouch,
+                                        bool aIsPrimary);
+
+  static bool ShouldGeneratePointerEventFromMouse(WidgetGUIEvent* aEvent) {
+    return aEvent->mMessage == eMouseDown || aEvent->mMessage == eMouseUp ||
+           aEvent->mMessage == eMouseMove ||
+           aEvent->mMessage == eMouseExitFromWidget;
+  }
+
+  static bool ShouldGeneratePointerEventFromTouch(WidgetGUIEvent* aEvent) {
+    return aEvent->mMessage == eTouchStart || aEvent->mMessage == eTouchMove ||
+           aEvent->mMessage == eTouchEnd || aEvent->mMessage == eTouchCancel ||
+           aEvent->mMessage == eTouchPointerCancel;
+  }
+
+  static MOZ_ALWAYS_INLINE int32_t GetSpoofedPointerIdForRFP() {
+    return sSpoofedPointerId.valueOr(0);
+  }
+
+  static void NotifyDestroyPresContext(nsPresContext* aPresContext);
+
+ private:
+  // Set pointer capture of the specified pointer by the element.
+  static void SetPointerCaptureById(uint32_t aPointerId,
+                                    dom::Element* aElement);
+
+  // GetPointerType returns pointer type like mouse, pen or touch for pointer
+  // event with pointerId. The return value must be one of
+  // MouseEvent_Binding::MOZ_SOURCE_*
+  static uint16_t GetPointerType(uint32_t aPointerId);
+
+  // GetPointerPrimaryState returns state of attribute isPrimary for pointer
+  // event with pointerId
+  static bool GetPointerPrimaryState(uint32_t aPointerId);
+
+  MOZ_CAN_RUN_SCRIPT
+  static void DispatchGotOrLostPointerCaptureEvent(
+      bool aIsGotCapture, const WidgetPointerEvent* aPointerEvent,
+      dom::Element* aCaptureTarget);
+
+  // The cached spoofed pointer ID for fingerprinting resistance. We will use a
+  // mouse pointer id for desktop. For mobile, we should use the touch pointer
+  // id as the spoofed one, and this work will be addressed in Bug 1492775.
+  static Maybe<int32_t> sSpoofedPointerId;
+
+  // A helper function to cache the pointer id of the spoofed interface, we
+  // would only cache the pointer id once. After that, we would always stick to
+  // that pointer id for fingerprinting resistance.
+  static void MaybeCacheSpoofedPointerID(uint16_t aInputSource,
+                                         uint32_t aPointerId);
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_PointerEventHandler_h