Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 388 insertions, 0 deletions

diff --git a/dom/events/EventDispatcher.h b/dom/events/EventDispatcher.h
new file mode 100644
index 0000000000..a7305f177f
--- /dev/null
+++ b/dom/events/EventDispatcher.h
@@ -0,0 +1,388 @@
+/* -*- 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/. */
+
+#ifdef MOZILLA_INTERNAL_API
+#  ifndef mozilla_EventDispatcher_h_
+#    define mozilla_EventDispatcher_h_
+
+#    include "mozilla/dom/BindingDeclarations.h"
+#    include "mozilla/dom/Touch.h"
+#    include "mozilla/EventForwards.h"
+#    include "mozilla/Maybe.h"
+#    include "nsCOMPtr.h"
+#    include "nsTArray.h"
+
+// Microsoft's API Name hackery sucks
+#    undef CreateEvent
+
+class nsIContent;
+class nsPresContext;
+
+template <class E>
+class nsCOMArray;
+
+namespace mozilla {
+namespace dom {
+class Event;
+class EventTarget;
+}  // namespace dom
+
+/**
+ * About event dispatching:
+ * When either EventDispatcher::Dispatch or
+ * EventDispatcher::DispatchDOMEvent is called an event target chain is
+ * created. EventDispatcher creates the chain by calling GetEventTargetParent
+ * on each event target and the creation continues until either the mCanHandle
+ * member of the EventChainPreVisitor object is false or the mParentTarget
+ * does not point to a new target. The event target chain is created in the
+ * heap.
+ *
+ * If the event needs retargeting, mEventTargetAtParent must be set in
+ * GetEventTargetParent.
+ *
+ * The capture, target and bubble phases of the event dispatch are handled
+ * by iterating through the event target chain. Iteration happens twice,
+ * first for the default event group and then for the system event group.
+ * While dispatching the event for the system event group PostHandleEvent
+ * is called right after calling event listener for the current event target.
+ */
+
+class MOZ_STACK_CLASS EventChainVisitor {
+ public:
+  // For making creators of this class instances guarantee the lifetime of
+  // aPresContext, this needs to be marked as MOZ_CAN_RUN_SCRIPT.
+  MOZ_CAN_RUN_SCRIPT
+  EventChainVisitor(nsPresContext* aPresContext, WidgetEvent* aEvent,
+                    dom::Event* aDOMEvent,
+                    nsEventStatus aEventStatus = nsEventStatus_eIgnore)
+      : mPresContext(aPresContext),
+        mEvent(aEvent),
+        mDOMEvent(aDOMEvent),
+        mEventStatus(aEventStatus),
+        mItemFlags(0) {}
+
+  /**
+   * The prescontext, possibly nullptr.
+   * Note that the lifetime of mPresContext is guaranteed by the creators.
+   */
+  MOZ_KNOWN_LIVE nsPresContext* const mPresContext;
+
+  /**
+   * The WidgetEvent which is being dispatched. Never nullptr.
+   */
+  WidgetEvent* const mEvent;
+
+  /**
+   * The DOM Event assiciated with the mEvent. Possibly nullptr if a DOM Event
+   * is not (yet) created.
+   */
+  dom::Event* mDOMEvent;
+
+  /**
+   * The status of the event.
+   * @see nsEventStatus.h
+   */
+  nsEventStatus mEventStatus;
+
+  /**
+   * Bits for items in the event target chain.
+   * Set in GetEventTargetParent() and used in PostHandleEvent().
+   *
+   * @note These bits are different for each item in the event target chain.
+   *       It is up to the Pre/PostHandleEvent implementation to decide how to
+   *       use these bits.
+   *
+   * @note Using uint16_t because that is used also in EventTargetChainItem.
+   */
+  uint16_t mItemFlags;
+
+  /**
+   * Data for items in the event target chain.
+   * Set in GetEventTargetParent() and used in PostHandleEvent().
+   *
+   * @note This data is different for each item in the event target chain.
+   *       It is up to the Pre/PostHandleEvent implementation to decide how to
+   *       use this.
+   */
+  nsCOMPtr<nsISupports> mItemData;
+};
+
+class MOZ_STACK_CLASS EventChainPreVisitor final : public EventChainVisitor {
+ public:
+  MOZ_CAN_RUN_SCRIPT
+  EventChainPreVisitor(nsPresContext* aPresContext, WidgetEvent* aEvent,
+                       dom::Event* aDOMEvent, nsEventStatus aEventStatus,
+                       bool aIsInAnon,
+                       dom::EventTarget* aTargetInKnownToBeHandledScope)
+      : EventChainVisitor(aPresContext, aEvent, aDOMEvent, aEventStatus),
+        mCanHandle(true),
+        mAutomaticChromeDispatch(true),
+        mForceContentDispatch(false),
+        mRelatedTargetIsInAnon(false),
+        mOriginalTargetIsInAnon(aIsInAnon),
+        mWantsWillHandleEvent(false),
+        mMayHaveListenerManager(true),
+        mWantsPreHandleEvent(false),
+        mRootOfClosedTree(false),
+        mItemInShadowTree(false),
+        mParentIsSlotInClosedTree(false),
+        mParentIsChromeHandler(false),
+        mRelatedTargetRetargetedInCurrentScope(false),
+        mIgnoreBecauseOfShadowDOM(false),
+        mWantsActivationBehavior(false),
+        mParentTarget(nullptr),
+        mEventTargetAtParent(nullptr),
+        mRetargetedRelatedTarget(nullptr),
+        mTargetInKnownToBeHandledScope(aTargetInKnownToBeHandledScope) {}
+
+  void Reset() {
+    mItemFlags = 0;
+    mItemData = nullptr;
+    mCanHandle = true;
+    mAutomaticChromeDispatch = true;
+    mForceContentDispatch = false;
+    mWantsWillHandleEvent = false;
+    mMayHaveListenerManager = true;
+    mWantsPreHandleEvent = false;
+    mRootOfClosedTree = false;
+    mItemInShadowTree = false;
+    mParentIsSlotInClosedTree = false;
+    mParentIsChromeHandler = false;
+    // Note, we don't clear mRelatedTargetRetargetedInCurrentScope explicitly,
+    // since it is used during event path creation to indicate whether
+    // relatedTarget may need to be retargeted.
+    mIgnoreBecauseOfShadowDOM = false;
+    mWantsActivationBehavior = false;
+    mParentTarget = nullptr;
+    mEventTargetAtParent = nullptr;
+    mRetargetedRelatedTarget = nullptr;
+    mRetargetedTouchTargets.reset();
+  }
+
+  dom::EventTarget* GetParentTarget() { return mParentTarget; }
+
+  void SetParentTarget(dom::EventTarget* aParentTarget, bool aIsChromeHandler) {
+    mParentTarget = aParentTarget;
+    if (mParentTarget) {
+      mParentIsChromeHandler = aIsChromeHandler;
+    }
+  }
+
+  void IgnoreCurrentTargetBecauseOfShadowDOMRetargeting();
+
+  /**
+   * Member that must be set in GetEventTargetParent by event targets. If set to
+   * false, indicates that this event target will not be handling the event and
+   * construction of the event target chain is complete. The target that sets
+   * mCanHandle to false is NOT included in the event target chain.
+   */
+  bool mCanHandle;
+
+  /**
+   * If mCanHandle is false and mAutomaticChromeDispatch is also false
+   * event will not be dispatched to the chrome event handler.
+   */
+  bool mAutomaticChromeDispatch;
+
+  /**
+   * If mForceContentDispatch is set to true,
+   * content dispatching is not disabled for this event target.
+   * FIXME! This is here for backward compatibility. Bug 329119
+   */
+  bool mForceContentDispatch;
+
+  /**
+   * true if it is known that related target is or is a descendant of an
+   * element which is anonymous for events.
+   */
+  bool mRelatedTargetIsInAnon;
+
+  /**
+   * true if the original target of the event is inside anonymous content.
+   * This is set before calling GetEventTargetParent on event targets.
+   */
+  bool mOriginalTargetIsInAnon;
+
+  /**
+   * Whether or not EventTarget::WillHandleEvent will be
+   * called. Default is false;
+   */
+  bool mWantsWillHandleEvent;
+
+  /**
+   * If it is known that the current target doesn't have a listener manager
+   * when GetEventTargetParent is called, set this to false.
+   */
+  bool mMayHaveListenerManager;
+
+  /**
+   * Whether or not EventTarget::PreHandleEvent will be called. Default is
+   * false;
+   */
+  bool mWantsPreHandleEvent;
+
+  /**
+   * True if the current target is either closed ShadowRoot or root of
+   * chrome only access tree (for example native anonymous content).
+   */
+  bool mRootOfClosedTree;
+
+  /**
+   * If target is node and its root is a shadow root.
+   * https://dom.spec.whatwg.org/#event-path-item-in-shadow-tree
+   */
+  bool mItemInShadowTree;
+
+  /**
+   * True if mParentTarget is HTMLSlotElement in a closed shadow tree and the
+   * current target is assigned to that slot.
+   */
+  bool mParentIsSlotInClosedTree;
+
+  /**
+   * True if mParentTarget is a chrome handler in the event path.
+   */
+  bool mParentIsChromeHandler;
+
+  /**
+   * True if event's related target has been already retargeted in the
+   * current 'scope'. This should be set to false initially and whenever
+   * event path creation crosses shadow boundary.
+   */
+  bool mRelatedTargetRetargetedInCurrentScope;
+
+  /**
+   * True if Shadow DOM relatedTarget retargeting causes the current item
+   * to not show up in the event path.
+   */
+  bool mIgnoreBecauseOfShadowDOM;
+
+  /*
+   * True if the activation behavior of the current item should run
+   * See activationTarget in https://dom.spec.whatwg.org/#concept-event-dispatch
+   */
+  bool mWantsActivationBehavior;
+
+ private:
+  /**
+   * Parent item in the event target chain.
+   */
+  dom::EventTarget* mParentTarget;
+
+ public:
+  /**
+   * If the event needs to be retargeted, this is the event target,
+   * which should be used when the event is handled at mParentTarget.
+   */
+  dom::EventTarget* mEventTargetAtParent;
+
+  /**
+   * If the related target of the event needs to be retargeted, set this
+   * to a new EventTarget.
+   */
+  dom::EventTarget* mRetargetedRelatedTarget;
+
+  /**
+   * If mEvent is a WidgetTouchEvent and its mTouches needs retargeting,
+   * set the targets to this array. The array should contain one entry per
+   * each object in WidgetTouchEvent::mTouches.
+   */
+  mozilla::Maybe<nsTArray<RefPtr<dom::EventTarget>>> mRetargetedTouchTargets;
+
+  /**
+   * Set to the value of mEvent->mTarget of the previous scope in case of
+   * Shadow DOM or such, and if there is no anonymous content this just points
+   * to the initial target.
+   */
+  dom::EventTarget* mTargetInKnownToBeHandledScope;
+};
+
+class MOZ_STACK_CLASS EventChainPostVisitor final
+    : public mozilla::EventChainVisitor {
+ public:
+  // Note that for making guarantee the lifetime of mPresContext and mDOMEvent,
+  // creators should guarantee that aOther won't be deleted while the instance
+  // of this class is alive.
+  MOZ_CAN_RUN_SCRIPT
+  explicit EventChainPostVisitor(EventChainVisitor& aOther)
+      : EventChainVisitor(aOther.mPresContext, aOther.mEvent,
+                          MOZ_KnownLive(aOther.mDOMEvent),
+                          aOther.mEventStatus) {}
+};
+
+/**
+ * If an EventDispatchingCallback object is passed to Dispatch,
+ * its HandleEvent method is called after handling the default event group,
+ * before handling the system event group.
+ * This is used in PresShell.
+ */
+class MOZ_STACK_CLASS EventDispatchingCallback {
+ public:
+  MOZ_CAN_RUN_SCRIPT
+  virtual void HandleEvent(EventChainPostVisitor& aVisitor) = 0;
+};
+
+/**
+ * The generic class for event dispatching.
+ * Must not be used outside Gecko!
+ */
+class EventDispatcher {
+ public:
+  /**
+   * If the target of aEvent is set before calling this method, the target of
+   * aEvent is used as the target (unless there is event
+   * retargeting) and the originalTarget of the DOM Event.
+   * aTarget is always used as the starting point for constructing the event
+   * target chain, no matter what the value of aEvent->mTarget is.
+   * In other words, aEvent->mTarget is only a property of the event and it has
+   * nothing to do with the construction of the event target chain.
+   * Neither aTarget nor aEvent is allowed to be nullptr.
+   *
+   * If aTargets is non-null, event target chain will be created, but
+   * event won't be handled. In this case aEvent->mMessage should be
+   * eVoidEvent.
+   * @note Use this method when dispatching a WidgetEvent.
+   */
+  MOZ_CAN_RUN_SCRIPT static nsresult Dispatch(
+      dom::EventTarget* aTarget, nsPresContext* aPresContext,
+      WidgetEvent* aEvent, dom::Event* aDOMEvent = nullptr,
+      nsEventStatus* aEventStatus = nullptr,
+      EventDispatchingCallback* aCallback = nullptr,
+      nsTArray<dom::EventTarget*>* aTargets = nullptr);
+
+  /**
+   * Dispatches an event.
+   * If aDOMEvent is not nullptr, it is used for dispatching
+   * (aEvent can then be nullptr) and (if aDOMEvent is not |trusted| already),
+   * the |trusted| flag is set if the caller uses the system principal.
+   * Otherwise this works like EventDispatcher::Dispatch.
+   * @note Use this method when dispatching a dom::Event.
+   */
+  MOZ_CAN_RUN_SCRIPT static nsresult DispatchDOMEvent(
+      dom::EventTarget* aTarget, WidgetEvent* aEvent, dom::Event* aDOMEvent,
+      nsPresContext* aPresContext, nsEventStatus* aEventStatus);
+
+  /**
+   * Creates a DOM Event.  Returns null if the event type is unsupported.
+   */
+  static already_AddRefed<dom::Event> CreateEvent(
+      dom::EventTarget* aOwner, nsPresContext* aPresContext,
+      WidgetEvent* aEvent, const nsAString& aEventType,
+      dom::CallerType aCallerType = dom::CallerType::System);
+
+  static void GetComposedPathFor(WidgetEvent* aEvent,
+                                 nsTArray<RefPtr<dom::EventTarget>>& aPath);
+
+  /**
+   * Called at shutting down.
+   */
+  static void Shutdown();
+};
+
+}  // namespace mozilla
+
+#  endif  // mozilla_EventDispatcher_h_
+#endif