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authorMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
committerMatt A. Tobin <mattatobin@localhost.localdomain>2018-02-02 04:16:08 -0500
commit5f8de423f190bbb79a62f804151bc24824fa32d8 (patch)
tree10027f336435511475e392454359edea8e25895d /dom/events/EventDispatcher.h
parent49ee0794b5d912db1f95dce6eb52d781dc210db5 (diff)
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Add m-esr52 at 52.6.0
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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/. */
+
+#ifdef MOZILLA_INTERNAL_API
+#ifndef mozilla_EventDispatcher_h_
+#define mozilla_EventDispatcher_h_
+
+#include "mozilla/EventForwards.h"
+#include "nsCOMPtr.h"
+#include "nsTArray.h"
+
+// Microsoft's API Name hackery sucks
+#undef CreateEvent
+
+class nsIContent;
+class nsIDOMEvent;
+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 PreHandleEvent
+ * 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
+ * PreHandleEvent.
+ *
+ * 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 EventChainVisitor
+{
+public:
+ EventChainVisitor(nsPresContext* aPresContext,
+ WidgetEvent* aEvent,
+ nsIDOMEvent* aDOMEvent,
+ nsEventStatus aEventStatus = nsEventStatus_eIgnore)
+ : mPresContext(aPresContext)
+ , mEvent(aEvent)
+ , mDOMEvent(aDOMEvent)
+ , mEventStatus(aEventStatus)
+ , mItemFlags(0)
+ {
+ }
+
+ /**
+ * The prescontext, possibly nullptr.
+ */
+ 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.
+ */
+ nsIDOMEvent* mDOMEvent;
+
+ /**
+ * The status of the event.
+ * @see nsEventStatus.h
+ */
+ nsEventStatus mEventStatus;
+
+ /**
+ * Bits for items in the event target chain.
+ * Set in PreHandleEvent() 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 PreHandleEvent() 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 EventChainPreVisitor : public EventChainVisitor
+{
+public:
+ EventChainPreVisitor(nsPresContext* aPresContext,
+ WidgetEvent* aEvent,
+ nsIDOMEvent* aDOMEvent,
+ nsEventStatus aEventStatus,
+ bool aIsInAnon)
+ : EventChainVisitor(aPresContext, aEvent, aDOMEvent, aEventStatus)
+ , mCanHandle(true)
+ , mAutomaticChromeDispatch(true)
+ , mForceContentDispatch(false)
+ , mRelatedTargetIsInAnon(false)
+ , mOriginalTargetIsInAnon(aIsInAnon)
+ , mWantsWillHandleEvent(false)
+ , mMayHaveListenerManager(true)
+ , mParentTarget(nullptr)
+ , mEventTargetAtParent(nullptr)
+ {
+ }
+
+ void Reset()
+ {
+ mItemFlags = 0;
+ mItemData = nullptr;
+ mCanHandle = true;
+ mAutomaticChromeDispatch = true;
+ mForceContentDispatch = false;
+ mWantsWillHandleEvent = false;
+ mMayHaveListenerManager = true;
+ mParentTarget = nullptr;
+ mEventTargetAtParent = nullptr;
+ }
+
+ /**
+ * Member that must be set in PreHandleEvent 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 PreHandleEvent on event targets.
+ */
+ bool mOriginalTargetIsInAnon;
+
+ /**
+ * Whether or not nsIDOMEventTarget::WillHandleEvent will be
+ * called. Default is false;
+ */
+ bool mWantsWillHandleEvent;
+
+ /**
+ * If it is known that the current target doesn't have a listener manager
+ * when PreHandleEvent is called, set this to false.
+ */
+ bool mMayHaveListenerManager;
+
+ /**
+ * Parent item in the event target chain.
+ */
+ dom::EventTarget* mParentTarget;
+
+ /**
+ * 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;
+
+ /**
+ * An array of destination insertion points that need to be inserted
+ * into the event path of nodes that are distributed by the
+ * web components distribution algorithm.
+ */
+ nsTArray<nsIContent*> mDestInsertionPoints;
+};
+
+class EventChainPostVisitor : public mozilla::EventChainVisitor
+{
+public:
+ explicit EventChainPostVisitor(EventChainVisitor& aOther)
+ : EventChainVisitor(aOther.mPresContext, aOther.mEvent,
+ 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 nsPresShell.
+ */
+class MOZ_STACK_CLASS EventDispatchingCallback
+{
+public:
+ virtual void HandleEvent(EventChainPostVisitor& aVisitor) = 0;
+};
+
+/**
+ * The generic class for event dispatching.
+ * Must not be used outside Gecko!
+ */
+class EventDispatcher
+{
+public:
+ /**
+ * aTarget should QI to EventTarget.
+ * 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.
+ */
+ static nsresult Dispatch(nsISupports* aTarget,
+ nsPresContext* aPresContext,
+ WidgetEvent* aEvent,
+ nsIDOMEvent* 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 based on the UniversalXPConnect capability.
+ * Otherwise this works like EventDispatcher::Dispatch.
+ * @note Use this method when dispatching nsIDOMEvent.
+ */
+ static nsresult DispatchDOMEvent(nsISupports* aTarget,
+ WidgetEvent* aEvent,
+ nsIDOMEvent* 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);
+
+ /**
+ * Called at shutting down.
+ */
+ static void Shutdown();
+};
+
+} // namespace mozilla
+
+#endif // mozilla_EventDispatcher_h_
+#endif