mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-11-02 07:05:24 +00:00
284 lines
8.9 KiB
C++
284 lines
8.9 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
|
|
/* 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"
|
|
|
|
// Microsoft's API Name hackery sucks
|
|
#undef CreateEvent
|
|
|
|
class nsIDOMEvent;
|
|
class nsIScriptGlobalObject;
|
|
class nsPresContext;
|
|
|
|
template<class E> class nsCOMArray;
|
|
|
|
namespace mozilla {
|
|
namespace dom {
|
|
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;
|
|
};
|
|
|
|
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->target is.
|
|
* In other words, aEvent->target 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->message should be
|
|
* NS_EVENT_NULL.
|
|
* @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,
|
|
nsCOMArray<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.
|
|
*/
|
|
static nsresult CreateEvent(dom::EventTarget* aOwner,
|
|
nsPresContext* aPresContext,
|
|
WidgetEvent* aEvent,
|
|
const nsAString& aEventType,
|
|
nsIDOMEvent** aDOMEvent);
|
|
|
|
/**
|
|
* Called at shutting down.
|
|
*/
|
|
static void Shutdown();
|
|
};
|
|
|
|
} // namespace mozilla
|
|
|
|
#endif // mozilla_EventDispatcher_h_
|
|
#endif
|