diff options
Diffstat (limited to 'dom/events/EventTarget.h')
| -rw-r--r-- | dom/events/EventTarget.h | 412 |
1 files changed, 412 insertions, 0 deletions
diff --git a/dom/events/EventTarget.h b/dom/events/EventTarget.h new file mode 100644 index 0000000000..ae1f94f584 --- /dev/null +++ b/dom/events/EventTarget.h @@ -0,0 +1,412 @@ +/* -*- 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_dom_EventTarget_h_ +#define mozilla_dom_EventTarget_h_ + +#include "mozilla/dom/Nullable.h" +#include "nsISupports.h" +#include "nsWrapperCache.h" +#include "nsAtom.h" + +class nsIDOMEventListener; +class nsIGlobalObject; +class nsINode; +class nsPIDOMWindowInner; +class nsPIDOMWindowOuter; +class nsPIWindowRoot; + +namespace mozilla { + +class AsyncEventDispatcher; +class ErrorResult; +class EventChainPostVisitor; +class EventChainPreVisitor; +class EventChainVisitor; +class EventListenerManager; + +namespace dom { + +class AddEventListenerOptionsOrBoolean; +class Event; +class EventListener; +class EventListenerOptionsOrBoolean; +class EventHandlerNonNull; +class GlobalObject; +class WindowProxyHolder; +enum class CallerType : uint32_t; +enum class EventCallbackDebuggerNotificationType : uint8_t; + +// IID for the dom::EventTarget interface +#define NS_EVENTTARGET_IID \ + { \ + 0xde651c36, 0x0053, 0x4c67, { \ + 0xb1, 0x3d, 0x67, 0xb9, 0x40, 0xfc, 0x82, 0xe4 \ + } \ + } + +class EventTarget : public nsISupports, public nsWrapperCache { + public: + NS_DECLARE_STATIC_IID_ACCESSOR(NS_EVENTTARGET_IID) + + // WebIDL API + static already_AddRefed<EventTarget> Constructor(const GlobalObject& aGlobal, + ErrorResult& aRv); + void AddEventListener(const nsAString& aType, EventListener* aCallback, + const AddEventListenerOptionsOrBoolean& aOptions, + const Nullable<bool>& aWantsUntrusted, + ErrorResult& aRv); + void RemoveEventListener(const nsAString& aType, EventListener* aCallback, + const EventListenerOptionsOrBoolean& aOptions, + ErrorResult& aRv); + + protected: + /** + * This method allows addition of event listeners represented by + * nsIDOMEventListener, with almost the same semantics as the + * standard AddEventListener. The one difference is that it just + * has a "use capture" boolean, not an EventListenerOptions. + */ + nsresult AddEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, bool aUseCapture, + const Nullable<bool>& aWantsUntrusted); + + public: + /** + * Helper methods to make the nsIDOMEventListener version of + * AddEventListener simpler to call for consumers. + */ + nsresult AddEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, bool aUseCapture) { + return AddEventListener(aType, aListener, aUseCapture, Nullable<bool>()); + } + nsresult AddEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, bool aUseCapture, + bool aWantsUntrusted) { + return AddEventListener(aType, aListener, aUseCapture, + Nullable<bool>(aWantsUntrusted)); + } + + /** + * This method allows the removal of event listeners represented by + * nsIDOMEventListener from the event target, with the same semantics as the + * standard RemoveEventListener. + */ + void RemoveEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, bool aUseCapture); + /** + * RemoveSystemEventListener() should be used if you have used + * AddSystemEventListener(). + */ + void RemoveSystemEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, + bool aUseCapture); + + /** + * Add a system event listener with the default wantsUntrusted value. + */ + nsresult AddSystemEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, + bool aUseCapture) { + return AddSystemEventListener(aType, aListener, aUseCapture, + Nullable<bool>()); + } + + /** + * Add a system event listener with the given wantsUntrusted value. + */ + nsresult AddSystemEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, + bool aUseCapture, bool aWantsUntrusted) { + return AddSystemEventListener(aType, aListener, aUseCapture, + Nullable<bool>(aWantsUntrusted)); + } + + virtual bool IsNode() const { return false; } + inline nsINode* GetAsNode(); + inline const nsINode* GetAsNode() const; + inline nsINode* AsNode(); + inline const nsINode* AsNode() const; + + virtual bool IsInnerWindow() const { return false; } + virtual bool IsOuterWindow() const { return false; } + virtual bool IsRootWindow() const { return false; } + nsPIDOMWindowInner* GetAsWindowInner(); + const nsPIDOMWindowInner* GetAsWindowInner() const; + nsPIDOMWindowOuter* GetAsWindowOuter(); + const nsPIDOMWindowOuter* GetAsWindowOuter() const; + inline nsPIWindowRoot* GetAsWindowRoot(); + inline const nsPIWindowRoot* GetAsWindowRoot() const; + nsPIDOMWindowInner* AsWindowInner(); + const nsPIDOMWindowInner* AsWindowInner() const; + nsPIDOMWindowOuter* AsWindowOuter(); + const nsPIDOMWindowOuter* AsWindowOuter() const; + inline nsPIWindowRoot* AsWindowRoot(); + inline const nsPIWindowRoot* AsWindowRoot() const; + + /** + * Returns the EventTarget object which should be used as the target + * of DOMEvents. + * Usually |this| is returned, but for example Window (inner windw) returns + * the WindowProxy (outer window). + */ + virtual EventTarget* GetTargetForDOMEvent() { return this; }; + + /** + * Returns the EventTarget object which should be used as the target + * of the event and when constructing event target chain. + * Usually |this| is returned, but for example WindowProxy (outer window) + * returns the Window (inner window). + */ + virtual EventTarget* GetTargetForEventTargetChain() { return this; } + + /** + * The most general DispatchEvent method. This is the one the bindings call. + */ + // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230) + MOZ_CAN_RUN_SCRIPT_BOUNDARY virtual bool DispatchEvent(Event& aEvent, + CallerType aCallerType, + ErrorResult& aRv) = 0; + + /** + * A version of DispatchEvent you can use if you really don't care whether it + * succeeds or not and whether default is prevented or not. + */ + // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230) + MOZ_CAN_RUN_SCRIPT_BOUNDARY void DispatchEvent(Event& aEvent); + + /** + * A version of DispatchEvent you can use if you really don't care whether + * default is prevented or not. + */ + // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230) + MOZ_CAN_RUN_SCRIPT_BOUNDARY void DispatchEvent(Event& aEvent, + ErrorResult& aRv); + + nsIGlobalObject* GetParentObject() const { return GetOwnerGlobal(); } + + // Note, this takes the type in onfoo form! + EventHandlerNonNull* GetEventHandler(const nsAString& aType) { + RefPtr<nsAtom> type = NS_Atomize(aType); + return GetEventHandler(type); + } + + // Note, this takes the type in onfoo form! + void SetEventHandler(const nsAString& aType, EventHandlerNonNull* aHandler, + ErrorResult& rv); + + // For an event 'foo' aType will be 'onfoo'. + virtual void EventListenerAdded(nsAtom* aType) {} + + // For an event 'foo' aType will be 'onfoo'. + virtual void EventListenerRemoved(nsAtom* aType) {} + + // Returns an outer window that corresponds to the inner window this event + // target is associated with. Will return null if the inner window is not the + // current inner or if there is no window around at all. + Nullable<WindowProxyHolder> GetOwnerGlobalForBindings(); + virtual nsPIDOMWindowOuter* GetOwnerGlobalForBindingsInternal() = 0; + + // The global object this event target is associated with, if any. + // This may be an inner window or some other global object. This + // will never be an outer window. + virtual nsIGlobalObject* GetOwnerGlobal() const = 0; + + /** + * Get the event listener manager, creating it if it does not already exist. + */ + virtual EventListenerManager* GetOrCreateListenerManager() = 0; + + /** + * Get the event listener manager, returning null if it does not already + * exist. + */ + virtual EventListenerManager* GetExistingListenerManager() const = 0; + + virtual Maybe<EventCallbackDebuggerNotificationType> + GetDebuggerNotificationType() const { + return Nothing(); + } + + // Called from AsyncEventDispatcher to notify it is running. + virtual void AsyncEventRunning(AsyncEventDispatcher* aEvent) {} + + // Used by APZ to determine whether this event target has non-chrome event + // listeners for untrusted key events. + bool HasNonSystemGroupListenersForUntrustedKeyEvents() const; + + // Used by APZ to determine whether this event target has non-chrome and + // non-passive event listeners for untrusted key events. + bool HasNonPassiveNonSystemGroupListenersForUntrustedKeyEvents() const; + + virtual bool IsApzAware() const; + + /** + * Called before the capture phase of the event flow. + * This is used to create the event target chain and implementations + * should set the necessary members of EventChainPreVisitor. + * At least aVisitor.mCanHandle must be set, + * usually also aVisitor.mParentTarget if mCanHandle is true. + * mCanHandle says that this object can handle the aVisitor.mEvent event and + * the mParentTarget is the possible parent object for the event target chain. + * @see EventDispatcher.h for more documentation about aVisitor. + * + * @param aVisitor the visitor object which is used to create the + * event target chain for event dispatching. + * + * @note Only EventDispatcher should call this method. + */ + virtual void GetEventTargetParent(EventChainPreVisitor& aVisitor) = 0; + + /** + * Called before the capture phase of the event flow and after event target + * chain creation. This is used to handle things that must be executed before + * dispatching the event to DOM. + */ + virtual nsresult PreHandleEvent(EventChainVisitor& aVisitor) { return NS_OK; } + + /** + * If EventChainPreVisitor.mWantsWillHandleEvent is set true, + * called just before possible event handlers on this object will be called. + */ + virtual void WillHandleEvent(EventChainPostVisitor& aVisitor) {} + + /** + * Called after the bubble phase of the system event group. + * The default handling of the event should happen here. + * @param aVisitor the visitor object which is used during post handling. + * + * @see EventDispatcher.h for documentation about aVisitor. + * @note Only EventDispatcher should call this method. + */ + MOZ_CAN_RUN_SCRIPT + virtual nsresult PostHandleEvent(EventChainPostVisitor& aVisitor) = 0; + + protected: + EventHandlerNonNull* GetEventHandler(nsAtom* aType); + void SetEventHandler(nsAtom* aType, EventHandlerNonNull* aHandler); + + /** + * Hook for AddEventListener that allows it to compute the right + * wantsUntrusted boolean when one is not provided. If this returns failure, + * the listener will not be added. + * + * This hook will NOT be called unless aWantsUntrusted is null in + * AddEventListener. If you need to take action when event listeners are + * added, use EventListenerAdded. Especially because not all event listener + * additions go through AddEventListener! + */ + virtual bool ComputeDefaultWantsUntrusted(ErrorResult& aRv) = 0; + + /** + * A method to compute the right wantsUntrusted value for AddEventListener. + * This will call the above hook as needed. + * + * If aOptions is non-null, and it contains a value for mWantUntrusted, that + * value takes precedence over aWantsUntrusted. + */ + bool ComputeWantsUntrusted(const Nullable<bool>& aWantsUntrusted, + const AddEventListenerOptionsOrBoolean* aOptions, + ErrorResult& aRv); + + /** + * addSystemEventListener() adds an event listener of aType to the system + * group. Typically, core code should use the system group for listening to + * content (i.e., non-chrome) element's events. If core code uses + * EventTarget::AddEventListener for a content node, it means + * that the listener cannot listen to the event when web content calls + * stopPropagation() of the event. + * + * @param aType An event name you're going to handle. + * @param aListener An event listener. + * @param aUseCapture true if you want to listen the event in capturing + * phase. Otherwise, false. + * @param aWantsUntrusted true if you want to handle untrusted events. + * false if not. + * Null if you want the default behavior. + */ + nsresult AddSystemEventListener(const nsAString& aType, + nsIDOMEventListener* aListener, + bool aUseCapture, + const Nullable<bool>& aWantsUntrusted); +}; + +NS_DEFINE_STATIC_IID_ACCESSOR(EventTarget, NS_EVENTTARGET_IID) + +#define NS_IMPL_FROMEVENTTARGET_GENERIC(_class, _check, _const) \ + template <typename T> \ + static auto FromEventTarget(_const T& aEventTarget) \ + ->decltype(static_cast<_const _class*>(&aEventTarget)) { \ + return aEventTarget._check ? static_cast<_const _class*>(&aEventTarget) \ + : nullptr; \ + } \ + template <typename T> \ + static _const _class* FromEventTarget(_const T* aEventTarget) { \ + MOZ_DIAGNOSTIC_ASSERT(aEventTarget); \ + return FromEventTarget(*aEventTarget); \ + } \ + template <typename T> \ + static _const _class* FromEventTargetOrNull(_const T* aEventTarget) { \ + return aEventTarget ? FromEventTarget(*aEventTarget) : nullptr; \ + } + +#define NS_IMPL_FROMEVENTTARGET_HELPER(_class, _check) \ + NS_IMPL_FROMEVENTTARGET_GENERIC(_class, _check, ) \ + NS_IMPL_FROMEVENTTARGET_GENERIC(_class, _check, const) \ + template <typename T> \ + static _class* FromEventTarget(T&& aEventTarget) { \ + MOZ_DIAGNOSTIC_ASSERT(!!aEventTarget); \ + /* We need the double-cast in case aEventTarget is a smartptr. Those */ \ + /* can cast to superclasses of the type they're templated on, */ \ + /* but not directly to subclasses. */ \ + return aEventTarget->_check \ + ? static_cast<_class*>(static_cast<EventTarget*>(aEventTarget)) \ + : nullptr; \ + } \ + template <typename T> \ + static _class* FromEventTargetOrNull(T&& aEventTarget) { \ + return aEventTarget ? FromEventTarget(aEventTarget) : nullptr; \ + } + +// Unfortunately, nsPIDOMWindowInner and nsPIDOMWindowOuter do not inherit +// EventTarget directly, but they are public interfaces which should have +// these helper methods. Therefore, we cannot cast from EventTarget to +// the interfaces in their header file. That's the reason why we cannot use +// the zero cost casts nor decltype for the template methods which take a +// reference. +#define NS_IMPL_FROMEVENTTARGET_GENERIC_WITH_GETTER(_class, _getter, _const) \ + static _const _class* FromEventTarget( \ + _const mozilla::dom::EventTarget& aEventTarget) { \ + return aEventTarget._getter; \ + } \ + template <typename T> \ + static _const _class* FromEventTarget(_const T* aEventTarget) { \ + return aEventTarget->_getter; \ + } \ + template <typename T> \ + static _const _class* FromEventTargetOrNull(_const T* aEventTarget) { \ + return aEventTarget ? aEventTarget->_getter : nullptr; \ + } + +#define NS_IMPL_FROMEVENTTARGET_HELPER_WITH_GETTER_INNER(_class, _getter) \ + template <typename T> \ + static _class* FromEventTarget(T&& aEventTarget) { \ + return aEventTarget->_getter; \ + } \ + template <typename T> \ + static _class* FromEventTargetOrNull(T&& aEventTarget) { \ + return aEventTarget ? aEventTarget->_getter : nullptr; \ + } + +#define NS_IMPL_FROMEVENTTARGET_HELPER_WITH_GETTER(_class, _getter) \ + NS_IMPL_FROMEVENTTARGET_GENERIC_WITH_GETTER(_class, _getter, ) \ + NS_IMPL_FROMEVENTTARGET_GENERIC_WITH_GETTER(_class, _getter, const) \ + NS_IMPL_FROMEVENTTARGET_HELPER_WITH_GETTER_INNER(_class, _getter) + +} // namespace dom +} // namespace mozilla + +#endif // mozilla_dom_EventTarget_h_ |