dom/events/DOMEventTargetHelper.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_DOMEventTargetHelper_h_
   8 #define mozilla_DOMEventTargetHelper_h_
   9
  10 #include "mozilla/Attributes.h"
  11 #include "mozilla/dom/EventTarget.h"
  12 #include "mozilla/GlobalTeardownObserver.h"
  13 #include "mozilla/LinkedList.h"
  14 #include "mozilla/RefPtr.h"
  15 #include "nsAtom.h"
  16 #include "nsCOMPtr.h"
  17 #include "nsCycleCollectionParticipant.h"
  18 #include "nsDebug.h"
  19 #include "nsGkAtoms.h"
  20 #include "nsID.h"
  21 #include "nsIGlobalObject.h"
  22 #include "nsIScriptGlobalObject.h"
  23 #include "nsISupports.h"
  24 #include "nsISupportsUtils.h"
  25 #include "nsPIDOMWindow.h"
  26 #include "nsStringFwd.h"
  27 #include "nsTArray.h"
  28
  29 class nsCycleCollectionTraversalCallback;
  30
  31 namespace mozilla {
  32
  33 class ErrorResult;
  34 class EventChainPostVisitor;
  35 class EventChainPreVisitor;
  36 class EventListenerManager;
  37
  38 namespace dom {
  39 class Document;
  40 class Event;
  41 enum class CallerType : uint32_t;
  42 }  // namespace dom
  43
  44 #define NS_DOMEVENTTARGETHELPER_IID                  \
  45   {                                                  \
  46     0xa28385c6, 0x9451, 0x4d7e, {                    \
  47       0xa3, 0xdd, 0xf4, 0xb6, 0x87, 0x2f, 0xa4, 0x76 \
  48     }                                                \
  49   }
  50
  51 class DOMEventTargetHelper : public dom::EventTarget,
  52                              public GlobalTeardownObserver {
  53  public:
  54   DOMEventTargetHelper();
  55   explicit DOMEventTargetHelper(nsPIDOMWindowInner* aWindow);
  56   explicit DOMEventTargetHelper(nsIGlobalObject* aGlobalObject);
  57   explicit DOMEventTargetHelper(DOMEventTargetHelper* aOther);
  58
  59   NS_DECL_ISUPPORTS_INHERITED
  60   NS_IMETHOD_(void) DeleteCycleCollectable() override;
  61   NS_DECL_CYCLE_COLLECTION_SKIPPABLE_WRAPPERCACHE_CLASS_AMBIGUOUS(
  62       DOMEventTargetHelper, dom::EventTarget)
  63
  64   virtual EventListenerManager* GetExistingListenerManager() const override;
  65   virtual EventListenerManager* GetOrCreateListenerManager() override;
  66
  67   bool ComputeDefaultWantsUntrusted(ErrorResult& aRv) override;
  68
  69   using EventTarget::DispatchEvent;
  70   // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230)
  71   MOZ_CAN_RUN_SCRIPT_BOUNDARY bool DispatchEvent(dom::Event& aEvent,
  72                                                  dom::CallerType aCallerType,
  73                                                  ErrorResult& aRv) override;
  74
  75   void GetEventTargetParent(EventChainPreVisitor& aVisitor) override;
  76
  77   nsresult PostHandleEvent(EventChainPostVisitor& aVisitor) override;
  78
  79   NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOMEVENTTARGETHELPER_IID)
  80
  81   nsIGlobalObject* GetOwnerGlobal() const override {
  82     return GlobalTeardownObserver::GetOwnerGlobal();
  83   }
  84
  85   static DOMEventTargetHelper* FromSupports(nsISupports* aSupports) {
  86     dom::EventTarget* target = static_cast<dom::EventTarget*>(aSupports);
  87 #ifdef DEBUG
  88     {
  89       nsCOMPtr<dom::EventTarget> target_qi = do_QueryInterface(aSupports);
  90
  91       // If this assertion fires the QI implementation for the object in
  92       // question doesn't use the EventTarget pointer as the
  93       // nsISupports pointer. That must be fixed, or we'll crash...
  94       NS_ASSERTION(target_qi == target, "Uh, fix QI!");
  95     }
  96 #endif
  97
  98     return static_cast<DOMEventTargetHelper*>(target);
  99   }
 100
 101   bool HasListenersFor(const nsAString& aType) const;
 102
 103   bool HasListenersFor(nsAtom* aTypeWithOn) const;
 104
 105   virtual nsPIDOMWindowOuter* GetOwnerGlobalForBindingsInternal() override {
 106     return nsPIDOMWindowOuter::GetFromCurrentInner(GetOwner());
 107   }
 108
 109   // Like GetOwner, but only returns non-null if the window being returned is
 110   // current (in the "current document" sense of the HTML spec).
 111   nsPIDOMWindowInner* GetWindowIfCurrent() const;
 112   // Returns the document associated with this event target, if that document is
 113   // the current document of its browsing context.  Will return null otherwise.
 114   mozilla::dom::Document* GetDocumentIfCurrent() const;
 115
 116   void DisconnectFromOwner() override;
 117   using EventTarget::GetParentObject;
 118
 119   virtual void EventListenerAdded(nsAtom* aType) override;
 120
 121   virtual void EventListenerRemoved(nsAtom* aType) override;
 122
 123   // Dispatch a trusted, non-cancellable and non-bubbling event to |this|.
 124   nsresult DispatchTrustedEvent(const nsAString& aEventName);
 125
 126  protected:
 127   virtual ~DOMEventTargetHelper();
 128
 129   nsresult WantsUntrusted(bool* aRetVal);
 130
 131   void MaybeUpdateKeepAlive();
 132   void MaybeDontKeepAlive();
 133
 134   // If this method returns true your object is kept alive until it returns
 135   // false. You can use this method instead using
 136   // NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN macro.
 137   virtual bool IsCertainlyAliveForCC() const { return mIsKeptAlive; }
 138
 139   RefPtr<EventListenerManager> mListenerManager;
 140   // Make |event| trusted and dispatch |aEvent| to |this|.
 141   nsresult DispatchTrustedEvent(dom::Event* aEvent);
 142
 143   virtual void LastRelease() {}
 144
 145   void KeepAliveIfHasListenersFor(nsAtom* aType);
 146
 147   void IgnoreKeepAliveIfHasListenersFor(nsAtom* aType);
 148
 149  private:
 150   nsTArray<RefPtr<nsAtom>> mKeepingAliveTypes;
 151
 152   bool mIsKeptAlive = false;
 153 };
 154
 155 NS_DEFINE_STATIC_IID_ACCESSOR(DOMEventTargetHelper, NS_DOMEVENTTARGETHELPER_IID)
 156
 157 }  // namespace mozilla
 158
 159 // WebIDL event handlers
 160 #define IMPL_EVENT_HANDLER(_event)                                          \
 161   inline mozilla::dom::EventHandlerNonNull* GetOn##_event() {               \
 162     return GetEventHandler(nsGkAtoms::on##_event);                          \
 163   }                                                                         \
 164   inline void SetOn##_event(mozilla::dom::EventHandlerNonNull* aCallback) { \
 165     SetEventHandler(nsGkAtoms::on##_event, aCallback);                      \
 166   }
 167
 168 #endif  // mozilla_DOMEventTargetHelper_h_