dom/xul/XULBroadcastManager.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_dom_XULBroadcastManager_h
   8 #define mozilla_dom_XULBroadcastManager_h
   9
  10 #include "nsAtom.h"
  11 #include "nsTArray.h"
  12
  13 class PLDHashTable;
  14 class nsXULElement;
  15
  16 namespace mozilla {
  17
  18 class ErrorResult;
  19
  20 namespace dom {
  21
  22 class Document;
  23 class Element;
  24
  25 class XULBroadcastManager final {
  26  public:
  27   explicit XULBroadcastManager(Document* aDocument);
  28
  29   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(XULBroadcastManager)
  30
  31   /**
  32    * Checks whether an element uses any of the special broadcaster attributes
  33    * or is an observes element. This mimics the logic in FindBroadcaster, but
  34    * is intended to be a lighter weight check and doesn't actually guarantee
  35    * that the element will need a listener.
  36    */
  37   static bool MayNeedListener(const Element& aElement);
  38
  39   nsresult AddListener(Element* aElement);
  40   nsresult RemoveListener(Element* aElement);
  41   void AttributeChanged(Element* aElement, int32_t aNameSpaceID,
  42                         nsAtom* aAttribute);
  43   void MaybeBroadcast();
  44   void DropDocumentReference();  // notification that doc is going away
  45  protected:
  46   enum HookupAction { eHookupAdd = 0, eHookupRemove };
  47
  48   nsresult UpdateListenerHookup(Element* aElement, HookupAction aAction);
  49
  50   void RemoveListenerFor(Element& aBroadcaster, Element& aListener,
  51                          const nsAString& aAttr);
  52   void AddListenerFor(Element& aBroadcaster, Element& aListener,
  53                       const nsAString& aAttr, ErrorResult& aRv);
  54
  55   nsresult ExecuteOnBroadcastHandlerFor(Element* aBroadcaster,
  56                                         Element* aListener, nsAtom* aAttr);
  57   // The out params of FindBroadcaster only have values that make sense when
  58   // the method returns NS_FINDBROADCASTER_FOUND.  In all other cases, the
  59   // values of the out params should not be relied on (though *aListener and
  60   // *aBroadcaster do need to be released if non-null, of course).
  61   nsresult FindBroadcaster(Element* aElement, Element** aListener,
  62                            nsString& aBroadcasterID, nsString& aAttribute,
  63                            Element** aBroadcaster);
  64
  65   void SynchronizeBroadcastListener(Element* aBroadcaster, Element* aListener,
  66                                     const nsAString& aAttr);
  67
  68   // This reference is nulled by the Document in it's destructor through
  69   // DropDocumentReference().
  70   Document* MOZ_NON_OWNING_REF mDocument;
  71
  72   /**
  73    * A map from a broadcaster element to a list of listener elements.
  74    */
  75   PLDHashTable* mBroadcasterMap;
  76
  77   class nsDelayedBroadcastUpdate;
  78   nsTArray<nsDelayedBroadcastUpdate> mDelayedBroadcasters;
  79   nsTArray<nsDelayedBroadcastUpdate> mDelayedAttrChangeBroadcasts;
  80   bool mHandlingDelayedAttrChange;
  81   bool mHandlingDelayedBroadcasters;
  82
  83  private:
  84   ~XULBroadcastManager();
  85 };
  86
  87 }  // namespace dom
  88 }  // namespace mozilla
  89
  90 #endif  // mozilla_dom_XULBroadcastManager_h