accessible/base/DocManager.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5 #ifndef mozilla_a11_DocManager_h_
   6 #define mozilla_a11_DocManager_h_
   7
   8 #include "mozilla/ClearOnShutdown.h"
   9 #include "nsIDOMEventListener.h"
  10 #include "nsRefPtrHashtable.h"
  11 #include "nsIWebProgressListener.h"
  12 #include "nsWeakReference.h"
  13 #include "mozilla/StaticPtr.h"
  14 #include "nsINode.h"
  15
  16 namespace mozilla::dom {
  17 class Document;
  18 }
  19
  20 namespace mozilla {
  21 class PresShell;
  22
  23 namespace a11y {
  24
  25 class LocalAccessible;
  26 class DocAccessible;
  27 class xpcAccessibleDocument;
  28 class DocAccessibleParent;
  29
  30 /**
  31  * Manage the document accessible life cycle.
  32  */
  33 class DocManager : public nsIWebProgressListener,
  34                    public nsIDOMEventListener,
  35                    public nsSupportsWeakReference {
  36  public:
  37   NS_DECL_THREADSAFE_ISUPPORTS
  38   NS_DECL_NSIWEBPROGRESSLISTENER
  39   NS_DECL_NSIDOMEVENTLISTENER
  40
  41   /**
  42    * Return document accessible for the given DOM node.
  43    */
  44   DocAccessible* GetDocAccessible(dom::Document* aDocument);
  45
  46   /**
  47    * Return document accessible for the given presshell.
  48    */
  49   DocAccessible* GetDocAccessible(const PresShell* aPresShell);
  50
  51   /**
  52    * Search through all document accessibles for an accessible with the given
  53    * unique id.
  54    */
  55   LocalAccessible* FindAccessibleInCache(nsINode* aNode) const;
  56
  57   /**
  58    * Called by document accessible when it gets shutdown.
  59    * @param aAllowServiceShutdown true to shut down nsAccessibilityService
  60    *        if it is no longer required, false to prevent it.
  61    */
  62   void NotifyOfDocumentShutdown(DocAccessible* aDocument,
  63                                 dom::Document* aDOMDocument,
  64                                 bool aAllowServiceShutdown = true);
  65
  66   void RemoveFromXPCDocumentCache(DocAccessible* aDocument,
  67                                   bool aAllowServiceShutdown = true);
  68
  69   /**
  70    * Return XPCOM accessible document.
  71    */
  72   xpcAccessibleDocument* GetXPCDocument(DocAccessible* aDocument);
  73   xpcAccessibleDocument* GetCachedXPCDocument(DocAccessible* aDocument) const {
  74     return mXPCDocumentCache.GetWeak(aDocument);
  75   }
  76
  77   /*
  78    * Notification that a top level document in a content process has gone away.
  79    */
  80   static void RemoteDocShutdown(DocAccessibleParent* aDoc) {
  81     DebugOnly<bool> result = sRemoteDocuments->RemoveElement(aDoc);
  82     MOZ_ASSERT(result, "Why didn't we find the document!");
  83   }
  84
  85   /*
  86    * Notify of a new top level document in a content process.
  87    */
  88   static void RemoteDocAdded(DocAccessibleParent* aDoc);
  89
  90   static const nsTArray<DocAccessibleParent*>* TopLevelRemoteDocs() {
  91     return sRemoteDocuments;
  92   }
  93
  94   /**
  95    * Remove the xpc document for a remote document if there is one.
  96    */
  97   static void NotifyOfRemoteDocShutdown(DocAccessibleParent* adoc);
  98
  99   static void RemoveFromRemoteXPCDocumentCache(DocAccessibleParent* aDoc);
 100
 101   /**
 102    * Get a XPC document for a remote document.
 103    */
 104   static xpcAccessibleDocument* GetXPCDocument(DocAccessibleParent* aDoc);
 105   static xpcAccessibleDocument* GetCachedXPCDocument(
 106       const DocAccessibleParent* aDoc) {
 107     return sRemoteXPCDocumentCache ? sRemoteXPCDocumentCache->GetWeak(aDoc)
 108                                    : nullptr;
 109   }
 110
 111 #ifdef DEBUG
 112   bool IsProcessingRefreshDriverNotification() const;
 113 #endif
 114
 115  protected:
 116   DocManager();
 117   virtual ~DocManager() = default;
 118
 119   /**
 120    * Initialize the manager.
 121    */
 122   bool Init();
 123
 124   /**
 125    * Shutdown the manager.
 126    */
 127   void Shutdown();
 128
 129   bool HasXPCDocuments() {
 130     return mXPCDocumentCache.Count() > 0 ||
 131            (sRemoteXPCDocumentCache && sRemoteXPCDocumentCache->Count() > 0);
 132   }
 133
 134  private:
 135   DocManager(const DocManager&);
 136   DocManager& operator=(const DocManager&);
 137
 138  private:
 139   /**
 140    * Create an accessible document if it was't created and fire accessibility
 141    * events if needed.
 142    *
 143    * @param  aDocument       [in] loaded DOM document
 144    * @param  aLoadEventType  [in] specifies the event type to fire load event,
 145    *                           if 0 then no event is fired
 146    */
 147   void HandleDOMDocumentLoad(dom::Document* aDocument, uint32_t aLoadEventType);
 148
 149   /**
 150    * Add/remove 'pagehide' and 'DOMContentLoaded' event listeners.
 151    */
 152   void AddListeners(dom::Document* aDocument, bool aAddPageShowListener);
 153   void RemoveListeners(dom::Document* aDocument);
 154
 155   /**
 156    * Create document or root accessible.
 157    */
 158   DocAccessible* CreateDocOrRootAccessible(dom::Document* aDocument);
 159
 160   /**
 161    * Clear the cache and shutdown the document accessibles.
 162    */
 163   void ClearDocCache();
 164
 165   typedef nsRefPtrHashtable<nsPtrHashKey<const dom::Document>, DocAccessible>
 166       DocAccessibleHashtable;
 167   DocAccessibleHashtable mDocAccessibleCache;
 168
 169   typedef nsRefPtrHashtable<nsPtrHashKey<const DocAccessible>,
 170                             xpcAccessibleDocument>
 171       XPCDocumentHashtable;
 172   XPCDocumentHashtable mXPCDocumentCache;
 173   static StaticAutoPtr<nsRefPtrHashtable<
 174       nsPtrHashKey<const DocAccessibleParent>, xpcAccessibleDocument>>
 175       sRemoteXPCDocumentCache;
 176
 177   /*
 178    * The list of remote top level documents.
 179    */
 180   static StaticAutoPtr<nsTArray<DocAccessibleParent*>> sRemoteDocuments;
 181 };
 182
 183 /**
 184  * Return the existing document accessible for the document if any.
 185  * Note this returns the doc accessible for the primary pres shell if there is
 186  * more than one.
 187  */
 188 DocAccessible* GetExistingDocAccessible(const dom::Document* aDocument);
 189
 190 }  // namespace a11y
 191 }  // namespace mozilla
 192
 193 #endif  // mozilla_a11_DocManager_h_