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 "nsIDocument.h"
   9 #include "nsIDOMEventListener.h"
  10 #include "nsRefPtrHashtable.h"
  11 #include "nsIWebProgressListener.h"
  12 #include "nsWeakReference.h"
  13 #include "nsIPresShell.h"
  14
  15 namespace mozilla {
  16 namespace a11y {
  17
  18 class Accessible;
  19 class DocAccessible;
  20
  21 /**
  22  * Manage the document accessible life cycle.
  23  */
  24 class DocManager : public nsIWebProgressListener,
  25                    public nsIDOMEventListener,
  26                    public nsSupportsWeakReference
  27 {
  28 public:
  29   NS_DECL_THREADSAFE_ISUPPORTS
  30   NS_DECL_NSIWEBPROGRESSLISTENER
  31   NS_DECL_NSIDOMEVENTLISTENER
  32
  33   /**
  34    * Return document accessible for the given DOM node.
  35    */
  36   DocAccessible* GetDocAccessible(nsIDocument* aDocument);
  37
  38   /**
  39    * Return document accessible for the given presshell.
  40    */
  41   DocAccessible* GetDocAccessible(const nsIPresShell* aPresShell)
  42   {
  43     if (!aPresShell)
  44       return nullptr;
  45
  46     DocAccessible* doc = aPresShell->GetDocAccessible();
  47     if (doc)
  48       return doc;
  49
  50     return GetDocAccessible(aPresShell->GetDocument());
  51   }
  52
  53   /**
  54    * Search through all document accessibles for an accessible with the given
  55    * unique id.
  56    */
  57   Accessible* FindAccessibleInCache(nsINode* aNode) const;
  58
  59   /**
  60    * Called by document accessible when it gets shutdown.
  61    */
  62   inline void NotifyOfDocumentShutdown(nsIDocument* aDocument)
  63   {
  64     mDocAccessibleCache.Remove(aDocument);
  65     RemoveListeners(aDocument);
  66   }
  67
  68 #ifdef DEBUG
  69   bool IsProcessingRefreshDriverNotification() const;
  70 #endif
  71
  72 protected:
  73   DocManager();
  74   virtual ~DocManager() { }
  75
  76   /**
  77    * Initialize the manager.
  78    */
  79   bool Init();
  80
  81   /**
  82    * Shutdown the manager.
  83    */
  84   void Shutdown();
  85
  86 private:
  87   DocManager(const DocManager&);
  88   DocManager& operator =(const DocManager&);
  89
  90 private:
  91   /**
  92    * Create an accessible document if it was't created and fire accessibility
  93    * events if needed.
  94    *
  95    * @param  aDocument       [in] loaded DOM document
  96    * @param  aLoadEventType  [in] specifies the event type to fire load event,
  97    *                           if 0 then no event is fired
  98    */
  99   void HandleDOMDocumentLoad(nsIDocument* aDocument,
 100                              uint32_t aLoadEventType);
 101
 102   /**
 103    * Add/remove 'pagehide' and 'DOMContentLoaded' event listeners.
 104    */
 105   void AddListeners(nsIDocument *aDocument, bool aAddPageShowListener);
 106   void RemoveListeners(nsIDocument* aDocument);
 107
 108   /**
 109    * Create document or root accessible.
 110    */
 111   DocAccessible* CreateDocOrRootAccessible(nsIDocument* aDocument);
 112
 113   typedef nsRefPtrHashtable<nsPtrHashKey<const nsIDocument>, DocAccessible>
 114     DocAccessibleHashtable;
 115
 116   /**
 117    * Get first entry of the document accessible from cache.
 118    */
 119   static PLDHashOperator
 120     GetFirstEntryInDocCache(const nsIDocument* aKey,
 121                             DocAccessible* aDocAccessible,
 122                             void* aUserArg);
 123
 124   /**
 125    * Clear the cache and shutdown the document accessibles.
 126    */
 127   void ClearDocCache();
 128
 129   struct nsSearchAccessibleInCacheArg
 130   {
 131     Accessible* mAccessible;
 132     nsINode* mNode;
 133   };
 134
 135   static PLDHashOperator
 136     SearchAccessibleInDocCache(const nsIDocument* aKey,
 137                                DocAccessible* aDocAccessible,
 138                                void* aUserArg);
 139
 140 #ifdef DEBUG
 141   static PLDHashOperator
 142     SearchIfDocIsRefreshing(const nsIDocument* aKey,
 143                             DocAccessible* aDocAccessible, void* aUserArg);
 144 #endif
 145
 146   DocAccessibleHashtable mDocAccessibleCache;
 147 };
 148
 149 /**
 150  * Return the existing document accessible for the document if any.
 151  * Note this returns the doc accessible for the primary pres shell if there is
 152  * more than one.
 153  */
 154 inline DocAccessible*
 155 GetExistingDocAccessible(const nsIDocument* aDocument)
 156 {
 157   nsIPresShell* ps = aDocument->GetShell();
 158   return ps ? ps->GetDocAccessible() : nullptr;
 159 }
 160
 161 } // namespace a11y
 162 } // namespace mozilla
 163
 164 #endif // mozilla_a11_DocManager_h_