accessible/src/base/nsAccessibleEventData.h

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   2 /* ***** BEGIN LICENSE BLOCK *****
   3  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   4  *
   5  * The contents of this file are subject to the Mozilla Public License Version
   6  * 1.1 (the "License"); you may not use this file except in compliance with
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  11  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
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  15  * The Original Code is mozilla.org code.
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  17  * The Initial Developer of the Original Code is
  18  * Netscape Communications Corporation.
  19  * Portions created by the Initial Developer are Copyright (C) 1998
  20  * the Initial Developer. All Rights Reserved.
  21  *
  22  * Contributor(s):
  23  *   Kyle Yuan (kyle.yuan@sun.com)
  24  *   John Sun (john.sun@sun.com)
  25  *   Alexander Surkov <surkov.alexander@gmail.com>
  26  *
  27  * Alternatively, the contents of this file may be used under the terms of
  28  * either of the GNU General Public License Version 2 or later (the "GPL"),
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  38  *
  39  * ***** END LICENSE BLOCK ***** */
  40
  41 #ifndef _nsAccessibleEventData_H_
  42 #define _nsAccessibleEventData_H_
  43
  44 #include "nsAutoPtr.h"
  45 #include "nsCOMPtr.h"
  46 #include "nsCOMArray.h"
  47 #include "nsIAccessibleEvent.h"
  48 #include "nsIAccessible.h"
  49 #include "nsIAccessibleDocument.h"
  50 #include "nsIDOMNode.h"
  51 #include "nsString.h"
  52 #include "nsCycleCollectionParticipant.h"
  53
  54 class nsIPresShell;
  55
  56 #define NS_ACCEVENT_IMPL_CID                            \
  57 {  /* 55b89892-a83d-4252-ba78-cbdf53a86936 */           \
  58   0x55b89892,                                           \
  59   0xa83d,                                               \
  60   0x4252,                                               \
  61   { 0xba, 0x78, 0xcb, 0xdf, 0x53, 0xa8, 0x69, 0x36 }    \
  62 }
  63
  64 class nsAccEvent: public nsIAccessibleEvent
  65 {
  66 public:
  67
  68   // Rule for accessible events.
  69   // The rule will be applied when flushing pending events.
  70   enum EEventRule {
  71      // eAllowDupes : More than one event of the same type is allowed.
  72      //    This event will always be emitted.
  73      eAllowDupes,
  74      // eCoalesceFromSameSubtree : For events of the same type from the same
  75      //    subtree or the same node, only the umbrelle event on the ancestor
  76      //    will be emitted.
  77      eCoalesceFromSameSubtree,
  78      // eRemoveDupes : For repeat events, only the newest event in queue
  79      //    will be emitted.
  80      eRemoveDupes,
  81      // eDoNotEmit : This event is confirmed as a duplicate, do not emit it.
  82      eDoNotEmit
  83    };
  84
  85   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ACCEVENT_IMPL_CID)
  86
  87   // Initialize with an nsIAccessible
  88   nsAccEvent(PRUint32 aEventType, nsIAccessible *aAccessible,
  89              PRBool aIsAsynch = PR_FALSE,
  90              EEventRule aEventRule = eRemoveDupes);
  91   // Initialize with an nsIDOMNode
  92   nsAccEvent(PRUint32 aEventType, nsIDOMNode *aDOMNode,
  93              PRBool aIsAsynch = PR_FALSE,
  94              EEventRule aEventRule = eRemoveDupes);
  95   virtual ~nsAccEvent() {}
  96
  97   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
  98   NS_DECL_CYCLE_COLLECTION_CLASS(nsAccEvent)
  99
 100   NS_DECL_NSIACCESSIBLEEVENT
 101
 102   static void GetLastEventAttributes(nsIDOMNode *aNode,
 103                                      nsIPersistentProperties *aAttributes);
 104
 105 protected:
 106   already_AddRefed<nsIAccessible> GetAccessibleByNode();
 107
 108   void CaptureIsFromUserInput(PRBool aIsAsynch);
 109   PRBool mIsFromUserInput;
 110
 111   PRUint32 mEventType;
 112   EEventRule mEventRule;
 113   nsCOMPtr<nsIAccessible> mAccessible;
 114   nsCOMPtr<nsIDOMNode> mDOMNode;
 115   nsCOMPtr<nsIAccessibleDocument> mDocAccessible;
 116
 117 private:
 118   static PRBool gLastEventFromUserInput;
 119   static nsIDOMNode* gLastEventNodeWeak;
 120
 121 public:
 122   static PRUint32 EventType(nsIAccessibleEvent *aAccEvent) {
 123     PRUint32 eventType;
 124     aAccEvent->GetEventType(&eventType);
 125     return eventType;
 126   }
 127   static EEventRule EventRule(nsIAccessibleEvent *aAccEvent) {
 128     nsRefPtr<nsAccEvent> accEvent = GetAccEventPtr(aAccEvent);
 129     return accEvent->mEventRule;
 130   }
 131   static PRBool IsFromUserInput(nsIAccessibleEvent *aAccEvent) {
 132     PRBool isFromUserInput;
 133     aAccEvent->GetIsFromUserInput(&isFromUserInput);
 134     return isFromUserInput;
 135   }
 136
 137   static void ResetLastInputState()
 138    {gLastEventFromUserInput = PR_FALSE; gLastEventNodeWeak = nsnull; }
 139
 140   /**
 141    * Find and cache the last input state. This will be called automatically
 142    * for synchronous events. For asynchronous events it should be
 143    * called from the synchronous code which is the true source of the event,
 144    * before the event is fired.
 145    * @param aChangeNode that event will be on
 146    * @param aForceIsFromUserInput  PR_TRUE if the caller knows that this event was
 147    *                               caused by user input
 148    */
 149   static void PrepareForEvent(nsIDOMNode *aChangeNode,
 150                               PRBool aForceIsFromUserInput = PR_FALSE);
 151
 152   /**
 153    * The input state was previously stored with the nsIAccessibleEvent,
 154    * so use that state now -- call this when about to flush an event that
 155    * was waiting in an event queue
 156    */
 157   static void PrepareForEvent(nsIAccessibleEvent *aEvent,
 158                               PRBool aForceIsFromUserInput = PR_FALSE);
 159
 160   /**
 161    * Apply event rules to pending events, this method is called in
 162    * FlushingPendingEvents().
 163    * Result of this method:
 164    *   Event rule of filtered events will be set to eDoNotEmit.
 165    *   Events with other event rule are good to emit.
 166    */
 167   static void ApplyEventRules(nsCOMArray<nsIAccessibleEvent> &aEventsToFire);
 168
 169 private:
 170   static already_AddRefed<nsAccEvent> GetAccEventPtr(nsIAccessibleEvent *aAccEvent) {
 171     nsAccEvent* accEvent = nsnull;
 172     aAccEvent->QueryInterface(NS_GET_IID(nsAccEvent), (void**)&accEvent);
 173     return accEvent;
 174   }
 175
 176   /**
 177    * Apply aEventRule to same type event that from sibling nodes of aDOMNode.
 178    * @param aEventsToFire    array of pending events
 179    * @param aStart           start index of pending events to be scanned
 180    * @param aEnd             end index to be scanned (not included)
 181    * @param aEventType       target event type
 182    * @param aDOMNode         target are siblings of this node
 183    * @param aEventRule       the event rule to be applied
 184    *                         (should be eDoNotEmit or eAllowDupes)
 185    */
 186   static void ApplyToSiblings(nsCOMArray<nsIAccessibleEvent> &aEventsToFire,
 187                               PRUint32 aStart, PRUint32 aEnd,
 188                               PRUint32 aEventType, nsIDOMNode* aDOMNode,
 189                               EEventRule aEventRule);
 190 };
 191
 192 NS_DEFINE_STATIC_IID_ACCESSOR(nsAccEvent, NS_ACCEVENT_IMPL_CID)
 193
 194 class nsAccStateChangeEvent: public nsAccEvent,
 195                              public nsIAccessibleStateChangeEvent
 196 {
 197 public:
 198   nsAccStateChangeEvent(nsIAccessible *aAccessible,
 199                         PRUint32 aState, PRBool aIsExtraState,
 200                         PRBool aIsEnabled);
 201
 202   nsAccStateChangeEvent(nsIDOMNode *aNode,
 203                         PRUint32 aState, PRBool aIsExtraState,
 204                         PRBool aIsEnabled);
 205
 206   nsAccStateChangeEvent(nsIDOMNode *aNode,
 207                         PRUint32 aState, PRBool aIsExtraState);
 208
 209   NS_DECL_ISUPPORTS_INHERITED
 210   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 211   NS_DECL_NSIACCESSIBLESTATECHANGEEVENT
 212
 213 private:
 214   PRUint32 mState;
 215   PRBool mIsExtraState;
 216   PRBool mIsEnabled;
 217 };
 218
 219 class nsAccTextChangeEvent: public nsAccEvent,
 220                             public nsIAccessibleTextChangeEvent
 221 {
 222 public:
 223   nsAccTextChangeEvent(nsIAccessible *aAccessible, PRInt32 aStart, PRUint32 aLength,
 224                        PRBool aIsInserted, PRBool aIsAsynch = PR_FALSE);
 225
 226   NS_DECL_ISUPPORTS_INHERITED
 227   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 228   NS_DECL_NSIACCESSIBLETEXTCHANGEEVENT
 229
 230 private:
 231   PRInt32 mStart;
 232   PRUint32 mLength;
 233   PRBool mIsInserted;
 234   nsString mModifiedText;
 235 };
 236
 237 class nsAccCaretMoveEvent: public nsAccEvent,
 238                            public nsIAccessibleCaretMoveEvent
 239 {
 240 public:
 241   nsAccCaretMoveEvent(nsIAccessible *aAccessible, PRInt32 aCaretOffset);
 242   nsAccCaretMoveEvent(nsIDOMNode *aNode);
 243
 244   NS_DECL_ISUPPORTS_INHERITED
 245   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 246   NS_DECL_NSIACCESSIBLECARETMOVEEVENT
 247
 248 private:
 249   PRInt32 mCaretOffset;
 250 };
 251
 252 class nsAccTableChangeEvent : public nsAccEvent,
 253                               public nsIAccessibleTableChangeEvent {
 254 public:
 255   nsAccTableChangeEvent(nsIAccessible *aAccessible, PRUint32 aEventType,
 256                         PRInt32 aRowOrColIndex, PRInt32 aNumRowsOrCols,
 257                         PRBool aIsAsynch);
 258
 259   NS_DECL_ISUPPORTS
 260   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 261   NS_DECL_NSIACCESSIBLETABLECHANGEEVENT
 262
 263 private:
 264   PRUint32 mRowOrColIndex;   // the start row/column after which the rows are inserted/deleted.
 265   PRUint32 mNumRowsOrCols;   // the number of inserted/deleted rows/columns
 266 };
 267
 268 #endif
 269