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
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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
  53 class nsIPresShell;
  54
  55 #define NS_ACCEVENT_IMPL_CID                            \
  56 {  /* 55b89892-a83d-4252-ba78-cbdf53a86936 */           \
  57   0x55b89892,                                           \
  58   0xa83d,                                               \
  59   0x4252,                                               \
  60   { 0xba, 0x78, 0xcb, 0xdf, 0x53, 0xa8, 0x69, 0x36 }    \
  61 }
  62
  63 class nsAccEvent: public nsIAccessibleEvent
  64 {
  65 public:
  66
  67   // Rule for accessible events.
  68   // The rule will be applied when flushing pending events.
  69   enum EEventRule {
  70      // eAllowDupes : More than one event of the same type is allowed.
  71      //    This event will always be emitted.
  72      eAllowDupes,
  73      // eCoalesceFromSameSubtree : For events of the same type from the same
  74      //    subtree or the same node, only the umbrelle event on the ancestor
  75      //    will be emitted.
  76      eCoalesceFromSameSubtree,
  77      // eRemoveDupes : For repeat events, only the newest event in queue
  78      //    will be emitted.
  79      eRemoveDupes,
  80      // eDoNotEmit : This event is confirmed as a duplicate, do not emit it.
  81      eDoNotEmit
  82    };
  83
  84   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ACCEVENT_IMPL_CID)
  85
  86   // Initialize with an nsIAccessible
  87   nsAccEvent(PRUint32 aEventType, nsIAccessible *aAccessible,
  88              PRBool aIsAsynch = PR_FALSE,
  89              EEventRule aEventRule = eRemoveDupes);
  90   // Initialize with an nsIDOMNode
  91   nsAccEvent(PRUint32 aEventType, nsIDOMNode *aDOMNode,
  92              PRBool aIsAsynch = PR_FALSE,
  93              EEventRule aEventRule = eRemoveDupes);
  94   virtual ~nsAccEvent() {}
  95
  96   NS_DECL_ISUPPORTS
  97   NS_DECL_NSIACCESSIBLEEVENT
  98
  99   static void GetLastEventAttributes(nsIDOMNode *aNode,
 100                                      nsIPersistentProperties *aAttributes);
 101
 102 protected:
 103   already_AddRefed<nsIAccessible> GetAccessibleByNode();
 104
 105   void CaptureIsFromUserInput(PRBool aIsAsynch);
 106   PRBool mIsFromUserInput;
 107
 108 private:
 109   PRUint32 mEventType;
 110   EEventRule mEventRule;
 111   nsCOMPtr<nsIAccessible> mAccessible;
 112   nsCOMPtr<nsIDOMNode> mDOMNode;
 113   nsCOMPtr<nsIAccessibleDocument> mDocAccessible;
 114
 115   static PRBool gLastEventFromUserInput;
 116   static nsIDOMNode* gLastEventNodeWeak;
 117
 118 public:
 119   static PRUint32 EventType(nsIAccessibleEvent *aAccEvent) {
 120     PRUint32 eventType;
 121     aAccEvent->GetEventType(&eventType);
 122     return eventType;
 123   }
 124   static EEventRule EventRule(nsIAccessibleEvent *aAccEvent) {
 125     nsRefPtr<nsAccEvent> accEvent = GetAccEventPtr(aAccEvent);
 126     return accEvent->mEventRule;
 127   }
 128   static PRBool IsFromUserInput(nsIAccessibleEvent *aAccEvent) {
 129     PRBool isFromUserInput;
 130     aAccEvent->GetIsFromUserInput(&isFromUserInput);
 131     return isFromUserInput;
 132   }
 133
 134   static void ResetLastInputState()
 135    {gLastEventFromUserInput = PR_FALSE; gLastEventNodeWeak = nsnull; }
 136
 137   /**
 138    * Find and cache the last input state. This will be called automatically
 139    * for synchronous events. For asynchronous events it should be
 140    * called from the synchronous code which is the true source of the event,
 141    * before the event is fired.
 142    * @param aChangeNode that event will be on
 143    * @param aForceIsFromUserInput  PR_TRUE if the caller knows that this event was
 144    *                               caused by user input
 145    */
 146   static void PrepareForEvent(nsIDOMNode *aChangeNode,
 147                               PRBool aForceIsFromUserInput = PR_FALSE);
 148
 149   /**
 150    * The input state was previously stored with the nsIAccessibleEvent,
 151    * so use that state now -- call this when about to flush an event that
 152    * was waiting in an event queue
 153    */
 154   static void PrepareForEvent(nsIAccessibleEvent *aEvent,
 155                               PRBool aForceIsFromUserInput = PR_FALSE);
 156
 157   /**
 158    * Apply event rules to pending events, this method is called in
 159    * FlushingPendingEvents().
 160    * Result of this method:
 161    *   Event rule of filtered events will be set to eDoNotEmit.
 162    *   Events with other event rule are good to emit.
 163    */
 164   static void ApplyEventRules(nsCOMArray<nsIAccessibleEvent> &aEventsToFire);
 165
 166 private:
 167   static already_AddRefed<nsAccEvent> GetAccEventPtr(nsIAccessibleEvent *aAccEvent) {
 168     nsAccEvent* accEvent = nsnull;
 169     aAccEvent->QueryInterface(NS_GET_IID(nsAccEvent), (void**)&accEvent);
 170     return accEvent;
 171   }
 172
 173   /**
 174    * Apply aEventRule to same type event that from sibling nodes of aDOMNode.
 175    * @param aEventsToFire    array of pending events
 176    * @param aStart           start index of pending events to be scanned
 177    * @param aEnd             end index to be scanned (not included)
 178    * @param aEventType       target event type
 179    * @param aDOMNode         target are siblings of this node
 180    * @param aEventRule       the event rule to be applied
 181    *                         (should be eDoNotEmit or eAllowDupes)
 182    */
 183   static void ApplyToSiblings(nsCOMArray<nsIAccessibleEvent> &aEventsToFire,
 184                               PRUint32 aStart, PRUint32 aEnd,
 185                               PRUint32 aEventType, nsIDOMNode* aDOMNode,
 186                               EEventRule aEventRule);
 187 };
 188
 189 NS_DEFINE_STATIC_IID_ACCESSOR(nsAccEvent, NS_ACCEVENT_IMPL_CID)
 190
 191 class nsAccStateChangeEvent: public nsAccEvent,
 192                              public nsIAccessibleStateChangeEvent
 193 {
 194 public:
 195   nsAccStateChangeEvent(nsIAccessible *aAccessible,
 196                         PRUint32 aState, PRBool aIsExtraState,
 197                         PRBool aIsEnabled);
 198
 199   nsAccStateChangeEvent(nsIDOMNode *aNode,
 200                         PRUint32 aState, PRBool aIsExtraState,
 201                         PRBool aIsEnabled);
 202
 203   nsAccStateChangeEvent(nsIDOMNode *aNode,
 204                         PRUint32 aState, PRBool aIsExtraState);
 205
 206   NS_DECL_ISUPPORTS_INHERITED
 207   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 208   NS_DECL_NSIACCESSIBLESTATECHANGEEVENT
 209
 210 private:
 211   PRUint32 mState;
 212   PRBool mIsExtraState;
 213   PRBool mIsEnabled;
 214 };
 215
 216 class nsAccTextChangeEvent: public nsAccEvent,
 217                             public nsIAccessibleTextChangeEvent
 218 {
 219 public:
 220   nsAccTextChangeEvent(nsIAccessible *aAccessible, PRInt32 aStart, PRUint32 aLength,
 221                        PRBool aIsInserted, PRBool aIsAsynch = PR_FALSE);
 222
 223   NS_DECL_ISUPPORTS_INHERITED
 224   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 225   NS_DECL_NSIACCESSIBLETEXTCHANGEEVENT
 226
 227 private:
 228   PRInt32 mStart;
 229   PRUint32 mLength;
 230   PRBool mIsInserted;
 231   nsString mModifiedText;
 232 };
 233
 234 class nsAccCaretMoveEvent: public nsAccEvent,
 235                            public nsIAccessibleCaretMoveEvent
 236 {
 237 public:
 238   nsAccCaretMoveEvent(nsIAccessible *aAccessible, PRInt32 aCaretOffset);
 239   nsAccCaretMoveEvent(nsIDOMNode *aNode);
 240
 241   NS_DECL_ISUPPORTS_INHERITED
 242   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 243   NS_DECL_NSIACCESSIBLECARETMOVEEVENT
 244
 245 private:
 246   PRInt32 mCaretOffset;
 247 };
 248
 249 class nsAccTableChangeEvent : public nsAccEvent,
 250                               public nsIAccessibleTableChangeEvent {
 251 public:
 252   nsAccTableChangeEvent(nsIAccessible *aAccessible, PRUint32 aEventType,
 253                         PRInt32 aRowOrColIndex, PRInt32 aNumRowsOrCols,
 254                         PRBool aIsAsynch);
 255
 256   NS_DECL_ISUPPORTS
 257   NS_FORWARD_NSIACCESSIBLEEVENT(nsAccEvent::)
 258   NS_DECL_NSIACCESSIBLETABLECHANGEEVENT
 259
 260 private:
 261   PRUint32 mRowOrColIndex;   // the start row/column after which the rows are inserted/deleted.
 262   PRUint32 mNumRowsOrCols;   // the number of inserted/deleted rows/columns
 263 };
 264
 265 #endif
 266