The Tor Browser: accessible/src/jsat/EventManager.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/EventManager.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/EventManager.jsm

Wed, 31 Dec 2014 07:16:47 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 07:16:47 +0100
branch: TOR_BUG_9701
changeset 3: 141e0f1194b1
permissions: -rw-r--r--

Revert simplistic fix pending revisit of Mozilla integration attempt.

 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/. */
 'use strict';
 const Ci = Components.interfaces;
 const Cu = Components.utils;
 const TEXT_NODE = 3;
 Cu.import('resource://gre/modules/XPCOMUtils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Services',
   'resource://gre/modules/Services.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Utils',
   'resource://gre/modules/accessibility/Utils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Logger',
   'resource://gre/modules/accessibility/Utils.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Presentation',
   'resource://gre/modules/accessibility/Presentation.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'TraversalRules',
   'resource://gre/modules/accessibility/TraversalRules.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Roles',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'Events',
   'resource://gre/modules/accessibility/Constants.jsm');
 XPCOMUtils.defineLazyModuleGetter(this, 'States',
   'resource://gre/modules/accessibility/Constants.jsm');
 this.EXPORTED_SYMBOLS = ['EventManager'];
 this.EventManager = function EventManager(aContentScope) {
   this.contentScope = aContentScope;
   this.addEventListener = this.contentScope.addEventListener.bind(
     this.contentScope);
   this.removeEventListener = this.contentScope.removeEventListener.bind(
     this.contentScope);
   this.sendMsgFunc = this.contentScope.sendAsyncMessage.bind(
     this.contentScope);
   this.webProgress = this.contentScope.docShell.
     QueryInterface(Ci.nsIInterfaceRequestor).
     getInterface(Ci.nsIWebProgress);
 };
 this.EventManager.prototype = {
   editState: {},
   start: function start() {
     try {
       if (!this._started) {
         Logger.debug('EventManager.start');
         this._started = true;
         AccessibilityEventObserver.addListener(this);
         this.webProgress.addProgressListener(this,
           (Ci.nsIWebProgress.NOTIFY_STATE_ALL |
            Ci.nsIWebProgress.NOTIFY_LOCATION));
         this.addEventListener('wheel', this, true);
         this.addEventListener('scroll', this, true);
         this.addEventListener('resize', this, true);
       }
       this.present(Presentation.tabStateChanged(null, 'newtab'));
     } catch (x) {
       Logger.logException(x, 'Failed to start EventManager');
     }
   },
   // XXX: Stop is not called when the tab is closed (|TabClose| event is too
   // late). It is only called when the AccessFu is disabled explicitly.
   stop: function stop() {
     if (!this._started) {
       return;
     }
     Logger.debug('EventManager.stop');
     AccessibilityEventObserver.removeListener(this);
     try {
       this.webProgress.removeProgressListener(this);
       this.removeEventListener('wheel', this, true);
       this.removeEventListener('scroll', this, true);
       this.removeEventListener('resize', this, true);
     } catch (x) {
       // contentScope is dead.
     } finally {
       this._started = false;
     }
   },
   handleEvent: function handleEvent(aEvent) {
     Logger.debug(() => {
       return ['DOMEvent', aEvent.type];
     });
     try {
       switch (aEvent.type) {
       case 'wheel':
       {
         let attempts = 0;
         let delta = aEvent.deltaX || aEvent.deltaY;
         this.contentScope.contentControl.autoMove(
          null,
          { moveMethod: delta > 0 ? 'moveNext' : 'movePrevious',
            onScreenOnly: true, noOpIfOnScreen: true, delay: 500 });
         break;
       }
       case 'scroll':
       case 'resize':
       {
         // the target could be an element, document or window
         let window = null;
         if (aEvent.target instanceof Ci.nsIDOMWindow)
           window = aEvent.target;
         else if (aEvent.target instanceof Ci.nsIDOMDocument)
           window = aEvent.target.defaultView;
         else if (aEvent.target instanceof Ci.nsIDOMElement)
           window = aEvent.target.ownerDocument.defaultView;
         this.present(Presentation.viewportChanged(window));
         break;
       }
       }
     } catch (x) {
       Logger.logException(x, 'Error handling DOM event');
     }
   },
   handleAccEvent: function handleAccEvent(aEvent) {
     Logger.debug(() => {
       return ['A11yEvent', Logger.eventToString(aEvent),
               Logger.accessibleToString(aEvent.accessible)];
     });
     // Don't bother with non-content events in firefox.
     if (Utils.MozBuildApp == 'browser' &&
         aEvent.eventType != Events.VIRTUALCURSOR_CHANGED &&
         // XXX Bug 442005 results in DocAccessible::getDocType returning
         // NS_ERROR_FAILURE. Checking for aEvent.accessibleDocument.docType ==
         // 'window' does not currently work.
         (aEvent.accessibleDocument.DOMDocument.doctype &&
          aEvent.accessibleDocument.DOMDocument.doctype.name === 'window')) {
       return;
     }
     switch (aEvent.eventType) {
       case Events.VIRTUALCURSOR_CHANGED:
       {
         let pivot = aEvent.accessible.
           QueryInterface(Ci.nsIAccessibleDocument).virtualCursor;
         let position = pivot.position;
         if (position && position.role == Roles.INTERNAL_FRAME)
           break;
         let event = aEvent.
           QueryInterface(Ci.nsIAccessibleVirtualCursorChangeEvent);
         let reason = event.reason;
         let oldAccessible = event.oldAccessible;
         if (this.editState.editing) {
           aEvent.accessibleDocument.takeFocus();
         }
         this.present(
           Presentation.pivotChanged(position, oldAccessible, reason,
                                     pivot.startOffset, pivot.endOffset));
         break;
       }
       case Events.STATE_CHANGE:
       {
         let event = aEvent.QueryInterface(Ci.nsIAccessibleStateChangeEvent);
         let state = Utils.getState(event);
         if (state.contains(States.CHECKED)) {
           this.present(
             Presentation.
               actionInvoked(aEvent.accessible,
                             event.isEnabled ? 'check' : 'uncheck'));
         } else if (state.contains(States.SELECTED)) {
           this.present(
             Presentation.
               actionInvoked(aEvent.accessible,
                             event.isEnabled ? 'select' : 'unselect'));
         }
         break;
       }
       case Events.SCROLLING_START:
       {
         this.contentScope.contentControl.autoMove(aEvent.accessible);
         break;
       }
       case Events.TEXT_CARET_MOVED:
       {
         let acc = aEvent.accessible;
         let characterCount = acc.
           QueryInterface(Ci.nsIAccessibleText).characterCount;
         let caretOffset = aEvent.
           QueryInterface(Ci.nsIAccessibleCaretMoveEvent).caretOffset;
         // Update editing state, both for presenter and other things
         let state = Utils.getState(acc);
         let editState = {
           editing: state.contains(States.EDITABLE),
           multiline: state.contains(States.MULTI_LINE),
           atStart: caretOffset == 0,
           atEnd: caretOffset == characterCount
         };
         // Not interesting
         if (!editState.editing && editState.editing == this.editState.editing)
           break;
         if (editState.editing != this.editState.editing)
           this.present(Presentation.editingModeChanged(editState.editing));
         if (editState.editing != this.editState.editing ||
             editState.multiline != this.editState.multiline ||
             editState.atEnd != this.editState.atEnd ||
             editState.atStart != this.editState.atStart)
           this.sendMsgFunc("AccessFu:Input", editState);
         this.present(Presentation.textSelectionChanged(acc.getText(0,-1),
                      caretOffset, caretOffset, 0, 0, aEvent.isFromUserInput));
         this.editState = editState;
         break;
       }
       case Events.SHOW:
       {
         let {liveRegion, isPolite} = this._handleLiveRegion(aEvent,
           ['additions', 'all']);
         // Only handle show if it is a relevant live region.
         if (!liveRegion) {
           break;
         }
         // Show for text is handled by the EVENT_TEXT_INSERTED handler.
         if (aEvent.accessible.role === Roles.TEXT_LEAF) {
           break;
         }
         this._dequeueLiveEvent(Events.HIDE, liveRegion);
         this.present(Presentation.liveRegion(liveRegion, isPolite, false));
         break;
       }
       case Events.HIDE:
       {
         let evt = aEvent.QueryInterface(Ci.nsIAccessibleHideEvent);
         let {liveRegion, isPolite} = this._handleLiveRegion(
           evt, ['removals', 'all']);
         if (liveRegion) {
           // Hide for text is handled by the EVENT_TEXT_REMOVED handler.
           if (aEvent.accessible.role === Roles.TEXT_LEAF) {
             break;
           }
           this._queueLiveEvent(Events.HIDE, liveRegion, isPolite);
         } else {
           let vc = Utils.getVirtualCursor(this.contentScope.content.document);
           if (vc.position &&
             (Utils.getState(vc.position).contains(States.DEFUNCT) ||
               Utils.isInSubtree(vc.position, aEvent.accessible))) {
             this.contentScope.contentControl.autoMove(
               evt.targetPrevSibling || evt.targetParent,
               { moveToFocused: true, delay: 500 });
           }
         }
         break;
       }
       case Events.TEXT_INSERTED:
       case Events.TEXT_REMOVED:
       {
         let {liveRegion, isPolite} = this._handleLiveRegion(aEvent,
           ['text', 'all']);
         if (aEvent.isFromUserInput || liveRegion) {
           // Handle all text mutations coming from the user or if they happen
           // on a live region.
           this._handleText(aEvent, liveRegion, isPolite);
         }
         break;
       }
       case Events.FOCUS:
       {
         // Put vc where the focus is at
         let acc = aEvent.accessible;
         let doc = aEvent.accessibleDocument;
         if (acc.role != Roles.DOCUMENT && doc.role != Roles.CHROME_WINDOW) {
          this.contentScope.contentControl.autoMove(acc);
        }
        break;
       }
       case Events.DOCUMENT_LOAD_COMPLETE:
       {
         if (aEvent.accessible === aEvent.accessibleDocument) {
           break;
         }
         this.contentScope.contentControl.autoMove(
           aEvent.accessible, { delay: 500 });
         break;
       }
       case Events.VALUE_CHANGE:
       {
         let position = this.contentScope.contentControl.vc.position;
         let target = aEvent.accessible;
         if (position === target ||
             Utils.getEmbeddedControl(position) === target) {
           this.present(Presentation.valueChanged(target));
         }
       }
     }
   },
   _handleText: function _handleText(aEvent, aLiveRegion, aIsPolite) {
     let event = aEvent.QueryInterface(Ci.nsIAccessibleTextChangeEvent);
     let isInserted = event.isInserted;
     let txtIface = aEvent.accessible.QueryInterface(Ci.nsIAccessibleText);
     let text = '';
     try {
       text = txtIface.getText(0, Ci.nsIAccessibleText.TEXT_OFFSET_END_OF_TEXT);
     } catch (x) {
       // XXX we might have gotten an exception with of a
       // zero-length text. If we did, ignore it (bug #749810).
       if (txtIface.characterCount) {
         throw x;
       }
     }
     // If there are embedded objects in the text, ignore them.
     // Assuming changes to the descendants would already be handled by the
     // show/hide event.
     let modifiedText = event.modifiedText.replace(/\uFFFC/g, '').trim();
     if (!modifiedText) {
       return;
     }
     if (aLiveRegion) {
       if (aEvent.eventType === Events.TEXT_REMOVED) {
         this._queueLiveEvent(Events.TEXT_REMOVED, aLiveRegion, aIsPolite,
           modifiedText);
       } else {
         this._dequeueLiveEvent(Events.TEXT_REMOVED, aLiveRegion);
         this.present(Presentation.liveRegion(aLiveRegion, aIsPolite, false,
           modifiedText));
       }
     } else {
       this.present(Presentation.textChanged(isInserted, event.start,
         event.length, text, modifiedText));
     }
   },
   _handleLiveRegion: function _handleLiveRegion(aEvent, aRelevant) {
     if (aEvent.isFromUserInput) {
       return {};
     }
     let parseLiveAttrs = function parseLiveAttrs(aAccessible) {
       let attrs = Utils.getAttributes(aAccessible);
       if (attrs['container-live']) {
         return {
           live: attrs['container-live'],
           relevant: attrs['container-relevant'] || 'additions text',
           busy: attrs['container-busy'],
           atomic: attrs['container-atomic'],
           memberOf: attrs['member-of']
         };
       }
       return null;
     };
     // XXX live attributes are not set for hidden accessibles yet. Need to
     // climb up the tree to check for them.
     let getLiveAttributes = function getLiveAttributes(aEvent) {
       let liveAttrs = parseLiveAttrs(aEvent.accessible);
       if (liveAttrs) {
         return liveAttrs;
       }
       let parent = aEvent.targetParent;
       while (parent) {
         liveAttrs = parseLiveAttrs(parent);
         if (liveAttrs) {
           return liveAttrs;
         }
         parent = parent.parent
       }
       return {};
     };
     let {live, relevant, busy, atomic, memberOf} = getLiveAttributes(aEvent);
     // If container-live is not present or is set to |off| ignore the event.
     if (!live || live === 'off') {
       return {};
     }
     // XXX: support busy and atomic.
     // Determine if the type of the mutation is relevant. Default is additions
     // and text.
     let isRelevant = Utils.matchAttributeValue(relevant, aRelevant);
     if (!isRelevant) {
       return {};
     }
     return {
       liveRegion: aEvent.accessible,
       isPolite: live === 'polite'
     };
   },
   _dequeueLiveEvent: function _dequeueLiveEvent(aEventType, aLiveRegion) {
     let domNode = aLiveRegion.DOMNode;
     if (this._liveEventQueue && this._liveEventQueue.has(domNode)) {
       let queue = this._liveEventQueue.get(domNode);
       let nextEvent = queue[0];
       if (nextEvent.eventType === aEventType) {
         Utils.win.clearTimeout(nextEvent.timeoutID);
         queue.shift();
         if (queue.length === 0) {
           this._liveEventQueue.delete(domNode)
         }
       }
     }
   },
   _queueLiveEvent: function _queueLiveEvent(aEventType, aLiveRegion, aIsPolite, aModifiedText) {
     if (!this._liveEventQueue) {
       this._liveEventQueue = new WeakMap();
     }
     let eventHandler = {
       eventType: aEventType,
       timeoutID: Utils.win.setTimeout(this.present.bind(this),
 , // Wait for a possible EVENT_SHOW or EVENT_TEXT_INSERTED event.
         Presentation.liveRegion(aLiveRegion, aIsPolite, true, aModifiedText))
     };
     let domNode = aLiveRegion.DOMNode;
     if (this._liveEventQueue.has(domNode)) {
       this._liveEventQueue.get(domNode).push(eventHandler);
     } else {
       this._liveEventQueue.set(domNode, [eventHandler]);
     }
   },
   present: function present(aPresentationData) {
     this.sendMsgFunc("AccessFu:Present", aPresentationData);
   },
   onStateChange: function onStateChange(aWebProgress, aRequest, aStateFlags, aStatus) {
     let tabstate = '';
     let loadingState = Ci.nsIWebProgressListener.STATE_TRANSFERRING |
       Ci.nsIWebProgressListener.STATE_IS_DOCUMENT;
     let loadedState = Ci.nsIWebProgressListener.STATE_STOP |
       Ci.nsIWebProgressListener.STATE_IS_NETWORK;
     if ((aStateFlags & loadingState) == loadingState) {
       tabstate = 'loading';
     } else if ((aStateFlags & loadedState) == loadedState &&
                !aWebProgress.isLoadingDocument) {
       tabstate = 'loaded';
     }
     if (tabstate) {
       let docAcc = Utils.AccRetrieval.getAccessibleFor(aWebProgress.DOMWindow.document);
       this.present(Presentation.tabStateChanged(docAcc, tabstate));
     }
   },
   onProgressChange: function onProgressChange() {},
   onLocationChange: function onLocationChange(aWebProgress, aRequest, aLocation, aFlags) {
     let docAcc = Utils.AccRetrieval.getAccessibleFor(aWebProgress.DOMWindow.document);
     this.present(Presentation.tabStateChanged(docAcc, 'newdoc'));
   },
   onStatusChange: function onStatusChange() {},
   onSecurityChange: function onSecurityChange() {},
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIWebProgressListener,
                                          Ci.nsISupportsWeakReference,
                                          Ci.nsISupports,
                                          Ci.nsIObserver])
 };
 const AccessibilityEventObserver = {
   /**
    * A WeakMap containing [content, EventManager] pairs.
    */
   eventManagers: new WeakMap(),
   /**
    * A total number of registered eventManagers.
    */
   listenerCount: 0,
   /**
    * An indicator of an active 'accessible-event' observer.
    */
   started: false,
   /**
    * Start an AccessibilityEventObserver.
    */
   start: function start() {
     if (this.started || this.listenerCount === 0) {
       return;
     }
     Services.obs.addObserver(this, 'accessible-event', false);
     this.started = true;
   },
   /**
    * Stop an AccessibilityEventObserver.
    */
   stop: function stop() {
     if (!this.started) {
       return;
     }
     Services.obs.removeObserver(this, 'accessible-event');
     // Clean up all registered event managers.
     this.eventManagers.clear();
     this.listenerCount = 0;
     this.started = false;
   },
   /**
    * Register an EventManager and start listening to the
    * 'accessible-event' messages.
    *
    * @param aEventManager EventManager
    *        An EventManager object that was loaded into the specific content.
    */
   addListener: function addListener(aEventManager) {
     let content = aEventManager.contentScope.content;
     if (!this.eventManagers.has(content)) {
       this.listenerCount++;
     }
     this.eventManagers.set(content, aEventManager);
     // Since at least one EventManager was registered, start listening.
     Logger.debug('AccessibilityEventObserver.addListener. Total:',
       this.listenerCount);
     this.start();
   },
   /**
    * Unregister an EventManager and, optionally, stop listening to the
    * 'accessible-event' messages.
    *
    * @param aEventManager EventManager
    *        An EventManager object that was stopped in the specific content.
    */
   removeListener: function removeListener(aEventManager) {
     let content = aEventManager.contentScope.content;
     if (!this.eventManagers.delete(content)) {
       return;
     }
     this.listenerCount--;
     Logger.debug('AccessibilityEventObserver.removeListener. Total:',
       this.listenerCount);
     if (this.listenerCount === 0) {
       // If there are no EventManagers registered at the moment, stop listening
       // to the 'accessible-event' messages.
       this.stop();
     }
   },
   /**
    * Lookup an EventManager for a specific content. If the EventManager is not
    * found, walk up the hierarchy of parent windows.
    * @param content Window
    *        A content Window used to lookup the corresponding EventManager.
    */
   getListener: function getListener(content) {
     let eventManager = this.eventManagers.get(content);
     if (eventManager) {
       return eventManager;
     }
     let parent = content.parent;
     if (parent === content) {
       // There is no parent or the parent is of a different type.
       return null;
     }
     return this.getListener(parent);
   },
   /**
    * Handle the 'accessible-event' message.
    */
   observe: function observe(aSubject, aTopic, aData) {
     if (aTopic !== 'accessible-event') {
       return;
     }
     let event = aSubject.QueryInterface(Ci.nsIAccessibleEvent);
     if (!event.accessibleDocument) {
       Logger.warning(
         'AccessibilityEventObserver.observe: no accessible document:',
         Logger.eventToString(event), "accessible:",
         Logger.accessibleToString(event.accessible));
       return;
     }
     let content = event.accessibleDocument.window;
     // Match the content window to its EventManager.
     let eventManager = this.getListener(content);
     if (!eventManager || !eventManager._started) {
       if (Utils.MozBuildApp === 'browser' &&
           !(content instanceof Ci.nsIDOMChromeWindow)) {
         Logger.warning(
           'AccessibilityEventObserver.observe: ignored event:',
           Logger.eventToString(event), "accessible:",
           Logger.accessibleToString(event.accessible), "document:",
           Logger.accessibleToString(event.accessibleDocument));
       }
       return;
     }
     try {
       eventManager.handleAccEvent(event);
     } catch (x) {
       Logger.logException(x, 'Error handing accessible event');
     } finally {
       return;
     }
   }
 };

The Tor Browser / annotate

accessible/src/jsat/EventManager.jsm@141e0f1194b1 (annotated)

accessible/src/jsat/EventManager.jsm