gecko-dev/accessible/jsat/EventManager.jsm

724 строки
24 KiB
JavaScript

/* 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, '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, aContentControl) {
this.contentScope = aContentScope;
this.contentControl = aContentControl;
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: { editing: false },
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._preDialogPosition = new WeakMap();
}
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._preDialogPosition.clear();
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.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 &&
!Utils.getState(position).contains(States.FOCUSED)) {
aEvent.accessibleDocument.takeFocus();
}
this.present(
Presentation.pivotChanged(position, oldAccessible, reason,
pivot.startOffset, pivot.endOffset,
aEvent.isFromUserInput));
break;
}
case Events.STATE_CHANGE:
{
let event = aEvent.QueryInterface(Ci.nsIAccessibleStateChangeEvent);
let state = Utils.getState(event);
if (state.contains(States.CHECKED)) {
if (aEvent.accessible.role === Roles.SWITCH) {
this.present(
Presentation.
actionInvoked(aEvent.accessible,
event.isEnabled ? 'on' : 'off'));
} else {
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.NAME_CHANGE:
{
let acc = aEvent.accessible;
if (acc === this.contentControl.vc.position) {
this.present(Presentation.nameChanged(acc));
} else {
let {liveRegion, isPolite} = this._handleLiveRegion(aEvent,
['text', 'all']);
if (liveRegion) {
this.present(Presentation.nameChanged(acc, isPolite));
}
}
break;
}
case Events.SCROLLING_START:
{
this.contentControl.autoMove(aEvent.accessible);
break;
}
case Events.TEXT_CARET_MOVED:
{
let acc = aEvent.accessible.QueryInterface(Ci.nsIAccessibleText);
let caretOffset = aEvent.
QueryInterface(Ci.nsIAccessibleCaretMoveEvent).caretOffset;
// We could get a caret move in an accessible that is not focused,
// it doesn't mean we are not on any editable accessible. just not
// on this one..
let state = Utils.getState(acc);
if (state.contains(States.FOCUSED)) {
this._setEditingMode(aEvent, caretOffset);
if (state.contains(States.EDITABLE)) {
this.present(Presentation.textSelectionChanged(acc.getText(0, -1),
caretOffset, caretOffset, 0, 0, aEvent.isFromUserInput));
}
}
break;
}
case Events.OBJECT_ATTRIBUTE_CHANGED:
{
let evt = aEvent.QueryInterface(
Ci.nsIAccessibleObjectAttributeChangedEvent);
if (evt.changedAttribute.toString() !== 'aria-hidden') {
// Only handle aria-hidden attribute change.
break;
}
let hidden = Utils.isHidden(aEvent.accessible);
this[hidden ? '_handleHide' : '_handleShow'](evt);
if (this.inTest) {
this.sendMsgFunc("AccessFu:AriaHidden", { hidden: hidden });
}
break;
}
case Events.SHOW:
{
this._handleShow(aEvent);
break;
}
case Events.HIDE:
{
let evt = aEvent.QueryInterface(Ci.nsIAccessibleHideEvent);
this._handleHide(evt);
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;
this._setEditingMode(aEvent);
if ([Roles.CHROME_WINDOW,
Roles.DOCUMENT,
Roles.APPLICATION].indexOf(acc.role) < 0) {
this.contentControl.autoMove(acc);
}
if (this.inTest) {
this.sendMsgFunc("AccessFu:Focused");
}
break;
}
case Events.DOCUMENT_LOAD_COMPLETE:
{
let position = this.contentControl.vc.position;
// Check if position is in the subtree of the DOCUMENT_LOAD_COMPLETE
// event's dialog accesible or accessible document
let subtreeRoot = aEvent.accessible.role === Roles.DIALOG ?
aEvent.accessible : aEvent.accessibleDocument;
if (aEvent.accessible === aEvent.accessibleDocument ||
(position && Utils.isInSubtree(position, subtreeRoot))) {
// Do not automove into the document if the virtual cursor is already
// positioned inside it.
break;
}
this._preDialogPosition.set(aEvent.accessible.DOMNode, position);
this.contentControl.autoMove(aEvent.accessible, { delay: 500 });
break;
}
case Events.VALUE_CHANGE:
case Events.TEXT_VALUE_CHANGE:
{
let position = this.contentControl.vc.position;
let target = aEvent.accessible;
if (position === target ||
Utils.getEmbeddedControl(position) === target) {
this.present(Presentation.valueChanged(target));
} else {
let {liveRegion, isPolite} = this._handleLiveRegion(aEvent,
['text', 'all']);
if (liveRegion) {
this.present(Presentation.valueChanged(target, isPolite));
}
}
}
}
},
_setEditingMode: function _setEditingMode(aEvent, aCaretOffset) {
let acc = aEvent.accessible;
let accText, characterCount;
let caretOffset = aCaretOffset;
try {
accText = acc.QueryInterface(Ci.nsIAccessibleText);
} catch (e) {
// No text interface on this accessible.
}
if (accText) {
characterCount = accText.characterCount;
if (caretOffset === undefined) {
caretOffset = accText.caretOffset;
}
}
// Update editing state, both for presenter and other things
let state = Utils.getState(acc);
let editState = {
editing: state.contains(States.EDITABLE) &&
state.contains(States.FOCUSED),
multiline: state.contains(States.MULTI_LINE),
atStart: caretOffset === 0,
atEnd: caretOffset === characterCount
};
// Not interesting
if (!editState.editing && editState.editing === this.editState.editing) {
return;
}
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.editState = editState;
},
_handleShow: function _handleShow(aEvent) {
let {liveRegion, isPolite} = this._handleLiveRegion(aEvent,
['additions', 'all']);
// Only handle show if it is a relevant live region.
if (!liveRegion) {
return;
}
// Show for text is handled by the EVENT_TEXT_INSERTED handler.
if (aEvent.accessible.role === Roles.TEXT_LEAF) {
return;
}
this._dequeueLiveEvent(Events.HIDE, liveRegion);
this.present(Presentation.liveRegion(liveRegion, isPolite, false));
},
_handleHide: function _handleHide(aEvent) {
let {liveRegion, isPolite} = this._handleLiveRegion(
aEvent, ['removals', 'all']);
let acc = aEvent.accessible;
if (liveRegion) {
// Hide for text is handled by the EVENT_TEXT_REMOVED handler.
if (acc.role === Roles.TEXT_LEAF) {
return;
}
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, acc))) {
let position = this._preDialogPosition.get(aEvent.accessible.DOMNode) ||
aEvent.targetPrevSibling || aEvent.targetParent;
if (!position) {
try {
position = acc.previousSibling;
} catch (x) {
// Accessible is unattached from the accessible tree.
position = acc.parent;
}
}
this.contentControl.autoMove(position,
{ moveToFocused: true, delay: 500 });
}
}
},
_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, '');
if (modifiedText != event.modifiedText && !modifiedText.trim()) {
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(aEvent.accessible, 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),
20, // 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;
}
}
};