gecko-dev/accessible/jsat/ContentControl.jsm

506 lines
16 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/. */
let Ci = Components.interfaces;
let Cu = Components.utils;
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, 'Roles',
'resource://gre/modules/accessibility/Constants.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'TraversalRules',
'resource://gre/modules/accessibility/TraversalRules.jsm');
XPCOMUtils.defineLazyModuleGetter(this, 'Presentation',
'resource://gre/modules/accessibility/Presentation.jsm');
this.EXPORTED_SYMBOLS = ['ContentControl'];
const MOVEMENT_GRANULARITY_CHARACTER = 1;
const MOVEMENT_GRANULARITY_WORD = 2;
const MOVEMENT_GRANULARITY_PARAGRAPH = 8;
this.ContentControl = function ContentControl(aContentScope) {
this._contentScope = Cu.getWeakReference(aContentScope);
this._vcCache = new WeakMap();
this._childMessageSenders = new WeakMap();
};
this.ContentControl.prototype = {
messagesOfInterest: ['AccessFu:MoveCursor',
'AccessFu:ClearCursor',
'AccessFu:MoveToPoint',
'AccessFu:AutoMove',
'AccessFu:Activate',
'AccessFu:MoveCaret',
'AccessFu:MoveByGranularity'],
start: function cc_start() {
let cs = this._contentScope.get();
for (let message of this.messagesOfInterest) {
cs.addMessageListener(message, this);
}
cs.addEventListener('mousemove', this);
},
stop: function cc_stop() {
let cs = this._contentScope.get();
for (let message of this.messagesOfInterest) {
cs.removeMessageListener(message, this);
}
cs.removeEventListener('mousemove', this);
},
get document() {
return this._contentScope.get().content.document;
},
get window() {
return this._contentScope.get().content;
},
get vc() {
return Utils.getVirtualCursor(this.document);
},
receiveMessage: function cc_receiveMessage(aMessage) {
Logger.debug(() => {
return ['ContentControl.receiveMessage',
aMessage.name,
JSON.stringify(aMessage.json)];
});
// If we get an explicit message, we should immediately cancel any autoMove
this.cancelAutoMove();
try {
let func = this['handle' + aMessage.name.slice(9)]; // 'AccessFu:'.length
if (func) {
func.bind(this)(aMessage);
} else {
Logger.warning('ContentControl: Unhandled message:', aMessage.name);
}
} catch (x) {
Logger.logException(
x, 'Error handling message: ' + JSON.stringify(aMessage.json));
}
},
handleMoveCursor: function cc_handleMoveCursor(aMessage) {
let origin = aMessage.json.origin;
let action = aMessage.json.action;
let adjustRange = aMessage.json.adjustRange;
let vc = this.vc;
if (origin != 'child' && this.sendToChild(vc, aMessage)) {
// Forwarded succesfully to child cursor.
return;
}
if (adjustRange && this.adjustRange(vc.position, action === 'moveNext')) {
return;
}
let moved = vc[action](TraversalRules[aMessage.json.rule]);
if (moved) {
if (origin === 'child') {
// We just stepped out of a child, clear child cursor.
Utils.getMessageManager(aMessage.target).sendAsyncMessage(
'AccessFu:ClearCursor', {});
} else {
// We potentially landed on a new child cursor. If so, we want to
// either be on the first or last item in the child doc.
let childAction = action;
if (action === 'moveNext') {
childAction = 'moveFirst';
} else if (action === 'movePrevious') {
childAction = 'moveLast';
}
// Attempt to forward move to a potential child cursor in our
// new position.
this.sendToChild(vc, aMessage, { action: childAction }, true);
}
} else if (!this._childMessageSenders.has(aMessage.target) &&
origin !== 'top') {
// We failed to move, and the message is not from a parent, so forward
// to it.
this.sendToParent(aMessage);
} else {
this._contentScope.get().sendAsyncMessage('AccessFu:Present',
Presentation.noMove(action));
}
},
handleEvent: function cc_handleEvent(aEvent) {
if (aEvent.type === 'mousemove') {
this.handleMoveToPoint(
{ json: { x: aEvent.screenX, y: aEvent.screenY, rule: 'Simple' } });
}
if (!Utils.getMessageManager(aEvent.target)) {
aEvent.preventDefault();
} else {
aEvent.target.focus();
}
},
handleMoveToPoint: function cc_handleMoveToPoint(aMessage) {
let [x, y] = [aMessage.json.x, aMessage.json.y];
let rule = TraversalRules[aMessage.json.rule];
let dpr = this.window.devicePixelRatio;
this.vc.moveToPoint(rule, x * dpr, y * dpr, true);
},
handleClearCursor: function cc_handleClearCursor(aMessage) {
let forwarded = this.sendToChild(this.vc, aMessage);
this.vc.position = null;
if (!forwarded) {
this._contentScope.get().sendAsyncMessage('AccessFu:CursorCleared');
}
this.document.activeElement.blur();
},
handleAutoMove: function cc_handleAutoMove(aMessage) {
this.autoMove(null, aMessage.json);
},
handleActivate: function cc_handleActivate(aMessage) {
let activateAccessible = (aAccessible) => {
Logger.debug(() => {
return ['activateAccessible', Logger.accessibleToString(aAccessible)];
});
try {
if (aMessage.json.activateIfKey &&
!Utils.isActivatableOnFingerUp(aAccessible)) {
// Only activate keys, don't do anything on other objects.
return;
}
} catch (e) {
// accessible is invalid. Silently fail.
return;
}
if (aAccessible.actionCount > 0) {
aAccessible.doAction(0);
} else {
let control = Utils.getEmbeddedControl(aAccessible);
if (control && control.actionCount > 0) {
control.doAction(0);
}
// XXX Some mobile widget sets do not expose actions properly
// (via ARIA roles, etc.), so we need to generate a click.
// Could possibly be made simpler in the future. Maybe core
// engine could expose nsCoreUtiles::DispatchMouseEvent()?
let docAcc = Utils.AccRetrieval.getAccessibleFor(this.document);
let docX = {}, docY = {}, docW = {}, docH = {};
docAcc.getBounds(docX, docY, docW, docH);
let objX = {}, objY = {}, objW = {}, objH = {};
aAccessible.getBounds(objX, objY, objW, objH);
let x = Math.round((objX.value - docX.value) + objW.value / 2);
let y = Math.round((objY.value - docY.value) + objH.value / 2);
let node = aAccessible.DOMNode || aAccessible.parent.DOMNode;
for (let eventType of ['mousedown', 'mouseup']) {
let evt = this.document.createEvent('MouseEvents');
evt.initMouseEvent(eventType, true, true, this.window,
x, y, 0, 0, 0, false, false, false, false, 0, null);
node.dispatchEvent(evt);
}
}
if (!Utils.isActivatableOnFingerUp(aAccessible)) {
// Keys will typically have a sound of their own.
this._contentScope.get().sendAsyncMessage('AccessFu:Present',
Presentation.actionInvoked(aAccessible, 'click'));
}
};
let focusedAcc = Utils.AccRetrieval.getAccessibleFor(
this.document.activeElement);
if (focusedAcc && this.vc.position === focusedAcc
&& focusedAcc.role === Roles.ENTRY) {
let accText = focusedAcc.QueryInterface(Ci.nsIAccessibleText);
let oldOffset = accText.caretOffset;
let newOffset = aMessage.json.offset;
let text = accText.getText(0, accText.characterCount);
if (newOffset >= 0 && newOffset <= accText.characterCount) {
accText.caretOffset = newOffset;
}
this.presentCaretChange(text, oldOffset, accText.caretOffset);
return;
}
// recursively find a descendant that is activatable.
let getActivatableDescendant = (aAccessible) => {
if (aAccessible.actionCount > 0) {
return aAccessible;
}
for (let acc = aAccessible.firstChild; acc; acc = acc.nextSibling) {
let activatable = getActivatableDescendant(acc);
if (activatable) {
return activatable;
}
}
return null;
};
let vc = this.vc;
if (!this.sendToChild(vc, aMessage, null, true)) {
let position = vc.position;
activateAccessible(getActivatableDescendant(position) || position);
}
},
adjustRange: function cc_adjustRange(aAccessible, aStepUp) {
let acc = Utils.getEmbeddedControl(aAccessible) || aAccessible;
try {
acc.QueryInterface(Ci.nsIAccessibleValue);
} catch (x) {
// This is not an adjustable, return false.
return false;
}
let elem = acc.DOMNode;
if (!elem) {
return false;
}
if (elem.tagName === 'INPUT' && elem.type === 'range') {
elem[aStepUp ? 'stepDown' : 'stepUp']();
let evt = this.document.createEvent('UIEvent');
evt.initEvent('change', true, true);
elem.dispatchEvent(evt);
} else {
let evt = this.document.createEvent('KeyboardEvent');
let keycode = aStepUp ? evt.DOM_VK_DOWN : evt.DOM_VK_UP;
evt.initKeyEvent(
"keypress", false, true, null, false, false, false, false, keycode, 0);
elem.dispatchEvent(evt);
}
return true;
},
handleMoveByGranularity: function cc_handleMoveByGranularity(aMessage) {
// XXX: Add sendToChild. Right now this is only used in Android, so no need.
let direction = aMessage.json.direction;
let granularity;
switch(aMessage.json.granularity) {
case MOVEMENT_GRANULARITY_CHARACTER:
granularity = Ci.nsIAccessiblePivot.CHAR_BOUNDARY;
break;
case MOVEMENT_GRANULARITY_WORD:
granularity = Ci.nsIAccessiblePivot.WORD_BOUNDARY;
break;
default:
return;
}
if (direction === 'Previous') {
this.vc.movePreviousByText(granularity);
} else if (direction === 'Next') {
this.vc.moveNextByText(granularity);
}
},
presentCaretChange: function cc_presentCaretChange(
aText, aOldOffset, aNewOffset) {
if (aOldOffset !== aNewOffset) {
let msg = Presentation.textSelectionChanged(aText, aNewOffset, aNewOffset,
aOldOffset, aOldOffset, true);
this._contentScope.get().sendAsyncMessage('AccessFu:Present', msg);
}
},
handleMoveCaret: function cc_handleMoveCaret(aMessage) {
let direction = aMessage.json.direction;
let granularity = aMessage.json.granularity;
let accessible = this.vc.position;
let accText = accessible.QueryInterface(Ci.nsIAccessibleText);
let oldOffset = accText.caretOffset;
let text = accText.getText(0, accText.characterCount);
let start = {}, end = {};
if (direction === 'Previous' && !aMessage.json.atStart) {
switch (granularity) {
case MOVEMENT_GRANULARITY_CHARACTER:
accText.caretOffset--;
break;
case MOVEMENT_GRANULARITY_WORD:
accText.getTextBeforeOffset(accText.caretOffset,
Ci.nsIAccessibleText.BOUNDARY_WORD_START, start, end);
accText.caretOffset = end.value === accText.caretOffset ?
start.value : end.value;
break;
case MOVEMENT_GRANULARITY_PARAGRAPH:
let startOfParagraph = text.lastIndexOf('\n', accText.caretOffset - 1);
accText.caretOffset = startOfParagraph !== -1 ? startOfParagraph : 0;
break;
}
} else if (direction === 'Next' && !aMessage.json.atEnd) {
switch (granularity) {
case MOVEMENT_GRANULARITY_CHARACTER:
accText.caretOffset++;
break;
case MOVEMENT_GRANULARITY_WORD:
accText.getTextAtOffset(accText.caretOffset,
Ci.nsIAccessibleText.BOUNDARY_WORD_END, start, end);
accText.caretOffset = end.value;
break;
case MOVEMENT_GRANULARITY_PARAGRAPH:
accText.caretOffset = text.indexOf('\n', accText.caretOffset + 1);
break;
}
}
this.presentCaretChange(text, oldOffset, accText.caretOffset);
},
getChildCursor: function cc_getChildCursor(aAccessible) {
let acc = aAccessible || this.vc.position;
if (Utils.isAliveAndVisible(acc) && acc.role === Roles.INTERNAL_FRAME) {
let domNode = acc.DOMNode;
let mm = this._childMessageSenders.get(domNode, null);
if (!mm) {
mm = Utils.getMessageManager(domNode);
mm.addWeakMessageListener('AccessFu:MoveCursor', this);
this._childMessageSenders.set(domNode, mm);
}
return mm;
}
return null;
},
sendToChild: function cc_sendToChild(aVirtualCursor, aMessage, aReplacer,
aFocus) {
let position = aVirtualCursor.position;
let mm = this.getChildCursor(position);
if (!mm) {
return false;
}
if (aFocus) {
position.takeFocus();
}
// XXX: This is a silly way to make a deep copy
let newJSON = JSON.parse(JSON.stringify(aMessage.json));
newJSON.origin = 'parent';
for (let attr in aReplacer) {
newJSON[attr] = aReplacer[attr];
}
mm.sendAsyncMessage(aMessage.name, newJSON);
return true;
},
sendToParent: function cc_sendToParent(aMessage) {
// XXX: This is a silly way to make a deep copy
let newJSON = JSON.parse(JSON.stringify(aMessage.json));
newJSON.origin = 'child';
aMessage.target.sendAsyncMessage(aMessage.name, newJSON);
},
/**
* Move cursor and/or present its location.
* aOptions could have any of these fields:
* - delay: in ms, before actual move is performed. Another autoMove call
* would cancel it. Useful if we want to wait for a possible trailing
* focus move. Default 0.
* - noOpIfOnScreen: if accessible is alive and visible, don't do anything.
* - forcePresent: present cursor location, whether we move or don't.
* - moveToFocused: if there is a focused accessible move to that. This takes
* precedence over given anchor.
* - moveMethod: pivot move method to use, default is 'moveNext',
*/
autoMove: function cc_autoMove(aAnchor, aOptions = {}) {
this.cancelAutoMove();
let moveFunc = () => {
let vc = this.vc;
let acc = aAnchor;
let rule = aOptions.onScreenOnly ?
TraversalRules.SimpleOnScreen : TraversalRules.Simple;
let forcePresentFunc = () => {
if (aOptions.forcePresent) {
this._contentScope.get().sendAsyncMessage(
'AccessFu:Present', Presentation.pivotChanged(
vc.position, null, Ci.nsIAccessiblePivot.REASON_NONE,
vc.startOffset, vc.endOffset, false));
}
};
if (aOptions.noOpIfOnScreen &&
Utils.isAliveAndVisible(vc.position, true)) {
forcePresentFunc();
return;
}
if (aOptions.moveToFocused) {
acc = Utils.AccRetrieval.getAccessibleFor(
this.document.activeElement) || acc;
}
let moved = false;
let moveMethod = aOptions.moveMethod || 'moveNext'; // default is moveNext
let moveFirstOrLast = moveMethod in ['moveFirst', 'moveLast'];
if (!moveFirstOrLast || acc) {
// We either need next/previous or there is an anchor we need to use.
moved = vc[moveFirstOrLast ? 'moveNext' : moveMethod](rule, acc, true,
false);
}
if (moveFirstOrLast && !moved) {
// We move to first/last after no anchor move happened or succeeded.
moved = vc[moveMethod](rule, false);
}
let sentToChild = this.sendToChild(vc, {
name: 'AccessFu:AutoMove',
json: {
moveMethod: aOptions.moveMethod,
moveToFocused: aOptions.moveToFocused,
noOpIfOnScreen: true,
forcePresent: true
}
}, null, true);
if (!moved && !sentToChild) {
forcePresentFunc();
}
};
if (aOptions.delay) {
this._autoMove = this.window.setTimeout(moveFunc, aOptions.delay);
} else {
moveFunc();
}
},
cancelAutoMove: function cc_cancelAutoMove() {
this.window.clearTimeout(this._autoMove);
this._autoMove = 0;
},
QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference,
Ci.nsIMessageListener
])
};