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/* 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
const MAX_TRIM_LENGTH = 100;
export const CommonUtils = {
/**
* Constant passed to getAccessible to indicate that it shouldn't fail if
* there is no accessible.
*/
DONOTFAIL_IF_NO_ACC: 1,
/**
* Constant passed to getAccessible to indicate that it shouldn't fail if it
* does not support an interface.
*/
DONOTFAIL_IF_NO_INTERFACE: 2,
/**
* nsIAccessibilityService service.
*/
get accService() {
if (!this._accService) {
this._accService = Cc["@mozilla.org/accessibilityService;1"].getService(
Ci.nsIAccessibilityService
);
}
return this._accService;
},
clearAccService() {
this._accService = null;
Cu.forceGC();
},
/**
* Adds an observer for an 'a11y-consumers-changed' event.
*/
addAccConsumersChangedObserver() {
const deferred = {};
this._accConsumersChanged = new Promise(resolve => {
deferred.resolve = resolve;
});
const observe = (subject, topic, data) => {
Services.obs.removeObserver(observe, "a11y-consumers-changed");
deferred.resolve(JSON.parse(data));
};
Services.obs.addObserver(observe, "a11y-consumers-changed");
},
/**
* Returns a promise that resolves when 'a11y-consumers-changed' event is
* fired.
*
* @return {Promise}
* event promise evaluating to event's data
*/
observeAccConsumersChanged() {
return this._accConsumersChanged;
},
/**
* Adds an observer for an 'a11y-init-or-shutdown' event with a value of "1"
* which indicates that an accessibility service is initialized in the current
* process.
*/
addAccServiceInitializedObserver() {
const deferred = {};
this._accServiceInitialized = new Promise((resolve, reject) => {
deferred.resolve = resolve;
deferred.reject = reject;
});
const observe = (subject, topic, data) => {
if (data === "1") {
Services.obs.removeObserver(observe, "a11y-init-or-shutdown");
deferred.resolve();
} else {
deferred.reject("Accessibility service is shutdown unexpectedly.");
}
};
Services.obs.addObserver(observe, "a11y-init-or-shutdown");
},
/**
* Returns a promise that resolves when an accessibility service is
* initialized in the current process. Otherwise (if the service is shutdown)
* the promise is rejected.
*/
observeAccServiceInitialized() {
return this._accServiceInitialized;
},
/**
* Adds an observer for an 'a11y-init-or-shutdown' event with a value of "0"
* which indicates that an accessibility service is shutdown in the current
* process.
*/
addAccServiceShutdownObserver() {
const deferred = {};
this._accServiceShutdown = new Promise((resolve, reject) => {
deferred.resolve = resolve;
deferred.reject = reject;
});
const observe = (subject, topic, data) => {
if (data === "0") {
Services.obs.removeObserver(observe, "a11y-init-or-shutdown");
deferred.resolve();
} else {
deferred.reject("Accessibility service is initialized unexpectedly.");
}
};
Services.obs.addObserver(observe, "a11y-init-or-shutdown");
},
/**
* Returns a promise that resolves when an accessibility service is shutdown
* in the current process. Otherwise (if the service is initialized) the
* promise is rejected.
*/
observeAccServiceShutdown() {
return this._accServiceShutdown;
},
/**
* Extract DOMNode id from an accessible. If the accessible is in the remote
* process, DOMNode is not present in parent process. However, if specified by
* the author, DOMNode id will be attached to an accessible object.
*
* @param {nsIAccessible} accessible accessible
* @return {String?} DOMNode id if available
*/
getAccessibleDOMNodeID(accessible) {
if (accessible instanceof Ci.nsIAccessibleDocument) {
// If accessible is a document, trying to find its document body id.
try {
return accessible.DOMNode.body.id;
} catch (e) {
/* This only works if accessible is not a proxy. */
}
}
try {
return accessible.DOMNode.id;
} catch (e) {
/* This will fail if DOMNode is in different process. */
}
try {
// When e10s is enabled, accessible will have an "id" property if its
// corresponding DOMNode has an id. If accessible is a document, its "id"
// property corresponds to the "id" of its body element.
return accessible.id;
} catch (e) {
/* This will fail if accessible is not a proxy. */
}
return null;
},
getObjAddress(obj) {
const exp = /native\s*@\s*(0x[a-f0-9]+)/g;
const match = exp.exec(obj.toString());
if (match) {
return match[1];
}
return obj.toString();
},
getNodePrettyName(node) {
try {
let tag = "";
if (node.nodeType == Node.DOCUMENT_NODE) {
tag = "document";
} else {
tag = node.localName;
if (node.nodeType == Node.ELEMENT_NODE && node.hasAttribute("id")) {
tag += `@id="${node.getAttribute("id")}"`;
}
}
return `"${tag} node", address: ${this.getObjAddress(node)}`;
} catch (e) {
return `" no node info "`;
}
},
/**
* Convert role to human readable string.
*/
roleToString(role) {
return this.accService.getStringRole(role);
},
/**
* Shorten a long string if it exceeds MAX_TRIM_LENGTH.
*
* @param aString the string to shorten.
*
* @returns the shortened string.
*/
shortenString(str) {
if (str.length <= MAX_TRIM_LENGTH) {
return str;
}
// Trim the string if its length is > MAX_TRIM_LENGTH characters.
const trimOffset = MAX_TRIM_LENGTH / 2;
return `${str.substring(0, trimOffset - 1)}…${str.substring(
str.length - trimOffset,
str.length
)}`;
},
normalizeAccTreeObj(obj) {
const key = Object.keys(obj)[0];
const roleName = `ROLE_${key}`;
if (roleName in Ci.nsIAccessibleRole) {
return {
role: Ci.nsIAccessibleRole[roleName],
children: obj[key],
};
}
return obj;
},
stringifyTree(obj) {
let text = this.roleToString(obj.role) + ": [ ";
if ("children" in obj) {
for (let i = 0; i < obj.children.length; i++) {
const c = this.normalizeAccTreeObj(obj.children[i]);
text += this.stringifyTree(c);
if (i < obj.children.length - 1) {
text += ", ";
}
}
}
return `${text}] `;
},
/**
* Return pretty name for identifier, it may be ID, DOM node or accessible.
*/
prettyName(identifier) {
if (identifier instanceof Array) {
let msg = "";
for (let idx = 0; idx < identifier.length; idx++) {
if (msg != "") {
msg += ", ";
}
msg += this.prettyName(identifier[idx]);
}
return msg;
}
if (identifier instanceof Ci.nsIAccessible) {
const acc = this.getAccessible(identifier);
const domID = this.getAccessibleDOMNodeID(acc);
let msg = "[";
try {
if (Services.appinfo.browserTabsRemoteAutostart) {
if (domID) {
msg += `DOM node id: ${domID}, `;
}
} else {
msg += `${this.getNodePrettyName(acc.DOMNode)}, `;
}
msg += `role: ${this.roleToString(acc.role)}`;
if (acc.name) {
msg += `, name: "${this.shortenString(acc.name)}"`;
}
} catch (e) {
msg += "defunct";
}
if (acc) {
msg += `, address: ${this.getObjAddress(acc)}`;
}
msg += "]";
return msg;
}
if (Node.isInstance(identifier)) {
return `[ ${this.getNodePrettyName(identifier)} ]`;
}
if (identifier && typeof identifier === "object") {
const treeObj = this.normalizeAccTreeObj(identifier);
if ("role" in treeObj) {
return `{ ${this.stringifyTree(treeObj)} }`;
}
return JSON.stringify(identifier);
}
return ` "${identifier}" `;
},
/**
* Return accessible for the given identifier (may be ID attribute or DOM
* element or accessible object) or null.
*
* @param accOrElmOrID
* identifier to get an accessible implementing the given interfaces
* @param aInterfaces
* [optional] the interface or an array interfaces to query it/them
* from obtained accessible
* @param elmObj
* [optional] object to store DOM element which accessible is obtained
* for
* @param doNotFailIf
* [optional] no error for special cases (see DONOTFAIL_IF_NO_ACC,
* DONOTFAIL_IF_NO_INTERFACE)
* @param doc
* [optional] document for when accOrElmOrID is an ID.
*/
getAccessible(accOrElmOrID, interfaces, elmObj, doNotFailIf, doc) {
if (!accOrElmOrID) {
return null;
}
let elm = null;
if (accOrElmOrID instanceof Ci.nsIAccessible) {
try {
elm = accOrElmOrID.DOMNode;
} catch (e) {}
} else if (Node.isInstance(accOrElmOrID)) {
elm = accOrElmOrID;
} else {
elm = doc.getElementById(accOrElmOrID);
if (!elm) {
Assert.ok(false, `Can't get DOM element for ${accOrElmOrID}`);
return null;
}
}
if (elmObj && typeof elmObj == "object") {
elmObj.value = elm;
}
let acc = accOrElmOrID instanceof Ci.nsIAccessible ? accOrElmOrID : null;
if (!acc) {
try {
acc = this.accService.getAccessibleFor(elm);
} catch (e) {}
if (!acc) {
if (!(doNotFailIf & this.DONOTFAIL_IF_NO_ACC)) {
Assert.ok(
false,
`Can't get accessible for ${this.prettyName(accOrElmOrID)}`
);
}
return null;
}
}
if (!interfaces) {
return acc;
}
if (!(interfaces instanceof Array)) {
interfaces = [interfaces];
}
for (let index = 0; index < interfaces.length; index++) {
if (acc instanceof interfaces[index]) {
continue;
}
try {
acc.QueryInterface(interfaces[index]);
} catch (e) {
if (!(doNotFailIf & this.DONOTFAIL_IF_NO_INTERFACE)) {
Assert.ok(
false,
`Can't query ${interfaces[index]} for ${accOrElmOrID}`
);
}
return null;
}
}
return acc;
},
/**
* Return the DOM node by identifier (may be accessible, DOM node or ID).
*/
getNode(accOrNodeOrID, doc) {
if (!accOrNodeOrID) {
return null;
}
if (Node.isInstance(accOrNodeOrID)) {
return accOrNodeOrID;
}
if (accOrNodeOrID instanceof Ci.nsIAccessible) {
return accOrNodeOrID.DOMNode;
}
const node = doc.getElementById(accOrNodeOrID);
if (!node) {
Assert.ok(false, `Can't get DOM element for ${accOrNodeOrID}`);
return null;
}
return node;
},
/**
* Return root accessible.
*
* @param {DOMNode} doc
* Chrome document.
*
* @return {nsIAccessible}
* Accessible object for chrome window.
*/
getRootAccessible(doc) {
const acc = this.getAccessible(doc);
return acc ? acc.rootDocument.QueryInterface(Ci.nsIAccessible) : null;
},
/**
* Analogy of SimpleTest.is function used to compare objects.
*/
isObject(obj, expectedObj, msg) {
if (obj == expectedObj) {
Assert.ok(true, msg);
return;
}
Assert.ok(
false,
`${msg} - got "${this.prettyName(obj)}", expected "${this.prettyName(
expectedObj
)}"`
);
},
};