// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
import {assertInstanceof} from '//resources/ash/common/assert.js';
/**
* Alias for document.getElementById. Found elements must be HTMLElements.
* @param {string} id The ID of the element to find.
* @return {HTMLElement} The found element or null if not found.
*/
export function $(id) {
// Disable getElementById restriction here, since we are instructing other
// places to re-use the $() that is defined here.
// eslint-disable-next-line no-restricted-properties
const el = document.getElementById(id);
return el ? assertInstanceof(el, HTMLElement) : null;
}
/**
* @return {?Element} The currently focused element (including elements that are
* behind a shadow root), or null if nothing is focused.
*/
export function getDeepActiveElement() {
let a = document.activeElement;
while (a && a.shadowRoot && a.shadowRoot.activeElement) {
a = a.shadowRoot.activeElement;
}
return a;
}
/**
* DEPRECATED (if using Polymer): Use IronA11yAnnouncer instead.
* TODO(crbug.com/985410): Replace all existing usages and remove this function.
* Add an accessible message to the page that will be announced to
* users who have spoken feedback on, but will be invisible to all
* other users. It's removed right away so it doesn't clutter the DOM.
* @param {string} msg The text to be pronounced.
*/
export function announceAccessibleMessage(msg) {
const element = document.createElement('div');
element.setAttribute('aria-live', 'polite');
element.style.position = 'fixed';
element.style.left = '-9999px';
element.style.height = '0px';
element.innerText = msg;
document.body.appendChild(element);
window.setTimeout(function() {
document.body.removeChild(element);
}, 50);
}
/**
* Check the directionality of the page.
* @return {boolean} True if Chrome is running an RTL UI.
*/
export function isRTL() {
return document.documentElement.dir === 'rtl';
}
/**
* Get an element that's known to exist by its ID. We use this instead of just
* calling getElementById and not checking the result because this lets us
* satisfy the JSCompiler type system.
* @param {string} id The identifier name.
* @return {!HTMLElement} the Element.
*/
export function getRequiredElement(id) {
return assertInstanceof(
$(id), HTMLElement, 'Missing required element: ' + id);
}
/**
* Creates a new URL which is the old URL with a GET param of key=value.
* @param {string} url The base URL. There is no validation checking on the URL
* so it must be passed in a proper format.
* @param {string} key The key of the param.
* @param {string} value The value of the param.
* @return {string} The new URL.
*/
export function appendParam(url, key, value) {
const param = encodeURIComponent(key) + '=' + encodeURIComponent(value);
if (url.indexOf('?') === -1) {
return url + '?' + param;
}
return url + '&' + param;
}
/**
* Creates an element of a specified type with a specified class name.
* @param {string} type The node type.
* @param {string} className The class name to use.
* @return {Element} The created element.
*/
export function createElementWithClassName(type, className) {
const elm = document.createElement(type);
elm.className = className;
return elm;
}
/**
* transitionend does not always fire (e.g. when animation is aborted
* or when no paint happens during the animation). This function sets up
* a timer and emulate the event if it is not fired when the timer expires.
* @param {!HTMLElement} el The element to watch for transitionend.
* @param {number=} timeOut The maximum wait time in milliseconds for the
* transitionend to happen. If not specified, it is fetched from |el|
* using the transitionDuration style value.
*/
export function ensureTransitionEndEvent(el, timeOut) {
if (timeOut === undefined) {
const style = getComputedStyle(el);
timeOut = parseFloat(style.transitionDuration) * 1000;
// Give an additional 50ms buffer for the animation to complete.
timeOut += 50;
}
let fired = false;
el.addEventListener('transitionend', function f(e) {
el.removeEventListener('transitionend', f);
fired = true;
});
window.setTimeout(function() {
if (!fired) {
el.dispatchEvent(new CustomEvent('transitionend',
{bubbles: true, composed: true}));
}
}, timeOut);
}
/**
* Replaces '&', '<', '>', '"', and ''' characters with their HTML encoding.
* @param {string} original The original string.
* @return {string} The string with all the characters mentioned above replaced.
*/
export function HTMLEscape(original) {
return original.replace(/&/g, '&')
.replace(/</g, '<')
.replace(/>/g, '>')
.replace(/"/g, '"')
.replace(/'/g, ''');
}
/**
* Quote a string so it can be used in a regular expression.
* @param {string} str The source string.
* @return {string} The escaped string.
*/
export function quoteString(str) {
return str.replace(/([\\\.\+\*\?\[\^\]\$\(\)\{\}\=\!\<\>\|\:])/g, '\\$1');
}
/**
* Calls |callback| and stops listening the first time any event in |eventNames|
* is triggered on |target|.
* @param {!EventTarget} target
* @param {!Array<string>|string} eventNames Array or space-delimited string of
* event names to listen to (e.g. 'click mousedown').
* @param {function(!Event)} callback Called at most once. The
* optional return value is passed on by the listener.
*/
export function listenOnce(target, eventNames, callback) {
if (!Array.isArray(eventNames)) {
eventNames = eventNames.split(/ +/);
}
const removeAllAndCallCallback = function(event) {
eventNames.forEach(function(eventName) {
target.removeEventListener(eventName, removeAllAndCallCallback, false);
});
return callback(event);
};
eventNames.forEach(function(eventName) {
target.addEventListener(eventName, removeAllAndCallCallback, false);
});
}
/**
* @param {!Event} e
* @return {boolean} Whether a modifier key was down when processing |e|.
*/
export function hasKeyModifiers(e) {
return !!(e.altKey || e.ctrlKey || e.metaKey || e.shiftKey);
}
/**
* @param {!Element} el
* @return {boolean} Whether the element is interactive via text input.
*/
export function isTextInputElement(el) {
return el.tagName === 'INPUT' || el.tagName === 'TEXTAREA';
}
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