molstar
Version:
A comprehensive macromolecular library.
176 lines (175 loc) • 6.52 kB
JavaScript
/**
* Copyright (c) 2017 mol* contributors, licensed under MIT, See LICENSE file for more info.
*
* @author David Sehnal <david.sehnal@gmail.com>
*/
function createImmediateActions() {
const thisGlobal = (function () {
const _window = typeof window !== 'undefined' && window;
const _self = typeof self !== 'undefined' && typeof WorkerGlobalScope !== 'undefined' && self instanceof WorkerGlobalScope && self;
const _global = typeof global !== 'undefined' && global;
return _window || _global || _self;
})();
const tasksByHandle = {};
const doc = typeof document !== 'undefined' ? document : void 0;
let nextHandle = 1; // Spec says greater than zero
let registerImmediate;
function setImmediate(callback, ...args) {
// Callback can either be a function or a string
if (typeof callback !== 'function') {
callback = new Function('' + callback);
}
// Store and register the task
const task = { callback: callback, args: args };
tasksByHandle[nextHandle] = task;
registerImmediate(nextHandle);
return nextHandle++;
}
function clearImmediate(handle) {
delete tasksByHandle[handle];
}
function run(task) {
const callback = task.callback;
const args = task.args;
switch (args.length) {
case 0:
callback();
break;
case 1:
callback(args[0]);
break;
case 2:
callback(args[0], args[1]);
break;
case 3:
callback(args[0], args[1], args[2]);
break;
default:
callback.apply(undefined, args);
break;
}
}
function runIfPresent(handle) {
const task = tasksByHandle[handle];
clearImmediate(handle);
run(task);
}
function installNextTickImplementation() {
registerImmediate = function (handle) {
process.nextTick(function () { runIfPresent(handle); });
};
}
function canUsePostMessage() {
if (thisGlobal && thisGlobal.postMessage && !thisGlobal.importScripts) {
let postMessageIsAsynchronous = true;
const oldOnMessage = thisGlobal.onmessage;
thisGlobal.onmessage = function () {
postMessageIsAsynchronous = false;
};
thisGlobal.postMessage('', '*');
thisGlobal.onmessage = oldOnMessage;
return postMessageIsAsynchronous;
}
}
function installPostMessageImplementation() {
// Installs an event handler on `global` for the `message` event: see
// * https://developer.mozilla.org/en/DOM/window.postMessage
// * http://www.whatwg.org/specs/web-apps/current-work/multipage/comms.html#crossDocumentMessages
const messagePrefix = 'setImmediate$' + Math.random() + '$';
const onGlobalMessage = function (event) {
if (event.source === thisGlobal &&
typeof event.data === 'string' &&
event.data.indexOf(messagePrefix) === 0) {
runIfPresent(+event.data.slice(messagePrefix.length));
}
};
if (window.addEventListener) {
window.addEventListener('message', onGlobalMessage, false);
}
else {
window.attachEvent('onmessage', onGlobalMessage);
}
registerImmediate = function (handle) {
window.postMessage(messagePrefix + handle, '*');
};
}
function installMessageChannelImplementation() {
const channel = new MessageChannel();
channel.port1.onmessage = function (event) {
const handle = event.data;
runIfPresent(handle);
};
registerImmediate = function (handle) {
channel.port2.postMessage(handle);
};
}
function installReadyStateChangeImplementation() {
const html = doc.documentElement;
registerImmediate = function (handle) {
// Create a <script> element; its readystatechange event will be fired asynchronously once it is inserted
// into the document. Do so, thus queuing up the task. Remember to clean up once it's been called.
let script = doc.createElement('script');
script.onreadystatechange = function () {
runIfPresent(handle);
script.onreadystatechange = null;
html.removeChild(script);
script = null;
};
html.appendChild(script);
};
}
function installSetTimeoutImplementation() {
registerImmediate = function (handle) {
setTimeout(runIfPresent, 0, handle);
};
}
// Don't get fooled by e.g. browserify environments.
if (typeof process !== 'undefined' && {}.toString.call(process) === '[object process]') {
// For Node.js before 0.9
installNextTickImplementation();
}
else if (canUsePostMessage()) {
// For non-IE10 modern browsers
installPostMessageImplementation();
}
else if (typeof MessageChannel !== 'undefined') {
// For web workers, where supported
installMessageChannelImplementation();
}
else if (doc && 'onreadystatechange' in doc.createElement('script')) {
// For IE 6–8
installReadyStateChangeImplementation();
}
else {
// For older browsers
installSetTimeoutImplementation();
}
return {
setImmediate,
clearImmediate
};
}
const immediateActions = (function () {
if (typeof setImmediate !== 'undefined') {
if (typeof window !== 'undefined') {
return {
setImmediate: (handler, ...args) => window.setImmediate(handler, ...args),
clearImmediate: (handle) => window.clearImmediate(handle)
};
}
else {
return { setImmediate, clearImmediate };
}
}
return createImmediateActions();
}());
function resolveImmediate(res) {
immediateActions.setImmediate(res);
}
const Scheduler = {
setImmediate: immediateActions.setImmediate,
clearImmediate: immediateActions.clearImmediate,
immediatePromise() { return new Promise(resolveImmediate); },
delay(timeout, value = void 0) { return new Promise(r => setTimeout(r, timeout, value)); }
};
export { Scheduler };