resources/src/mediawiki/mediawiki.requestIdleCallback.js

   1 /*!
   2  * An interface for scheduling background tasks.
   3  *
   4  * Loosely based on https://w3c.github.io/requestidlecallback/
   5  */
   6 ( function ( mw, $ ) {
   7         var tasks = [],
   8                 maxIdleDuration = 50,
   9                 timeout = null;
  10
  11         function schedule( trigger ) {
  12                 clearTimeout( timeout );
  13                 timeout = setTimeout( trigger, 700 );
  14         }
  15
  16         function triggerIdle() {
  17                 var elapsed,
  18                         start = mw.now();
  19
  20                 while ( tasks.length ) {
  21                         elapsed = mw.now() - start;
  22                         if ( elapsed < maxIdleDuration ) {
  23                                 tasks.shift().callback();
  24                         } else {
  25                                 // Idle moment expired, try again later
  26                                 schedule( triggerIdle );
  27                                 break;
  28                         }
  29                 }
  30         }
  31
  32         mw.requestIdleCallbackInternal = function ( callback ) {
  33                 var task = { callback: callback };
  34                 tasks.push( task );
  35
  36                 $( function () { schedule( triggerIdle ); } );
  37         };
  38
  39         /**
  40          * Schedule a deferred task to run in the background.
  41          *
  42          * @member mw
  43          * @param {Function} callback
  44          */
  45         mw.requestIdleCallback = window.requestIdleCallback
  46                 ? function ( callback ) {
  47                         window.requestIdleCallback( callback );
  48                 }
  49                 : mw.requestIdleCallbackInternal;
  50 }( mediaWiki, jQuery ) );