Source: loader/LoadingManager.js

  1. /**
  2.  * Handles and keeps track of loaded and pending data. A default global instance of this class is created and used by loaders if not supplied manually - see {@link zen3d.DefaultLoadingManager}.
  3.  * In general that should be sufficient, however there are times when it can be useful to have seperate loaders - for example if you want to show seperate loading bars for objects and textures.
  4.  * @constructor
  5.  * @author mrdoob / http://mrdoob.com/
  6.  * @param {Function} onLoad — (optional) this function will be called when all loaders are done.
  7.  * @param {Function} onProgress — (optional) this function will be called when an item is complete.
  8.  * @param {Function} onError — (optional) this function will be called a loader encounters errors.
  9.  */
  11. function LoadingManager(onLoad, onProgress, onError) {
  12. 	var scope = this;
  14. 	var isLoading = false;
  15. 	var itemsLoaded = 0;
  16. 	var itemsTotal = 0;
  17. 	var urlModifier = undefined;
  19. 	// Refer to #5689 for the reason why we don't set .onStart
  20. 	// in the constructor
  22. 	this.onStart = undefined;
  23. 	this.onLoad = onLoad;
  24. 	this.onProgress = onProgress;
  25. 	this.onError = onError;
  27. 	this.itemStart = function (url) {
  28. 		itemsTotal++;
  30. 		if (isLoading === false) {
  31. 			if (scope.onStart !== undefined) {
  32. 				scope.onStart(url, itemsLoaded, itemsTotal);
  33. 			}
  34. 		}
  36. 		isLoading = true;
  37. 	};
  39. 	this.itemEnd = function (url) {
  40. 		itemsLoaded++;
  42. 		if (scope.onProgress !== undefined) {
  43. 			scope.onProgress(url, itemsLoaded, itemsTotal);
  44. 		}
  46. 		if (itemsLoaded === itemsTotal) {
  47. 			isLoading = false;
  49. 			if (scope.onLoad !== undefined) {
  50. 				scope.onLoad();
  51. 			}
  52. 		}
  53. 	};
  55. 	this.itemError = function (url) {
  56. 		if (scope.onError !== undefined) {
  57. 			scope.onError(url);
  58. 		}
  59. 	};
  61. 	this.resolveURL = function (url) {
  62. 		if (urlModifier) {
  63. 			return urlModifier(url);
  64. 		}
  66. 		return url;
  67. 	};
  69. 	this.setURLModifier = function (transform) {
  70. 		urlModifier = transform;
  71. 		return this;
  72. 	};
  73. }
  75. var DefaultLoadingManager = new LoadingManager();
  78. export { DefaultLoadingManager, LoadingManager };