Last change
on this file since 18630 was
12865,
checked in by rvelices, 12 years ago
|
feature 2548 multisize - added a page to build missing derivatives
- browser driven, chained ws calls to retrieve urls, visual feedback of progress through slideshow
|
File size:
1.6 KB
|
Rev | Line | |
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[12865] | 1 | |
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| 2 | function ImageLoader(opts) { |
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| 3 | this.opts = jQuery.extend( { |
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| 4 | maxRequests: 6, |
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| 5 | onChanged: jQuery.noop |
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| 6 | }, opts||{} ); |
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| 7 | } |
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| 8 | |
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| 9 | ImageLoader.prototype = { |
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| 10 | loaded: 0, |
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| 11 | errors: 0, |
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| 12 | errorEma: 0, |
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| 13 | |
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| 14 | pause: false, |
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| 15 | |
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| 16 | current: [], |
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| 17 | queue: [], |
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| 18 | pool: [], |
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| 19 | |
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| 20 | remaining: function() { |
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| 21 | return this.current.length + this.queue.length; |
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| 22 | }, |
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| 23 | |
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| 24 | add: function(urls) { |
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| 25 | this.queue = this.queue.concat( urls ); |
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| 26 | this._fireChanged("add"); |
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| 27 | this._checkQueue(); |
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| 28 | }, |
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| 29 | |
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| 30 | clear: function() { |
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| 31 | this.queue.length = 0; |
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| 32 | while (this.current.length) |
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| 33 | jQuery( this.current.pop() ).unbind(); |
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| 34 | this.loaded = this.errors = this.errorEma = 0; |
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| 35 | }, |
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| 36 | |
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| 37 | pause: function(val) { |
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| 38 | if (val !== undefined) |
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| 39 | { |
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| 40 | this.paused = val; |
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| 41 | this._checkQueue(); |
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| 42 | } |
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| 43 | return this.paused; |
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| 44 | }, |
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| 45 | |
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| 46 | _checkQueue: function() { |
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| 47 | while (!this.paused |
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| 48 | && this.queue.length |
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| 49 | && this.current.length < this.opts.maxRequests) |
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| 50 | { |
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| 51 | this._processOne( this.queue.shift() ); |
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| 52 | } |
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| 53 | }, |
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| 54 | |
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| 55 | _processOne: function(url) { |
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| 56 | var img = this.pool.shift() || new Image; |
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| 57 | this.current.push(img); |
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| 58 | var that = this; |
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| 59 | jQuery(img).bind( "load error abort", function(e) { |
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| 60 | //img.onload = function(e) { |
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| 61 | jQuery(img).unbind(); |
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| 62 | img.onload=null; |
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| 63 | that.current.splice(jQuery.inArray(img, that.current), 1); |
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| 64 | if (e.type==="load") { |
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| 65 | that.loaded++; |
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| 66 | that.errorEma *= 0.9; |
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| 67 | } |
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| 68 | else { |
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| 69 | that.errors++; |
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| 70 | that.errorEma++; |
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| 71 | if (that.errorEma>=20 && that.errorEma<21) |
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| 72 | that.paused = true; |
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| 73 | } |
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| 74 | that._fireChanged(e.type, img); |
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| 75 | that._checkQueue(); |
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| 76 | that.pool.push(img); |
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| 77 | } ); |
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| 78 | img.src = url; |
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| 79 | }, |
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| 80 | |
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| 81 | _fireChanged: function(type, img) { |
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| 82 | this.opts.onChanged(type, img); |
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| 83 | } |
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| 84 | } |
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