skins/fileupload.js

   1 // © 2013 Benoît Pin MINES ParisTech
   2 var DDFileUploader;
   3
   4 (function(){
   5
   6 DDFileUploader = function(dropbox, uploadUrl) {
   7         this.dropbox = dropbox;
   8         this.uploadUrl = uploadUrl;
   9         this.slideSize = 222;
  10         this.progressBarMaxSize = 200; // pixels
  11         this.thumbnailSize = 180;
  12         this.previewQueue = [];
  13         this._previewQueueRunning = false;
  14         this.uploadQueue = [];
  15         this._uploadQueueRunning = false;
  16         var self = this;
  17         addListener(dropbox, 'dragenter', function(evt){self.dragenter(evt);});
  18         addListener(dropbox, 'dragover', function(evt){self.dragover(evt);});
  19         addListener(dropbox, 'drop', function(evt){self.drop(evt);});
  20 };
  21
  22 // Drag and drop
  23 DDFileUploader.prototype.dragenter = function(evt) {
  24         disableDefault(evt);
  25         disablePropagation(evt);
  26 };
  27
  28 DDFileUploader.prototype.dragover = function(evt) {
  29         disableDefault(evt);
  30         disablePropagation(evt);
  31         evt = getEventObject(evt);
  32         var dt = evt.dataTransfer;
  33         dt.dropEffect = 'copy';
  34 };
  35
  36 DDFileUploader.prototype.drop = function(evt) {
  37         disableDefault(evt);
  38         disablePropagation(evt);
  39         getEventObject(evt);
  40         var dt = evt.dataTransfer;
  41         dt.dropEffect = 'copy';
  42         this.handleFiles(dt.files);
  43 };
  44
  45 // Methods about upload
  46 DDFileUploader.prototype.handleFiles = function(files) {
  47         var file, i, slide;
  48         for (i = 0; i < files.length; i++) {
  49                 file = files[i];
  50                 slide = this.createSlide(file);
  51                 this.previewQueuePush(slide);
  52                 this.uploadQueuePush(slide);
  53         }
  54 };
  55
  56 DDFileUploader.prototype.upload = function(slide) {
  57         var reader = new FileReader();
  58         var req = new XMLHttpRequest();
  59         var file = slide.file;
  60         this.previewImg = slide.img;
  61         this.progressBar = slide.progressBar;
  62         var self = this;
  63
  64         addListener(req.upload, 'progress', function(evt){self.progressHandler(evt);});
  65         addListener(req.upload, 'load', function(evt){self.uploadCompleteHandler(evt);});
  66
  67         req.open("PUT", this.uploadUrl + '/' + file.name);
  68         req.setRequestHeader("Content-Type", file.type);
  69         addListener(reader, 'load', function(evt){req.sendAsBinary(evt.target.result);});
  70         reader.readAsBinaryString(file);
  71 };
  72
  73 DDFileUploader.prototype.uploadCompleteHandler = function(evt) {
  74         this.progressBar.parentNode.removeChild(this.progressBar);
  75         this.uploadQueueLoadNext();
  76 };
  77
  78 DDFileUploader.prototype.progressHandler = function(evt) {
  79         if (evt.lengthComputable) {
  80                 var progress = evt.loaded / evt.total;
  81                 this.updateProgressBar(progress);
  82                 var currentOpacity = this.previewImg.style.opacity;
  83                 this.previewImg.style.opacity = Math.max(currentOpacity, progress);
  84         }
  85 };
  86
  87 // Method about queues
  88
  89 DDFileUploader.prototype.previewQueuePush = function(slide) {
  90         this.previewQueue.push(slide);
  91         if (!this._previewQueueRunning)
  92                 this.startPreviewQueue();
  93 };
  94
  95 DDFileUploader.prototype.startPreviewQueue = function() {
  96         this._previewQueueRunning = true;
  97         this.previewQueueLoadNext();
  98 };
  99
 100 DDFileUploader.prototype.previewQueueLoadNext = function() {
 101         var slide = this.previewQueue.shift();
 102         if (slide)
 103                 this.previewUploadedImage(slide);
 104         else
 105                 this._previewQueueRunning = false;
 106 };
 107
 108 DDFileUploader.prototype.uploadQueuePush = function(slide) {
 109         this.uploadQueue.push(slide);
 110         if (!this._uploadQueueRunning)
 111                 this.startUploadQueue();
 112 };
 113
 114 DDFileUploader.prototype.startUploadQueue = function() {
 115         this._uploadQueueRunning = true;
 116         this.uploadQueueLoadNext();
 117 };
 118
 119
 120 DDFileUploader.prototype.uploadQueueLoadNext = function() {
 121         var slide = this.uploadQueue.shift();
 122         if (slide)
 123                 this.upload(slide);
 124         else
 125                 this._uploadQueueRunning = false;
 126 };
 127
 128
 129 // User interface
 130 DDFileUploader.prototype.createSlide = function(file) {
 131         var slide = document.createElement('span');
 132         slide.file = file;
 133
 134         var a = document.createElement('a');
 135         a.href = '#';
 136         a.className = 'slide';
 137
 138         var img = document.createElement('img');
 139         img.className = 'hidden';
 140         var size = this.thumbnailSize;
 141         var self = this;
 142         img.onload = function(evt) {
 143                 if (img.width > img.height) { // landscape
 144                         img.height = Math.round(size * img.height / img.width);
 145                         img.width = size;
 146                 }
 147                 else {
 148                         img.width = Math.round(size * img.width / img.height);
 149                         img.height = size;
 150                 }
 151                 img.style.marginLeft = Math.round((self.slideSize - img.width) / 2) + 'px';
 152                 img.style.marginTop = Math.round((self.slideSize - img.height) / 2) + 'px';
 153                 img.style.opacity = 0.2;
 154                 img.className = undefined;
 155         };
 156         a.appendChild(img);
 157         slide.img = img;
 158
 159         var progressBar = document.createElement('span');
 160         progressBar.className = 'upload-progress';
 161         slide.progressBar = progressBar;
 162
 163         slide.appendChild(a);
 164         slide.appendChild(progressBar);
 165         this.dropbox.appendChild(slide);
 166
 167         return slide;
 168 };
 169
 170 DDFileUploader.prototype.updateProgressBar = function(progress) {
 171         // 0 <= progress <= 1
 172         var size = this.progressBarMaxSize * progress;
 173         size = Math.round(size);
 174         this.progressBar.style.width = size + 'px';
 175 };
 176
 177 DDFileUploader.prototype.previewUploadedImage = function(slide) {
 178         var reader = new FileReader();
 179         var size = this.thumbnailSize;
 180         var self = this;
 181
 182         reader.onload = function(evt) {
 183                 slide.img.src = evt.target.result;
 184                 setTimeout(function(){self.previewQueueLoadNext();}, 500);
 185         };
 186         reader.readAsDataURL(slide.file);
 187 };
 188
 189 }());