skins/fileupload.js

   1 // © 2013 Benoît Pin MINES ParisTech
   2 var DDFileUploader;
   3
   4 (function(){
   5 // nombre maximun d'image chargées en local
   6 var MAX_PREVIEW = 2;
   7
   8 DDFileUploader = function(dropbox, uploadUrl) {
   9         this.dropbox = dropbox;
  10         this.uploadUrl = uploadUrl;
  11         this.slideSize = 222;
  12         this.progressBarMaxSize = 200; // pixels
  13         this.thumbnailSize = 180;
  14         this.previewQueue = [];
  15         this._previewQueueRunning = false;
  16         this.previewsLoaded = 0;
  17         this.uploadQueue = [];
  18         this._uploadQueueRunning = false;
  19         var self = this;
  20         addListener(dropbox, 'dragenter', function(evt){self.dragenter(evt);});
  21         addListener(dropbox, 'dragover', function(evt){self.dragover(evt);});
  22         addListener(dropbox, 'drop', function(evt){self.drop(evt);});
  23 };
  24
  25 // Drag and drop
  26 DDFileUploader.prototype.dragenter = function(evt) {
  27         disableDefault(evt);
  28         disablePropagation(evt);
  29 };
  30
  31 DDFileUploader.prototype.dragover = function(evt) {
  32         disableDefault(evt);
  33         disablePropagation(evt);
  34         evt = getEventObject(evt);
  35         var dt = evt.dataTransfer;
  36         dt.dropEffect = 'copy';
  37 };
  38
  39 DDFileUploader.prototype.drop = function(evt) {
  40         disableDefault(evt);
  41         disablePropagation(evt);
  42         getEventObject(evt);
  43         var dt = evt.dataTransfer;
  44         dt.dropEffect = 'copy';
  45         this.handleFiles(dt.files);
  46 };
  47
  48 // Methods about upload
  49 DDFileUploader.prototype.handleFiles = function(files) {
  50         var file, i, slide;
  51         for (i = 0; i < files.length; i++) {
  52                 file = files[i];
  53                 slide = this.createSlide(file);
  54         this.previewQueuePush(slide);
  55         this.uploadQueuePush(slide);
  56         }
  57 };
  58
  59 DDFileUploader.prototype.upload = function(slide) {
  60         var reader = new FileReader();
  61         var req = new XMLHttpRequest();
  62         var file = slide.file;
  63         this.uploadedSlide = slide;
  64         this.previewImg = slide.img;
  65         this.progressBar = slide.progressBar;
  66         var self = this;
  67
  68         addListener(req.upload, 'progress', function(evt){self.progressHandler(evt);});
  69         addListener(req, 'readystatechange',
  70                 function(evt) {
  71                         if (req.readyState === 4) {
  72                                 self.uploadCompleteHandler(req);
  73                         }
  74                 });
  75
  76         req.open("PUT", this.uploadUrl);
  77         req.setRequestHeader("Content-Type", file.type);
  78         req.setRequestHeader("X-File-Name", file.name);
  79         addListener(reader, 'load',
  80                 function(evt){
  81                         try {
  82                                 req.sendAsBinary(evt.target.result);
  83                         }
  84                         catch(e){}
  85                 });
  86         reader.readAsBinaryString(file);
  87 };
  88
  89 DDFileUploader.prototype.uploadCompleteHandler = function(req) {
  90         var slide = this.uploadedSlide;
  91         this.uploadedSlide.removeChild(slide.label);
  92     this.uploadedSlide.removeChild(slide.progressBar);
  93         var fragment = getCopyOfNode(req.responseXML.documentElement.firstChild);
  94         var img = fragment.getElementsByTagName('img')[0];
  95         img.onload = function(evt) {
  96                 // accelerate GC before replacing
  97                 slide.img.src = '';
  98                 slide.img.parentNode.removeChild(slide.img);
  99                 slide.img = undefined;
 100                 slide.parentNode.replaceChild(fragment, slide);
 101         };
 102         this.previewsLoaded--;
 103         this.previewQueueLoadNext();
 104         this.uploadQueueLoadNext();
 105 };
 106
 107 DDFileUploader.prototype.progressHandler = function(evt) {
 108         if (evt.lengthComputable) {
 109                 var progress = evt.loaded / evt.total;
 110                 this.updateProgressBar(progress);
 111                 var currentOpacity = this.previewImg.style.opacity;
 112                 this.previewImg.style.opacity = Math.max(currentOpacity, progress);
 113         }
 114 };
 115
 116 // Method about queues
 117
 118 DDFileUploader.prototype.previewQueuePush = function(slide) {
 119         this.previewQueue.push(slide);
 120         if (!this._previewQueueRunning) {
 121                 this.startPreviewQueue();
 122         }
 123 };
 124
 125 DDFileUploader.prototype.startPreviewQueue = function() {
 126         this._previewQueueRunning = true;
 127         this.previewQueueLoadNext();
 128 };
 129
 130 DDFileUploader.prototype.previewQueueLoadNext = function() {
 131         if (this.previewQueue.length && this.previewsLoaded < MAX_PREVIEW) {
 132                 var slide = this.previewQueue.shift();
 133                 this.previewUploadedImage(slide);
 134                 this.previewsLoaded++;
 135         }
 136         else {
 137                 this._previewQueueRunning = false;
 138         }
 139 };
 140
 141 DDFileUploader.prototype.uploadQueuePush = function(slide) {
 142         this.uploadQueue.push(slide);
 143         if (!this._uploadQueueRunning) {
 144                 this.startUploadQueue();
 145         }
 146 };
 147
 148 DDFileUploader.prototype.startUploadQueue = function() {
 149         this._uploadQueueRunning = true;
 150         this.uploadQueueLoadNext();
 151 };
 152
 153
 154 DDFileUploader.prototype.uploadQueueLoadNext = function() {
 155         var slide = this.uploadQueue.shift();
 156         if (slide) {
 157                 this.upload(slide);
 158         }
 159         else {
 160                 this._uploadQueueRunning = false;
 161         }
 162 };
 163
 164
 165 // User interface
 166 DDFileUploader.prototype.createSlide = function(file) {
 167         var slide = document.createElement('span');
 168         slide.file = file;
 169
 170         var a = document.createElement('a');
 171         a.href = '#';
 172         a.className = 'slide';
 173
 174         var img = document.createElement('img');
 175         img.className = 'hidden';
 176         var size = this.thumbnailSize;
 177         var self = this;
 178         img.onload = function(evt) {
 179                 if (img.width > img.height) { // landscape
 180                         img.height = Math.round(size * img.height / img.width);
 181                         img.width = size;
 182                 }
 183                 else {
 184                         img.width = Math.round(size * img.width / img.height);
 185                         img.height = size;
 186                 }
 187                 img.style.marginLeft = Math.floor((self.slideSize - img.width) / 2) + 'px';
 188                 img.style.marginTop = Math.floor((self.slideSize - img.height) / 2) + 'px';
 189                 img.style.opacity = 0.2;
 190                 img.className = undefined;
 191         };
 192         a.appendChild(img);
 193         slide.img = img;
 194
 195         var label = document.createElement('span');
 196         slide.label = label;
 197         label.className = 'label';
 198         label.innerHTML = file.name;
 199
 200         var progressBar = document.createElement('span');
 201         progressBar.className = 'upload-progress';
 202         slide.progressBar = progressBar;
 203
 204         slide.appendChild(a);
 205         slide.appendChild(progressBar);
 206         slide.appendChild(label);
 207         this.dropbox.appendChild(slide);
 208
 209         return slide;
 210 };
 211
 212 DDFileUploader.prototype.updateProgressBar = function(progress) {
 213         // 0 <= progress <= 1
 214         var size = this.progressBarMaxSize * progress;
 215         size = Math.round(size);
 216         this.progressBar.style.width = size + 'px';
 217 };
 218
 219 DDFileUploader.prototype.previewUploadedImage = function(slide) {
 220         var reader = new FileReader();
 221         var size = this.thumbnailSize;
 222         var self = this;
 223
 224         reader.onload = function(evt) {
 225                 slide.img.src = evt.target.result;
 226                 setTimeout(function(){self.previewQueueLoadNext();}, 500);
 227         };
 228         reader.readAsDataURL(slide.file);
 229 };
 230
 231 }());