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
  96 DDFileUploader.prototype.startPreviewQueue = function() {
  97         this._previewQueueRunning = true;
  98         this.previewQueueLoadNext();
  99 };
 100
 101 DDFileUploader.prototype.previewQueueLoadNext = function() {
 102         var slide = this.previewQueue.shift();
 103         if (slide) {
 104                 this.previewUploadedImage(slide);
 105         }
 106         else {
 107                 this._previewQueueRunning = false;
 108         }
 109 };
 110
 111 DDFileUploader.prototype.uploadQueuePush = function(slide) {
 112         this.uploadQueue.push(slide);
 113         if (!this._uploadQueueRunning) {
 114                 this.startUploadQueue();
 115         }
 116 };
 117
 118 DDFileUploader.prototype.startUploadQueue = function() {
 119         this._uploadQueueRunning = true;
 120         this.uploadQueueLoadNext();
 121 };
 122
 123
 124 DDFileUploader.prototype.uploadQueueLoadNext = function() {
 125         var slide = this.uploadQueue.shift();
 126         if (slide) {
 127                 this.upload(slide);
 128         }
 129         else {
 130                 this._uploadQueueRunning = false;
 131         }
 132 };
 133
 134
 135 // User interface
 136 DDFileUploader.prototype.createSlide = function(file) {
 137         var slide = document.createElement('span');
 138         slide.file = file;
 139
 140         var a = document.createElement('a');
 141         a.href = '#';
 142         a.className = 'slide';
 143
 144         var img = document.createElement('img');
 145         img.className = 'hidden';
 146         var size = this.thumbnailSize;
 147         var self = this;
 148         img.onload = function(evt) {
 149                 if (img.width > img.height) { // landscape
 150                         img.height = Math.round(size * img.height / img.width);
 151                         img.width = size;
 152                 }
 153                 else {
 154                         img.width = Math.round(size * img.width / img.height);
 155                         img.height = size;
 156                 }
 157                 img.style.marginLeft = Math.round((self.slideSize - img.width) / 2) + 'px';
 158                 img.style.marginTop = Math.round((self.slideSize - img.height) / 2) + 'px';
 159                 img.style.opacity = 0.2;
 160                 img.className = undefined;
 161         };
 162         a.appendChild(img);
 163         slide.img = img;
 164
 165         var progressBar = document.createElement('span');
 166         progressBar.className = 'upload-progress';
 167         slide.progressBar = progressBar;
 168
 169         slide.appendChild(a);
 170         slide.appendChild(progressBar);
 171         this.dropbox.appendChild(slide);
 172
 173         return slide;
 174 };
 175
 176 DDFileUploader.prototype.updateProgressBar = function(progress) {
 177         // 0 <= progress <= 1
 178         var size = this.progressBarMaxSize * progress;
 179         size = Math.round(size);
 180         this.progressBar.style.width = size + 'px';
 181 };
 182
 183 DDFileUploader.prototype.previewUploadedImage = function(slide) {
 184         var reader = new FileReader();
 185         var size = this.thumbnailSize;
 186         var self = this;
 187
 188         reader.onload = function(evt) {
 189                 slide.img.src = evt.target.result;
 190                 setTimeout(function(){self.previewQueueLoadNext();}, 500);
 191         };
 192         reader.readAsDataURL(slide.file);
 193 };
 194
 195 }());