Continuing fairexpand #6663

1. Expanding divs to improve text selection. (Yury)
2. Adding enhanceTextSelection as an option.
3. Moving feature functionality from text_layer_builder.js to text_layer.js.
4. Added expandTextDivs method to only load expanded divs on first click, and only show on subsequent clicks

web/app.js

@@ -101,6 +101,7 @@ var SCALE_SELECT_CONTAINER_PADDING = 8;
 var SCALE_SELECT_PADDING = 22;
 var PAGE_NUMBER_LOADING_INDICATOR = 'visiblePageIsLoading';
 var DISABLE_AUTO_FETCH_LOADING_BAR_TIMEOUT = 5000;
+var ENHANCE_TEXT_SELECTION = false;
 
 function configure(PDFJS) {
   PDFJS.imageResourcesPath = './images/';
@@ -209,7 +210,8 @@ var PDFViewerApplication = {
       eventBus: eventBus,
       renderingQueue: pdfRenderingQueue,
       linkService: pdfLinkService,
-      downloadManager: downloadManager
+      downloadManager: downloadManager,
+      enhanceTextSelection: ENHANCE_TEXT_SELECTION,
     });
     pdfRenderingQueue.setViewer(this.pdfViewer);
     pdfLinkService.setViewer(this.pdfViewer);

web/default_preferences.json

@@ -12,4 +12,4 @@
   "disableTextLayer": false,
   "useOnlyCssZoom": false,
   "externalLinkTarget": 0
-}
+}

web/interfaces.js

@@ -98,9 +98,11 @@ IPDFTextLayerFactory.prototype = {
    * @param {HTMLDivElement} textLayerDiv
    * @param {number} pageIndex
    * @param {PageViewport} viewport
+   * @param {Boolean} enhanceTextSelection
    * @returns {TextLayerBuilder}
    */
-  createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport) {}
+  createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport,
+                                    enhanceTextSelection) {}
 };
 
 /**

web/pdf_page_view.js

@@ -50,6 +50,8 @@ var TEXT_LAYER_RENDER_DELAY = 200; // ms
  * @property {PDFRenderingQueue} renderingQueue - The rendering queue object.
  * @property {IPDFTextLayerFactory} textLayerFactory
  * @property {IPDFAnnotationLayerFactory} annotationLayerFactory
+ * @property {boolean} enhanceTextSelection - Turns on the text selection
+ * enhancement. The default is `false`.
  */
 
 /**
@@ -69,6 +71,7 @@ var PDFPageView = (function PDFPageViewClosure() {
     var renderingQueue = options.renderingQueue;
     var textLayerFactory = options.textLayerFactory;
     var annotationLayerFactory = options.annotationLayerFactory;
+    var enhanceTextSelection = options.enhanceTextSelection || false;
 
     this.id = id;
     this.renderingId = 'page' + id;
@@ -78,6 +81,7 @@ var PDFPageView = (function PDFPageViewClosure() {
     this.viewport = defaultViewport;
     this.pdfPageRotate = defaultViewport.rotation;
     this.hasRestrictedScaling = false;
+    this.enhanceTextSelection = enhanceTextSelection;
 
     this.eventBus = options.eventBus || domEvents.getGlobalEventBus();
     this.renderingQueue = renderingQueue;
@@ -395,9 +399,9 @@ var PDFPageView = (function PDFPageViewClosure() {
           div.appendChild(textLayerDiv);
         }
 
-        textLayer = this.textLayerFactory.createTextLayerBuilder(textLayerDiv,
-                                                                 this.id - 1,
-                                                                 this.viewport);
+        textLayer = this.textLayerFactory.
+          createTextLayerBuilder(textLayerDiv, this.id - 1, this.viewport,
+                                 this.enhanceTextSelection);
       }
       this.textLayer = textLayer;
 

web/pdf_viewer.js

@@ -76,6 +76,8 @@ var DEFAULT_CACHE_SIZE = 10;
  *   queue object.
  * @property {boolean} removePageBorders - (optional) Removes the border shadow
  *   around the pages. The default is false.
+ * @property {boolean} enhanceTextSelection - (optional) Enables the improved
+ *   text selection behaviour. The default is `false`.
  */
 
 /**
@@ -127,6 +129,7 @@ var PDFViewer = (function pdfViewer() {
     this.linkService = options.linkService || new SimpleLinkService();
     this.downloadManager = options.downloadManager || null;
     this.removePageBorders = options.removePageBorders || false;
+    this.enhanceTextSelection = options.enhanceTextSelection || false;
 
     this.defaultRenderingQueue = !options.renderingQueue;
     if (this.defaultRenderingQueue) {
@@ -352,7 +355,8 @@ var PDFViewer = (function pdfViewer() {
             defaultViewport: viewport.clone(),
             renderingQueue: this.renderingQueue,
             textLayerFactory: textLayerFactory,
-            annotationLayerFactory: this
+            annotationLayerFactory: this,
+            enhanceTextSelection: this.enhanceTextSelection,
           });
           bindOnAfterAndBeforeDraw(pageView);
           this._pages.push(pageView);
@@ -798,13 +802,16 @@ var PDFViewer = (function pdfViewer() {
      * @param {PageViewport} viewport
      * @returns {TextLayerBuilder}
      */
-    createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport) {
+    createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport,
+                                      enhanceTextSelection) {
       return new TextLayerBuilder({
         textLayerDiv: textLayerDiv,
         eventBus: this.eventBus,
         pageIndex: pageIndex,
         viewport: viewport,
-        findController: this.isInPresentationMode ? null : this.findController
+        findController: this.isInPresentationMode ? null : this.findController,
+        enhanceTextSelection: this.isInPresentationMode ? false :
+                                                          enhanceTextSelection,
       });
     },
 

web/text_layer_builder.js

@@ -35,6 +35,8 @@
  * @property {number} pageIndex - The page index.
  * @property {PageViewport} viewport - The viewport of the text layer.
  * @property {PDFFindController} findController
+ * @property {boolean} enhanceTextSelection - Option to turn on improved
+ * text selection.
  */
 
 /**
@@ -57,6 +59,7 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
     this.textDivs = [];
     this.findController = options.findController || null;
     this.textLayerRenderTask = null;
+    this.enhanceTextSelection = options.enhanceTextSelection;
     this._bindMouse();
   }
 
@@ -64,9 +67,11 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
     _finishRendering: function TextLayerBuilder_finishRendering() {
       this.renderingDone = true;
 
-      var endOfContent = document.createElement('div');
-      endOfContent.className = 'endOfContent';
-      this.textLayerDiv.appendChild(endOfContent);
+      if (!this.enhanceTextSelection) {
+        var endOfContent = document.createElement('div');
+        endOfContent.className = 'endOfContent';
+        this.textLayerDiv.appendChild(endOfContent);
+      }
 
       this.eventBus.dispatch('textlayerrendered', {
         source: this,
@@ -96,7 +101,8 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
         container: textLayerFrag,
         viewport: this.viewport,
         textDivs: this.textDivs,
-        timeout: timeout
+        timeout: timeout,
+        enhanceTextSelection: this.enhanceTextSelection,
       });
       this.textLayerRenderTask.promise.then(function () {
         this.textLayerDiv.appendChild(textLayerFrag);
@@ -314,7 +320,12 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
      */
     _bindMouse: function TextLayerBuilder_bindMouse() {
       var div = this.textLayerDiv;
+      var self = this;
       div.addEventListener('mousedown', function (e) {
+        if (self.enhanceTextSelection && self.textLayerRenderTask) {
+          self.textLayerRenderTask.expandTextDivs(true);
+          return;
+        }
         var end = div.querySelector('.endOfContent');
         if (!end) {
           return;
@@ -338,6 +349,10 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
         end.classList.add('active');
       });
       div.addEventListener('mouseup', function (e) {
+        if (self.enhanceTextSelection && self.textLayerRenderTask) {
+          self.textLayerRenderTask.expandTextDivs(false);
+          return;
+        }
         var end = div.querySelector('.endOfContent');
         if (!end) {
           return;
@@ -362,13 +377,16 @@ DefaultTextLayerFactory.prototype = {
    * @param {HTMLDivElement} textLayerDiv
    * @param {number} pageIndex
    * @param {PageViewport} viewport
+   * @param {boolean} enhanceTextSelection
    * @returns {TextLayerBuilder}
    */
-  createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport) {
+  createTextLayerBuilder: function (textLayerDiv, pageIndex, viewport,
+                                    enhanceTextSelection) {
     return new TextLayerBuilder({
       textLayerDiv: textLayerDiv,
       pageIndex: pageIndex,
-      viewport: viewport
+      viewport: viewport,
+      enhanceTextSelection: enhanceTextSelection
     });
   }
 };