Multiline text blocks

examples/text-selection/js/minimal.js

@@ -21,6 +21,7 @@ window.onload = function () {
 
   var scale = 1.5; //Set this to whatever you want. This is basically the "zoom" factor for the PDF.
   PDFJS.workerSrc = '../../build/generic/build/pdf.worker.js';
+  var fontMetrics = new FontMetrics();
 
   function loadPdf(pdfPath) {
     var pdf = PDFJS.getDocument(pdfPath);
@@ -74,7 +75,8 @@ window.onload = function () {
       var textLayer = new TextLayerBuilder({
         textLayerDiv: $textLayerDiv.get(0),
         viewport: viewport,
-        pageIndex: 0
+        pageIndex: 0,
+        fontMetrics: fontMetrics
       });
       textLayer.setTextContent(textContent);
 

make.js

@@ -456,7 +456,8 @@ function cleanupJSSource(file) {
   var content = cat(file);
 
   // Strip out all the vim/license headers.
-  var reg = /\n\/\* -\*- Mode(.|\n)*?Mozilla Foundation(.|\n)*?'use strict';/g;
+  var reg = new RegExp('\\n\\/\\* -\\*- Mode(.|\\n)*?' +
+    '(Mozilla Foundation|Opera Software ASA)(.|\\n)*?\'use strict\';', 'g');
   content = content.replace(reg, '');
 
   content.to(file);

src/display/api.js

@@ -133,6 +133,16 @@ PDFJS.disableWebGL = (PDFJS.disableWebGL === undefined ?
 PDFJS.verbosity = (PDFJS.verbosity === undefined ?
                    PDFJS.VERBOSITY_LEVELS.warnings : PDFJS.verbosity);
 
+/**
+ * Disables creation of multi-line text blocks in the text layer.
+ * Currently disabled by default.
+ * @var {boolean}
+ */
+
+PDFJS.disableMultilineTextLayer =
+  (PDFJS.disableMultilineTextLayer === undefined ?
+   true : PDFJS.disableMultilineTextLayer);
+
 /**
  * Document initialization / loading parameters object.
  *

web/font_metrics.js

@@ -0,0 +1,82 @@
+/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set shiftwidth=2 tabstop=2 autoindent cindent expandtab: */
+
+/* Copyright 2014 Opera Software ASA
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+var FontMetrics = (function FontMetricsClosure () {
+
+  function FontMetrics () {
+    this.canvas = document.createElement('canvas');
+    this.ctx = this.canvas.getContext('2d');
+    this.canvas.width = 100;
+    this.canvas.height = 100;
+    this.cache = Object.create(null);
+  }
+
+  FontMetrics.prototype = {
+    getFirstNoneWhitePixelTop: function FontMetricsGetFirstNoneWhitePixelTop() {
+      var x = 0;
+      var y = 0;
+      var width = this.canvas.width;
+      var height = this.canvas.height;
+      var pixels = null;
+      while (y < height) {
+        pixels = this.ctx.getImageData(0, y, width, 1).data;
+        for (x = 0; x < width * 4; x += 4) {
+          if (pixels[x] === 0) {
+            break;
+          }
+        }
+
+        if (x < width) {
+          break;
+        }
+        y++;
+      }
+      return y;
+    },
+
+    getFontAscent: function FontMetricsDetFontAscent(font, str) {
+      if (this.cache[font]) {
+        return this.cache[font];
+      }
+
+      if (!str) {
+        str = 'The quick brown fox jumps over the lazy dog';
+      }
+      var height = parseFloat(font);
+      var textBaselines = ['alphabetic', 'top'];
+      var results = [];
+      for (var i = 0; i < 2; i++) {
+        this.ctx.fillStyle = '#fff';
+        this.ctx.fillRect(0, 0, this.canvas.width, this.canvas.height);
+        this.ctx.textBaseline = textBaselines[i];
+        this.ctx.fillStyle = '#000';
+        this.ctx.font = font;
+        this.ctx.fillText(str, 0, height);
+        results[i] = this.getFirstNoneWhitePixelTop();
+      }
+      var ascent = results[1] - results[0];
+      this.cache[font] = ascent;
+      return ascent;
+    }
+  };
+
+  return FontMetrics;
+
+})();

web/page_view.js

@@ -494,7 +494,8 @@ var PageView = function pageView(container, id, scale,
         pageIndex: this.id - 1,
         lastScrollSource: PDFView,
         viewport: this.viewport,
-        isViewerInPresentationMode: PresentationMode.active
+        isViewerInPresentationMode: PresentationMode.active,
+        fontMetrics: PDFView.fontMetrics
       }) : null;
     // TODO(mack): use data attributes to store these
     ctx._scaleX = outputScale.sx;