/**
* Copyright (C) 2005-2016 Alfresco Software Limited.
*
* This file is part of Alfresco
*
* Alfresco is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Alfresco is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* <p>This code was adapted from a Share Extras (http://share-extras.github.io/)
* project and was then integrated into Alfresco Share for version 5.0. That code was in turn
* originally adapted from the Mozilla pdf.js project (https://github.com/mozilla/pdf.js).</p>
*
* <p>TextLayerBuilder provides text-selection functionality for the PDF. It does this
* by creating overlay divs over the PDF text. This divs contain text that matches
* the PDF text they are overlaying. This object also provides for a way to highlight
* text that is being searched for.</p>
*
* @module alfresco/preview/PdfJs/TextLayerBuilder
* @author Dave Draper
* @author Will Abson
* @auther Peter Löfgren
* @author Kevin Roast
*/
define(["dojo/_base/declare",
"dojo/dom-style"],
function(declare, domStyle) {
return declare([], {
/**
* Copied from pdf.js viewer.
*/
FIND_SCROLL_OFFSET_TOP: -50,
FIND_SCROLL_OFFSET_LEFT: -400,
/**
*
*
* @instance
* // TODO: Add parameters
*/
constructor: function alfresco_preview_PdfJs_TextLayerBuilder__constructor(textLayerDiv, pageIdx, pdfJsPlugin, viewport) {
this.textLayerFrag = document.createDocumentFragment();
this.textDivs = [];
// ALFRESCO CHANGES
this.viewport = viewport;
this.textLayerDiv = textLayerDiv;
this.layoutDone = false;
this.divContentDone = false;
this.pageIdx = pageIdx;
this.matches = [];
this.pdfJsPlugin = pdfJsPlugin;
this.isViewerInPresentationMode = false;
// END ALFRESCO CHANGES
if (typeof this.pdfJsPlugin._findController === "undefined") {
this.pdfJsPlugin._findController = null;
}
if (typeof this.lastScrollSource === "undefined") {
this.lastScrollSource = null;
}
},
/**
*
*
* @instance
*/
renderLayer: function alfresco_preview_PdfJs_TextLayerBuilder__renderLayer() {
var textDivs = this.textDivs;
var canvas = document.createElement("canvas");
var ctx = canvas.getContext("2d");
// No point in rendering so many divs as it'd make the browser unusable
// even after the divs are rendered
var MAX_TEXT_DIVS_TO_RENDER = 100000;
if (textDivs.length > MAX_TEXT_DIVS_TO_RENDER) {
return;
}
for (var i = 0, ii = textDivs.length; i < ii; i++) {
var textDiv = textDivs[i];
if ("isWhitespace" in textDiv.dataset) {
continue;
}
ctx.font = textDiv.style.fontSize + " " + textDiv.style.fontFamily;
var width = ctx.measureText(textDiv.textContent).width;
if (width > 0) {
this.textLayerFrag.appendChild(textDiv);
var textScale = textDiv.dataset.canvasWidth / width;
var rotation = textDiv.dataset.angle;
var transform = "scale(" + textScale + ", 1)";
transform = "rotate(" + rotation + "deg) " + transform;
// ALFRESCO CHANGES
// Share extras changed to use Yahoo dom.
// TODO: Work out some more efficient way of determining
// prefix as original method do, instead of setting all.
domStyle.set(textDiv, "-ms-transform", "scale(" + textScale + ", 1)");
domStyle.set(textDiv, "-webkit-transform", "scale(" + textScale + ", 1)");
domStyle.set(textDiv, "-moz-transform", "scale(" + textScale + ", 1)");
domStyle.set(textDiv, "-ms-transformOrigin", "0% 0%");
domStyle.set(textDiv, "-webkit-transformOrigin", "0% 0%");
domStyle.set(textDiv, "-moz-transformOrigin", "0% 0%");
// END ALFRESCO CHANGES
}
}
this.textLayerDiv.appendChild(this.textLayerFrag);
this.renderingDone = true;
this.updateMatches();
},
/**
*
*
* @instance
*/
setupRenderLayoutTimer: function alfresco_preview_PdfJs_TextLayerBuilder__setupRenderLayoutTimer() {
// Schedule renderLayout() if user has been scrolling, otherwise
// run it right away
var RENDER_DELAY = 200; // in ms
var self = this;
var lastScroll = (this.lastScrollSource === null ?
0 : this.lastScrollSource.lastScroll);
if (Date.now() - lastScroll > RENDER_DELAY)
{
// Render right away
this.renderLayer();
}
else
{
// Schedule
if (this.renderTimer)
{
clearTimeout(this.renderTimer);
}
this.renderTimer = setTimeout(function() {
self.setupRenderLayoutTimer();
}, RENDER_DELAY);
}
},
/**
*
*
* @instance
*/
appendText: function alfresco_preview_PdfJs_TextLayerBuilder__appendText(geom, styles) {
var style = styles[geom.fontName];
var textDiv = document.createElement("div");
this.textDivs.push(textDiv);
if (!/\S/.test(geom.str)) {
textDiv.dataset.isWhitespace = true;
return;
}
var tx = PDFJS.Util.transform(this.viewport.transform, geom.transform);
var angle = Math.atan2(tx[1], tx[0]);
if (style.vertical) {
angle += Math.PI / 2;
}
var fontHeight = Math.sqrt((tx[2] * tx[2]) + (tx[3] * tx[3]));
var fontAscent = (style.ascent ? style.ascent * fontHeight :
(style.descent ? (1 + style.descent) * fontHeight : fontHeight));
textDiv.style.position = "absolute";
textDiv.style.left = (tx[4] + (fontAscent * Math.sin(angle))) + "px";
textDiv.style.top = (tx[5] - (fontAscent * Math.cos(angle))) + "px";
textDiv.style.fontSize = fontHeight + "px";
textDiv.style.fontFamily = style.fontFamily;
textDiv.textContent = geom.str;
textDiv.dataset.fontName = geom.fontName;
textDiv.dataset.angle = angle * (180 / Math.PI);
if (style.vertical) {
textDiv.dataset.canvasWidth = geom.height * this.viewport.scale;
} else {
textDiv.dataset.canvasWidth = geom.width * this.viewport.scale;
}
},
/**
*
*
* @instance
*/
setTextContent: function alfresco_preview_PdfJs_TextLayerBuilder__setTextContent(textContent) {
this.textContent = textContent;
var textItems = textContent.items;
for (var i = 0; i < textItems.length; i++) {
this.appendText(textItems[i], textContent.styles);
}
this.divContentDone = true;
this.setupRenderLayoutTimer();
},
/**
*
*
* @instance
*/
convertMatches: function alfresco_preview_PdfJs_TextLayerBuilder__convertMatches(matches) {
/*jshint devel:true*/
var i = 0;
var iIndex = 0;
var bidiTexts = this.textContent.items;
var end = bidiTexts.length - 1;
var queryLen = (this.pdfJsPlugin._findController === null ?
0 : this.pdfJsPlugin._findController.state.query.length);
var ret = [];
// Loop over all the matches.
for (var m = 0; m < matches.length; m++) {
var matchIdx = matches[m];
// # Calculate the begin position.
// Loop over the divIdxs.
while (i !== end && matchIdx >= (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
}
// TODO: Do proper handling here if something goes wrong.
if (i === bidiTexts.length) {
console.error("Could not find matching mapping");
}
var match = {
begin: {
divIdx: i,
offset: matchIdx - iIndex
}
};
// # Calculate the end position.
matchIdx += queryLen;
// Somewhat same array as above, but use a > instead of >= to get the end
// position right.
while (i !== end && matchIdx > (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
}
match.end = {
divIdx: i,
offset: matchIdx - iIndex
};
ret.push(match);
}
return ret;
},
/**
*
*
* @instance
*/
renderMatches: function alfresco_preview_PdfJs_TextLayerBuilder__renderMatches(matches) {
/*jshint maxcomplexity:false,maxstatements:false*/
// Early exit if there is nothing to render.
if (matches.length === 0) {
return;
}
var bidiTexts = this.textContent.items;
var textDivs = this.textDivs;
var prevEnd = null;
var isSelectedPage = (this.pdfJsPlugin._findController === null ?
false : (this.pageIdx === this.pdfJsPlugin._findController.selected.pageIdx));
var selectedMatchIdx = (this.pdfJsPlugin._findController === null ?
-1 : this.pdfJsPlugin._findController.selected.matchIdx);
var highlightAll = (this.pdfJsPlugin._findController === null ?
false : this.pdfJsPlugin._findController.state.highlightAll);
var infty = {
divIdx: -1,
offset: undefined
};
function appendTextToDiv(divIdx, fromOffset, toOffset, className) {
var div = textDivs[divIdx];
var content = bidiTexts[divIdx].str.substring(fromOffset, toOffset);
var node = document.createTextNode(content);
if (className) {
var span = document.createElement("span");
span.className = className;
span.appendChild(node);
div.appendChild(span);
return;
}
div.appendChild(node);
}
function beginText(begin, className) {
var divIdx = begin.divIdx;
var div = textDivs[divIdx];
div.textContent = "";
appendTextToDiv(divIdx, 0, begin.offset, className);
}
function appendText(from, to, className) {
appendTextToDiv(from.divIdx, from.offset, to.offset, className);
}
function highlightDiv(divIdx, className) {
textDivs[divIdx].className = className;
}
var i0 = selectedMatchIdx, i1 = i0 + 1, i;
if (highlightAll) {
i0 = 0;
i1 = matches.length;
} else if (!isSelectedPage) {
// Not highlighting all and this isn't the selected page, so do nothing.
return;
}
for (i = i0; i < i1; i++) {
var match = matches[i];
var begin = match.begin;
var end = match.end;
var isSelected = isSelectedPage && i === selectedMatchIdx;
var highlightSuffix = (isSelected ? " selected" : "");
if (isSelected && !this.isViewerInPresentationMode) {
// ALFRESCO - change reference to select correct pageIdx
this.pdfJsPlugin.documentView.pages[this.pageIdx].scrollIntoView(textDivs[begin.divIdx],
{ top: this.FIND_SCROLL_OFFSET_TOP, left: this.FIND_SCROLL_OFFSET_LEFT });
// END ALFRESCO
}
// Match inside new div.
if (!prevEnd || begin.divIdx !== prevEnd.divIdx) {
// If there was a previous div, then add the text at the end
if (prevEnd !== null) {
appendText(prevEnd, infty);
}
// clears the divs and set the content until the begin point.
beginText(begin);
} else {
appendText(prevEnd, begin);
}
if (begin.divIdx === end.divIdx) {
appendText(begin, end, "highlight" + highlightSuffix);
} else {
appendText(begin, infty, "highlight begin" + highlightSuffix);
for (var n = begin.divIdx + 1; n < end.divIdx; n++) {
highlightDiv(n, "highlight middle" + highlightSuffix);
}
beginText(end, "highlight end" + highlightSuffix);
}
prevEnd = end;
}
if (prevEnd) {
appendText(prevEnd, infty);
}
},
/**
*
*
* @instance
*/
updateMatches: function alfresco_preview_PdfJs_TextLayerBuilder__updateMatches() {
// Only show matches, once all rendering is done.
if (!this.renderingDone) {
return;
}
// Clear out all matches.
var matches = this.matches;
var textDivs = this.textDivs;
var bidiTexts = this.textContent.items;
var clearedUntilDivIdx = -1;
// Clear out all current matches.
for (var i = 0; i < matches.length; i++) {
var match = matches[i];
var begin = Math.max(clearedUntilDivIdx, match.begin.divIdx);
for (var n = begin; n <= match.end.divIdx; n++) {
var div = textDivs[n];
div.textContent = bidiTexts[n].str;
div.className = "";
}
clearedUntilDivIdx = match.end.divIdx + 1;
}
if (this.pdfJsPlugin._findController === null || !this.pdfJsPlugin._findController.active) {
return;
}
// Convert the matches on the page controller into the match format used
// for the textLayer.
this.matches = matches =
(this.convertMatches(this.pdfJsPlugin._findController === null ? [] : (this.pdfJsPlugin._findController.pageMatches[this.pageIdx] || [])));
this.renderMatches(this.matches);
}
});
});
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