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invoiceninja/public/vendor/pdfjs/web/text_layer_builder.js
2014-04-22 14:33:53 +03:00

387 lines
12 KiB
JavaScript

/* -*- Mode: Java; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* Copyright 2012 Mozilla Foundation
*
* 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.
*/
/* globals CustomStyle, PDFFindController, scrollIntoView */
'use strict';
var FIND_SCROLL_OFFSET_TOP = -50;
var FIND_SCROLL_OFFSET_LEFT = -400;
/**
* 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.
*/
var TextLayerBuilder = function textLayerBuilder(options) {
var textLayerFrag = document.createDocumentFragment();
this.textLayerDiv = options.textLayerDiv;
this.layoutDone = false;
this.divContentDone = false;
this.pageIdx = options.pageIndex;
this.matches = [];
this.lastScrollSource = options.lastScrollSource;
this.viewport = options.viewport;
this.isViewerInPresentationMode = options.isViewerInPresentationMode;
if (typeof PDFFindController === 'undefined') {
window.PDFFindController = null;
}
if (typeof this.lastScrollSource === 'undefined') {
this.lastScrollSource = null;
}
this.beginLayout = function textLayerBuilderBeginLayout() {
this.textDivs = [];
this.renderingDone = false;
};
this.endLayout = function textLayerBuilderEndLayout() {
this.layoutDone = true;
this.insertDivContent();
};
this.renderLayer = function textLayerBuilderRenderLayer() {
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) {
textLayerFrag.appendChild(textDiv);
var textScale = textDiv.dataset.canvasWidth / width;
var rotation = textDiv.dataset.angle;
var transform = 'scale(' + textScale + ', 1)';
transform = 'rotate(' + rotation + 'deg) ' + transform;
CustomStyle.setProp('transform' , textDiv, transform);
CustomStyle.setProp('transformOrigin' , textDiv, '0% 0%');
}
}
this.textLayerDiv.appendChild(textLayerFrag);
this.renderingDone = true;
this.updateMatches();
};
this.setupRenderLayoutTimer = function textLayerSetupRenderLayoutTimer() {
// 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);
}
};
this.appendText = function textLayerBuilderAppendText(geom) {
var textDiv = document.createElement('div');
// vScale and hScale already contain the scaling to pixel units
var fontHeight = geom.fontSize * Math.abs(geom.vScale);
textDiv.dataset.canvasWidth = geom.canvasWidth * Math.abs(geom.hScale);
textDiv.dataset.fontName = geom.fontName;
textDiv.dataset.angle = geom.angle * (180 / Math.PI);
textDiv.style.fontSize = fontHeight + 'px';
textDiv.style.fontFamily = geom.fontFamily;
var fontAscent = (geom.ascent ? geom.ascent * fontHeight :
(geom.descent ? (1 + geom.descent) * fontHeight : fontHeight));
textDiv.style.left = (geom.x + (fontAscent * Math.sin(geom.angle))) + 'px';
textDiv.style.top = (geom.y - (fontAscent * Math.cos(geom.angle))) + 'px';
// The content of the div is set in the `setTextContent` function.
this.textDivs.push(textDiv);
};
this.insertDivContent = function textLayerUpdateTextContent() {
// Only set the content of the divs once layout has finished, the content
// for the divs is available and content is not yet set on the divs.
if (!this.layoutDone || this.divContentDone || !this.textContent) {
return;
}
this.divContentDone = true;
var textDivs = this.textDivs;
var bidiTexts = this.textContent;
for (var i = 0; i < bidiTexts.length; i++) {
var bidiText = bidiTexts[i];
var textDiv = textDivs[i];
if (!/\S/.test(bidiText.str)) {
textDiv.dataset.isWhitespace = true;
continue;
}
textDiv.textContent = bidiText.str;
// TODO refactor text layer to use text content position
/**
* var arr = this.viewport.convertToViewportPoint(bidiText.x, bidiText.y);
* textDiv.style.left = arr[0] + 'px';
* textDiv.style.top = arr[1] + 'px';
*/
// bidiText.dir may be 'ttb' for vertical texts.
textDiv.dir = bidiText.dir;
}
this.setupRenderLayoutTimer();
};
this.setTextContent = function textLayerBuilderSetTextContent(textContent) {
this.textContent = textContent;
this.insertDivContent();
};
this.convertMatches = function textLayerBuilderConvertMatches(matches) {
var i = 0;
var iIndex = 0;
var bidiTexts = this.textContent;
var end = bidiTexts.length - 1;
var queryLen = (PDFFindController === null ?
0 : PDFFindController.state.query.length);
var lastDivIdx = -1;
var pos;
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;
};
this.renderMatches = function textLayerBuilder_renderMatches(matches) {
// Early exit if there is nothing to render.
if (matches.length === 0) {
return;
}
var bidiTexts = this.textContent;
var textDivs = this.textDivs;
var prevEnd = null;
var isSelectedPage = (PDFFindController === null ?
false : (this.pageIdx === PDFFindController.selected.pageIdx));
var selectedMatchIdx = (PDFFindController === null ?
-1 : PDFFindController.selected.matchIdx);
var highlightAll = (PDFFindController === null ?
false : PDFFindController.state.highlightAll);
var infty = {
divIdx: -1,
offset: undefined
};
function beginText(begin, className) {
var divIdx = begin.divIdx;
var div = textDivs[divIdx];
div.textContent = '';
var content = bidiTexts[divIdx].str.substring(0, begin.offset);
var node = document.createTextNode(content);
if (className) {
var isSelected = isSelectedPage &&
divIdx === selectedMatchIdx;
var span = document.createElement('span');
span.className = className + (isSelected ? ' selected' : '');
span.appendChild(node);
div.appendChild(span);
return;
}
div.appendChild(node);
}
function appendText(from, to, className) {
var divIdx = from.divIdx;
var div = textDivs[divIdx];
var content = bidiTexts[divIdx].str.substring(from.offset, to.offset);
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 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) {
scrollIntoView(textDivs[begin.divIdx], { top: FIND_SCROLL_OFFSET_TOP,
left: FIND_SCROLL_OFFSET_LEFT });
}
// 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);
}
};
this.updateMatches = function textLayerUpdateMatches() {
// 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;
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 (PDFFindController === null || !PDFFindController.active) {
return;
}
// Convert the matches on the page controller into the match format used
// for the textLayer.
this.matches = matches = (this.convertMatches(PDFFindController === null ?
[] : (PDFFindController.pageMatches[this.pageIdx] || [])));
this.renderMatches(this.matches);
};
};