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Convert the text layer builder to a class

Tim van der Meij 11 years ago
parent
2a052c4aad
commit
a968da8887
1 changed files with 261 additions and 256 deletions
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  1. 517
      web/text_layer_builder.js

517
web/text_layer_builder.js
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@ -28,298 +28,303 @@ var RENDER_DELAY = 200; // ms @@ -28,298 +28,303 @@ var RENDER_DELAY = 200; // ms
* contain text that matches the PDF text they are overlaying. This object
* also provides a way to highlight text that is being searched for.
*/
var TextLayerBuilder = function textLayerBuilder(options) {
this.textLayerDiv = options.textLayerDiv;
this.layoutDone = false;
this.divContentDone = false;
this.pageIdx = options.pageIndex;
this.matches = [];
this.lastScrollSource = options.lastScrollSource || null;
this.viewport = options.viewport;
this.isViewerInPresentationMode = options.isViewerInPresentationMode;
this.textDivs = [];
if (typeof PDFFindController === 'undefined') {
window.PDFFindController = null;
}
this.renderLayer = function textLayerBuilder_renderLayer() {
var textLayerFrag = document.createDocumentFragment();
var textDivs = this.textDivs;
var textDivsLength = textDivs.length;
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
// No point in rendering many divs as it would make the browser
// unusable even after the divs are rendered.
if (textDivsLength > MAX_TEXT_DIVS_TO_RENDER) {
return;
var TextLayerBuilder = (function TextLayerBuilderClosure() {
function TextLayerBuilder(options) {
this.textLayerDiv = options.textLayerDiv;
this.layoutDone = false;
this.divContentDone = false;
this.pageIdx = options.pageIndex;
this.matches = [];
this.lastScrollSource = options.lastScrollSource || null;
this.viewport = options.viewport;
this.isViewerInPresentationMode = options.isViewerInPresentationMode;
this.textDivs = [];
if (typeof PDFFindController === 'undefined') {
window.PDFFindController = null;
}
}
for (var i = 0; i < textDivsLength; i++) {
var textDiv = textDivs[i];
if (textDiv.dataset.isWhitespace !== undefined) {
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%');
TextLayerBuilder.prototype = {
renderLayer: function TextLayerBuilder_renderLayer() {
var textLayerFrag = document.createDocumentFragment();
var textDivs = this.textDivs;
var textDivsLength = textDivs.length;
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
// No point in rendering many divs as it would make the browser
// unusable even after the divs are rendered.
if (textDivsLength > MAX_TEXT_DIVS_TO_RENDER) {
return;
}
}
this.textLayerDiv.appendChild(textLayerFrag);
this.renderingDone = true;
this.updateMatches();
};
for (var i = 0; i < textDivsLength; i++) {
var textDiv = textDivs[i];
if (textDiv.dataset.isWhitespace !== undefined) {
continue;
}
this.setupRenderLayoutTimer =
function textLayerBuilder_setupRenderLayoutTimer() {
// Schedule renderLayout() if the user has been scrolling,
// otherwise run it right away.
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);
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.renderTimer = setTimeout(function() {
self.setupRenderLayoutTimer();
}, RENDER_DELAY);
}
};
this.appendText = function 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;
}
};
this.textLayerDiv.appendChild(textLayerFrag);
this.renderingDone = true;
this.updateMatches();
},
setupRenderLayoutTimer:
function TextLayerBuilder_setupRenderLayoutTimer() {
// Schedule renderLayout() if the user has been scrolling,
// otherwise run it right away.
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);
}
},
appendText: function 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;
}
},
this.setTextContent = function textLayerBuilder_setTextContent(textContent) {
this.textContent = textContent;
setTextContent: function TextLayerBuilder_setTextContent(textContent) {
this.textContent = textContent;
var textItems = textContent.items;
for (var i = 0, len = textItems.length; i < len; i++) {
this.appendText(textItems[i], textContent.styles);
}
this.divContentDone = true;
this.setupRenderLayoutTimer();
};
this.convertMatches = function textLayerBuilder_convertMatches(matches) {
var i = 0;
var iIndex = 0;
var bidiTexts = this.textContent.items;
var end = bidiTexts.length - 1;
var queryLen = (PDFFindController === null ?
0 : PDFFindController.state.query.length);
var ret = [];
for (var m = 0, len = matches.length; m < len; m++) {
// Calculate the start position.
var matchIdx = matches[m];
// Loop over the divIdxs.
while (i !== end && matchIdx >= (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
var textItems = textContent.items;
for (var i = 0, len = textItems.length; i < len; i++) {
this.appendText(textItems[i], textContent.styles);
}
this.divContentDone = true;
this.setupRenderLayoutTimer();
},
convertMatches: function TextLayerBuilder_convertMatches(matches) {
var i = 0;
var iIndex = 0;
var bidiTexts = this.textContent.items;
var end = bidiTexts.length - 1;
var queryLen = (PDFFindController === null ?
0 : PDFFindController.state.query.length);
var ret = [];
for (var m = 0, len = matches.length; m < len; m++) {
// Calculate the start position.
var matchIdx = matches[m];
// Loop over the divIdxs.
while (i !== end && matchIdx >= (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
}
if (i === bidiTexts.length) {
console.error('Could not find a matching mapping');
}
if (i === bidiTexts.length) {
console.error('Could not find a matching mapping');
}
var match = {
begin: {
divIdx: i,
offset: matchIdx - iIndex
}
};
// Calculate the end position.
matchIdx += queryLen;
// Somewhat the same array as above, but use > instead of >= to get
// the end position right.
while (i !== end && matchIdx > (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
}
var match = {
begin: {
match.end = {
divIdx: i,
offset: matchIdx - iIndex
}
};
};
ret.push(match);
}
// Calculate the end position.
matchIdx += queryLen;
return ret;
},
// Somewhat the same array as above, but use > instead of >= to get
// the end position right.
while (i !== end && matchIdx > (iIndex + bidiTexts[i].str.length)) {
iIndex += bidiTexts[i].str.length;
i++;
renderMatches: function TextLayerBuilder_renderMatches(matches) {
// Early exit if there is nothing to render.
if (matches.length === 0) {
return;
}
match.end = {
divIdx: i,
offset: matchIdx - iIndex
var bidiTexts = this.textContent.items;
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 infinity = {
divIdx: -1,
offset: undefined
};
ret.push(match);
}
return ret;
};
this.renderMatches = function textLayerBuilder_renderMatches(matches) {
// Early exit if there is nothing to render.
if (matches.length === 0) {
return;
}
function beginText(begin, className) {
var divIdx = begin.divIdx;
textDivs[divIdx].textContent = '';
appendTextToDiv(divIdx, 0, begin.offset, className);
}
var bidiTexts = this.textContent.items;
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 infinity = {
divIdx: -1,
offset: undefined
};
function beginText(begin, className) {
var divIdx = begin.divIdx;
textDivs[divIdx].textContent = '';
appendTextToDiv(divIdx, 0, begin.offset, className);
}
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 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);
var i0 = selectedMatchIdx, i1 = i0 + 1;
if (highlightAll) {
i0 = 0;
i1 = matches.length;
} else if (!isSelectedPage) {
// Not highlighting all and this isn't the selected page, so do nothing.
return;
}
div.appendChild(node);
}
var i0 = selectedMatchIdx, i1 = i0 + 1;
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 (var 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 });
}
for (var 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) {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
}
// Clear the divs and set the content until the starting point.
beginText(begin);
} else {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, begin.offset);
}
// 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) {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
if (begin.divIdx === end.divIdx) {
appendTextToDiv(begin.divIdx, begin.offset, end.offset,
'highlight' + highlightSuffix);
} else {
appendTextToDiv(begin.divIdx, begin.offset, infinity.offset,
'highlight begin' + highlightSuffix);
for (var n0 = begin.divIdx + 1, n1 = end.divIdx; n0 < n1; n0++) {
textDivs[n0].className = 'highlight middle' + highlightSuffix;
}
beginText(end, 'highlight end' + highlightSuffix);
}
// Clear the divs and set the content until the starting point.
beginText(begin);
} else {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, begin.offset);
prevEnd = end;
}
if (begin.divIdx === end.divIdx) {
appendTextToDiv(begin.divIdx, begin.offset, end.offset,
'highlight' + highlightSuffix);
} else {
appendTextToDiv(begin.divIdx, begin.offset, infinity.offset,
'highlight begin' + highlightSuffix);
for (var n0 = begin.divIdx + 1, n1 = end.divIdx; n0 < n1; n0++) {
textDivs[n0].className = 'highlight middle' + highlightSuffix;
}
beginText(end, 'highlight end' + highlightSuffix);
if (prevEnd) {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
}
prevEnd = end;
}
},
if (prevEnd) {
appendTextToDiv(prevEnd.divIdx, prevEnd.offset, infinity.offset);
}
};
updateMatches: function TextLayerBuilder_updateMatches() {
// Only show matches when all rendering is done.
if (!this.renderingDone) {
return;
}
this.updateMatches = function textLayerBuilder_updateMatches() {
// Only show matches when all rendering is done.
if (!this.renderingDone) {
return;
}
// Clear all matches.
var matches = this.matches;
var textDivs = this.textDivs;
var bidiTexts = this.textContent.items;
var clearedUntilDivIdx = -1;
// Clear all current matches.
for (var i = 0, len = matches.length; i < len; i++) {
var match = matches[i];
var begin = Math.max(clearedUntilDivIdx, match.begin.divIdx);
for (var n = begin, end = match.end.divIdx; n <= end; n++) {
var div = textDivs[n];
div.textContent = bidiTexts[n].str;
div.className = '';
}
clearedUntilDivIdx = match.end.divIdx + 1;
}
// Clear all matches.
var matches = this.matches;
var textDivs = this.textDivs;
var bidiTexts = this.textContent.items;
var clearedUntilDivIdx = -1;
// Clear all current matches.
for (var i = 0, len = matches.length; i < len; i++) {
var match = matches[i];
var begin = Math.max(clearedUntilDivIdx, match.begin.divIdx);
for (var n = begin, end = match.end.divIdx; n <= end; n++) {
var div = textDivs[n];
div.textContent = bidiTexts[n].str;
div.className = '';
if (PDFFindController === null || !PDFFindController.active) {
return;
}
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 = this.convertMatches(PDFFindController === null ?
[] : (PDFFindController.pageMatches[this.pageIdx] || []));
this.renderMatches(this.matches);
}
// Convert the matches on the page controller into the match format
// used for the textLayer.
this.matches = this.convertMatches(PDFFindController === null ?
[] : (PDFFindController.pageMatches[this.pageIdx] || []));
this.renderMatches(this.matches);
};
};
return TextLayerBuilder;
})();

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