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epubreader/vendor/pdfjs/controllers/textlayer_controller.js.simple
2020-04-21 22:37:42 +02:00

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PDFJS.reader.TextLayerController = function() {
var TextLayerBuilder = function textLayerBuilder(textLayerDiv, pageIdx) {
var textLayerFrag = document.createDocumentFragment();
this.textLayerDiv = textLayerDiv;
this.layoutDone = false;
this.divContentDone = false;
this.pageIdx = pageIdx;
this.matches = [];
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 bidiTexts = this.textContent.bidiTexts;
var textLayerDiv = this.textLayerDiv;
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;
}
textLayerFrag.appendChild(textDiv);
ctx.font = textDiv.style.fontSize + ' ' + textDiv.style.fontFamily;
var width = ctx.measureText(textDiv.textContent).width;
if (width > 0) {
var textScale = textDiv.dataset.canvasWidth / width;
var transform = 'scale(' + textScale + ', 1)';
if (bidiTexts[i].dir === 'ttb') {
transform = 'rotate(90deg) ' + transform;
}
CustomStyle.setProp('transform', textDiv, transform);
CustomStyle.setProp('transformOrigin', textDiv, '0% 0%');
textLayerDiv.appendChild(textDiv);
}
}
this.renderingDone = true;
textLayerDiv.appendChild(textLayerFrag);
};
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;
//0 was originally PDFView.lastScroll
if (Date.now() - 0 > 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 * geom.hScale;
textDiv.dataset.fontName = geom.fontName;
textDiv.style.fontSize = fontHeight + 'px';
textDiv.style.fontFamily = geom.fontFamily;
textDiv.style.left = geom.x + 'px';
textDiv.style.top = (geom.y - fontHeight) + '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.bidiTexts;
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;
// bidiText.dir may be 'ttb' for vertical texts.
textDiv.dir = bidiText.dir === 'rtl' ? 'rtl' : 'ltr';
}
this.setupRenderLayoutTimer();
};
this.setTextContent = function textLayerBuilderSetTextContent(textContent) {
this.textContent = textContent;
this.insertDivContent();
};
};
};
var CustomStyle = (function CustomStyleClosure() {
// As noted on: http://www.zachstronaut.com/posts/2009/02/17/
// animate-css-transforms-firefox-webkit.html
// in some versions of IE9 it is critical that ms appear in this list
// before Moz
var prefixes = ['ms', 'Moz', 'Webkit', 'O'];
var _cache = { };
function CustomStyle() {
}
CustomStyle.getProp = function get(propName, element) {
// check cache only when no element is given
if (arguments.length == 1 && typeof _cache[propName] == 'string') {
return _cache[propName];
}
element = element || document.documentElement;
var style = element.style, prefixed, uPropName;
// test standard property first
if (typeof style[propName] == 'string') {
return (_cache[propName] = propName);
}
// capitalize
uPropName = propName.charAt(0).toUpperCase() + propName.slice(1);
// test vendor specific properties
for (var i = 0, l = prefixes.length; i < l; i++) {
prefixed = prefixes[i] + uPropName;
if (typeof style[prefixed] == 'string') {
return (_cache[propName] = prefixed);
}
}
//if all fails then set to undefined
return (_cache[propName] = 'undefined');
};
CustomStyle.setProp = function set(propName, element, str) {
var prop = this.getProp(propName);
if (prop != 'undefined')
element.style[prop] = str;
};
return CustomStyle;
})();