epubreader/vendor/pdfjs/controllers/textlayer_controller.js.simple

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;
})();