79 lines
1.9 KiB
JavaScript
79 lines
1.9 KiB
JavaScript
/* global $ */
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/**
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* Utility functions.
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*/
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var Util = (function (my) {
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/**
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* Returns the text width for the given element.
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*
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* @param el the element
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*/
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my.getTextWidth = function (el) {
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return (el.clientWidth + 1);
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};
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/**
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* Returns the text height for the given element.
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*
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* @param el the element
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*/
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my.getTextHeight = function (el) {
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return (el.clientHeight + 1);
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};
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/**
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* Casts the given number to integer.
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*
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* @param number the number to cast
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*/
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my.toInteger = function (number) {
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return Math.round(Number(number));
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};
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/**
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* Plays the sound given by id.
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*
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* @param id the identifier of the audio element.
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*/
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my.playSoundNotification = function (id) {
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document.getElementById(id).play();
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};
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/**
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* Escapes the given text.
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*/
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my.escapeHtml = function (unsafeText) {
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return $('<div/>').text(unsafeText).html();
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};
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/**
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* Returns the available video width.
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*/
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my.getAvailableVideoWidth = function () {
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var chatspaceWidth
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= $('#chatspace').is(":visible") ? $('#chatspace').width() : 0;
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return window.innerWidth - chatspaceWidth;
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};
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my.imageToGrayScale = function(canvas) {
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var context = canvas.getContext('2d');
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var imgData = context.getImageData(0, 0, canvas.width, canvas.height);
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var pixels = imgData.data;
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for (var i = 0, n = pixels.length; i < n; i += 4) {
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var grayscale
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= pixels[i] * .3 + pixels[i+1] * .59 + pixels[i+2] * .11;
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pixels[i ] = grayscale; // red
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pixels[i+1] = grayscale; // green
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pixels[i+2] = grayscale; // blue
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// pixels[i+3] is alpha
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}
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// redraw the image in black & white
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context.putImageData(imgData, 0, 0);
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};
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return my;
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}(Util || {}));
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