jiti-meet/util.js

92 lines
2.4 KiB
JavaScript

/* global $ */
/**
* Utility functions.
*/
var Util = (function (my) {
/**
* Returns the text width for the given element.
*
* @param el the element
*/
my.getTextWidth = function (el) {
return (el.clientWidth + 1);
};
/**
* Returns the text height for the given element.
*
* @param el the element
*/
my.getTextHeight = function (el) {
return (el.clientHeight + 1);
};
/**
* Casts the given number to integer.
*
* @param number the number to cast
*/
my.toInteger = function (number) {
return Math.round(Number(number));
};
/**
* Plays the sound given by id.
*
* @param id the identifier of the audio element.
*/
my.playSoundNotification = function (id) {
document.getElementById(id).play();
};
/**
* Escapes the given text.
*/
my.escapeHtml = function (unsafeText) {
return $('<div/>').text(unsafeText).html();
};
my.imageToGrayScale = function (canvas) {
var context = canvas.getContext('2d');
var imgData = context.getImageData(0, 0, canvas.width, canvas.height);
var pixels = imgData.data;
for (var i = 0, n = pixels.length; i < n; i += 4) {
var grayscale
= pixels[i] * .3 + pixels[i+1] * .59 + pixels[i+2] * .11;
pixels[i ] = grayscale; // red
pixels[i+1] = grayscale; // green
pixels[i+2] = grayscale; // blue
// pixels[i+3] is alpha
}
// redraw the image in black & white
context.putImageData(imgData, 0, 0);
};
my.setTooltip = function (element, tooltipText, position) {
element.setAttribute("data-content", tooltipText);
element.setAttribute("data-toggle", "popover");
element.setAttribute("data-placement", position);
element.setAttribute("data-html", true);
element.setAttribute("data-container", "body");
};
my.createExpBackoffTimer = function (step) {
var count = 1;
return function (reset) {
// Reset call
if (reset) {
count = 1;
return;
}
// Calculate next timeout
var timeout = Math.pow(2, count - 1);
count += 1;
return timeout * step;
};
};
return my;
}(Util || {}));