presentazione-papero/js/utils/util.js

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/**
* Extend object a with the properties of object b.
* If there's a conflict, object b takes precedence.
*
* @param {object} a
* @param {object} b
*/
export const extend = ( a, b ) => {
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for( let i in b ) {
a[ i ] = b[ i ];
}
return a;
}
/**
* Converts the target object to an array.
*
* @param {object} o
* @return {object[]}
*/
export const toArray = ( o ) => {
return Array.prototype.slice.call( o );
}
/**
* Utility for deserializing a value.
*
* @param {*} value
* @return {*}
*/
export const deserialize = ( value ) => {
if( typeof value === 'string' ) {
if( value === 'null' ) return null;
else if( value === 'true' ) return true;
else if( value === 'false' ) return false;
else if( value.match( /^-?[\d\.]+$/ ) ) return parseFloat( value );
}
return value;
}
/**
* Measures the distance in pixels between point a
* and point b.
*
* @param {object} a point with x/y properties
* @param {object} b point with x/y properties
*
* @return {number}
*/
export const distanceBetween = ( a, b ) => {
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let dx = a.x - b.x,
dy = a.y - b.y;
return Math.sqrt( dx*dx + dy*dy );
}
/**
* Applies a CSS transform to the target element.
*
* @param {HTMLElement} element
* @param {string} transform
*/
export const transformElement = ( element, transform ) => {
element.style.transform = transform;
}
/**
* Find the closest parent that matches the given
* selector.
*
* @param {HTMLElement} target The child element
* @param {String} selector The CSS selector to match
* the parents against
*
* @return {HTMLElement} The matched parent or null
* if no matching parent was found
*/
export const closestParent = ( target, selector ) => {
let parent = target.parentNode;
while( parent ) {
// There's some overhead doing this each time, we don't
// want to rewrite the element prototype but should still
// be enough to feature detect once at startup...
let matchesMethod = parent.matches || parent.matchesSelector || parent.msMatchesSelector;
// If we find a match, we're all set
if( matchesMethod && matchesMethod.call( parent, selector ) ) {
return parent;
}
// Keep searching
parent = parent.parentNode;
}
return null;
}
/**
* Handling the fullscreen functionality via the fullscreen API
*
* @see http://fullscreen.spec.whatwg.org/
* @see https://developer.mozilla.org/en-US/docs/DOM/Using_fullscreen_mode
*/
export const enterFullscreen = () => {
let element = document.documentElement;
// Check which implementation is available
let requestMethod = element.requestFullscreen ||
element.webkitRequestFullscreen ||
element.webkitRequestFullScreen ||
element.mozRequestFullScreen ||
element.msRequestFullscreen;
if( requestMethod ) {
requestMethod.apply( element );
}
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}
/**
* Injects the given CSS styles into the DOM.
*
* @param {string} value
*/
export const createStyleSheet = ( value ) => {
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let tag = document.createElement( 'style' );
tag.type = 'text/css';
if( value && value.length > 0 ) {
if( tag.styleSheet ) {
tag.styleSheet.cssText = value;
}
else {
tag.appendChild( document.createTextNode( value ) );
}
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}
document.head.appendChild( tag );
return tag;
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}