Sha256: 8ad56e9941e537af9cc1b649d3b2db491808fcbff18be22007de3189ad4ee941
Contents?: true
Size: 1.2 KB
Versions: 16
Compression:
Stored size: 1.2 KB
Contents
/**
*
* @param {Func} cb
* @param {Object} options
*/
export default function Lazyload(cb, threshold = 120 ) {
this.lastScroll = 0
this.cb = cb
this.threshold = threshold
this._boundHandleScroll = this.handleScroll.bind(this)
}
/**
* Add event listener
*/
Lazyload.prototype.start = function() {
// Keep initial scroll position
this.lastScroll = getScrollTop()
window.addEventListener('scroll', this._boundHandleScroll)
}
/**
* Remove event listener
*/
Lazyload.prototype.stop = function() {
window.removeEventListener('scroll', this._boundHandleScroll)
}
/**
* Handle scroll
*/
Lazyload.prototype.handleScroll = function(event) {
if (!this.ticking) {
window.requestAnimationFrame(() => {
// Get current scroll position
const currentScroll = getScrollTop()
// If user has scrolled down and more than threshold
if (currentScroll - this.lastScroll >= this.threshold) {
// Execute callback
this.cb.call()
// Keep new milestone
this.lastScroll = currentScroll
}
this.ticking = false
})
}
this.ticking = true
}
function getScrollTop() {
return window.pageYOffset || document.documentElement.scrollTop
}
Version data entries
16 entries across 16 versions & 1 rubygems