/**
* @module performance
*/
/**
* Reusable throttle creator
* @param {Function} timer Function like requestAnimationFrame
* @returns {Function} Function to be used to create throttled functions based on passed timer
*/
export function throttle(timer) {
let queued;
return callback => {
if (!queued) {
timer(() => {
const cb = queued;
queued = null;
cb();
});
}
queued = callback;
};
}
/**
* Returns a function, that, as long as it continues to be invoked, will not be triggered
* @param {Function} callback Function to invoke
* @param {Number} wait Amount of time after (milliseconds)
* @param {Boolean} immediate trigger the function on the leading edge, instead of the trailing.
* @param {Object} valueThis Context for function
* @return {Function} A new debounced function. It also includes a `.cancel()` method to clear any pending execution.
* @author David Walsh
* - https://davidwalsh.name/javascript-debounce-function
* - Updated to have cancel method
*/
export function debounce(callback, wait, immediate, valueThis) {
let timeout;
const executedFunction = function() {
const context = valueThis || this;
const args = arguments;
const later = function() {
timeout = null;
if (!immediate) {
callback.apply(context, args);
}
};
const callNow = immediate && !timeout;
clearTimeout(timeout);
timeout = setTimeout(later, wait);
if (callNow) {
callback.apply(context, args);
}
};
// Add cancel method to function for user to remove debounce
executedFunction.cancel = function() {
clearTimeout(timeout);
timeout = null;
};
return executedFunction;
}