react-native-easy-guesture-responder/src/TimerMixin.js

A powerful and easy to use function for React Native guesture responders. Supporting both iOS and Android. Free and made possible along with costly maintenance and updates by [Lue Hang](https://www.facebook.com/lue.hang) (the author).

"use strict";

/*
TimerMixin provides timer functions for executing code in
the future that are safely cleaned up when the component unmounts

Using bare setTimeout, setInterval, setImmediate and requestAnimationFrame calls
is very dangerous because if you forget to cancel the request before the
component is unmounted, you risk the callback throwing an exception.

If you include TimerMixin, then you can replace your calls to
`setTimeout(fn, 500)` with `this.setTimeout(fn, 500)` (just prepend `this.`) and
everything will be properly cleaned up for you.

## Example

```js
var React = require("react");
var TimerMixin = require("react-timer-mixin");

var Component = React.createClass({
  mixins: [TimerMixin],
  componentDidMount() {
    this.setTimeout(
      () => { console.log("I do not leak!"); },
      500
    );
  }
});
```
*/

var GLOBAL = typeof window === "undefined" ? global : window;

var setter = function(_setter, _clearer, array) {
    return function(callback, delta) {
        var id = _setter(function() {
            _clearer.call(this, id);
            callback.apply(this, arguments);
        }.bind(this), delta);

        if (!this[array]) {
            this[array] = [id];
        } else {
            this[array].push(id);
        }
        return id;
    };
};

var clearer = function(_clearer, array) {
    return function(id) {
        if (this[array]) {
            var index = this[array].indexOf(id);
            if (index !== -1) {
                this[array].splice(index, 1);
            }
        }
        _clearer(id);
    };
};

var _timeouts = "TimerMixin_timeouts";
var _clearTimeout = clearer(GLOBAL.clearTimeout, _timeouts);
var _setTimeout = setter(GLOBAL.setTimeout, _clearTimeout, _timeouts);

var _intervals = "TimerMixin_intervals";
var _clearInterval = clearer(GLOBAL.clearInterval, _intervals);
var _setInterval = setter(GLOBAL.setInterval, function() {/* noop */}, _intervals);

var _immediates = "TimerMixin_immediates";
var _clearImmediate = clearer(GLOBAL.clearImmediate, _immediates);
var _setImmediate = setter(GLOBAL.setImmediate, _clearImmediate, _immediates);

var _rafs = "TimerMixin_rafs";
var _cancelAnimationFrame = clearer(GLOBAL.cancelAnimationFrame, _rafs);
var _requestAnimationFrame = setter(GLOBAL.requestAnimationFrame, _cancelAnimationFrame, _rafs);

var TimerMixin = {
    componentWillUnmount: function() {
        this[_timeouts] && this[_timeouts].forEach(function(id) {
            GLOBAL.clearTimeout(id);
        });
        this[_timeouts] = null;
        this[_intervals] && this[_intervals].forEach(function(id) {
            GLOBAL.clearInterval(id);
        });
        this[_intervals] = null;
        this[_immediates] && this[_immediates].forEach(function(id) {
            GLOBAL.clearImmediate(id);
        });
        this[_immediates] = null;
        this[_rafs] && this[_rafs].forEach(function(id) {
            GLOBAL.cancelAnimationFrame(id);
        });
        this[_rafs] = null;
    },

    setTimeout: _setTimeout,
    clearTimeout: _clearTimeout,

    setInterval: _setInterval,
    clearInterval: _clearInterval,

    setImmediate: _setImmediate,
    clearImmediate: _clearImmediate,

    requestAnimationFrame: _requestAnimationFrame,
    cancelAnimationFrame: _cancelAnimationFrame,
};

module.exports = TimerMixin;