react-native-reanimated/lib/reanimated2/js-reanimated/MutableValue.js

More powerful alternative to Animated library for React Native.

export default class MutableValue {
    constructor(value, setter) {
        this._animation = null;
        this._listeners = [];
        this._id = MutableValue.MUTABLE_ID++;
        this._value = value;
        this._setter = setter;
    }
    get value() {
        return this._value;
    }
    set value(nextValue) {
        this._setter(nextValue);
    }
    // this changes the value finally and is supposed to be called from this._setter
    _setValue(newValue) {
        this._value = newValue;
        this._triggerListener();
    }
    addListener(listener) {
        this._listeners.push(listener);
    }
    _triggerListener() {
        for (let i = 0, len = this._listeners.length; i < len; ++i) {
            this._listeners[i]();
        }
    }
}
MutableValue.MUTABLE_ID = 1;