Animated.ValueXY

Creating a new Animated.ValueXY({x: 0, y: 0}) is almost exactly the same as Animated.Value with a few exceptions. The ValueXY are often used to help with position of components and or when you're dealing with gestures.

A few additional helper methods are added that make it easy to pass appropriate animated values to left/top, as well as translateX/translateY. There are other helpers for dealing with gestures and such so there is no jump when users press down first (that's solved with setOffset).

Animated.ValueXY() is an instance that adds those additional helper methods, but also exposes .x and .y attributes. The .x and .y are merely new Animated.Value() instances.

You create them just the same as you would new Animated.Value():

getInitialState: function() {
    return {
        someAnimatedValue: new Animate.ValueXY()
    }
}

constructor(props) {
    super(props)
    this.state = {
        someAnimatedValue: new Animate.ValueXY()
    }
}

componentWillMount: function() {
    this._someAnimatedValue = new Animated.ValueXY()
}

They default to {x: 0, y:0}. However, if you want to change the default values, you can pass in an object, such as new Animated.ValueXY({x: 15, y: 15}), which would set the default internal Animated.Values both to 15.

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