Method _set

packages/core/src/SpringValue.ts:936–957

* Update the current value from outside the frameloop, * and return the `Animated` node.

(arg: T | FluidValue<T>, idle = true)

   * and return the `Animated` node.
   */
  protected _set(arg: T | FluidValue<T>, idle = true): Animated | undefined {
    const value = getFluidValue(arg)
    if (!is.und(value)) {
      const oldNode = getAnimated(this)
      if (!oldNode || !isEqual(value, oldNode.getValue())) {
        // Create a new node or update the existing node.
        const nodeType = getAnimatedType(value)
        if (!oldNode || oldNode.constructor != nodeType) {
          setAnimated(this, nodeType.create(value))
        } else {
          oldNode.setValue(value)
        }
        // Never emit a "change" event for the initial value.
        if (oldNode) {
          raf.batchedUpdates(() => {
            this._onChange(value, idle)
          })
        }
      }
    }
    return getAnimated(this)
  }

  protected _onStart() {
    const anim = this.animation