useTransition

Demo

Cubic bezier curve: 0.00

Custom function: 0.00

Vector: [0.00, 0.00]

Usage

Define a numeric source value to follow, and when changed the output will transition to the new value. If the source changes while a transition is in progress, a new transition will begin from where the previous one was interrupted.

import { TransitionPresets, useTransition } from '@vueuse/core'
import { shallowRef } from 'vue'

const source = shallowRef(0)

const output = useTransition(source, {
  duration: 1000,
  transition: TransitionPresets.easeInOutCubic,
})

To synchronize transitions, use an array of numbers. As an example, here is how we could transition between colors.

const source = shallowRef([0, 0, 0])

const output = useTransition(source)

const color = computed(() => {
  const [r, g, b] = output.value
  return `rgb(${r}, ${g}, ${b})`
})

Transition easing can be customized using cubic bezier curves. Transitions defined this way work the same as CSS easing functions.

useTransition(source, {
  transition: [0.75, 0, 0.25, 1],
})

The following transitions are available via the TransitionPresets constant.

For more complex transitions, a custom function can be provided.

function easeOutElastic(n) {
  return n === 0
    ? 0
    : n === 1
      ? 1
      : (2 ** (-10 * n)) * Math.sin((n * 10 - 0.75) * ((2 * Math.PI) / 3)) + 1
}

useTransition(source, {
  transition: easeOutElastic,
})

To control when a transition starts, set a delay value. To choreograph behavior around a transition, define onStarted or onFinished callbacks.

useTransition(source, {
  delay: 1000,
  onStarted() {
    // called after the transition starts
  },
  onFinished() {
    // called after the transition ends
  },
})

To temporarily stop transitioning, define a boolean disabled property. Be aware, this is not the same a duration of 0. Disabled transitions track the source value synchronously. They do not respect a delay, and do not fire onStarted or onFinished callbacks.

For more control, transitions can be executed manually by using executeTransition. This function returns a promise that resolves upon completion. Manual transitions can be cancelled by defining an abort function that returns a truthy value.

import { executeTransition } from '@vueuse/core'

await executeTransition(source, from, to, {
  duration: 1000,
})

Type Declarations

Show Type Declarations

/**
 * Cubic bezier points
 */
export type CubicBezierPoints = [number, number, number, number]
/**
 * Easing function
 */
export type EasingFunction = (n: number) => number
/**
 * Transition options
 */
export interface TransitionOptions extends ConfigurableWindow {
  /**
   * Manually abort a transition
   */
  abort?: () => any
  /**
   * Transition duration in milliseconds
   */
  duration?: MaybeRef<number>
  /**
   * Easing function or cubic bezier points for calculating transition values
   */
  transition?: MaybeRef<EasingFunction | CubicBezierPoints>
}
export interface UseTransitionOptions extends TransitionOptions {
  /**
   * Milliseconds to wait before starting transition
   */
  delay?: MaybeRef<number>
  /**
   * Disables the transition
   */
  disabled?: MaybeRef<boolean>
  /**
   * Callback to execute after transition finishes
   */
  onFinished?: () => void
  /**
   * Callback to execute after transition starts
   */
  onStarted?: () => void
}
declare const _TransitionPresets: {
  readonly easeInSine: readonly [0.12, 0, 0.39, 0]
  readonly easeOutSine: readonly [0.61, 1, 0.88, 1]
  readonly easeInOutSine: readonly [0.37, 0, 0.63, 1]
  readonly easeInQuad: readonly [0.11, 0, 0.5, 0]
  readonly easeOutQuad: readonly [0.5, 1, 0.89, 1]
  readonly easeInOutQuad: readonly [0.45, 0, 0.55, 1]
  readonly easeInCubic: readonly [0.32, 0, 0.67, 0]
  readonly easeOutCubic: readonly [0.33, 1, 0.68, 1]
  readonly easeInOutCubic: readonly [0.65, 0, 0.35, 1]
  readonly easeInQuart: readonly [0.5, 0, 0.75, 0]
  readonly easeOutQuart: readonly [0.25, 1, 0.5, 1]
  readonly easeInOutQuart: readonly [0.76, 0, 0.24, 1]
  readonly easeInQuint: readonly [0.64, 0, 0.78, 0]
  readonly easeOutQuint: readonly [0.22, 1, 0.36, 1]
  readonly easeInOutQuint: readonly [0.83, 0, 0.17, 1]
  readonly easeInExpo: readonly [0.7, 0, 0.84, 0]
  readonly easeOutExpo: readonly [0.16, 1, 0.3, 1]
  readonly easeInOutExpo: readonly [0.87, 0, 0.13, 1]
  readonly easeInCirc: readonly [0.55, 0, 1, 0.45]
  readonly easeOutCirc: readonly [0, 0.55, 0.45, 1]
  readonly easeInOutCirc: readonly [0.85, 0, 0.15, 1]
  readonly easeInBack: readonly [0.36, 0, 0.66, -0.56]
  readonly easeOutBack: readonly [0.34, 1.56, 0.64, 1]
  readonly easeInOutBack: readonly [0.68, -0.6, 0.32, 1.6]
}
/**
 * Common transitions
 *
 * @see https://easings.net
 */
export declare const TransitionPresets: Record<
  keyof typeof _TransitionPresets,
  CubicBezierPoints
> & {
  linear: EasingFunction
}
/**
 * Transition from one value to another.
 *
 * @param source
 * @param from
 * @param to
 * @param options
 */
export declare function executeTransition<T extends number | number[]>(
  source: Ref<T>,
  from: MaybeRefOrGetter<T>,
  to: MaybeRefOrGetter<T>,
  options?: TransitionOptions,
): PromiseLike<void>
export declare function useTransition(
  source: MaybeRefOrGetter<number>,
  options?: UseTransitionOptions,
): ComputedRef<number>
export declare function useTransition<T extends MaybeRefOrGetter<number>[]>(
  source: [...T],
  options?: UseTransitionOptions,
): ComputedRef<{
  [K in keyof T]: number
}>
export declare function useTransition<T extends MaybeRefOrGetter<number[]>>(
  source: T,
  options?: UseTransitionOptions,
): ComputedRef<number[]>