State Animations

@posva

Amsterdam 16 Feb

Eduardo

San Martin Morote

Vue core team

Author of VueFire 2, VueMotion, VueTweezing

Vue Instructor around Europe

@posva

Demo

https://bit.ly/posva-ams

Made with Nuxt!

Animations are hard

Activity monitor Jardson Almeida

Animations should be fast

Hi there 👋

I'm taking

my time

to appear...

Animating when...

The user does something
We need user's attention
We want to make things fun

<Transition/>

<Transition-group/>

Based on

```
v-if
```
```
v-show
```
```
key
```
```
v-for
```

:key

<transition name="fade" mode="out-in">
  <router-view :key="$route.fullPath"/>
</transition>

trick

Using

CSS or

Javascript

Limited to

Elements appearing
Elements disappearing
Elements reordering
CSS properties

State Animations

What is it?

How to go from one state to another

Boolean toggling
Easings
Physics

Boolean state Class switching

👎 rotation, translation, scaling (unless linear easing)

👍 opacity, colours, etc

👉 Basic Transition

👌 with computed properties

computed: {
  checkoutButtonClasses () {
    return {
      // apply a transition on colour
      'is-disabled': this.cart.length > 0
    }
  }
}

Easing

Go from 10 to 100 Bouncing out in 1 second

10: initial value

100: target value

Bouncing out: Easing

1s: duration

👉 Easing graph

SPRING

Go to 100 quickly and no oscillation

100: target value

quickly: high stiffness

no oscillation: low damping

👉 Motion graph

Easing

highly customisable
many existing easings
custom duration
easy to chain
playback control

Spring

two parameters
always feels natural
handles interruptions/changes

Tween.js

(or any other tweening lib)

// setup the animation loop
// (do it somewhere, but only once)
function animate(time) {
  requestAnimationFrame(animate)
  TWEEN.update(time)
}
requestAnimationFrame(animate)

const container = { x: 0 } // Tween modifies this
const tween = new TWEEN.Tween(container)
  .to({ x: 300 }, 1000) // change to 300 in 1s
  .easing(TWEEN.Easing.Quadratic.Out)
  .onUpdate(() => {
    // container.x is updated
  })
  .start() // Start the tween immediately.

Necessary boilerplate to create one single tween 😱

Tweening with

Vue tweezing

Easings controlled by scroll/Mouse

Using the scroll instead of time as input

👉 Easing with mouse

✨ Declarative Tweening

<Tweezing
  :to="1" tween="custom"
  :time="mouseYPer"
>
  <div slot-scope="value">
    <pre>{{ value }}</pre>
    <div class="ball" :style="ballStyle(value)">
    </div>
  </div>
</Tweezing>

Polygon example

Originally from docs

by @chrisvfritz

👉 Polygon

✨ Declarative Tweening

<Tweezing
  :to="stats"
  :duration="updateInterval"
  :easing="easing"
>
  <polygon
    slot-scope="pointsArray"
    :points="transformToPoints(pointsArray)"
  ></polygon>
</Tweezing>

Tweezing component

Watch target value ➡️ create Tween
Provide tweened value with a scoped slot

this.rotation // 10
this.rotation = 220
// triggers a new tweening

Tween engines

import {
  Tweezing,
  tweenjsHelper,
} from 'vue-tweezing'
import TWEEN from '@tweenjs/tween.js'

Vue.use(Tweezing, {
  tweenjs: tweenjsHelper(TWEEN),
})

Tween.js

export function tweenjsHelper (TWEEN) {
  return function (value, end, opts) {
    const container = { value }
    // cancel previous tween
    return new TWEEN.Tween(container)
      .to({ value: end }, opts.duration)
      .interpolation(opts.interpolation || TWEEN.Interpolation.Linear)
      .easing(opts.easing || TWEEN.Easing.Quadratic.Out)
    // TODO should probably emit the name of the property too
    // default could be the name if only one value is provided
      .onStart(() => this.$emit('start'))
      .onUpdate(() => {
        opts.$setValue(container.value)
      })
      .onComplete(() => this.$emit('end'))
      .start()
  }
}

Tweezing

🗜< 1kb

Springs

with

vue motion

svg Chart

Codepen

by @sarah_edo

👉 Plot

✨ Declarative Spring

<Motion tag="g" :values="selectedValues">
  <template slot-scope="values">
    <g v-for="(y, i) in values" class="bars">
      <rect
        :x="i * 10 + 20"
        :y="getMax - y * 10"
        width="10"
        :height="y * 10"
      />
    </g>
  </template>
</Motion>

Lazy sudoku example

Originally from docs

by @chrisvfritz

👉 Sudoku

Original

with springs

✨ Declarative Spring

<Motion :values="positions" spring="wobbly">
  <template slot-scope="positions">
    <div v-for="cell in cells"
      :style="{\
        transform: `translate(\
          ${positions[cell.id].x}px,\
          ${positions[cell.id].y}px)\
      `}"
    >
      {{ cell.number }}
    </div>
  </template>
</Motion>

Bonus

🔈 Sounds

🙉

Getting started

⚠️ vue-motion and vue-tweezing are experimental

🗣Feedback is very welcome!

Thanks! 🖖

@posva