@cheprasov/web-animation

@cheprasov/web-animation v0.1.0

Simple class WebAnimation for perform an animation on the web via JavaScript. It is based on requestAnimationFrame for performance.

Features:

• Based on requestAnimationFrame for performance.
• It allows to use any functions fo easing.
• Easy to use for looped animation.

1. How to install

> npm install @cheprasov/web-animation

2. Quick examples

Example 1: Moving div to left on 500px for 2 sec with easing f(x) = n^2.

import WebAnimation from 'js-web-animation';

const div1 = document.getElementById('div1');

const animation = new WebAnimation({
    duration: 2000,
    easing: n => n ** 2,
});

const move = 500;

animation.setOnStep((progress) => {
    const shiftX = progress.tween * move;
    div1.style.transform = `translate3d(${shiftX}px, 0, 0)`;
});

animation.setOnFinish(() => {
    div1.style.transform = 'none';
    div1.style.left = `${move}px`;
});

animation.run();

3. Documentation

constructor ( options = {...} )

• duration: number, optional, default = 1000. Duration time (ms) for animation.

• easing: function, optional, default = (n => n). Easing function for animation tween. Arguments:

  • ratio: number - Ratio of elapsedTime / duration

  Returns number. Return of the function will be used like tween for animation progress.

• rAF: function, optional, default = window.requestAnimationFrame. Function for animation tick. Arguments:

  • function - the functions which should be called on animation tick.

• onStep: function, optional, default = null. Function will be called on each animation step. Arguments:

  • progress - object with progress state of animation (see more below).
  • animation - link to instance of WebAnimation class.

• onStop: function, optional, default = null. Function will be called when animation terminated by call stop() method. Arguments:

  • progress - object with progress state of animation (see more below).
  • animation - link to instance of WebAnimation class.

• onFinish: function, optional, default = null. Function will be called when animation is finished. Arguments:

  • progress - object with progress state of animation (see more below).
  • animation - link to instance of WebAnimation class.

Example:

const options = {
    duration: 2000,
    easing: n => n ** 2,
    onStep: (progress) => {
        someDiv.style.opacity = progress.tween;
    },
    onFinish: (progress) => {
        someDiv.style.display = 'none';
    },
};

const animation = new WebAnimation(options);

Object progress for onStep, onStop, onFinish methods

• elapsedTime: number - Elapsed time
• ratio: number - Ratio of elapsed time / duration. 0 <= n <= 1
• tween: number - Tween value for animation. tween = easing(ratio)
• isFinished: boolean - Is animation finished?

Example:

{
    elapsedTime: 1000,
    ratio: 0.2,
    tween: 0.04,
    isFinished: false,
}

run()

Method run to perform animation.

const animation = new WebAnimation();
animation.run();

stop()

Method run to stop animation. It will call onStop callback;

const animation = new WebAnimation({
    duration: 1000,
    onStop: (progress) => {
        console.log('Animation progress', progress);    
    },
});

animation.run();

setTimeout(() => {
    animation.stop();
}, 500);

setOnStop(function)

Setter for onStop callback.

animation.setOnStop((progress, animation) => {
    console.log('Animation is stopped');
})

setOnStep(function)

Setter for onStep callback.

animation.setOnStep((progress, animation) => {
    console.log('Animation step');
})

setOnFinish(function)

Setter for onFinish callback.

animation.setOnFinish((progress, animation) => {
    console.log('Animation is finished');
})

getProgress(): progress

Get progress state of animation. See progress object above.

setTimeout(() => {
    console.log('Animation progress', animation.getProgress());
}, 100);

Something does not work

Feel free to fork project, fix bugs, tests and finally request for pull