Keyframes

Keyframes allows dynamic generation of CSS keyframes with callback events and other niceness.

Overview

CSS3 introduced fancy features like transformations, translations, rotations and scaling. Keyframes allows you to manage and execute animations using Javascript.

Installation

Install from npm:

npm install @keyframes/core --save

Import into your project using the following line:

import Keyframes from '@keyframes/core';

Be sure to define and play animations after the page has loaded by including your script tag at the bottom of the document or using window.onload.

Usage

Detecting CSS animation support

var supportedFlag = Keyframes.isSupported();

Adding a new animation sequence (keyframe)

Keyframes.define([{
    name: 'trapdoor-sequence',
    '0%': {'height': '70px'},
    '30%': {'height': '10px'},
    '60%': {'height': '30px'},
    '100%': {'height': '10px'}
}]);

Adding a single frame style

Keyframes.define({
    name: 'ball-roll',
    from: {
        'transform': 'rotate(0deg)' //Note that 'transform' will be autoprefixed for you
    },
    to: {
        'transform': 'rotate(360deg)' //Note that 'transform' will be autoprefixed for you
    }
});

Adding multiple frame styles

Keyframes.define([{
	name: 'roll-clockwise',
	'0%': {
	    'margin-left' : '0px',
	    'background-color' : 'red',
	    'transform' : 'rotate(0deg)'
	},
	'100%': {
	    'margin-left' : '600px',
	    'transform' : 'rotate(360deg)'
	}
    },{
	name: 'roll-anti-clockwise',
	'0%': {
	    'margin-left' : '0px',
	    'background-color' : 'red',
	    'transform' : 'rotate(0deg)'
	},
	'100%': {
	    'margin-left' : '600px',
	    'transform' : 'rotate(-360deg)'
	}
    }
]);

Adding styles and properties in array fashion

Gives resemblance to CSS styling definitions

var shake_start = {'transform': 'translate(0px)'};
var shake_odd1 = {'transform': 'translate(-10px, -10px)'};
var shake_even1 = {'transform': 'translate(10px, 10px)'};
var shake_odd2 = {'transform': 'translate(10px, -10px)'};
var shake_even2 = {'transform': 'translate(-10px, 10px)'};

Keyframes.define([{
	name: 'crazy',
	'0%': shake_start,
	'10%': shake_odd2,
	'20%': shake_even1,
	'30%': shake_odd2,
	'40%': shake_even2,
	'50%': shake_odd2,
	'60%': shake_even1,
	'70%': shake_odd1,
	'80%': shake_even2,
	'90%': shake_odd1
    }
]);

Please note, you can add as many properties to the array as you want to

Responsive animations

Keyframes.define([{
    name: 'roll-clockwise',
    media: 'screen and (max-width: 700px)',
    from: {
        'margin-left' : '0px'
    },
    to: {
        'margin-left' : '600px'
    }
    }
]);

Playing an animation

First we must create an instance of a keyframe.

const ball = new Keyframes(document.getElementById('ball'));

The css3 animation methods available are better documented here: http://www.w3schools.com/css/css3_animations.asp

ball.play({
    name: 'trapdoor-sequence', // name of the keyframe you want to bind to the selected element
    duration: '1s', // [optional, default: 0, in ms] how long you want it to last in milliseconds
    timingFunction: 'linear', // [optional, default: ease] specifies the speed curve of the animation
    delay: '0s', //[optional, default: 0s]  how long you want to wait before the animation starts
    iterationCount: 'infinite', //[optional, default:1]  how many times you want the animation to repeat
    direction: 'normal', //[optional, default: 'normal']  which direction you want the frames to flow
    fillMode: 'forwards', //[optional, default: 'forward']  how to apply the styles outside the animation time, default value is forwards
    complete: function(){} //[optional] Function fired after the animation is complete. If repeat is infinite, the function will be fired every time the animation is restarted.
});

Playing an animation (shorthand)

ball.play(
    'trapdoor-sequence 1s linear 0s infinite normal forwards',
    complete
);

Playing multiple animations

ball.play([
    'trapdoor-sequence 1s linear 0s infinite',
    {
      name: 'ball-roll',
      duration: "3s",
      timingFunction: 'ease',
      iterationCount: 1
    }
], complete);

Reset the animation

ball.reset(callback);

Freeze keyframe animation and kill callbacks

ball.pause();

Resume keyframe animation

ball.resume();

Want more control?

Generate the defined keyframes css

let css = Keyframes.defineCSS({
    name: 'ball-spin',
    from: {
        transform: 'rotate(90deg)',
    },
    to: {
        transform: 'rotate(450deg)',
    },
}); // "@keyframes ball-spin {from {transform:rotate(90deg);}to {transform:rotate(450deg);}"

Generate the "animation" rule's value (play)

const css = Keyframes.playCSS({
    name: 'ball-spin',
    duration: '1s',
    iterationCount: 1
}); // "ball-spin 1s ease 0s 1 normal forwards"

Plugins!

Installing a plugin is simple...

import Pathfinder from '@keyframes/pathfinder';
Keyframes.plugin(Pathfinder); // You can also pass an array of plugins for convenience.

See other plugins that allow for spritesheets & more complex movement paths: https://github.com/Keyframes

Changelog

1.1.1

Reset now uses requestAnimationFrame instead of timeouts.
Allow an array of plugins to be added
Code reduction. 1.1.0
Use insertRule to add keyframes to a single style tag in the header. 1.0.7
Add playCSS and defineCSS generation functions 1.0.3
Make it a module
Add plugin function 1.0.0
Vanilla project initiated