Animations

Jesús López

Animations

Basics

Use the mui-animation mixin to create CSS keyframe animations. The mixin accepts a keyframe function, like this:

.spin-cw {
  @include mui-animation(spin(in, 360deg));
}

The CSS output looks like this:

@keyframes spin-cw-360deg {
  0% {
    transform: rotate(0deg); }
  100% {
    transform: rotate(360deg); }
}

.spin-cw {
  animation-name: spin-cw-360deg;
}

Note that in order to play properly, the element must have at least the property animation-duration applied to it as well.

There are seven keyframe functions:

  • fade($from, $to)
  • hinge($state, $from, $axis, $perspective, $turn-origin)
  • shake($intensity)
  • slide($state, $direction, $amount)
  • spin($state, $direction, $amount)
  • wiggle($intensity)
  • zoom($from, $to)

All keyframe functions have parameters that customize the effect. For example, with shake() and wiggle() you can set the intensity of the effect, and with spin() you can set how many degrees the spin goes.

If you’re using a keyframe effect as-is, it can be inserted as a plain string instead of a function call, like so:

.zoom-in { @include mui-animation(zoom); }

Combination Effects

Multiple keyframe effects can be combined into one. For example, you can combine a fade, slide, and spin into one animation, for something truly monstrous.

To create a combined effect, just add more keyframe functions to the mui-animation mixin, as additional parameters.

.slide-and-fade-and-spin {
  @include mui-animation(slide, fade, spin(120deg));
}

Note that this doesn’t work with the shake() or wiggle() animations. Only animations with single start and end keyframes can be combined.

Series Animations

Multiple elements can be animated in series.

To set it up, make sure each animating element shares a common parent.

<div class="animation-wrapper">
  <div class="shake"></div>
  <div class="spin"></div>
  <div class="wiggle"></div>
</div>

Begin your series with the mui-series() mixin. Inside this mixin, attach animations to classes with the mui-queue() mixin. The first parameter is the length of the animation, the second parameter is an optional pause to create before the next animation, and the remaining parameters are a set of keyframe functions.

@include mui-series {
  // 2 second shake
  .shake    { @include mui-queue(2s, 0s, shake); }
  // 1 second spin with a 2 second pause
  .spin     { @include mui-queue(1s, 2s, spin); }
  // 1 second zoom and fade
  .fade-zoom { @include mui-queue(1s, 0s, fade, zoom); }
}

To add a delay to the start of the queue, add the length in seconds to the mui-series mixin.

// 2 second delay before the first shake
@include mui-series(2s) {
  .shake  { @include mui-queue(2s, 0s, shake()); }
  .spin   { @include mui-queue(1s, 2s, spin()); }
  .wiggle { @include mui-queue(wiggle); }
}

To trigger the queue, add the class .is-animating to the parent container. This can be done easily in JavaScript:

// Plain JavaScript (IE10+)
document.querySelector('.animation-wrapper').classList.add('is-animating');

// jQuery
$('.animation-wrapper').addClass('is-animating');

Mixins

mui-animation()

Creates a keyframe from one or more effect functions and assigns it to the element by adding the animation-name property.

Parameters:

  • effects... (Function) - One or more effect functions to build the keyframe with.

mui-keyframes()

Creates a keyframe from one or more effect functions. Use this function instead of mui-animation if you want to create a keyframe animation without automatically assigning it to the element.

Parameters:

  • name (String) - Name of the keyframe.
  • effects... (Function) - One or more effect functions to build the keyframe with.

mui-series()

Creates a new animation queue.

Parameters:

  • delay (Duration) - Delay in seconds or milliseconds to place at the front of the animation queue. (Default: 0s)

mui-queue()

Adds an animation to an animation queue. Only use this mixin inside of mui-series().

Parameters:

  • duration (Duration) - Length of the animation. (Default: 1s)
  • gap (Duration) - Amount of time to pause before playing the animation after this one. Use a negative value to make the next effect overlap with the current one. (Default: 0s)
  • keyframes... (Function) - One or more effect functions to build the keyframe with.

Functions

fade()

Creates a fading animation.

Parameters:

  • from (Number) - Opacity to start at. (Default: 0)
  • to (Number) - Opacity to end at. (Default: 1)

hinge()

Creates a hinge effect by rotating the element.

Parameters:

  • state (Keyword) - State to transition to. (Default: in)
  • from (Keyword) - Edge of the element to rotate from. Can be top, right, bottom, or left. (Default: left)
  • axis (Keyword) - Axis of the element to rotate on. Can be edge or center. (Default: edge)
  • perspective (Number) - Perceived distance between the viewer and the element. A higher number will make the rotation effect more pronounced. (Default: 2000px)
  • turn-origin (Keyword) - Side of the element to start the rotation from. Can be from-back or from-front. (Default: from-back)

shake()

Creates a shaking animation.

Parameters:

  • intensity (Percentage) - Intensity of the shake, as a percentage value. (Default: 7%)

slide()

Creates a sliding animation.

Parameters:

  • state (Keyword) - Whether to move to (in) or from (out) the element’s default position. (Default: in)
  • direction (Keyword) - Direction to move. Can be up, down, left, or right. (Default: up)
  • amount (Number) - Distance to move. Can be any CSS length unit. (Default: 100%)

spin()

Creates a spinning animation.

Parameters:

  • direction (Keyword) - Direction to spin. Should be cw (clockwise) or ccw (counterclockwise). (Default: cw)
  • amount (Number) - Amount to spin. Can be any CSS angle unit. (Default: 360deg)

wiggle()

Creates a wiggling animation.

Parameters:

  • intensity (Number) - Intensity of the wiggle. Can be any CSS angle unit. (Default: 7deg)

zoom()

Creates a scaling transition. A scale of 1 means the element is the same size. Larger numbers make the element bigger, while numbers less than 1 make the element smaller.

Parameters:

  • from (Number) - Size to start at. (Default: 1.5)
  • from (Number) - Size to end at. (Default: 1)