SASS Mixins

_mixins.scss

@mixin flex($direction: center) {
  @include display(flex);
  @include align-items($direction);
  @include justify-content($direction);
}

.flex-center { @include flex(center);}
.flex-start  { @include flex(start);}
.flex-end    { @include flex(end);}

@mixin size($length: 32px) {
  height: $length;
  width: $length;
}

.16px{@include size(16px);}
.32px{@include size(32px);}
.128px{@include size(128px);}
.256px{@include size(256px);}

@mixin gradient($color: deeppink, $color1: dodgerblue, $direction: left){
  linear-gradient($color, $color1) $direction repeat);
}

@mixin transition ($args...) {
  -webkit-transition: $args;
  -moz-transition: $args;
  -o-transition: $args;
  transition: $args;
}
@mixin clearfix {
	&:after {
	  content: "";
	  display: table;
	  clear: both;
	}
}
@mixin vertical-align {
  position: relative;
  top: 50%;
  transform: translateY(-50%);
}

@include transition(color .3s ease, font-size .5s ease);

@function calculateRem($size) {
  $remSize: $size / 16px;
  @return $remSize * 1rem;
}

@mixin font-size($size) {
  font-size: $size;
  font-size: calculateRem($size);
}

@include font-size(14px);

// Flexbox Containers
//
// The 'flex' value causes an element to generate a block-level flex
// container box.
//
// The 'inline-flex' value causes an element to generate a inline-level
// flex container box.
//
// display: flex | inline-flex
//
// http://w3.org/tr/css3-flexbox/#flex-containers
//
// (Placeholder selectors for each type, for those who rather @extend)

@mixin flexbox {
	display: -webkit-box;
	display: -webkit-flex;
	display: -moz-flex;
	display: -ms-flexbox;
	display: flex;
}

%flexbox { @include flexbox; }

//----------------------------------

@mixin inline-flex {
	display: -webkit-inline-box;
	display: -webkit-inline-flex;
	display: -moz-inline-flex;
	display: -ms-inline-flexbox;
	display: inline-flex;
}

%inline-flex { @include inline-flex; }

//----------------------------------------------------------------------

// Flexbox Direction
//
// The 'flex-direction' property specifies how flex items are placed in
// the flex container, by setting the direction of the flex container's
// main axis. This determines the direction that flex items are laid out in.
//
// Values: row | row-reverse | column | column-reverse
// Default: row
//
// http://w3.org/tr/css3-flexbox/#flex-direction-property

@mixin flex-direction($value: row) {
	@if $value == row-reverse {
		-webkit-box-direction: reverse;
		-webkit-box-orient: horizontal;
	} @else if $value == column {
		-webkit-box-direction: normal;
		-webkit-box-orient: vertical;
	} @else if $value == column-reverse {
		-webkit-box-direction: reverse;
		-webkit-box-orient: vertical;
	} @else {
		-webkit-box-direction: normal;
		-webkit-box-orient: horizontal;
	}
	-webkit-flex-direction: $value;
	-moz-flex-direction: $value;
	-ms-flex-direction: $value;
	flex-direction: $value;
}
	// Shorter version:
	@mixin flex-dir($args...) { @include flex-direction($args...); }

//----------------------------------------------------------------------

// Flexbox Wrap
//
// The 'flex-wrap' property controls whether the flex container is single-line
// or multi-line, and the direction of the cross-axis, which determines
// the direction new lines are stacked in.
//
// Values: nowrap | wrap | wrap-reverse
// Default: nowrap
//
// http://w3.org/tr/css3-flexbox/#flex-wrap-property

@mixin flex-wrap($value: nowrap) {
	// No Webkit Box fallback.
	-webkit-flex-wrap: $value;
	-moz-flex-wrap: $value;
	@if $value == nowrap {
		-ms-flex-wrap: none;
	} @else {
		-ms-flex-wrap: $value;
	}
	flex-wrap: $value;
}

//----------------------------------------------------------------------

// Flexbox Flow (shorthand)
//
// The 'flex-flow' property is a shorthand for setting the 'flex-direction'
// and 'flex-wrap' properties, which together define the flex container's
// main and cross axes.
//
// Values: <flex-direction> | <flex-wrap>
// Default: row nowrap
//
// http://w3.org/tr/css3-flexbox/#flex-flow-property

@mixin flex-flow($values: (row nowrap)) {
	// No Webkit Box fallback.
	-webkit-flex-flow: $values;
	-moz-flex-flow: $values;
	-ms-flex-flow: $values;
	flex-flow: $values;
}

//----------------------------------------------------------------------

// Flexbox Order
//
// The 'order' property controls the order in which flex items appear within
// their flex container, by assigning them to ordinal groups.
//
// Default: 0
//
// http://w3.org/tr/css3-flexbox/#order-property

@mixin order($int: 0) {
	-webkit-box-ordinal-group: $int + 1;
	-webkit-order: $int;
	-moz-order: $int;
	-ms-flex-order: $int;
	order: $int;
}

//----------------------------------------------------------------------

// Flexbox Grow
//
// The 'flex-grow' property sets the flex grow factor. Negative numbers
// are invalid.
//
// Default: 0
//
// http://w3.org/tr/css3-flexbox/#flex-grow-property

@mixin flex-grow($int: 0) {
	-webkit-box-flex: $int;
	-webkit-flex-grow: $int;
	-moz-flex-grow: $int;
	-ms-flex-positive: $int;
	flex-grow: $int;
}

//----------------------------------------------------------------------

// Flexbox Shrink
//
// The 'flex-shrink' property sets the flex shrink factor. Negative numbers
// are invalid.
//
// Default: 1
//
// http://w3.org/tr/css3-flexbox/#flex-shrink-property

@mixin flex-shrink($int: 1) {
	-webkit-flex-shrink: $int;
	-moz-flex-shrink: $int;
	-ms-flex-negative: $int;
	flex-shrink: $int;
}

//----------------------------------------------------------------------

// Flexbox Basis
//
// The 'flex-basis' property sets the flex basis. Negative lengths are invalid.
//
// Values: Like "width"
// Default: auto
//
// http://www.w3.org/TR/css3-flexbox/#flex-basis-property

@mixin flex-basis($value: auto) {
	-webkit-flex-basis: $value;
	-moz-flex-basis: $value;
	-ms-flex-preferred-size: $value;
	flex-basis: $value;
}

//----------------------------------------------------------------------

// Flexbox "Flex" (shorthand)
//
// The 'flex' property specifies the components of a flexible length: the
// flex grow factor and flex shrink factor, and the flex basis. When an
// element is a flex item, 'flex' is consulted instead of the main size
// property to determine the main size of the element. If an element is
// not a flex item, 'flex' has no effect.
//
// Values: none | <flex-grow> <flex-shrink> || <flex-basis>
// Default: See individual properties (1 1 0).
//
// http://w3.org/tr/css3-flexbox/#flex-property

@mixin flex($fg: 1, $fs: null, $fb: null) {

	// Set a variable to be used by box-flex properties
	$fg-boxflex: $fg;

	// Box-Flex only supports a flex-grow value so let's grab the
	// first item in the list and just return that.
	@if type-of($fg) == 'list' {
		$fg-boxflex: nth($fg, 1);
	}

	-webkit-box-flex: $fg-boxflex;
	-webkit-flex: $fg $fs $fb;
	-moz-box-flex: $fg-boxflex;
	-moz-flex: $fg $fs $fb;
	-ms-flex: $fg $fs $fb;
	flex: $fg $fs $fb;
}

//----------------------------------------------------------------------

// Flexbox Justify Content
//
// The 'justify-content' property aligns flex items along the main axis
// of the current line of the flex container. This is done after any flexible
// lengths and any auto margins have been resolved. Typically it helps distribute
// extra free space leftover when either all the flex items on a line are
// inflexible, or are flexible but have reached their maximum size. It also
// exerts some control over the alignment of items when they overflow the line.
//
// Note: 'space-*' values not supported in older syntaxes.
//
// Values: flex-start | flex-end | center | space-between | space-around
// Default: flex-start
//
// http://w3.org/tr/css3-flexbox/#justify-content-property

@mixin justify-content($value: flex-start) {
	@if $value == flex-start {
		-webkit-box-pack: start;
		-ms-flex-pack: start;
	} @else if $value == flex-end {
		-webkit-box-pack: end;
		-ms-flex-pack: end;
	} @else if $value == space-between {
		-webkit-box-pack: justify;
		-ms-flex-pack: justify;
	} @else if $value == space-around {
		-ms-flex-pack: distribute;
	} @else {
		-webkit-box-pack: $value;
		-ms-flex-pack: $value;
	}
	-webkit-justify-content: $value;
	-moz-justify-content: $value;
	justify-content: $value;
}
	// Shorter version:
	@mixin flex-just($args...) { @include justify-content($args...); }

//----------------------------------------------------------------------

// Flexbox Align Items
//
// Flex items can be aligned in the cross axis of the current line of the
// flex container, similar to 'justify-content' but in the perpendicular
// direction. 'align-items' sets the default alignment for all of the flex
// container's items, including anonymous flex items. 'align-self' allows
// this default alignment to be overridden for individual flex items. (For
// anonymous flex items, 'align-self' always matches the value of 'align-items'
// on their associated flex container.)
//
// Values: flex-start | flex-end | center | baseline | stretch
// Default: stretch
//
// http://w3.org/tr/css3-flexbox/#align-items-property

@mixin align-items($value: stretch) {
	@if $value == flex-start {
		-webkit-box-align: start;
		-ms-flex-align: start;
	} @else if $value == flex-end {
		-webkit-box-align: end;
		-ms-flex-align: end;
	} @else {
		-webkit-box-align: $value;
		-ms-flex-align: $value;
	}
	-webkit-align-items: $value;
	-moz-align-items: $value;
	align-items: $value;
}

//----------------------------------

// Flexbox Align Self
//
// Values: auto | flex-start | flex-end | center | baseline | stretch
// Default: auto

@mixin align-self($value: auto) {
	// No Webkit Box Fallback.
	-webkit-align-self: $value;
	-moz-align-self: $value;
	@if $value == flex-start {
		-ms-flex-item-align: start;
	} @else if $value == flex-end {
		-ms-flex-item-align: end;
	} @else {
		-ms-flex-item-align: $value;
	}
	align-self: $value;
}

//----------------------------------------------------------------------

// Flexbox Align Content
//
// The 'align-content' property aligns a flex container's lines within the
// flex container when there is extra space in the cross-axis, similar to
// how 'justify-content' aligns individual items within the main-axis. Note,
// this property has no effect when the flexbox has only a single line.
//
// Values: flex-start | flex-end | center | space-between | space-around | stretch
// Default: stretch
//
// http://w3.org/tr/css3-flexbox/#align-content-property

@mixin align-content($value: stretch) {
	// No Webkit Box Fallback.
	-webkit-align-content: $value;
	-moz-align-content: $value;
	@if $value == flex-start {
		-ms-flex-line-pack: start;
	} @else if $value == flex-end {
		-ms-flex-line-pack: end;
	} @else {
		-ms-flex-line-pack: $value;
	}
	align-content: $value;
}


/****************************
 HIGH PPI DISPLAY BACKGROUNDS
*****************************/

@mixin background-2x($path, $ext: "png", $w: auto, $h: auto, $pos: left top, $repeat: no-repeat) {

  $at1x_path: "#{$path}.#{$ext}";
  $at2x_path: "#{$path}@2x.#{$ext}";

  background-image: url("#{$at1x_path}");
  background-size: $w $h;
  background-position: $pos;
  background-repeat: $repeat;

  @media all and (-webkit-min-device-pixel-ratio : 1.5),
  all and (-o-min-device-pixel-ratio: 3/2),
  all and (min--moz-device-pixel-ratio: 1.5),
  all and (min-device-pixel-ratio: 1.5) {
    background-image: url("#{$at2x_path}");
  }
}