_mixins.scss

/**
 * Breakpoint mixins
 */

@mixin break-huge() {
	@media (min-width: #{ ($break-huge) }) {
		@content;
	}
}

@mixin break-wide() {
	@media (min-width: #{ ($break-wide) }) {
		@content;
	}
}

@mixin break-xlarge() {
	@media (min-width: #{ ($break-xlarge) }) {
		@content;
	}
}

@mixin break-large() {
	@media (min-width: #{ ($break-large) }) {
		@content;
	}
}

@mixin break-medium() {
	@media (min-width: #{ ($break-medium) }) {
		@content;
	}
}

@mixin break-small() {
	@media (min-width: #{ ($break-small) }) {
		@content;
	}
}

@mixin break-mobile() {
	@media (min-width: #{ ($break-mobile) }) {
		@content;
	}
}

@mixin break-zoomed-in() {
	@media (min-width: #{ ($break-zoomed-in) }) {
		@content;
	}
}


/**
 * Long content fade mixin
 *
 * Creates a fading overlay to signify that the content is longer
 * than the space allows.
 */

@mixin long-content-fade($direction: right, $size: 20%, $color: #fff, $edge: 0, $z-index: false) {
	content: "";
	display: block;
	position: absolute;
	-webkit-touch-callout: none;
	-webkit-user-select: none;
	-khtml-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
	pointer-events: none;

	@if $z-index {
		z-index: $z-index;
	}

	@if $direction == "bottom" {
		background: linear-gradient(to top, rgba($color, 0), $color 90%);
		left: $edge;
		right: $edge;
		top: $edge;
		bottom: calc(100% - $size);
		width: auto;
	}

	@if $direction == "top" {
		background: linear-gradient(to bottom, rgba($color, 0), $color 90%);
		top: calc(100% - $size);
		left: $edge;
		right: $edge;
		bottom: $edge;
		width: auto;
	}

	@if $direction == "left" {
		background: linear-gradient(to left, rgba($color, 0), $color 90%);
		top: $edge;
		left: $edge;
		bottom: $edge;
		right: auto;
		width: $size;
		height: auto;
	}

	@if $direction == "right" {
		background: linear-gradient(to right, rgba($color, 0), $color 90%);
		top: $edge;
		bottom: $edge;
		right: $edge;
		left: auto;
		width: $size;
		height: auto;
	}
}

/**
 * Button states and focus styles
 */

// Buttons with rounded corners.
@mixin button-style__disabled {
	opacity: 0.6;
	cursor: default;
}

@mixin button-style__active() {
	outline: none;
	background-color: $white;
	color: $dark-gray-900;
	box-shadow: inset 0 0 0 1px $light-gray-700, inset 0 0 0 2px $white;
}

@mixin button-style__focus-active() {
	box-shadow: 0 0 0 1px color($theme-color);

	// Windows High Contrast mode will show this outline, but not the box-shadow.
	outline: 1px solid transparent;
}

// Switch.
@mixin switch-style__focus-active() {
	box-shadow: 0 0 0 2px $white, 0 0 0 3px $dark-gray-300;

	// Windows High Contrast mode will show this outline, but not the box-shadow.
	outline: 2px solid transparent;
	outline-offset: 2px;
}


/**
 * Block Toolbar/Formatting Buttons
 */

@mixin block-toolbar-button-style__focus() {
	box-shadow: inset 0 0 0 2px color($theme-color), inset 0 0 0 4px $white; // Inner halo makes this work on top of a toggled button.
	outline: 2px solid transparent; // Shown to Windows 10 High Contrast Mode.
}


// Tabs, Inputs, Square buttons.
@mixin input-style__neutral() {
	box-shadow: 0 0 0 transparent;
	transition: box-shadow 0.1s linear;
	border-radius: $radius-round-rectangle;
	border: $border-width solid $dark-gray-200;
	@include reduce-motion("transition");
}

@mixin input-style__focus() {
	color: $dark-gray-900;
	border-color: $blue-medium-focus;
	box-shadow: 0 0 0 1px $blue-medium-focus;

	// Windows High Contrast mode will show this outline, but not the box-shadow.
	outline: 2px solid transparent;
}

// Square buttons.
@mixin square-style__neutral() {
	outline-offset: -1px;
}

@mixin square-style__focus() {
	color: $dark-gray-900;
	outline-offset: -1px;
	outline: 1px dotted $dark-gray-500;
}

// Menu items.
@mixin menu-style__neutral() {
	border: none;
	box-shadow: none;
}

@mixin menu-style__hover() {
	color: $dark-gray-900;
	border: none;
	box-shadow: none;
	background: $light-gray-200;
}

@mixin menu-style__focus() {
	color: $dark-gray-900;
	border: none;
	box-shadow: none;
	outline-offset: -2px;
	outline: 1px dotted $dark-gray-500;
}

// Blocks in the Library.
@mixin block-style__disabled {
	opacity: 0.6;
	cursor: default;
}

@mixin block-style__hover {
	border-color: $theme-color;
	color: $theme-color !important;
}

@mixin block-style__focus() {
	box-shadow: inset 0 0 0 1px $white, 0 0 0 2px $theme-color;

	// Windows High Contrast mode will show this outline, but not the box-shadow.
	outline: 2px solid transparent;
}

@mixin block-style__is-active() {
	color: $white;
	background: $dark-gray-primary;

	// Windows High Contrast mode will show this outline, but not the box-shadow.
	outline: 2px solid transparent;
	outline-offset: -2px;
}


/**
 * Applies editor left position to the selector passed as argument
 */

@mixin editor-left($selector) {
	#{$selector} { /* Set left position when auto-fold is not on the body element. */
		left: 0;

		@include break-medium() {
			left: $admin-sidebar-width;
		}
	}

	.auto-fold #{$selector} { /* Auto fold is when on smaller breakpoints, nav menu auto collapses. */
		@include break-medium() {
			left: $admin-sidebar-width-collapsed;
		}

		@media (min-width: #{ ($break-large + 1) }) {
			left: $admin-sidebar-width;
		}
	}

	/* Sidebar manually collapsed. */
	.folded #{$selector} {
		left: 0;

		@include break-medium() {
			left: $admin-sidebar-width-collapsed;
		}
	}

	/* Mobile menu opened. */
	@media (max-width: #{ ($break-medium) }) {
		.auto-fold .wp-responsive-open #{$selector} {
			left: $admin-sidebar-width-big;
		}
	}

	/* In small screens with responsive menu expanded there is small white space. */
	@media (max-width: #{ ($break-small) }) {
		.auto-fold .wp-responsive-open #{$selector} {
			margin-left: -18px;
		}
	}

	body.is-fullscreen-mode #{$selector} {
		left: 0 !important;
	}
}

/**
 * Styles that are reused verbatim in a few places
 */

// These are additional styles for all captions, when the theme opts in to block styles.
@mixin caption-style() {
	margin-top: 0.5em;
	margin-bottom: 1em;
}

@mixin caption-style-theme() {
	color: $dark-gray-500;
	font-size: $default-font-size;
	text-align: center;
}


/**
 * Allows users to opt-out of animations via OS-level preferences.
 */

@mixin reduce-motion($property: "") {

	@if $property == "transition" {
		@media (prefers-reduced-motion: reduce) {
			transition-duration: 0s;
		}
	}

	@else if $property == "animation" {
		@media (prefers-reduced-motion: reduce) {
			animation-duration: 1ms;
		}
	}

	@else {
		@media (prefers-reduced-motion: reduce) {
			transition-duration: 0s;
			animation-duration: 1ms;
		}
	}

}

/**
 * Reset default styles for JavaScript UI based pages.
 * This is a WP-admin agnostic reset
 */
@mixin reset {
	box-sizing: border-box;

	*,
	*::before,
	*::after {
		box-sizing: inherit;
	}

	.input-control, // Upstream name is `.regular-text`.
	input[type="text"],
	input[type="search"],
	input[type="radio"],
	input[type="tel"],
	input[type="time"],
	input[type="url"],
	input[type="week"],
	input[type="password"],
	input[type="checkbox"],
	input[type="color"],
	input[type="date"],
	input[type="datetime"],
	input[type="datetime-local"],
	input[type="email"],
	input[type="month"],
	input[type="number"],
	select,
	textarea {
		font-family: $default-font;
		padding: 6px 8px;
		@include input-style__neutral();

		/* Fonts smaller than 16px causes mobile safari to zoom. */
		font-size: $mobile-text-min-font-size;
		/* Override core line-height. To be reviewed. */
		line-height: normal;
		@include break-small {
			font-size: $default-font-size;
			/* Override core line-height. To be reviewed. */
			line-height: normal;
		}

		&:focus {
			@include input-style__focus();
		}
	}

	input[type="number"] {
		padding-left: 4px;
		padding-right: 4px;
	}

	select {
		padding: 3px 24px 3px 8px;
		font-size: $default-font-size;
		color: $dark-gray-500;

		&:focus {
			border-color: $blue-medium-600;
			// Windows High Contrast mode will show this outline
			outline: 2px solid transparent;
			outline-offset: 0;
		}
	}

	input[type="checkbox"],
	input[type="radio"] {
		border: $border-width + 1 solid $medium-gray-text;
		margin-right: $grid-unit-15;
		transition: none;

		&:focus {
			border-color: $medium-gray-text;
			box-shadow: 0 0 0 1px $medium-gray-text;
		}

		&:checked {
			background: theme(toggle);
			border-color: theme(toggle);
		}

		&:checked:focus {
			box-shadow: 0 0 0 2px $medium-gray-text;
		}
	}

	input[type="checkbox"] {
		border-radius: $radius-block-ui;

		&:checked::before,
		&[aria-checked="mixed"]::before {
			margin: -3px -5px;
			color: $white;

			@include break-medium() {
				margin: -4px 0 0 -5px;
			}
		}

		&[aria-checked="mixed"] {
			background: theme(toggle);
			border-color: theme(toggle);

			&::before {
				// Inherited from `forms.css`.
				// See: https://github.com/WordPress/wordpress-develop/tree/5.1.1/src/wp-admin/css/forms.css#L122-L132
				content: "\f460";
				float: left;
				display: inline-block;
				vertical-align: middle;
				width: 16px;
				/* stylelint-disable */
				font: normal 30px/1 dashicons;
				/* stylelint-enable */
				speak: none;
				-webkit-font-smoothing: antialiased;
				-moz-osx-font-smoothing: grayscale;

				@include break-medium() {
					float: none;
					font-size: 21px;
				}
			}

			&:focus {
				box-shadow: 0 0 0 2px $dark-gray-500;
			}
		}
	}

	// We provide explicit pixel dimensions to ensure a crisp appearance.
	// This radio button style should be ported upstream.
	input[type="radio"] {
		border-radius: $radius-round;

		&:checked::before {
			width: 6px;
			height: 6px;
			margin: 6px 0 0 6px;
			background-color: $white;

			@include break-medium() {
				margin: 3px 0 0 3px;
			}
		}
	}

	// Placeholder colors
	input,
	textarea {
		// Use opacity to work in various editor styles.
		&::-webkit-input-placeholder {
			color: $dark-opacity-300;
		}

		&::-moz-placeholder {
			opacity: 1; // Necessary because Firefox reduces this from 1.
			color: $dark-opacity-300;
		}

		&:-ms-input-placeholder {
			color: $dark-opacity-300;
		}

		.is-dark-theme & {
			&::-webkit-input-placeholder {
				color: $light-opacity-300;
			}

			&::-moz-placeholder {
				opacity: 1; // Necessary because Firefox reduces this from 1.
				color: $light-opacity-300;
			}

			&:-ms-input-placeholder {
				color: $light-opacity-300;
			}
		}
	}
}

/**
 * Reset the WP Admin page styles for Gutenberg-like pages.
 */
@mixin wp-admin-reset( $content-container ) {
	background: $white;

	#wpcontent {
		padding-left: 0;
	}

	#wpbody-content {
		padding-bottom: 0;
	}

	/* We hide legacy notices in Gutenberg Based Pages, because they were not designed in a way that scaled well.
	   Plugins can use Gutenberg notices if they need to pass on information to the user when they are editing. */
	#wpbody-content > div:not(#{ $content-container }):not(#screen-meta) {
		display: none;
	}

	#wpfooter {
		display: none;
	}

	.a11y-speak-region {
		left: -1px;
		top: -1px;
	}

	ul#adminmenu a.wp-has-current-submenu::after,
	ul#adminmenu > li.current > a.current::after {
		border-right-color: $white;
	}

	.media-frame select.attachment-filters:last-of-type {
		width: auto;
		max-width: 100%;
	}
}