@material/elevation

Elevation

Shadows provide important visual cues about objects’ depth and directional movement. They are the only visual cue indicating the amount of separation between surfaces. An object’s elevation determines the appearance of its shadow. The elevation values are mapped out in a "z-space" and range from 0 to 24.

A note about "z-space": Within the spec, elevation is normally referred to as having a dp value. In other words, how many "pixels" above the base material is a piece of material elevated. On a computer, this is normally represented by a 3-d coordinate system. We like z-space (or just "z" for short) because it aligns with the technical definition of, and nomenclature for, a 3-d coordinate system. Therefore, we feel it makes more sense than dp. However, when we refer to z-space (or z), that can be used interchangeably with the spec's dp.

Design & API Documentation

• Material Design guidelines: Shadows & elevation
• Demo

Installation

npm install @material/elevation

Basic Usage

HTML

Elevation is often already included within the baseline styles of other components (e.g. raised buttons, elevated cards).

However, you can also apply elevation to specific components using mdc-elevation--z<N> classes:

  <div class="mdc-elevation--z1">
    <!-- ... content ... -->
  </div>

Elevation Overlay

The elevation overlay should appear above the component container in the stacking context but below the ripple. To accomplish this, the .mdc-elevation-overlay element should appear before the .mdc-<component>__ripple element in the DOM context. Here's sample markup for a button with a touch target.

<button class="mdc-button mdc-button--raised">
  <div class="mdc-elevation-overlay"></div>
  <div class="mdc-button__ripple"></div>
  <i class="material-icons mdc-button__icon" aria-hidden="true">favorite</i>
  <span class="mdc-button__label">Font Icon</span>
</button>

This ensures the ripple parts are rendered above the overlay.

Styles

@use "@material/elevation/mdc-elevation";

Style Customization

CSS Classes

Some components have a set elevation. For example, a raised MDC Button has elevation 2.

If you want to set the elevation of an element, which is not a Material Design component, you can apply the following CSS classes.

CSS Class	Description
mdc-elevation--z<N>	Sets the elevation to the (N)dp, where 1 <= N <= 24
mdc-elevation-transition	Applies the correct css rules to transition an element between elevations

Sass Mixins, Variables, Functions, and Custom Properties

Mixin	Description
elevation($z-value, $color, $opacity-boost)	Sets the elevation to the z-space for that given elevation, and optionally sets the color and/or boosts the opacity of the shadow
overlay-common	Called once per application to setup the universal elevation overlay styles
shadow($box-shadow)	Sets the box-shadow of the closest parent selector
overlay-surface-position	Sets the positioning of the overlay's surface element so that the overlay can be appropriately centered
overlay-dimensions($width, $height: $width, $has-content-sizing: true)	Sets the dimensions of the elevation overlay
overlay-fill-color($color)	Sets the color of the elevation overlay
overlay-opacity($opacity)	Sets the opacity of the elevation overlay

Function	Description
transition-value($duration, $easing)	Returns a value for the transition property to transition an element between elevations
overlay-transition-value($duration, $easing)	Returns a value for the transition property to transition the elevation overlay between elevations
elevation-box-shadow($z-value, $color, $opacity-boost)	Returns the box-shadow for the elevation z-space for that given elevation z-value, and optionally sets the color and/or boosts the opacity of the shadow

Variable	Description
$property	Default property for elevation transitions
$transition-duration	Default duration value for elevation transitions
$transition-timing-function	Default easing value for elevation transitions
$overlay-color	Default color for the elevation overlay
$overlay-property	Default property for the elevation overlay transitions

If you need more configurability over your transitions, use the transition-value function in conjunction with the exported sass variables.

Custom Property | Default value | Description --- | --- --mdc-elevation-overlay-opacity | 0 | The opacity of the elevation overlay. --mdc-elevation-overlay-fill-color | #fff | The color of the elevation overlay

If you need more configurability over your transitions, use the transition-value function in conjunction with the exported sass variables.

@use "@material/elevation";

.my-component-with-custom-transitions {

  transition:
    elevation.transition-value(),
    /* Configure opacity to use same duration and easing values as elevation */
    opacity elevation.$transition-duration elevation.$transition-timing-function;
  opacity: .7;
  will-change: elevation.$property, opacity;
}

Changelog

14.0.0 (2022-04-27)

Bug Fixes

• button: update HCM shim to use the existing focus-ring (a657abb)
• checkbox: Add explicit system color for checkmark in HCM. (8c4da22)
• checkbox: move forced-colors theme out of static styles (bbd1126)
• checkbox: Update checkbox theme styles mixin to accept css vars (c14e977)
• chips: Fix typography selector in GMDC-Wiz chips theming (43c7d87)
• datatable: Adjust data table last row border-radius to support setting row background-color. (ba78e87)
• dialog: Render dividers in Firefox 94 on Windows HCM (fae6c65)
• dialog: Set default z-index for close button in FloatingSheet dialog. (3366a71)
• fab: Add focus ring in HCM. (d57ec74)
• focus-ring: add 2d padding customizability, RTL bugfix (f81fb1d)
• focus-ring: box-sizing bugfix to content-box. If box-sizing border-box is inherited the ring spacing will collapse. (e58552c)
• focus-ring: ignore pointer events (3ef470e)
• focus-ring: RTL bugfix (e00181e)
• iconbutton: Fixed max width and height for high contrast mode focus ring on icon buttons. Display only in forced colors mode. (cf42927)
• iconbutton: Set icon button ripple z-index to -1. (586e740)
• list: Improve a11y for multi-select lists (9736ddc)
• list: Remove conflicting validation for checkbox list in setEnabled (353ca7e)
• list: Update lastSelectedIndex when toggling a checkbox range (dcba26f)
• menusurface: Add a getOwnerDocument() method to MDCMenuSurfaceAdapter to provide a reference to the document that owns the menu surface DOM element. (3486659)
• radio: Fix disabled state in Firefox Windows high contrast mode (23043ac)
• radio: Modify theme styles Sass mixin validation to validate only keys (390220e)
• select: Add border to select menu in HCM. (5d80969)
• select: revert down/up arrow on anchor changing selected index (43d08ba)
• slider: Fix bug where secondary click moves slider thumb. (3ab9565)
• slider: Fix IE11 bug - unset is unsupported in IE. (f460e23)
• slider: In updateUI, fix behavior to match jsdoc claim that when thumb param is undefined it updates both thumbs. Input attributes were not being updated at all. (cc4ed13)
• slider: Make the slider errors easier to debug by providing all relevant values in the error message. (8687937)
• snackbar: address Trusted Types violation (cbd9358)
• tooltip: Adjusts logic in validateTooltipWithCaretDistances method. (3e30054)
• typography: Fixes typography theme-styles mixin... the value being retreived from the $theme map and css property name was swapped. The mixin would request font-size/font-weight/letter-spacing from the $theme map (which expects size/weight/tracking)... so these values would always be null. (32b3913)
• Remove /** @override */ tags from TypeScript code. (c3cdff0)
• Simplify MDCAttachable interface to be any object (Function) that has attachTo. (05db65e)
• Snackbar action button ripple color is applied to the ripple element. (4e66fb2)
• Work around bug in Sass (037285f), closes sass/sass#3259
• switch: Restore Firefox 94 HCM outlines (39cf14b)
• textfield: Fix breaking tests due to no valid pointerId being associated with pointer events. (15db4f1)
• tooltip: Only sends notification of a tooltip being hidden if showTimeout is not set (indicating that this tooltip is about to be re-shown). (6ca8b8f)

Features

• banner: Add disableAutoClose params for both banner actions to prevent the banner buttons from automatically closing the banner. Add adapter #notifyActionClicked method. (b094eaa)
• chips: add focus ring styles (783f6fd)
• chips: Added elevation tint layer color support in chips (c78ff04)
• data-table: separate table structure into its own mixin (9f9d928)
• dialog: Add styling for floating sheets (78305b6)
• dialog: Add styling for floating sheets with content padding (3e20c1d)
• Dialog: Adds an API to hide the header for GMDC Fullscreen Dialog in non-fullscreen mode (ab4aba1)
• Dialog: Adds an API to set custom position for GMDC Dialog (ea9b5b4)
• Dialog: Adds an API to set custom z-index for GMDC Dialog (96ea061)
• focus-ring: added a new mixin so we can override just the focus-ring color (641ed08)
• focus-ring: added a new mixin so we can override just the focus-ring radius (7321d62)
• iconbutton: Add link icon button Sass. (9803d2d)
• mdc-list: introduce selection change event (7d8ea46)
• menu: allow preferentially opening surface below anchor (261f2db)
• MenuSurface: Add opening event for menus. (53b3cad)
• select: Add theming mixin boilerplate code to select (ae8a6a3)
• select: Add validation getter methods. (bdf1d37)
• select: Added theme mixins to MDC select (dcfe49c)
• slider: Add minRange param to range sliders to request a minimum gap between the two thumbs. (8fffcb5)
• slider: Add an option to hide focus styles after pointer interaction. (ec54d90)
• slider: Keep the slider value indicator within the bounds of the slider if possible. (c047f7c)
• state: make context aware (b2fe352)
• switch: Add high contrast mode focus ring to switch (f31a833)
• text-field: Add theming mixin boilerplate code to text-field (eb382f3)
• text-field: Added theme mixins to MDC text field (344d528)
• textfield: adding input-font-size mixin (207230e)
• theme: allow custom property strings in theme.validate-theme() (4e372fb)
• add new class and mixin for open state of a menu item (9a02b6e)
• Indicate which thumb valueToAriaValueTextFn and valueToValueIndicatorTextFn functions are called for. (b6510c8)
• textfield: adding input-font-family mixin (991fb99)
• Describe how to add child lists into a list item. (758ce31)

BREAKING CHANGES

• MenuSurface: Adds #notifyOpening method to menu surface adapter.

PiperOrigin-RevId: 444830518

• slider: Adds #getValueIndicatorContainerWidth method to slider adapter.

PiperOrigin-RevId: 419837612