Tab Indicator
A Tab Indicator is a visual guide that shows which Tab is active.
Design & API Documentation
Installation
npm install @material/tab-indicator
Basic Usage
HTML Structure
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<span class="mdc-tab-indicator">
<span class="mdc-tab-indicator__content"></span>
</span>
Styles
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@use "@material/tab-indicator/mdc-tab-indicator";
JavaScript Instantiation
import {MDCTabIndicator} from '@material/tab-indicator';
const tabIndicator = new MDCTabIndicator(document.querySelector('.mdc-tab-indicator'));
See
Importing the JS component for more information on how to import JavaScript.
Variants
Active Indicator
Add the mdc-tab-indicator--active class to the mdc-tab-indicator element to make the Tab Indicator active.
Indicator Types and Transitions
The Tab Indicator may be represented in one of two ways:
- Underline, indicated by the mdc-tab-indicator__content--underline class
- Icon, indicated by the mdc-tab-indicator__content--icon class
NOTE: One of these classes must be applied to the Tab Indicator's content element.
The Tab Indicator may transition in one of two ways:
- Slide, the default behavior
- Fade, indicated by the mdc-tab-indicator--fade class
Sliding Underline Indicator
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<span class="mdc-tab-indicator">
<span class="mdc-tab-indicator__content mdc-tab-indicator__content--underline"></span>
</span>
Icon Indicators
We recommend using
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<head>
<link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
</head>
However, you can also use SVG,
Remember to include aria-hidden="true", since the active indicator is already signified via the aria-selected attribute on the tab.
Fading Icon Indicator
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<span class="mdc-tab-indicator mdc-tab-indicator--fade">
<span class="mdc-tab-indicator__content mdc-tab-indicator__content--icon material-icons" aria-hidden="true">star</span>
</span>
Sliding Icon Indicator
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<span class="mdc-tab-indicator">
<span class="mdc-tab-indicator__content mdc-tab-indicator__content--icon material-icons" aria-hidden="true">star</span>
</span>
Style Customization
CSS Classes
CSS Class | Description |
---|---|
mdc-tab-indicator | Mandatory. Contains the tab indicator content. |
mdc-tab-indicator__content | Mandatory. Denotes the tab indicator content. |
mdc-tab-indicator--active | Optional. Visually activates the indicator. |
mdc-tab-indicator--fade | Optional. Sets up the tab indicator to fade in on activation and fade out on deactivation. |
mdc-tab-indicator__content--underline | Optional. Denotes an underline tab indicator. |
mdc-tab-indicator__content--icon | Optional. Denotes an icon tab indicator. |
NOTE: Exactly one of the --underline or --icon content modifier classes should be present.
Sass Mixins
To customize the tab indicator, use the following mixins.
Mixin | Description |
---|---|
surface | Mandatory. Must be applied to the parent element of the mdc-tab-indicator. |
underline-color($color) | Customizes the color of the underline. |
icon-color($color) | Customizes the color of the icon subelement. |
underline-height($height) | Customizes the height of the underline. |
icon-height($height) | Customizes the height of the icon subelement. |
underline-top-corner-radius($radius) | Customizes the top left and top right border radius of the underline child element. |
MDCTabIndicator Methods
Method Signature | Description |
---|---|
activate(previousIndicatorClientRect?: ClientRect) => void | Activates the tab indicator. |
deactivate() => void | Deactivates the tab indicator. |
computeContentClientRect() => ClientRect | Returns the content element bounding client rect. |
Usage within Web Frameworks
If you are using a JavaScript framework, such as React or Angular, you can create a Tab Indicator for your framework. Depending on your needs, you can use the Simple Approach: Wrapping MDC Web Vanilla Components, or the Advanced Approach: Using Foundations and Adapters. Please follow the instructions
MDCTabIndicatorAdapter
Method Signature | Description |
---|---|
addClass(className: string) => void | Adds a class to the root element. |
removeClass(className: string) => void | Removes a class from the root element. |
setContentStyleProperty(property: string, value: string) => void | Sets the style property of the content element. |
computeContentClientRect() => ClientRect | Returns the content element's bounding client rect. |
MDCTabIndicatorFoundation
Method Signature | Description |
---|---|
handleTransitionEnd(evt: Event) => void | Handles the logic for the "transitionend" event on the root element. |
activate(previousIndicatorClientRect?: ClientRect) => void | Activates the tab indicator. |
deactivate() => void | Deactivates the tab indicator. |
computeContentClientRect() => ClientRect | Returns the content element's bounding client rect. |