@material/top-app-bar

Top app bar

The top app bar provides content and actions related to the current screen. It’s used for branding, screen titles, navigation, and actions.

There are two types of top app bar:

1. Regular top app bar
2. Contextual action bar

A regular top app bar can transform into a contextual action bar.

Using the top app bar

Installation

npm install @material/top-app-bar

Styles

@use "@material/icon-button";
@use "@material/top-app-bar/mdc-top-app-bar";

@include icon-button.core-styles;

JavaScript Instantiation

import {MDCTopAppBar} from '@material/top-app-bar';

// Instantiation
const topAppBarElement = document.querySelector('.mdc-top-app-bar');
const topAppBar = new MDCTopAppBar(topAppBarElement);

Note: See Importing the JS component for more information on how to import JavaScript.

Regular top app bar

The top app bar provides content and actions related to the current screen. It’s used for branding, screen titles, navigation, and actions.

Regular top app bar example

<header class="mdc-top-app-bar">
  <div class="mdc-top-app-bar__row">
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-start">
      <button class="material-icons mdc-top-app-bar__navigation-icon mdc-icon-button" aria-label="Open navigation menu">menu</button>
      <span class="mdc-top-app-bar__title">Page title</span>
    </section>
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-end" role="toolbar">
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Favorite">favorite</button>
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Search">search</button>
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Options">more_vert</button>
    </section>
  </div>
</header>
<main class="mdc-top-app-bar--fixed-adjust">
  App content
</main>

Menu icons

Top app bars can contain action items which are placed on the side opposite the navigation icon. You must also attach the mdc-icon-button class to both the mdc-top-app-bar__navigation-icon and the mdc-top-app-bar__action-item elements in order to get the correct styles applied.

For further documentation on icons, please see the mdc-icon-button docs.

Contextual action bar

A top app bar can transform into a contextual action bar to provide contextual actions to selected items. For example, upon user selection of photos from a gallery, the top app bar transforms to a contextual app bar with actions related to the selected photos.

When a top app bar transforms into a contextual action bar, the following changes occur:

• The bar color changes
• Navigation icon is replaced with a close icon
• Top app bar title text converts to contextual action bar text
• Top app bar actions are replaced with contextual actions
• Upon closing, the contextual action bar transforms back into a top app bar.

Contextual action bar example

The following example shows a contextual action bar with a contextual title, a close icon, two contextual action icons, and an overflow menu:

<header class="mdc-top-app-bar">
  <div class="mdc-top-app-bar__row">
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-start">
      <button class="material-icons mdc-top-app-bar__navigation-icon mdc-icon-button" aria-label="Close">close</button>
      <span class="mdc-top-app-bar__title">Contextual title</span>
    </section>
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-end" role="toolbar">
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Share">share</button>
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Delete">delete</button>
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Open menu">more_vert</button>
    </section>
  </div>
</header>
<main class="mdc-top-app-bar--fixed-adjust">
  App content
</main>

Other Variants

Short

Short top app bars are top app bars that can collapse to the navigation icon side when scrolled.

<header class="mdc-top-app-bar mdc-top-app-bar--short">
  <div class="mdc-top-app-bar__row">
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-start">
      <button class="material-icons mdc-top-app-bar__navigation-icon mdc-icon-button">menu</button>
      <span class="mdc-top-app-bar__title">Title</span>
    </section>
    <section class="mdc-top-app-bar__section mdc-top-app-bar__section--align-end" role="toolbar">
      <button class="material-icons mdc-top-app-bar__action-item mdc-icon-button" aria-label="Bookmark this page">bookmark</button>
    </section>
  </div>
</header>
<main class="mdc-top-app-bar--short-fixed-adjust">
  App content
</main>

Note: Short top app bars should be used with no more than 1 action item.

Short - always closed

Short top app bars can be configured to always appear collapsed by applying the mdc-top-app-bar--short-collapsed before instantiating the component :

<header class="mdc-top-app-bar mdc-top-app-bar--short mdc-top-app-bar--short-collapsed">
  ...
</header>
<main class="mdc-top-app-bar--short-fixed-adjust">
  App content
</main>

Fixed

Fixed top app bars stay at the top of the page and elevate above the content when scrolled.

<header class="mdc-top-app-bar mdc-top-app-bar--fixed">
  ...
</header>
<main class="mdc-top-app-bar--fixed-adjust">
  App content
</main>

Prominent

The prominent top app bar is taller.

<header class="mdc-top-app-bar mdc-top-app-bar--prominent">
  ...
</header>
<main class="mdc-top-app-bar--prominent-fixed-adjust">
  App content
</main>

Dense

The dense top app bar is shorter.

<header class="mdc-top-app-bar mdc-top-app-bar--dense">
  ...
</header>
<main class="mdc-top-app-bar--dense-fixed-adjust">
  App content
</main>

Style customization

CSS classes

Class	Description
mdc-top-app-bar	Mandatory.
mdc-top-app-bar--fixed	Class used to style the top app bar as a fixed top app bar.
mdc-top-app-bar--fixed-adjust	Class used to style the content below the top app bar to prevent the top app bar from covering it.
mdc-top-app-bar--prominent	Class used to style the top app bar as a prominent top app bar.
mdc-top-app-bar--prominent-fixed-adjust	Class used to style the content below the prominent top app bar to prevent the top app bar from covering it.
mdc-top-app-bar--dense	Class used to style the top app bar as a dense top app bar.
mdc-top-app-bar--dense-fixed-adjust	Class used to style the content below the dense top app bar to prevent the top app bar from covering it.
mdc-top-app-bar--dense-prominent-fixed-adjust	Class used to style the content below the top app bar when styled as both dense and prominent, to prevent the top app bar from covering it.
mdc-top-app-bar--short	Class used to style the top app bar as a short top app bar.
mdc-top-app-bar--short-collapsed	Class used to indicate the short top app bar is collapsed.
mdc-top-app-bar--short-fixed-adjust	Class used to style the content below the short top app bar to prevent the top app bar from covering it.

Sass mixins

Mixin	Description
ink-color($color)	Sets the ink color of the top app bar.
icon-ink-color($color)	Sets the ink color of the top app bar icons.
fill-color($color)	Sets the fill color of the top app bar.
fill-color-accessible($color)	Sets the fill color of the top app bar and automatically sets a high-contrast ink color.
short-shape-radius($radius, $rtl-reflexive)	Sets the rounded shape to short top app bar variant (when it is collapsed) with given radius size. Set $rtl-reflexive to true to flip radius values in RTL context, defaults to true.

MDCTopAppBar properties and methods

Method Signature	Description
setScrollTarget(target: element) => void	Sets scroll target to different DOM node (default is window).

Events

Event Name	Event Data Structure	Description
MDCTopAppBar:nav	None	Emits when the navigation icon is clicked.

Usage within web frameworks

If you are using a JavaScript framework, such as React or Angular, you can create a Top App Bar 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 here.

MDCTopAppBarAdapter

Method Signature	Description
addClass(className: string) => void	Adds a class to the root element of the component.
removeClass(className: string) => void	Removes a class from the root element of the component.
hasClass(className: string) => boolean	Checks if the root element of the component has the given className.
setStyle(property: string, value: string) => void	Sets the specified CSS property to the given value on the root element.
getTopAppBarHeight() => number	Gets the height in px of the top app bar.
getViewportScrollY() => number	Gets the number of pixels that the content of body is scrolled from the top of the page.
getTotalActionItems() => number	Gets the number of action items in the top app bar.
notifyNavigationIconClicked() => void	Emits a custom event MDCTopAppBar:nav when the navigation icon is clicked.

Foundations

MDCTopAppBarBaseFoundation, MDCTopAppBarFoundation, MDCFixedTopAppBarFoundation and MDCShortTopAppBarFoundation

All foundations provide the following methods:

Method Signature	Description
handleTargetScroll() => void	Handles scroll event on specified scrollTarget (defaults to window).
handleWindowResize() => void	Handles resize event on window.
handleNavigationClick() => void	Handles click event on navigation icon.

MDCShortTopAppBarFoundation

In addition to the methods above, the short variant provides the following public methods and properties:

Method Signature	Description
setAlwaysCollapsed(value: boolean) => void	When value is true, sets the short top app bar to always be collapsed.
getAlwaysCollapsed() => boolean	Gets if the short top app bar is in the "always collapsed" state.

Property	Value Type	Description
isCollapsed	boolean (read-only)	Indicates whether the short top app bar is in the collapsed state.