Material Design

Top App Bar

Top App Bar screenshot

MDC Top App Bar acts as a container for items such as application title, navigation icon, and action items.

Design & API Documentation

Installation

npm install @material/top-app-bar

Basic Usage

HTML Structure

<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">
      <a href="#" class="material-icons mdc-top-app-bar__navigation-icon">menu</a>
      <span class="mdc-top-app-bar__title">Title</span>
    </section>
  </div>
</header>

We recommend using Material Icons from Google Fonts:

<head>
  <link rel="stylesheet" href="https://fonts.googleapis.com/icon?family=Material+Icons">
</head>

However, you can also use SVG, Font Awesome, or any other icon library you wish.

Styles

@import "@material/top-app-bar/mdc-top-app-bar";

JavaScript Instantiation

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

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

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

Variants

Top App Bar With Action Items

Top app bars can contain action items which are placed on the side opposite the navigation icon.

<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">
      <a href="#" class="material-icons mdc-top-app-bar__navigation-icon">menu</a>
      <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">
      <a href="#" class="material-icons mdc-top-app-bar__action-item" aria-label="Download" alt="Download">file_download</a>
      <a href="#" class="material-icons mdc-top-app-bar__action-item" aria-label="Print this page" alt="Print this page">print</a>
      <a href="#" class="material-icons mdc-top-app-bar__action-item" aria-label="Bookmark this page" alt="Bookmark this page">bookmark</a>
    </section>
  </div>
</header>

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">
      <a href="#" class="material-icons mdc-top-app-bar__navigation-icon">menu</a>
      <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">
      <a href="#" class="material-icons mdc-top-app-bar__action-item" aria-label="Bookmark this page" alt="Bookmark this page">bookmark</a>
    </section>
  </div>
</header>

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>

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>

Prominent

The prominent top app bar is taller.

<header class="mdc-top-app-bar mdc-top-app-bar--prominent">
  ...
</header>

Dense

The dense top app bar is shorter.

<header class="mdc-top-app-bar mdc-top-app-bar--dense">
  ...
</header>

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 standard and fixed 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 prominent and dense, 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
mdc-top-app-bar-ink-color($color) Sets the ink color of the top app bar.
mdc-top-app-bar-icon-ink-color($color) Sets the ink color of the top app bar icons.
mdc-top-app-bar-fill-color($color) Sets the fill color of the top app bar.
mdc-top-app-bar-fill-color-accessible($color) Sets the fill color of the top app bar and automatically sets a high-contrast ink color.
mdc-top-app-bar-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
hasClass(className: string) => boolean Checks if the root element of the component has the given className.
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.
registerNavigationIconInteractionHandler(evtType: string, handler: EventListener) => void Registers an event listener on the native navigation icon element for a given event.
deregisterNavigationIconInteractionHandler(evtType: string, handler: EventListener) => void Deregisters an event listener on the native navigation icon element for a given event.
notifyNavigationIconClicked() => void Emits a custom event MDCTopAppBar:nav when the navigation icon is clicked.
registerScrollHandler(handler) => void Registers a handler to be called when user scrolls. Our default implementation adds the handler as a listener to the window’s scroll event.
deregisterScrollHandler(handler) => void Unregisters a handler to be called when user scrolls. Our default implementation removes the handler as a listener to the window’s scroll event.
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.

Foundations: MDCTopAppBarBaseFoundation, MDCTopAppBarFoundation, MDCFixedTopAppBarFoundation and MDCShortTopAppBarFoundation

Method Signature Description
initScrollHandler(handler: function) => void Registers a scroll handler on a specific target element.
destroyScrollHandler(handler: function) => void Deregisters the current scroll handler set by the foundation.