| <!--docs: |
| title: "App bars: bottom" |
| layout: detail |
| section: components |
| excerpt: "A bottom app bar displays navigation and key actions at the bottom of the screen." |
| iconId: bottom_app_bar |
| path: /catalog/bottomappbar/ |
| api_doc_root: true |
| --> |
| |
| <!-- This file was auto-generated using ./scripts/generate_readme BottomAppBar --> |
| |
| # App bars: bottom |
| |
| [](https://github.com/material-components/material-components-ios/issues?q=is%3Aopen+is%3Aissue+label%3Atype%3ABug+label%3A%5BBottomAppBar%5D) |
| |
| A bottom app bar displays navigation and key actions at the bottom of the screen. Bottom app bars |
| work like [navigation bars](../NavigationBar), but with the additional option to show a |
| [floating action button](../Buttons). |
| |
| <div class="article__asset article__asset--screenshot"> |
| <img src="docs/assets/bottomappbar.png" alt="A screenshot of a bottom app bar." width="375"> |
| </div> |
| |
| ## Design & API documentation |
| |
| <ul class="icon-list"> |
| <li class="icon-list-item icon-list-item--spec"><a href="https://material.io/go/design-app-bar-bottom">Material Design guidelines: App bars: bottom</a></li> |
| <li class="icon-list-item icon-list-item--link">Class: <a href="https://material.io/components/ios/catalog/bottomappbar/api-docs/Classes/MDCBottomAppBarView.html">MDCBottomAppBarView</a></li> |
| <li class="icon-list-item icon-list-item--link">Enumeration: <a href="https://material.io/components/ios/catalog/bottomappbar/api-docs/Enums.html">Enumerations</a></li> |
| <li class="icon-list-item icon-list-item--link">Enumeration: <a href="https://material.io/components/ios/catalog/bottomappbar/api-docs/Enums/MDCBottomAppBarFloatingButtonElevation.html">MDCBottomAppBarFloatingButtonElevation</a></li> |
| <li class="icon-list-item icon-list-item--link">Enumeration: <a href="https://material.io/components/ios/catalog/bottomappbar/api-docs/Enums/MDCBottomAppBarFloatingButtonPosition.html">MDCBottomAppBarFloatingButtonPosition</a></li> |
| </ul> |
| |
| ## Table of contents |
| |
| - [Overview](#overview) |
| - [Installation](#installation) |
| - [Installation with CocoaPods](#installation-with-cocoapods) |
| - [Importing](#importing) |
| - [Usage](#usage) |
| - [Typical use](#typical-use) |
| - [Extensions](#extensions) |
| - [Color Theming](#color-theming) |
| - [Accessibility](#accessibility) |
| - [Set `-accessibilityLabel`](#set-`-accessibilitylabel`) |
| - [Set `-accessibilityHint`](#set-`-accessibilityhint`) |
| |
| - - - |
| |
| ## Overview |
| |
| Bottom app bars follow a recommended Material Design interaction design pattern for providing primary and secondary actions that are easily accessible. With a bottom app bar users are more easily able to use single-handed touch interaction with an application since actions are displayed close to the bottom of the screen within easy reach of a user's thumb. |
| |
| The bottom app bar includes a <a href="https://material.io/components/ios/catalog/buttons/api-docs/Classes/MDCFloatingButton.html">floating action button</a> that is intended to provide users with a primary action. Secondary actions are available on a <a href="https://material.io/components/ios/catalog/flexible-headers/navigation-bars/">navigation bar</a> that can be customized with several buttons on the left and right sides of the navigation bar. The primary action floating action button is centered on the bottom app bar by default. |
| |
| MDCBottomAppBarView should be attached to the bottom of the screen or used in conjunction with an expandable bottom drawer. The MDCBottomAppBarView API includes properties that allow changes to the elevation, position and visibility of the embedded floating action button. |
| |
| UIBarButtonItems can be added to the navigation bar of the MDCBottomAppBarView. Leading and trailing navigation items will be shown and hidden based on the position of the floating action button. |
| |
| Transitions between floating action button position, elevation and visibility states are animated by default, but can be disabled if desired. |
| |
| ## Installation |
| |
| <!-- Extracted from docs/../../../docs/component-installation.md --> |
| |
| ### Installation with CocoaPods |
| |
| Add the following to your `Podfile`: |
| |
| ```bash |
| pod 'MaterialComponents/BottomAppBar' |
| ``` |
| <!--{: .code-renderer.code-renderer--install }--> |
| |
| Then, run the following command: |
| |
| ```bash |
| pod install |
| ``` |
| |
| ### Importing |
| |
| To import the component: |
| |
| <!--<div class="material-code-render" markdown="1">--> |
| #### Swift |
| ```swift |
| import MaterialComponents.MaterialBottomAppBar |
| ``` |
| |
| #### Objective-C |
| |
| ```objc |
| #import "MaterialBottomAppBar.h" |
| ``` |
| <!--</div>--> |
| |
| |
| ## Usage |
| |
| <!-- Extracted from docs/typical-use.md --> |
| |
| ### Typical use |
| |
| MDCBottomAppBarView can be added to a view hierarchy like any UIView. Material Design guidelines |
| recommend always placing the bottom app bar at the bottom of the screen. |
| |
| |
| ## Extensions |
| |
| <!-- Extracted from docs/color-theming.md --> |
| |
| ### Color Theming |
| |
| MDCBottomAppBarView does not yet have a Material Design color system theming extension. Please |
| indicate interest by commenting on https://github.com/material-components/material-components-ios/issues/7172. |
| |
| ## Accessibility |
| |
| <!-- Extracted from docs/accessibility.md --> |
| |
| To help ensure your bottom app bar is accessible to as many users as possible, please be sure to review the |
| following recommendations: |
| |
| ### Set `-accessibilityLabel` |
| |
| Set an appropriate |
| [`accessibilityLabel`](https://developer.apple.com/documentation/uikit/uiaccessibilityelement/1619577-accessibilitylabel) |
| to all buttons within the bottom app bar. |
| |
| <!--<div class="material-code-render" markdown="1">--> |
| #### Swift |
| |
| ```swift |
| bottomAppBar.floatingButton.accessibilityLabel = "Compose" |
| let trailingButton = UIBarButtonItem() |
| trailingButton.accessibilityLabel = "Buy" |
| bottomAppBar.trailingBarButtonItems = [ trailingButton ] |
| ``` |
| |
| #### Objective-C |
| |
| ```objc |
| bottomAppBar.floatingButton.accessibilityLabel = @"Compose"; |
| UIBarButtonItem *trailingButton = |
| [[UIBarButtonItem alloc] initWithTitle:nil |
| style:UIBarButtonItemStylePlain |
| target:self |
| action:@selector(didTapTrailing:)]; |
| trailingButton.accessibilityLabel = @"Buy"; |
| [bottomAppBar setTrailingBarButtonItems:@[ trailingButton ]]; |
| ``` |
| <!--</div>--> |
| |
| ### Set `-accessibilityHint` |
| |
| Set an appropriate |
| [`accessibilityHint`](https://developer.apple.com/documentation/objectivec/nsobject/1615093-accessibilityhint) |
| to all buttons within the bottom app bar. |
| |
| <!--<div class="material-code-render" markdown="1">--> |
| #### Swift |
| |
| ```swift |
| bottomAppBar.floatingButton.accessibilityHint = "Create new email" |
| let trailingButton = UIBarButtonItem() |
| trailingButton.accessibilityHint = "Purchase the item" |
| bottomAppBar.trailingBarButtonItems = [ trailingButton ] |
| ``` |
| |
| #### Objective-C |
| |
| ```objc |
| bottomAppBar.floatingButton.accessibilityHint = @"Create new email"; |
| UIBarButtonItem *trailingButton = |
| [[UIBarButtonItem alloc] initWithTitle:nil |
| style:UIBarButtonItemStylePlain |
| target:self |
| action:@selector(didTapTrailing:)]; |
| trailingButton.accessibilityHint = @"Purchase the item"; |
| [bottomAppBar setTrailingBarButtonItems:@[ trailingButton ]]; |
| ``` |
| <!--</div>--> |
| |
