# Styling Options

You can style the navigator appearance and behavior by passing an `options` object. This object can be passed when the screen is originally created; can be defined per-screen by setting `static get options()` on the screen component; and can be overridden when a screen is pushed.

The easiest way to style your screen is by adding `static get options()` to your screen React component definition.

```js
export default class StyledScreen extends Component {
  static get options() {
    return {
      topBar: {
        title: {
          text: 'My Screen'
        },
        drawBehind: true,
        visible: false,
        animate: false
      }
    };
  }

  constructor(props) {
    super(props);
  }
  render() {
    return (
      <View style={{flex: 1}}>...</View>
     );
  }
```

## Enabling persistent styling properties
In v2 we added `setDefaultOptions` API for styles that should be applied on all components.

> `setDefaultOptions` Does not update options of existing component, therefore it should be called before `setRoot`

```js
Navigation.setDefaultOptions({
  topBar: {
    visible: false
  }
});
```

## Setting styles dynamically
Use the `mergeOptions` method to change a screen's style dynamically.

```js
Navigation.mergeOptions(this.props.componentId, {
  topBar: {
    visible: true
  }
});
```

## Options object format

### Common options

```js
{
  statusBar: {
    visible: false,
    style: 'light' | 'dark'
  },
  layout: {
    backgroundColor: 'white',
    orientation: ['portrait', 'landscape'] // An array of supported orientations
  },
  modalPresentationStyle: 'overCurrentContext', // Supported styles are: 'formSheet', 'pageSheet', 'overFullScreen', 'overCurrentContext', 'currentContext', 'popOver', 'fullScreen' and 'none'. On Android, only overCurrentContext and none are supported.
  topBar: {
    visible: true,
    animate: false, // Controls wether TopBar visibility changes should be animated
    hideOnScroll: true,
    buttonColor: 'black',
    drawBehind: false,
    testID: 'topBar',
    searchBar: true, // iOS 11+ native UISearchBar inside topBar
    searchBarHiddenWhenScrolling: true,
    searchBarPlaceholder: 'Search', // iOS 11+ SearchBar placeholder
    // iOS 11+ Large Title
    largeTitle: {
      visible: true,
      fontSize: 30,
      color: 'red',
      fontFamily: 'Helvetica'
    },
    title: {
      text: 'Title',
      fontSize: 14,
      color: 'red',
      fontFamily: 'Helvetica',
      component: {
        name: 'example.CustomTopBarTitle',
        alignment: 'center'
      }
    },
    subtitle: {
      text: 'Title',
      fontSize: 14,
      color: 'red',
      fontFamily: 'Helvetica',
      alignment: 'center'
    },
    backButton: {
      icon: require('icon.png'),
      visible: true
    },
    background: {
      color: '#00ff00',
      component: {
        name: 'example.CustomTopBarBackground'
      }
    }
  },
  bottomTabs: {
    visible: true,
    animate: false, // Controls wether BottomTabs visibility changes should be animated
    currentTabIndex: 0,
    currentTabId: 'currentTabId',
    testID: 'bottomTabsTestID',
    drawBehind: false,
    backgroundColor: 'white'
  },
  bottomTab: {
    text: 'Tab 1',
    badge: '2',
    testID: 'bottomTabTestID',
    icon: require('tab.png'),
    iconColor: 'red',
    selectedIconColor: 'blue',
    textColor: 'red',
    selectedTextColor: 'blue',
    fontFamily: 'Helvetica',
    fontSize: 10
  },
  sideMenu: {
    left: {
      visible: false,
      enabled: true
    },
    right: {
      visible: false,
      enabled: true
    }
  },
  overlay: {
    interceptTouchOutside: true
  },
  preview: {
    elementId: 'PreviewId',
    width: 100,
    height: 100,
    commit: false,
    actions: [{
      id: 'ActionId1',
      title: 'Action title',
      style: 'selected', // default, selected, destructive,
      actions: [/* ... */]
    }]
  }  
}
```

### iOS specific options
```js
{
  statusBar: {
    hideWithTopBar: false,
    blur: true
  },
  popGesture: true,
  backgroundImage: require('background.png'),
  rootBackgroundImage: require('rootBackground.png'),
  topBar: {
    translucent: true,
    transparent: false,
    noBorder: false,
    blur: false,
    backButton: {
      title: 'Back',
      showTitle: false
    },
    largeTitle: {
      visible: true,
      fontSize: 30,
      color: 'red',
      fontFamily: 'Helvetica'
    },
  },
  bottomTabs: {
    translucent: true,
    hideShadow: false
  },
  bottomTab: {
    iconInsets: { top: 0, left: 0, bottom: 0, right: 0 },
    selectedIcon: require('selectedTab.png'),
    disableIconTint: true, //set true if you want to disable the icon tinting
    disableSelectedIconTint: true
  }
}
```

### Android specific options

```js
{
  statusBar: {
    backgroundColor: 'red',
    drawBehind: true,
    visible: false
  },
  layout: {
    topMargin: Navigation.constants().statusBarHeight // Set the layout's top margin
  },
  topBar: {
    height: 70, // TopBar height in dp
    borderColor: 'red',
    borderHeight: 1.3,
    elevation: 1.5, // TopBar elevation in dp
    title: {
      height: 70 // TitleBar height in dp
    }
  },
  bottomTabs: {
    titleDisplayMode: 'alwaysShow' | 'showWhenActive' | 'alwaysHide' // Sets the title state for each tab.
  }
}
```

## Styling the StatusBar
If you set any styles related to the Status Bar, make sure that in Xcode > project > Info.plist, the property `View controller-based status bar appearance` is set to `YES`.

## Custom fonts
If you'd like to use a custom font, you'll first have to edit your project.

* Android - add the `.ttf` or `.otf` files to `src/main/assets/fonts/`

* iOS - follow this [guide](https://medium.com/@dabit3/adding-custom-fonts-to-react-native-b266b41bff7f)

## Customizing screen animations
Animation used for navigation commands that modify the layout hierarchy can be controlled in options. Animations can be modified per command and it's also possible to change the default animation for each command.

## Animation properties

The following properties can be animated:
* x
* y
* alpha
* scaleX
* scaleY
* rotationX
* rotationY
* rotation

```js
{
  from: 0, // Mandatory, initial value
  to: 1, // Mandatory, end value
  duration: 400, // Default value is 300 ms
  startDelay: 100, // Default value is 0
  interpolation: 'accelerate' | 'decelerate' // Optional
}
```

For example, changing the animation used when the app is first launched:
```js
Navigation.setDefaultOptions({
  animations: {
    startApp: {
      y: {
        from: 1000,
        to: 0,
        duration: 500,
        interpolation: 'accelerate',
      },
      alpha: {
        from: 0,
        to: 1,
        duration: 400,
        startDelay: 100,
        interpolation: 'accelerate'
      }
    }
  }
});
```

## Customizing navigation commands animation

Animations for the following set of commands can be customized
* startApp
* push
* pop
* showModal
* dismissModal

## Customizing stack command animation

When *pushing* and *popping* screens to and from a stack, you can control the TopBar, BottomTabs and actual content animations as separately.

```js
animations: {
  push: {
    topBar: {
      id: 'TEST', // Optional, id of the TopBar we'd like to animate.
      alpha: {
        from: 0,
        to: 1
      }
    },
    bottomTabs: {
      alpha: {
        from: 0,
        to: 1
      }
    },
    content: {
      alpha: {
        from: 0,
        to: 1
      }
    }
  }
}
```
