## rn-collapsing-tab-bar
## For Collapsing tabbar, see CollapseExample in example folder.
## Expo Link

```
https://snack.expo.io/By0FEomKf

```
This is probably my favorite navigation pattern on Android, I wish it
were more common on iOS! This is a very simple JavaScript-only
implementation of it for React Native. For more information about how
the animations behind this work, check out the Rebound section of the
[React Native Animation Guide](https://facebook.github.io/react-native/docs/animations.html)
 

 Thanks to ,
 https://github.com/skv-headless/react-native-scrollable-tab-view

## Add it to your project

1. Run `npm install rn-collapsing-tab-bar --save`
2. `var ScrollableTabView = require('rn-collapsing-tab-bar');`

## Basic usage

```javascript
var ScrollableTabView = require('rn-collapsing-tab-bar');

var App = React.createClass({
  render() {
    return (
      <ScrollableTabView>
        <ReactPage tabLabel="React" />
        <FlowPage tabLabel="Flow" />
        <JestPage tabLabel="Jest" />
      </ScrollableTabView>
    );
  }
});
```

```
DEMO
```
![Demo](https://user-images.githubusercontent.com/19853363/37208053-e784dd06-23c5-11e8-81dd-a21883c8536b.gif)


## Injecting a custom tab bar

Suppose we had a custom tab bar called `CustomTabBar`, we would inject
it into our `ScrollableTabView` like this:

```javascript
var ScrollableTabView = require('rn-collapsing-tab-bar');
var CustomTabBar = require('./CustomTabBar');

var App = React.createClass({
  render() {
    return (
      <ScrollableTabView renderTabBar={() => <CustomTabBar someProp={'here'} />}>
        <ReactPage tabLabel="React" />
        <FlowPage tabLabel="Flow" />
        <JestPage tabLabel="Jest" />
      </ScrollableTabView>
    );
  }
});
```

## Props

- **`renderTabBar`** _(Function:ReactComponent)_ - accept 1 argument `props` and should return a component to use as
  the tab bar. The component has `goToPage`, `tabs`, `activeTab` and
  `ref` added to the props, and should implement `setAnimationValue` to
  be able to animate itself along with the tab content. You can manually pass the `props` to the TabBar component.
- **`tabBarPosition`** _(String)_ Defaults to `"top"`.
  - `"bottom"` to position the tab bar below content.
  - `"overlayTop"` or `"overlayBottom"` for a semitransparent tab bar that overlays content. Custom tab bars must consume a style prop on their outer element to support this feature: `style={this.props.style}`.
- **`onChangeTab`** _(Function)_ - function to call when tab changes, should accept 1 argument which is an Object containing two keys: `i`: the index of the tab that is selected, `ref`: the ref of the tab that is selected
- **`onScroll`** _(Function)_ - function to call when the pages are sliding, should accept 1 argument which is an Float number representing the page position in the slide frame.
- **`locked`** _(Bool)_ - disables horizontal dragging to scroll between tabs, default is false.
- **`initialPage`** _(Integer)_ - the index of the initially selected tab, defaults to 0 === first tab.
- **`page`** _(Integer)_ - set selected tab
- **`children`** _(ReactComponents)_ - each top-level child component should have a `tabLabel` prop that can be used by the tab bar component to render out the labels. The default tab bar expects it to be a string, but you can use anything you want if you make a custom tab bar.
- **`tabBarUnderlineStyle`** _([View.propTypes.style](https://facebook.github.io/react-native/docs/view.html#style))_ - style of the default tab bar's underline.
- **`tabBarBackgroundColor`** _(String)_ - color of the default tab bar's background, defaults to `white`
- **`tabBarActiveTextColor`** _(String)_ - color of the default tab bar's text when active, defaults to `navy`
- **`tabBarInactiveTextColor`** _(String)_ - color of the default tab bar's text when inactive, defaults to `black`
- **`tabBarTextStyle`** _(Object)_ - Additional styles to the tab bar's text. Example: `{fontFamily: 'Roboto', fontSize: 15}`
- **`style`** _([View.propTypes.style](https://facebook.github.io/react-native/docs/view.html#style))_
- **`contentProps`** _(Object)_ - props that are applied to root `ScrollView`/`ViewPagerAndroid`. Note that overriding defaults set by the library may break functionality; see the source for details.
- **`scrollWithoutAnimation`** _(Bool)_ - on tab press change tab without animation.
- **`scrollToTopAnimation`** _(Bool)_ - setting animation scroll to top when user change tab.
- **`prerenderingSiblingsNumber`** _(Integer)_ - pre-render nearby # sibling, `Infinity` === render all the siblings, default to 0 === render current page.

**MIT Licensed**