Summary:
Enable back navigation on Apple TV (with the remote's menu button) in code making use of BackAndroid. The module is renamed to BackHandler. BackAndroid is still exported to ReactNative for now, until external projects switch to using the new name for the module. The navigation in https://github.com/react-community/react-navigation makes use of this module.
**Test plan**: Manual testing with an example app (https://github.com/dlowder-salesforce/react-nav-example).
Closes https://github.com/facebook/react-native/pull/12571
Differential Revision: D4665152
Pulled By: ericvicenti
fbshipit-source-id: 925400ce216379267e014457be6f5eedbe4453ec
Summary:
This does 2 things:
- modernize the component to use ES6 + flow
- assign `rootTag` to the child context
Each view in RN has its own `reactTag`. The reactTag for a root view is called `rootTag`. When there are multiple react root views active within the app (e.g. in a hybrid environment), rootTag is the only reliable "label" to differentiate them. This is especially useful when we want to limit an event/activity on a particular root view, instead of affecting all active root views. This allows components to do:
```
class Foo extends React.Component {
static contextTypes = {
rootTag: React.PropTypes.number,
};
componentDidMount() {
// Get the root tag of this component, which is static for all components under the same root view
console.log(this.context.rootTag);
}
}
```
In a pure JS RN app environment, there will always be exactly 1 root view, so `rootTag` may usually be ignored.
Reviewed By: yungsters
Differential Revision: D4130376
fbshipit-source-id: 559b67615f487bad754b5832ad4a02bcef05be2a
Douglas Lowder
Gabe Levi
Kevin Gozali
Tim Yung
Pieter De Baets