How to disable the left-to-right transition animation during initial app launch?

[wenbinf]

I use TabNavigator and here's the full code:

class HomeScreen extends React.Component {
    render() {
        return <View style={{flexDirection:'row', backgroundColor: 'red', height: 300,
            justifyContent:'flex-end', paddingTop: 30}}>
            <Text>Hello, Navigation!</Text>
        </View>
    }
}

class SecondScreen extends React.Component {
    render() {
        return <View style={{flexDirection:'row', justifyContent:'flex-end', paddingTop: 30}}>
            <Text>Hello, Second!</Text>
        </View>
    }
}

const AppContainer = TabNavigator({
        HomePage: {screen: HomeScreen},
        SecondPage: {screen: SecondScreen}
    }
)

As you can see, when app initially launches, the text "flies" in ... How can I disable this effect?

Thanks in advance!

[satya164]

I think you need to set flex: 1 on your view.

[wenbinf]

Thanks @satya164 , but now it becomes this:

I added "flex: 1"

class HomeScreen extends React.Component {
    render() {
        return <View style={{flex: 1, flexDirection:'row', backgroundColor: 'red', height: 300,
            justifyContent:'flex-end', paddingTop: 30}}>
            <Text>Hello, Navigation!</Text>
        </View>
    }
}

btw, StackNavigator and DrawerNavigator don't have this issue. It's only TabNavigator.

[satya164]

So seems it only happens when you've flexDirection: row. For example, the following works fine,

class HomeScreen extends React.Component {
  render() {
    return (
      <View>
        <View
          style={{
            flexDirection: 'row',
            backgroundColor: 'red',
            height: 300,
            justifyContent: 'flex-end',
            paddingTop: 30,
          }}
        >
          <Text>Hello, Navigation!</Text>
        </View>
      </View>
    );
  }
}

[wenbinf]

hmm ... I ran your code snippet, but it still doesn't work.

The version that I'm using is "react-navigation": "^1.0.0-beta.1".

Let me dig more ...

[satya164]

@wenbinf hmm. I just tested this on simulator and couldn't reproduce the issue anymore.

[wenbinf]

For the record, this was the environment that I tested

• node v7.2.1
• iOS Simulator: iPhone 6 + iOS 8.4 / iOS 10, iPhone 7 + iOS 10.2
• real iphone 6 + iOS 10.2
• "react-navigation": "^1.0.0-beta.1"
• "react-native": "0.40.0",

Just in case someone on the Internet encounters the same problem :)

[hilkeheremans]

This is still an issue on latest master as of this post. When testing, please also use react-native-debugger to make sure the embedded chrome debugger doesnt hide the issue.

To reproduce, use a TabNavigator as follows:

export const TestTabAnim = TabNavigator({
        splash: {
            screen: () => (<View style={{ flex: 1, backgroundColor: 'red' }}><Text>Tab 1</Text></View>)
        },
        login: {
            screen: () => (<View style={{ flex: 1, backgroundColor: 'blue' }}><Text>Tab 1</Text></View>)
        },
        home: {
            screen: () => (<View style={{ flex: 1, backgroundColor: 'purple' }}><Text>Tab 1</Text></View>)
        }
    })

I have tracked down the root cause, and it lies within the react-native-tab-view dependency. More specifically, when an AnimatedTabView tries to mount initially, it has no knowledge of the actual dimensions it should render in, and thus has no idea of what to animate to. In order to circumvent this, the TabViewTransitioner component in react-native-tab-view seems to use onLayout to immediately change the animation target to the actual width and height of the view (https://github.com/react-native-community/react-native-tab-view/blob/master/src/TabViewTransitioner.js#L110). This causes a "one frame delay in rendering", which is also what you notice visually.

A not-so-practical workaround to avoid this animation issue would then be to somehow pass the tab navigator's width and height before mount. I tested this hypothesis by directly passing a hardcoded initialLayout={{ height: <height>, width: <width> }} prop to the AnimatedTabView from TabView in react-native-navigation (ie here: https://github.com/react-community/react-navigation/blob/master/src/views/TabView/TabView.js#L184). This resolves the issue albeit not in a very practical way :-).

@satya164 Seems like you are 'the man to talk to' re react-native-tab-view -- any further insights? Thanks!

[satya164]

A not-so-practical workaround to avoid this animation issue would then be to somehow pass the tab navigator's width and height before mount

We don't need that. The one frame delay is only for things like indicator which absolutely need the width before rendering. Tab view knows how to handle the layout before measurement is done, so that there is no delay. There were some missing styles in the scrollview based pager that iOS uses, which prevented it from working properly. I just pushed an update with fixed styles.

When testing, please also use react-native-debugger to make sure the embedded chrome debugger doesnt hide the issue

Debuggers often change the behaviour. So it's better not to use any debuggers while testing an issue.

[hilkeheremans]

Thanks!

[wenbinf]

npm install --save react-community/react-navigation
node_modules/react-native/packager/packager.sh --reset-cache

Then it works!

Thanks a lot! @satya164