@Ilyahas/react-native-inviewport
Based on @coffeebeanslabs/react-native-inviewport.
*Fix freezing app with "Please report: Excessive number of pending callbacks: 501"
Warning.
If you have the same issue, try this npm.
Detect if component is in device viewport.
I based this off:https://github.com/yamill/react-native-inviewport with some slight modifications.
Install
npm i @ilyahas/react-native-inviewport
Usage
Assuming you already setup your component, here's a quick example.
import InViewPort from "@coffeebeanslabs/react-native-inviewport";
checkVisible = isVisible => this.setState({visible: isVisible});
render() {
return (
<ScrollView style={{flex: 1}}>
<InViewPort onChange={(isVisible) => this.checkVisible(isVisible)}>
<View style={{flex: 1, height: 200, backgroundColor: 'blue'}}>
<Text style={{color: 'white'}}>View is visible? {this.state.visible}</Text>
</View>
</InViewPort>
</ScrollView>
);
}
Configurable props
Event props
Configurable props
delay
A number that indicates milliseconds of periodically delay to check component visibility. By default it is 100ms.
Example:
<InViewPort delay={1000}>
...
</InViewPort>
disabled
InviewPort always keep checking the component with a delay of 100ms. This props can be used for disabling checking for component visibility.
Example:
<InViewPort disabled={true}>
...
</InViewPort>
Event props
onChange
Callback function that is called whenever the component visibility change. It returns true
or false
.
Example:
const onChangeVisibility = isVisible => console.log('is component visible ', isVisible);
<InViewPort onChange={onChangeVisibility}>
...
</InViewPort>
Other Examples:
Let's assume you want to check whether a component at scroll end has displayed or not and it is rendering components asynchronise on scrollview so you can use onScroll
event listener on scrollview.
Example
import InViewPort from "@coffeebeanslabs/react-native-inviewport";
this.state = {visible: false, isScrolling: false};
checkVisible = isVisible => this.setState({visible: isVisible});
const onScroll = () => this.setState({isScrolling: true});
render() {
return (
<ScrollView style={{flex: 1}} onScroll={onScroll}>
//list of images
//<Image..... />
//.......
{isScrolling && <InViewPort onChange={(isVisible) => this.checkVisible(isVisible)}>
<View style={{flex: 1, height: 200, backgroundColor: 'blue'}}>
<Text style={{color: 'white'}}>View is visible? {this.state.visible}</Text>
</View>
</InViewPort>}
</ScrollView>
);
}