I found one issue and can someone help me.
I use vertical scroll list(FlatList) and inside it i have also another vertical FlatList.
Inside child FlatList I use onScroll events for customise scroll animation.
issue: when I scroll parent FlatList I get onScroll events inside child and animation glitching.
How can I stop get wrong onScroll event inside child FlatList.
Also I do not use onScroll events inside parent component.
<Flatlist
onScroll={
Animated.event([{nativeEvent: {contentOffset: {y: scrollY}}}], {
useNativeDriver: false,
})
}
...
/>
Related
I have a Flatlist with Vertical Scrolling and inside each item of the Flatlist I have a SwipeListView from react-native-swipe-list-view.
Whenever I Swipe horizontally inside the SwipeListView, it gets cancelled if i also start scrolling vertically and then it starts vertically scrolling the Flatlist. I tried using useState to manage the scrollEnabled but this only works when the User slowly slides inside the SwipeListView. With increased velocity there are messed up animations. Also i feel like there must be a cleaner way of achieving this. Anyone know a way to basically disable FlatList scroll while scrolling inside of child component?
For starters, replace react-native-swipe-list-view with the swipable component that react native gesture handler exports. This is far more performant as it uses the UI thread to perform all animations. You can then import Flatlist as well from react-native-gesture-handler.
Generally, things should work as is. But if there is any glitchy behaviour you can wrap flatlist with a gestureHandlerRootView and pass RNGH ScrollView to the flatlist renderScrollComponent.
import Swipeable from 'react-native-gesture-handler/Swipeable';
import {Flatlist} from 'react-native-gesture-handler'
import {
GestureHandlerRootView,
PanGestureHandler,
ScrollView,
} from 'react-native-gesture-handler';
export default function App(){
<GestureHandlerRootView>
<Flatlist renderItem={<Swipeable />}
renderScrollComponent={ScrollView}/>
</GestureHandlerRootView>
}
You can try implementing the swipeableRow which can be used to disable scrolling in flatlist.
disableScroll() {
this.list.getScrollResponder().setNativeProps({
scrollEnabled: false
})
}
enableScroll() {
this.list.getScrollResponder().setNativeProps({
scrollEnabled: true
})
}
Then in your place of your swipeable component, add this:
<SwipeableRow onSwipeStart={disableScroll} onSwipeEnd={enableScroll} />
Also you can try adding this to the FlatList
scrollEnabled={false}
Im trying to use scroll to end function from scrollView docs,
but I don't know how to implement it.
right now I get errors: cant find variable scrollToEnd
my code for the scroll view:
<ScrollView onContentSizeChange={() => scrollToEnd({ duration: 500 })} style={styles.viewcontainer}>
and inside the scrollView i have content that grawing when button clicked.
I want that the view always go to the bottom.
how i implement the scrollToEnd method?
I am building a header that animates/hides as the user scrolls down a Flatlist.
Is there any way to find out the scroll position of the Flatlist in pixels?
I'm using react native 0.59.8.
I've tried using onScroll hoping it passes a value to the callback - it doesn't.
I've also tried onScrollBeginDrag, onScrollEndDrag and onMomentumScrollEnd.. None of them provide information of the current scroll position.
onSroll={(info)=>{console.log(info)}
I would expect to get some information about the scroll, but none is passed.
use the code
<FlatList onScroll={this.handleScrollView} />
handleScrollView: function(event: Object) {
this.setState({ scrollPosition: event.nativeEvent.contentOffset.y });
}
its working
onScroll={(r) => console.log(r.nativeEvent.contentOffset.y)}
post your code here if you want to find bug
A Flatlist, as said in the docs, has all the props of a ScrollView, so as answered here,
Add a handler to your FlatList:
<FlatList onScroll={this.handleScroll} />
And then:
handleScroll: function(event) {
console.log(event.nativeEvent.contentOffset.y);
},
Focussing of textinput of last item in flatlist appears keyboard but immeadiately keyboard disappears. In order to solve this,using a property removeClippedSubviews={false} of flatlist fixes this issue but it causes to another issue i.e,
Whenever an item is focussed aleardy in flatlist and tries to scrolling up the items, items are scrolling upto pagination limit and then right after items are scrolling down to the item that is focussed already of flatlist(focussed item appears on top of flatlist interms of visibility).Since it is not allowing scrolling up further.
Is there any property or workaround to fix these two issues? Do anyone got this issue? please provide solution if there is any?
Flatlist without "removeClippedSubviews={false}" property, scrolling is fine but for focussing of textinput of last item of flatlist causes keyboard appears and disappears.(keyboard should not disappear)
2.Using SafeAreaView, keeping flatlist in scrollview are also not working.
<FlatList style={styles.flatListSection}
keyExtractor={(item, index) => index.toString()}
data={this.state.serverData}
renderItem={this.iterateFlatListItem}
ItemSeparatorComponent={ () => this.seperatorComponent() }
ListFooterComponent={this.renderFooter.bind(this)}
onEndReachedThreshold={0.5}
onEndReached={()=>this.handleLoadMore()}
keyboardShouldPersistTaps='always'
extraData={this.props}
ref={ (r) => this.refFlatlist=r }/>
Scrolling up should work without scroll down automatically when textinput is focussed
Focus of text input of last item of flatlist, keyboard should not diappear once it appears unleass we dismiss it manually
Can I set the position of react native action button to fixed on a flat list?
I have added an action button but when I scroll the flat list, the action button hides!
Thanks, advance.
You'll want to use the Animated API
First you need to create a Flatlist that you can animate. This is easily done with Animated.createAnimatedComponent():
import { Flatlist, Animated } from 'react-native'
const AnimatedFlatlist = Animated.createAnimatedComponent(Flatlist)
Now in your parent component constructor create a new Animated.Value. This will be the value you use to animate your component to scroll along with your AnimatedFlatlist:
constructor(props) {
super(props)
this.state = { translateY: new Animated.Value(0)}
}
Then wrap the component you want to be fixed in an Animated.View and make sure you add a transform to the component style, passing it the animated value you created :
<Animated.View style={{ transform: [{ translateY: this.state.translateY }]}}>
{YourFixedComponent}
</Animated.View>
Finally, you need to attach an Animated.event to your AnimatedFlatlist. This is done using the onScroll prop:
<AnimatedFlatlist
data={...}
renderItem={...}
keyExtractor={...}
onScroll={Animated.event(
[{nativeEvent: {contentOffset: {y: this.state.translateY}}}],
{useNativeDriver: true}
)}
scrollEventThrottle={1}
/>
Now your element with move along with your Flatlist. This is a basic example, and you will probably need to mess with interpolation and CSS positioning to get it exactly as you want it.