GHAYOOR
Published on

Prevent multiline TextInputs inside a ScrollView in React Native from gaining focus and triggering the keyboard on scroll

Authors
  • avatar
    Name
    Ghayoor ul Haq
    Twitter

When developing React Native applications, handling user input within a ScrollView can present challenges, especially when using multiline TextInput fields. A common issue occurs when scrolling over a large multiline TextInput. The input can gain focus unexpectedly, causing the keyboard to appear and interrupt the scroll.

This blog will guide you through identifying the problem and implementing a solution to ensure smooth scrolling without the keyboard unexpectedly appearing.

Note: This issue occurs in [email protected].

Reproducing the Issue

To better understand the problem, let's reproduce it using a minimal example:

  • We'll use KeyboardAwareScrollView from react-native-keyboard-aware-scroll-view to manage scroll behavior and keyboard avoidance.
  • The TextInput component will have a larger height to simulate a multiline input.
import React, { useState, useEffect } from 'react';
import {
    Text,
    TextInput,
    StyleSheet,
    View,
    TouchableOpacity,
    Keyboard,
    SafeAreaView
} from 'react-native';
import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view';

const DynamicTextInput = () => {
    const [value, setValue] = useState('');

    return (
        <TextInput
            value={value}
            onChangeText={setValue}
            style={styles.textInput}
            multiline
            placeholder={'Type something here'}
        />
    );
};

const ScrollableComponent = () => {
    const [keyboardVisible, setKeyboardVisible] = useState(false);

    useEffect(() => {
        const keyboardDidShowListener = Keyboard.addListener('keyboardDidShow', () => {
            setKeyboardVisible(true);
        });
        const keyboardDidHideListener = Keyboard.addListener('keyboardDidHide', () => {
            setKeyboardVisible(false);
        });

        return () => {
            keyboardDidShowListener.remove();
            keyboardDidHideListener.remove();
        };
    }, []);

    const handleDonePress = () => {
        Keyboard.dismiss(); // Close the keyboard
    };

    return (
        <SafeAreaView style={styles.safeArea}>
            <View style={styles.wrapper}>
                {keyboardVisible && (
                    <TouchableOpacity style={styles.doneButton} onPress={handleDonePress}>
                        <Text style={styles.doneButtonText}>Done</Text>
                    </TouchableOpacity>
                )}
                <KeyboardAwareScrollView contentContainerStyle={styles.container}>
                    <Text style={styles.text}>This is some text inside a ScrollView.</Text>
                    <DynamicTextInput />
                    <DynamicTextInput />
                    <DynamicTextInput />
                    <DynamicTextInput />
                    <DynamicTextInput />
                    <DynamicTextInput />
                </KeyboardAwareScrollView>
            </View>
        </SafeAreaView>
    );
};

const styles = StyleSheet.create({
    safeArea: {
        flex: 1,
        backgroundColor: '#fff',
    },
    wrapper: {
        flex: 1,
    },
    container: {
        flexGrow: 1,
        padding: 20,
        justifyContent: 'center',
    },
    text: {
        fontSize: 18,
        marginBottom: 20,
    },
    textInput: {
        borderColor: '#ccc',
        borderWidth: 1,
        padding: 10,
        fontSize: 16,
        height: 200,
        textAlignVertical: 'top',
        marginBottom: 20,
        borderRadius: 20,
    },
    doneButton: {
        position: 'absolute',
        right: 20,
        backgroundColor: '#007AFF',
        padding: 10,
        borderRadius: 5,
        zIndex: 1,
    },
    doneButtonText: {
        color: 'white',
        fontWeight: 'bold',
    },
});

export default ScrollableComponent;

Now when we scroll by tapping on TextInput, TextInput will get focused and keyboard will appear interrupting the scroll behavior.

Explanation of the Solution

To fix this, we need to:

  • Tracking Scroll State Using the onScrollBeginDrag, onScrollEndDrag, onMomentumScrollBegin and onMomentumScrollEnd events.
  • Disable TextInput focus while scrolling and re-enable it once the scroll ends.
  • Blur the input if it gets focused during a scroll to prevent the keyboard from opening.

Step-by-Step Solution:

Create a Scroll State and Timeout Reference

We’ll use the isScrolling state to track whether the user is actively scrolling. We also use a scrollTimeout to clear timeouts that we'll add.

const [isScrolling, setIsScrolling] = useState(false);
const scrollTimeout = useRef(null);

Handle Scroll Events

  • handleScrollBegin is triggered when scrolling starts, setting isScrolling to true.
  • handleScrollEnd delays the scroll-end event and sets isScrolling to false once scrolling has stopped.
const handleScrollBegin = useCallback(() => {
  setIsScrolling(true);
  if (scrollTimeout.current) clearTimeout(scrollTimeout.current);
}, []);

const handleScrollEnd = useCallback(() => {
  if (scrollTimeout.current) clearTimeout(scrollTimeout.current);
  scrollTimeout.current = setTimeout(() => {
   setIsScrolling(false);
  }, 150);
}, []);

Add Scroll Handlers to KeyboardAwareScrollView

Pass handleScrollBegin and handleScrollEnd to the scroll events of KeyboardAwareScrollView. This ensures we track when the user is scrolling.

<KeyboardAwareScrollView
  onScrollBeginDrag={handleScrollBegin}
  onMomentumScrollBegin={handleScrollBegin}
  onMomentumScrollEnd={handleScrollEnd}
  onScrollEndDrag={handleScrollEnd}
  ...
>

Update DynamicTextInput Component

Inside the DynamicTextInput component, we blur the input field if isScrolling is true and disable editing during scrolling.

const DynamicTextInput = ({ isScrolling }) => {
  const [value, setValue] = useState('');

  return (
    <TextInput
      onFocus={(event) => {
        if (isScrolling) {
          event.target.blur(); // Prevent focus during scrolling
        }
      }}
      placeholder={'Type something here'}
      value={value}
      onChangeText={setValue}
      style={styles.textInput}
      multiline
      editable={!isScrolling} // Disable editing while scrolling
    />
  );
};

Final Solution Code

Here’s the final code incorporating all the changes:

import React, { useState, useEffect, useRef, useCallback } from 'react';
import {
  Text,
  TextInput,
  StyleSheet,
  View,
  TouchableOpacity,
  Keyboard,
  SafeAreaView
} from 'react-native';
import { KeyboardAwareScrollView } from 'react-native-keyboard-aware-scroll-view';

const DynamicTextInput = ({ placeholder, isScrolling }) => {
  const [value, setValue] = useState('');

  return (
    <TextInput
      onFocus={(event)=>{
        if (isScrolling) {
            event.target.blur();
        }
      }}
      placeholder={'Type something here'}
      value={value}
      onChangeText={setValue}
      style={styles.textInput}
      multiline
      editable={!isScrolling}
    />
  );
};

const ScrollableComponent = () => {
  const [keyboardVisible, setKeyboardVisible] = useState(false);
  const [isScrolling, setIsScrolling] = useState(false);
  const scrollTimeout = useRef(null);


  const handleScrollBegin = useCallback(() => {
    setIsScrolling(true);
    if (scrollTimeout.current) clearTimeout(scrollTimeout.current);
  }, []);

  const handleScrollEnd = useCallback(() => {
    if (scrollTimeout.current) clearTimeout(scrollTimeout.current);
    scrollTimeout.current = setTimeout(() => {
      setIsScrolling(false);
    }, 150);
  }, []);


  const handleDonePress = () => {
    Keyboard.dismiss(); // Close the keyboard
  };

  useEffect(() => {
    const keyboardDidShowListener = Keyboard.addListener('keyboardDidShow', () => {
      setKeyboardVisible(true);
    });
    const keyboardDidHideListener = Keyboard.addListener('keyboardDidHide', () => {
      setKeyboardVisible(false);
    });

    return () => {
      keyboardDidShowListener.remove();
      keyboardDidHideListener.remove();
    };
  }, []);

  return (
    <SafeAreaView style={styles.safeArea}>
      <View style={styles.wrapper}>
        {keyboardVisible && (
          <TouchableOpacity style={styles.doneButton} onPress={handleDonePress}>
            <Text style={styles.doneButtonText}>Done</Text>
          </TouchableOpacity>
        )}
        <KeyboardAwareScrollView
          onScrollBeginDrag={handleScrollBegin}
          onMomentumScrollBegin={handleScrollBegin}
          onMomentumScrollEnd={handleScrollEnd}
          onScrollEndDrag={handleScrollEnd}
          contentContainerStyle={styles.container}>
          <Text style={styles.text}>This is some text inside a ScrollView.</Text>

          {/* Multiple DynamicTextInput components */}
          <DynamicTextInput isScrolling={isScrolling}  />
          <DynamicTextInput isScrolling={isScrolling} />
          <DynamicTextInput isScrolling={isScrolling} />
          <DynamicTextInput isScrolling={isScrolling} />
          <DynamicTextInput isScrolling={isScrolling} />
          <DynamicTextInput isScrolling={isScrolling} />
        </KeyboardAwareScrollView>
      </View>
    </SafeAreaView>
  );
};

const styles = StyleSheet.create({
  safeArea: {
    flex: 1,
    backgroundColor: '#fff',
  },
  wrapper: {
    flex: 1,
  },
  container: {
    flexGrow: 1,
    padding: 20,
    justifyContent: 'center',
  },
  text: {
    fontSize: 18,
    marginBottom: 20,
  },
  textInput: {
    borderColor: '#ccc',
    borderWidth: 1,
    padding: 10,
    fontSize: 16,
    height: 200,
    textAlignVertical: 'top',
    marginBottom: 20,
    borderRadius: 20,
  },
  doneButton: {
    position: 'absolute',
    right: 20,
    backgroundColor: '#007AFF',
    padding: 10,
    borderRadius: 5,
    zIndex: 1,
  },
  doneButtonText: {
    color: 'white',
    fontWeight: 'bold',
  },
});

export default ScrollableComponent;

Note: This issue primarily occurs on iPhones. If that is the case in your implementation, consider adding a platform-specific check to apply this solution exclusively for iOS devices.

Conclusion

By tracking the scroll state and preventing TextInput fields from gaining focus on scrolling, we enhance the user experience by ensuring smooth, uninterrupted scrolling in React Native apps. The solution is simple, but it significantly improves the usability of apps with complex input forms.