KeyboardVisibilityBuilder - a Flutter widget that rebuilds when the keyboard is shown or dismissed

readme.md

KeyboardVisibilityBuilder - a Flutter widget that rebuilds when the keyboard is shown or dismissed

Created with <3 with dartpad.dev.

keyboard_visibility_builder.dart

import 'package:flutter/material.dart';

class KeyboardVisibilityBuilder extends StatefulWidget {
  const KeyboardVisibilityBuilder({
    required this.builder,
    this.child,
    Key? key,
  }) : super(key: key);

  final Widget Function(
    BuildContext context,
    bool isKeyboardVisible,
    Widget? child,
  ) builder;
  final Widget? child;

  @override
  _KeyboardVisibilityBuilderState createState() =>
      _KeyboardVisibilityBuilderState();
}

class _KeyboardVisibilityBuilderState extends State<KeyboardVisibilityBuilder>
    with WidgetsBindingObserver {
  late bool _isVisible;

  @override
  void initState() {
    super.initState();
    _isVisible = WidgetsBinding.instance!.window.viewInsets.bottom > 0.0;
    WidgetsBinding.instance!.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance!.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeMetrics() {
    final isVisible = WidgetsBinding.instance!.window.viewInsets.bottom > 0.0;
    if (isVisible != _isVisible) {
      setState(() {
        _isVisible = isVisible;
      });
    }
  }

  @override
  Widget build(BuildContext context) => widget.builder(
        context,
        _isVisible,
        widget.child,
      );
}

main.dart

import 'package:flutter/material.dart';

class KeyboardVisibilityBuilder extends StatefulWidget {
  const KeyboardVisibilityBuilder({
    required this.builder,
    this.child,
    super.key,
  });

  final Widget Function(
    BuildContext context,
    bool isKeyboardVisible,
    Widget? child,
  ) builder;
  final Widget? child;

  @override
  State<KeyboardVisibilityBuilder> createState() =>
      _KeyboardVisibilityBuilderState();
}

class _KeyboardVisibilityBuilderState extends State<KeyboardVisibilityBuilder>
    with WidgetsBindingObserver {
  late bool _isVisible;

  @override
  void initState() {
    super.initState();
    _isVisible = MediaQuery.of(context).viewInsets.bottom > 0.0;
    WidgetsBinding.instance.addObserver(this);
  }

  @override
  void dispose() {
    WidgetsBinding.instance.removeObserver(this);
    super.dispose();
  }

  @override
  void didChangeMetrics() {
    final isVisible = MediaQuery.of(context).viewInsets.bottom > 0.0;
    if (isVisible != _isVisible) {
      setState(() {
        _isVisible = isVisible;
      });
    }
  }

  @override
  Widget build(BuildContext context) => widget.builder(
        context,
        _isVisible,
        widget.child,
      );
}