hash-wallet/lib/src/widgets/animated_typing_text.dart

import 'package:flutter/material.dart';

class AnimatedTypingText extends StatefulWidget {
  final List<String> words;
  final TextStyle? style;
  final Duration typingSpeed;
  final Duration pauseDuration;
  final Color cursorColor;
  final double cursorWidth;
  final double cursorHeight;
  final Duration cursorBlinkDuration;

  const AnimatedTypingText({
    Key? key,
    required this.words,
    this.style,
    this.typingSpeed = const Duration(milliseconds: 100),
    this.pauseDuration = const Duration(milliseconds: 3000),
    this.cursorColor = Colors.black,
    this.cursorWidth = 2.0,
    this.cursorHeight = 20.0,
    this.cursorBlinkDuration = const Duration(milliseconds: 500),
  }) : super(key: key);

  @override
  State<AnimatedTypingText> createState() => _AnimatedTypingTextState();
}

class _AnimatedTypingTextState extends State<AnimatedTypingText> with TickerProviderStateMixin {
  late AnimationController _controller;
  late AnimationController _cursorController;
  late Animation<double> _cursorAnimation;

  String _displayText = '';

  int _currentWordIndex = 0;
  int _currentCharIndex = 0;

  bool _isTyping = true;
  bool _isPaused = false;
  bool _isWaitingForPause = false;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: widget.typingSpeed,
    );

    _cursorController = AnimationController(
      vsync: this,
      duration: widget.cursorBlinkDuration,
    )..repeat(reverse: true);

    _cursorAnimation = Tween<double>(begin: 1.0, end: 0.0).animate(
      CurvedAnimation(
        parent: _cursorController,
        curve: Curves.easeInOut,
      ),
    );

    _controller.addStatusListener((status) {
      if (status == AnimationStatus.completed) {
        _updateText();
        if (!_isWaitingForPause) {
          _controller.reset();
          _controller.forward();
        }
      }
    });

    _controller.forward();
  }

  void _updateText() {
    if (_isWaitingForPause) return;

    if (_isPaused) {
      if (_isTyping) {
        _isTyping = false;
        _isWaitingForPause = true;
        Future.delayed(widget.pauseDuration, () {
          if (mounted) {
            setState(() {
              _isPaused = false;
              _isWaitingForPause = false;
              _controller.reset();
              _controller.forward();
            });
          }
        });
      } else {
        _deletePrevChar();
      }
    } else {
      if (_isTyping) {
        _typeNextChar();
      } else {
        _deletePrevChar();
      }
    }

    setState(() {
      _displayText = widget.words[_currentWordIndex].substring(0, _currentCharIndex);
    });
  }

  void _typeNextChar() {
    if (_currentCharIndex < widget.words[_currentWordIndex].length) {
      _currentCharIndex++;
    } else {
      _isPaused = true;
    }
  }

  void _deletePrevChar() {
    if (_currentCharIndex > 0) {
      _currentCharIndex--;
    } else {
      _currentWordIndex = (_currentWordIndex + 1) % widget.words.length;
      _currentCharIndex = 0;
      _isTyping = true;
      _isPaused = false;
    }
  }

  @override
  void dispose() {
    _controller.dispose();
    _cursorController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      clipBehavior: Clip.none,
      children: [
        // Fixed cursor position
        Positioned(
          right: 0,
          bottom: 0,
          child: AnimatedBuilder(
            animation: _cursorAnimation,
            builder: (context, child) {
              return Opacity(
                opacity: _cursorAnimation.value,
                child: Container(
                  width: widget.cursorWidth,
                  height: widget.cursorHeight,
                  color: widget.cursorColor,
                ),
              );
            },
          ),
        ),
        // Animated text
        Align(
          alignment: Alignment.centerRight,
          child: Text(
            _displayText + ' ',
            style: widget.style,
          ),
        ),
      ],
    );
  }
}