플러터챌린지 7일차 심화문제 - 신현호 

readme.md

플러터챌린지 7일차 심화문제 - 신현호 

Created with <3 with dartpad.dev.

main.dart

import 'dart:math';

import 'package:flutter/material.dart';


void main() {
  runApp(
    const MaterialApp(
      debugShowCheckedModeBanner: false,
      home: ILoveFlutterBootScreen(),
    ),
  );
}

class ILoveFlutterBootScreen extends StatefulWidget {
  const ILoveFlutterBootScreen({super.key});

  @override
  State<ILoveFlutterBootScreen> createState() => _ILoveFlutterBootScreenState();
}

class _ILoveFlutterBootScreenState extends State<ILoveFlutterBootScreen> {
  static const NetworkImage background = NetworkImage('https://docs.flutter.dev/assets/images/dash/Dashatars.png');
  GlobalKey gKey = GlobalKey();

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(
          image: DecorationImage(
            image: background,
            fit: BoxFit.cover,
          ),
        ),
      ),
      floatingActionButton: GestureDetector(
        key: gKey,
        onTap: flyingDash,
        child: Container(
          decoration: BoxDecoration(
            shape: BoxShape.circle,
            border: Border.all(width: 2, color: Colors.blue),
          ),
          child: const Padding(
            padding: EdgeInsets.all(10.0),
            child: Icon(
              Icons.flutter_dash_rounded,
              color: Colors.blue,
              size: 40,
            ),
          )
        ),
      ),
    );
  }

  void flyingDash() {
    OverlayEntry? overlayEntry;
    overlayEntry = OverlayEntry(builder: (BuildContext context) {
      RenderBox renderBox = gKey.currentContext!.findRenderObject() as RenderBox;
      Offset beginOffset = renderBox.localToGlobal(Offset.zero);

      return FlutterDash(
        offset: beginOffset,
        entry: overlayEntry,
        arrival: MediaQuery.of(context).size.height / 2,
      );
    });

    Overlay.of(context, debugRequiredFor: widget).insert(overlayEntry);
  }
}

class FlutterDash extends StatefulWidget {
  final Offset offset;
  final OverlayEntry? entry;
  final double arrival;
  
  const FlutterDash({
    required this.offset,
    required this.entry,
    required this.arrival,
  });

  @override
  State<FlutterDash> createState() => _FlutterDashState();
}

class _FlutterDashState extends State<FlutterDash>
    with TickerProviderStateMixin {
  late AnimationController controller;
  late Animation animationX, animationY;
  late double currentX, currentY;
  late Color dashColor;
  late double dashSize;
  
  int getRandomInt(int maxValue) {
    return Random().nextInt(maxValue);
  }
  
  Color getRandomColor() {
    return Color.fromRGBO(getRandomInt(256), getRandomInt(256), getRandomInt(256), 0.5,);
  }
  
  double getRandomSize() {
    return 30 + getRandomInt(30).toDouble();
  }
  
  TweenSequence<double> backAndForth(double posX, int count) {
    List<TweenSequenceItem<double>> items = [];

    for (int i = 0; i < count; i++) {
      double gap = 2 + getRandomInt(80) / 10;
      items.add(
        TweenSequenceItem<double>(
          tween: Tween<double>(begin: posX + (i % 2 == 0 ? -gap : gap), end: posX + (i % 2 == 0 ? gap : -gap)),
          weight: 20,
        ),
      );
    }

    return TweenSequence<double>(items);
  }

  @override
  void initState() {
    super.initState();
    
    currentX = widget.offset.dx - 10 + Random().nextInt(30);
    currentY = widget.offset.dy;

    dashColor = getRandomColor();
    dashSize = getRandomSize();

    controller = AnimationController(
      vsync: this,
      duration: const Duration(seconds: 5),
    );
    
    animationX = backAndForth(currentX, 8).animate(controller);

    animationY = Tween<double>(
      begin: widget.offset.dy,
      end: widget.arrival,
    ).animate(controller)
      ..addListener(() {
        setState(() {
          currentX = animationX.value;
          currentY = animationY.value;
        });
      })
      ..addStatusListener((status) {
        if (status == AnimationStatus.completed) {
          setState(() {
            widget.entry?.remove();
          });
        }
      });

    controller.forward();
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: [
        AnimatedBuilder(
          animation: controller,
          builder: (context, child) {
            return Transform.translate(
              offset: Offset(currentX, currentY),
              child: Icon(Icons.flutter_dash, size: dashSize, color: dashColor),
            );
          },
        ),
      ],
    );
  }
}