I want to make somthing like this in flutter

whitch is a blue iamge above a text but it's displied part by part ,how I can made somthing like this or if there is any good libery for that I on ready google it but I didnt find what excatly what I want

I try this but it's not what I want excatly

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: "App",
      home: Test(),
    );
  }
}

class Test extends StatefulWidget {
  @override
  _TestState createState() => _TestState();
}

class _TestState extends State<Test> {
  double rightValue = 1000;
  @override
  void initState() {
    // TODO: implement initState
    super.initState();
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        backgroundColor: Colors.black,
        body: SafeArea(
          child: Center(
            child: Stack(
              alignment: Alignment.center,
              children: [
                AnimatedPositioned(
                  duration: Duration(seconds: 2),
                  right: rightValue,
                  child: Image.asset('assets/images/bg.png'),
                ),
                Center(
                  child: Text('Hello world',
                      style: TextStyle(
                          color: Colors.white,
                          fontSize: 24,
                          fontWeight: FontWeight.bold)),
                ),
                //),
              ],
            ),
          ),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () {
            setState(() {
              rightValue = 0;
            });
          },
        ),
      ),
    );
  }
}

CodePudding user response：

the idea is using CustomClipper, animate it to reveal image :

EDIT -- as of yeasin suggestion, you can animate the text with color tween, warp it in stack.

here edited result :

code :

class Testing extends StatefulWidget {
  const Testing({Key? key}) : super(key: key);

  @override
  State<Testing> createState() => _TestingState();
}

class _TestingState extends State<Testing> with SingleTickerProviderStateMixin {
  late final AnimationController _animationController;
  late final Animation<double> _animation;
  late final Animation<Color?> _animationColor;

  @override
  void initState() {
    // TODO: implement initState
    super.initState();
    _animationController = AnimationController(
        vsync: this, duration: const Duration(milliseconds: 1200))
      ..repeat(reverse: false);
    _animation = Tween<double>(begin: 0.0, end: 1.0).animate(
        CurvedAnimation(parent: _animationController, curve: Curves.ease));
    _animationColor = ColorTween(begin: Colors.black, end: Colors.white)
        .animate(
            CurvedAnimation(parent: _animationController, curve: Curves.ease));
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          Center(
            child: AnimatedBuilder(
              animation: _animationController,
              builder: (context, child) {
                return ClipPath(
                  clipper: MyClipper(anim: _animation.value),
                  child: Container(
                    height: 300.0,
                    width: 300.0,
                    color: Colors.blue,
                  ),
                );
              },
            ),
          ),
          AnimatedBuilder(
            animation: _animationController,
            builder: (context, _) {
              return Center(
                  child: Text(
                "your image",
                style: TextStyle(
                    fontSize: 20.0,
                    fontWeight: FontWeight.bold,
                    color: _animationColor.value),
              ));
            },
          ),
        ],
      ),
    );
  }
}

class MyClipper extends CustomClipper<Path> {
  final double anim;
  MyClipper({required this.anim});
  @override
  getClip(Size size) {
    // TODO: implement getClip
    var rect = Rect.fromLTWH(0.0, 0.0, size.width * anim, size.height);
    var path = Path();
    path.addRect(rect);
    return path;
  }

  @override
  bool shouldReclip(covariant MyClipper oldClipper) {
    return oldClipper != this;
  }
}