switch_when 0.0.1
switch_when: ^0.0.1 copied to clipboard
A function library that provides a more advanced switch method, does not limit the case expression to be constant, which is close to the when method of kotlin
import 'package:flutter/material.dart';
import 'package:switch_when/index.dart';
void main() {
runApp(MyApp());
}
class MyApp extends StatelessWidget {
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'tween_image_widget Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: MyHomePage(title: 'Tween Image Widget Home Page'),
);
}
}
class MyHomePage extends StatefulWidget {
MyHomePage({Key? key, required this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
_MyHomePageState createState() => _MyHomePageState();
}
extension Stringx on String {
String more() {
return "$this more";
}
}
class _MyHomePageState extends State<MyHomePage> {
testWhenString() {
int howManyFruits = 2;
int? index = whenString<int>("banana🍌", {
"water" + "melon".more(): () {
return 1;
},
"apple".more(): () {
return 2;
},
howManyFruits <= 1 ? "orange" : "oranges": () {
return 3;
},
"banana" + "🍌": () {
return 4;
},
"grape": () {
return 5;
},
});
return index;
}
testWhenInt() {
String? status = whenInt<String>(1, {
1: () {
return "good";
},
1 + 1: () {
return "nice";
},
int.parse("3"): () {
return "better";
},
});
return status;
}
testWhenDouble() {
String? status = whenDouble<String>(2.0, {
0.1: () {
return "good";
},
1.0 + 1: () {
return "nice";
},
double.parse("3.2"): () {
return "better";
},
});
return status;
}
testWhenValue() {
String? kind = whenValue<List, String>(
["apple", "orange"],
{
["cat", "dog"]: () {
return "pets";
},
["apple", "orange"]: () {
return "fruits";
},
["red", "white", "black"]: () {
return "colors";
},
},
);
return kind;
}
testWhen() {
String? winner = when<String>({
"Dart is Language".contains("UI"): () {
return "Flutter";
},
"Flutter is UI Framework".contains("UI"): () {
return "Flutter";
},
});
return winner;
}
testWhenTrue() {
String? something = whenTrue<String>({
() {
if (1 + 100 * 1000 < 2000) {
return false;
} else if ("Who is my lovely baby?".length > 10) {
return true;
} else {
return false;
}
}: () {
return "Test OK";
},
() {
return int.tryParse("3.14*") != null;
}: () {
return "PI get";
}
});
return something;
}
Map<String, Function> get data => {
"""
int howManyFruits = 2;
int? index = whenString<int>("banana🍌", {
"water" + "melon".more(): () {
return 1;
},
"apple".more(): () {
return 2;
},
howManyFruits <= 1 ? "orange" : "oranges": () {
return 3;
},
"banana" + "🍌": () {
return 4;
},
"grape": () {
return 5;
},
});
""": testWhenString,
"""
String? status = whenInt<String>(1, {
1: () {
return "good";
},
1 + 1: () {
return "nice";
},
int.parse("3"): () {
return "better";
},
});
""": testWhenInt,
"""
String? status = whenDouble<String>(2.0, {
0.1: () {
return "good";
},
1.0 + 1: () {
return "nice";
},
double.parse("3.2"): () {
return "better";
},
});
""": testWhenDouble,
"""
String? kind = whenValue<List, String>(
["apple", "orange"],
{
["cat", "dog"]: () {
return "pets";
},
["apple", "orange"]: () {
return "fruits";
},
["red", "white", "black"]: () {
return "colors";
},
},
);
""": testWhenValue,
"""
String? winner = when<String>({
"Dart is Language".contains("UI"): () {
return "Flutter";
},
"Flutter is UI Framework".contains("UI"): () {
return "Flutter";
},
});
""": testWhen,
"""
String? something = whenTrue<String>({
() {
if (1 + 100 * 1000 < 2000) {
return false;
} else if ("Who is my lovely baby?".length > 10) {
return true;
} else {
return false;
}
}: () {
return "Test OK";
},
() {
return int.tryParse("3.14*") != null;
}: () {
return "PI get";
}
});
""": testWhenTrue,
};
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: ListView(
children: data.entries
.map((method) => Column(
children: [
Text(method.key),
Text("run result=> ${method.value()}"),
SizedBox(
height: 20,
),
],
))
.toList(),
),
),
);
}
}