DevKhalyd

//Flatbutton also works.
RaisedButton(
      shape: RoundedRectangleBorder(
        borderRadius: BorderRadius.circular(18.0),
        side: BorderSide(color: Colors.red)),
      onPressed: () {},
      color: Colors.red,
      textColor: Colors.white,
      child: Text("Buy now".toUpperCase(),
        style: TextStyle(fontSize: 14)),

DevKhalyd

import 'package:flutter/material.dart';

class HeaderSlash extends StatelessWidget {
  @override
  Widget build(BuildContext context) => CustomPaint(
        painter: _HeaderSlashCustom(),//The container shape
        child: Container(
          height: double.infinity,
          width: double.infinity,
        ),

DevKhalyd

import 'package:flutter/material.dart';

class WaveHeader extends StatelessWidget {
  @override
  Widget build(BuildContext context) => CustomPaint(
        painter: _WaveHeaderCustom(), //The container shape
        child: Container(
          height: double.infinity,
          width: double.infinity,
        ),

DevKhalyd

//Return the same values and If you want to update any value you can put it
Task copyWith(
          {String id,
          String initDate,
          String endDate,
          String task,
          bool isComplete}) =>
      Task(
        id: id ?? this.id,
        initDate: initDate ?? this.initDate,

DevKhalyd

//Use CustomPaint Wiget
     Container(
            padding: EdgeInsets.all(5),
            width: 300,
            height: 300,
            //This class should be used
            child: CustomPaint(
              painter: _CustomPaint(porcentage),
            ),
          );

DevKhalyd

CupertinoAlertDialog(
      title: Text(title),
      content: Text(description),
      actions: [
        CupertinoDialogAction(
          child: Text('No'),
          onPressed: onNegativePressed,
        ),
        CupertinoDialogAction(
          child: Text('Yes'),

DevKhalyd

AlertDialog(
      title: Text(title),
      content: Text(description),
      elevation: 16.0,
      actions: [
        FlatButton(onPressed: onNegativePressed, child: Text('No')),
        FlatButton(onPressed: onAffirmativePressed, child: Text('Yes')),
      ],
    );

DevKhalyd

class MyHomePage extends StatefulWidget {
  @override
  MyHomePageState createState() {
    return new MyHomePageState();
  }
}

class MyHomePageState extends State<MyHomePage> {
  final _text = TextEditingController();
  bool _validate = false;

DevKhalyd

//With Map function the Iterable can be changed to another type or another value 
var numbersByTwo = [1, -2, 3, 42].map((number) => number * 2);
  print('Numbers: $numbersByTwo.');

DevKhalyd

import 'package:flutter/material.dart';

//Example: https://stackoverflow.com/questions/26748605/how-to-store-function-as-class-member-variable?rq=
//In dart the functions can be Objects
///
typedef Widget BuilderState(
    BuildContext context, void Function(void Function()) setState);

double getScreenWidth(BuildContext context) =>
    MediaQuery.of(context).size.width;