Coding All-in-One For Dummies, 2nd Edition

Chapter 9

Moving Right Along …

IN THIS CHAPTER

Creating animation

Mixing other people's code with your own code

Animating size and color changes

Dragging widgets without dropping them or breaking them

This chapter is about animation — making things change right before the user's eyes. When I think about animation, I immediately think of movement, but Flutter provides a much broader definition of animation. With Flutter, you can change almost any property of a widget on almost any time scale.

Setting the Stage for Flutter Animation

This chapter's first listing has a bunch of reusable code. Subsequent listings contain code that works cooperatively with the code in the first listing. Thanks to Dart's extensions feature, each new listing can create methods belonging to the first listing's classes. You can read all about Dart extensions in Book 4, Chapter 8.

The code in Listing 9-1 can't do anything on its own. Instead, this code relies on declarations in the chapter's other listings.

LISTING 9-1: Reuse This Code

// app09main.dartimport 'package:flutter/material.dart';import 'app0902.dart'; ...