Flutter For Dummies

Introduction 1 How to Use This Book 1 Conventions Used in This Book 2 What You Don't Have to Read 2 Foolish Assumptions 3 How This Book is Organized 4 Part 1, Getting Ready 4 Part 2, Flutter: A Burd's-Eye View 4 Part 3, Details, Details 4 Part 4, The Part of Tens 4 More on the web! 5 Icons Used in This Book 5 Beyond the Book 6 Where to Go from Here 6 Part 1: Getting Ready 7 Chapter 1: What is Flutter? 9 Hardware and Software (Things You May Already Know) 10 Where Does Flutter Fit In? 15 Cross-platform development 15 A quick-and-easy development cycle 17 A great way to think about app development 25 Enough New Terminology! What's Next? 28 Chapter 2: Setting Up Your Computer for Mobile App Development 29 The Stuff You Need 30 What to Do 32 Getting and installing the stuff 32 For Mac users only 34 Configuring Android Studio 35 Running your first app 36 Dealing with the Devil's Details 43 On installing Android Studio 43 On launching Android Studio for the first time 44 On installing Android Studio's Flutter plugin 44 On adding virtual devices 46 On installing Flutter 50 Divisiveness Among Devices 52 Running apps on an Android device 52 Testing apps on a physical device 53 Using Android Studio 59 Starting up 59 The main window 60 Running This Book's Sample Programs 63 Enjoying reruns 65 If you're finicky 65 Were These Setup Steps Fun or What? 66 Part 2: Flutter: A Burd's-Eye View 67 Chapter 3: Hello From Flutter 69 First Things First 69 What's it all about? 72 A constructor's parameters 75 A note about punctuation 76 Don't relent - simply indent 77 Classes, Objects, and Widgets 79 A brief treatise on within-ness 81 The documentation is your friend 82 Making Things Look Nicer 83 Creating a scaffold 86 Adding visual tweaks 88 Dart's enum feature 89 Hello from sunny California! 89 Adding another widget 91 Centering the text (Part 1) 94 Centering the text (Part 2) 97 Displaying an image 100 Hey, Wait a Minute 104 Chapter 4: Hello Again 105 Creating and Using a Function 106 The function declaration 107 A function call 108 Parameters and the return value 108 Programming in Dart: The Small Stuff 112 Statements and declarations 112 Dart's typing feature 113 Literals, variables, and expressions 114 Two for the price of one 117 Dart's var keyword 119 Built-in types 121 Types that aren't built-in 123 Using import declarations 123 Variations on a Theme from Die Flutter Mouse 124 Type names in function declarations 127 Naming your parameters 128 What about the build function? 129 More Fun to Come! 130 Chapter 5: Making Things Happen 131 Let's All Press a Floating Action Button 132 Stateless widgets and stateful widgets 134 Widgets have methods 135 Pay no attention to the framework behind the curtain 139 Enhancing Your App 146 More parameters, please 148 The override annotation 151 What does mean? 152 Anonymous functions 153 What belongs where 156 Names that start with an underscore 160 Whew! 162 Chapter 6: Laying Things Out 163 The Big Picture 164 Creating bite-size pieces of code 167 Creating a parameter list 169 Living color 170 Adding padding 171 Your humble servant, the Column widget 173 The SizedBox widget 175 Your friend, the Container widget 176 Nesting Rows and Columns 181 More Levels of Nesting 183 Using the Expanded Widget 186 Expanded versus unexpanded 189 Expanded widget saves the day 192 Flexing some muscles 196 How Big is My Device? 199 Part 3: Details, Details 205 Chapter 7: Interacting with the User 207 A Simple Switch 208 Dart's const keyword 211 Compatible or NOT? 213 Wait For It! 214 How Much Do You Love Flutter? 217 Dealing with Text Fields 220 Callouts 1 and 2 223 Callout 3 225 Callout 4 226 Callout 5 230 Creating Radio Buttons 230 Creating an enum 233 Building the radio group 233 Displaying the user's choice 235 Creating a Dropdown Button 239 Building the dropdown button 242 The little Reset button 244 Making a Map 245 Onward and Upward 246 Chapter 8: Navigation, Lists, and Other Goodies 247 Extending a Dart Class 248 From One Page to Another 251 An icon on a button 254 Pushing and popping 255 Passing Data from Source to Destination 256 Passing Data Back to the Source 261 Dart's async and await keywords 264 Taking control of the app bar's Back button 266 Passing Data in Both Directions 267 Creating Named Routes 272 Creating a List 276 The ListView widget 279 Creating list items one-by-one 285 Another new Dart language feature 288 Fetching Data from the Internet 290 Using a public API 293 Sending a URL to a server 295 Making sense of a JSON response 296 What's Next? 296 Chapter 9: Moving Right Along 297 Setting the Stage for Flutter Animation 297 Moving Along a Straight Line 303 Bouncing Around 308 Animating Size and Color Changes 310 Moving Along a Curve 312 Dragging Things Around 314 Where To Go From Here 319 Part 4: The Part of Tens 321 Chapter 10: Ten Ways to Avoid Mistakes 323 Put Capital Letters Where They Belong 323 Use Parentheses When (and Only When) They're Appropriate 323 Limit Access to Variables 324 Call setState 324 Make Adjustments for Indices Starting at Zero 324 Use the Expanded Widget 325 Add itemCount to Your ListView.builder 325 Add Imports When They're Required 325 Declare Assets and Dependencies in pubspec.yaml 325 Indent Your Code According to Dart Language Guidelines 326 Chapter 11: Ten Ways to Enhance Your App Development Career 327 Practice! Practice! 327 Critique Your Own Code 328 Have Others Review Your Code 328 Find Out Which Technologies Your Nearby Companies Use 328 Attend User Group Meetings 328 Ask Questions 329 Ask Yourself Whether You Truly Understand 329 Learn Things That You May Never Need to Know 329 Do What You Love to Do 330 Get Plenty of Sleep 330 Chapter 12: Ten Chapters about Flutter App Development 331 Introduction 331 What is Flutter? 331 Setting Up Your Computer for Mobile App Development 332 'Hello' from Flutter 332 Hello Again 332 Making Things Happen 332 Laying Things Out 332 Interacting with the User 332 Navigation, Lists, and Other Goodies 333 Moving Right Along 333 Part 5: Appendices 335 Appendix: Doris's Dating App 337 Index 347