توسعه اپلیکیشن فلاتر: چگونه به‌طور همزمان برای iOS و اندروید بنویسیم

Create apps for iOS and Android phones and tablets using Flutter, a Google framework that produces two outputs for a single app. Let's face it, creating iOS apps using Apple tools such as Swift and Xcode is extremely complicated. Creating Android apps with Kotlin and Android Studio is just as difficult. This book breaks down complex concepts and tasks into easily digestible segments with examples, full-color pictures, and hands-on labs with starters and solutions. As you work through the accompanying lab exercises, you'll learn the Dart programming language; the entire Flutter development toolchain; the differences between stateful and stateless widgets; and a working knowledge of the architecture of apps. You'll work with themes and styles, develop custom widgets, and even teach your app to respond to gestures like taps, swipes, and pinches. You'll also design, create, and control the layout of your app. Create tools to handle form data entry from users. And ultimately create killer multiscreen apps with navigation, menus, and tabs. Worldwide Praise for Flutter App Development: How to Write for iOS and Android at Once Table of Contents About the Author About the Technical Reviewer Who Is This Book For? Foreword Preface Chapter 1: Hello Flutter What Is Flutter? Why Flutter? The Other Options Native Solutions Conclusion Chapter 2: Developing in Flutter The Flutter Toolchain The Flutter SDK Installing the Flutter SDK IDEs VS Code from Microsoft Android Studio/IntelliJ from JetBrains Which IDE Should I Use? IDE DevTools Emulators iOS Simulator Android Emulator Keeping the Tools Up to Date Flutter doctor Flutter Upgrade The Flutter Development Process Scaffolding the App and Files Anatomy of a Flutter Project Running Your App Running It As a Web App Running It on a Tethered Device Hot Reloading Debugging Conclusion Chapter 3: Everything Is Widgets UI As Code Built-In Flutter Widgets Value Widgets Layout Widgets Navigation Widgets Other Widgets How to Create Your Own Stateless Widgets Widgets Have Keys Passing a Value into Your Widget Stateless and Stateful Widgets So Which One Should I Create? Conclusion Chapter 4: Value Widgets The Text Widget The Icon Widget The Image Widget Embedded Images Network Images Sizing an Image SnackBar Widget Input Widgets Text Fields Making Your TextField Fancy Password Boxes Adjusting the Soft Keyboard Restricting the Data That Can Be Typed Checkboxes Radio Buttons Sliders Dropdowns Putting the Form Widgets Together Form Widget FormField Widget TextFormField and DropdownButtonFormField onSaved validator Submitting the Form One Big Form Example Conclusion Chapter 5: Responding to Gestures Meet the Button Family ElevatedButton TextButton and IconButton FloatingActionButton (FAB) SegmentedButton CupertinoButton Dismissible Custom Gestures for Your Custom Widgets Step 1: Decide on Your Gestures and Behaviors Step 2: Create Your Custom Widget Step 3: Add a GestureDetector widget Step 4: Associate Your Gesture with Its Behavior Example 1: Reacting to a Long Press Example 2: Pinching to Add a New Item Example 3: Swiping Left or Right Conclusion Chapter 6: Navigation and Routing Stack Navigation Navigating Forward and Back Using Anonymous Routes Get Result After a Scene Is Closed Drawer Navigation The Drawer Widget Filling the Drawer Tab Navigation DefaultTabController TabBarView TabBar and Tabs TabBar at the Bottom The Dialog Widget showDialog() and AlertDialog Responses with a Dialog Navigation Methods Can Be Combined Chapter 7: Managing State What Is State? The Shape of a StatefulWidget The Most Important Rule About State! Passing State Down Lifting State Back Up An Example of State Management When Should We Use State? Conclusion Chapter 8: State Management Libraries The InheritedWidget The BLoC Pattern Some Libraries ScopedModel Redux and Hooks Provider Whoa! That’s a Lot of Packages! Raw State Riverpod 1. Install flutter_riverpod 2. Wrap Your App with a ProviderScope 3. Write a Provider Wait, What Is This Provider You Speak Of? 4. Inherit from ConsumerStateWidget 5. Read Data with ref.watch() 6. Write Data with ref.read() Conclusion Chapter 9: Making RESTful API Calls with HTTP What Is an API Call? The Flavors of API Requests Making an HTTP GET or DELETE Request Making an HTTP PUT, POST, or PATCH Request HTTP Responses to Widgets Brute Force – The Easy Way FutureBuilder – The Clean Way StreamBuilder Strongly Typed Classes Create a Business Class Write a .fromJSON() Method Use .fromJSON() to Hydrate the Object One Big Example Overview of the App Create the Flutter App Making a Strongly Typed Business Class list_people.dart A GET Request in Flutter A DELETE Request in Flutter upsert_person.dart A POST and PUT Request in Flutter Conclusion Chapter 10: Styling with Themes Thinking in Flutter Styles Individual Styles Styling Text Mass-Changing Values Themes 1. ColorScheme 2. TextTheme 3. Widget-Specific Themes 4. Put Them Together in a Theme 5. Override the Styles on Individual Widgets Final Styling Thoughts A Word About Colors Custom Fonts Conclusion Chapter 11: Laying Out Your Widgets Our Approach 1. Layout the Entire Screen (a.k.a. Scene) 2. Position Widgets Above and Below Each Other or Side by Side 3. Handle Situations When We Run Out of Space and Overflow the Scene 4. Handle Extra Space in the Scene 5. Make Finer Adjustments in Positioning Laying Out the Whole Scene MaterialApp Widget The Scaffold Widget The AppBar Widget SafeArea Widget Flutter’s Layout Algorithm The Dreaded “Unbounded Height” Error The Algorithm Itself Conclusion Chapter 12: Layout – Positioning Widgets Putting Widgets Next to or Below Others Responsive Design Responsive Design in Flutter Flex and MediaQuery Conclusion Chapter 13: Layout – Fixing Overflows Overflow Warning Bars Our Options to Correct Overflows A Sample Problem to Solve 1. Allow the Children to Wrap 2. Squeeze the Children Until They Fit 3. Allow the User to Scroll SingleChildScrollView Widget The ListView Widget ListView Is Memory Efficient ListView Is Very Flexible Regular ListView ListView.builder: When You’re Building Widgets from a List of Objects GridView Widget GridView.extent() GridView.count() Conclusion Chapter 14: Layout – Filling Extra Space What if There’s Extra Space Left Over? mainAxisAlignment crossAxisAlignment IntrinsicWidth Expanded Widget Open Space with Expandeds Conclusion Chapter 15: Layout – Fine-Tuning Positioning Container Widget and the Box Model EdgeInsets for Padding and Margin Alignment and Positioning Within a Container Container Sizes Are Not Obvious Container Decorations Border BorderRadius BoxShape Conclusion Chapter 16: Layout – Special Presentation Widgets Slivers Stack Widget Positioned Widget Card Widget The Table Widget Conclusion Appendix A: Dart Language Overview What Is Dart? Expected Features – Dart Cheat Sheet Data Types Arrays/Lists Conditional Expressions Looping Classes Class Constructors Unexpected Things About Dart Type Inference final vs. const Null Safety String interpolationwith $ Multiline Strings Spread Operator Map Functions Are Objects Big Arrow/Fat Arrow/Lambda Named Function Parameters Omitting “new” and “this.” Class Constructor Parameter Shorthand Private Class Members Mixins The Cascade Operator (..) No Overloading Named Constructors Appendix B: Futures, Async, and Await Flutter Apps Use an Event Loop Why Would It Wait? How Do We Get the Data from a Future? Await Async Summary Appendix C: Including Packages in Your Flutter App Finding a Library to Use Downloading the Library The pubspec.yaml File Using These Packages in Your Code Keeping Your Packages Current How to Upload Your Own Library Appendix D: How to Work with Files Including a File with Your App Writing a File And Reading It! Using JSON Writing Your App’s Memory to JSON Reading JSON into Your App’s Memory Shared Preferences To Write Preferences To Read Preferences Conclusion Appendix E: How to Debug Your Layout Index