EBook reader Application in Flutter

dependencies:
  flutter:
    sdk: flutter
  provider: ^6.1.4
  url_launcher: ^6.3.1
  http: ^1.3.0

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import 'screens/home_screen.dart';
import 'services/google_books_api.dart';

// Entry point of the Flutter application
void main() {
  runApp(const MyApp());
}

// Root widget of the application
class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MultiProvider(
      // Providing dependencies to the widget tree using MultiProvider
      providers: [
        // Registering GoogleBooksApi as a ChangeNotifier for state management
        ChangeNotifierProvider(create: (_) => GoogleBooksApi()),
      ],
      child: MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'EBook reader Application',
        // Sets the HomeScreen as the initial screen
        home: const HomeScreen(),
      ),
    );
  }
}

import 'dart:convert';               
import 'package:flutter/material.dart'; 
import 'package:http/http.dart' as http; 

class GoogleBooksApi extends ChangeNotifier {
  // List to store fetched books data from the API
  List books = [];                    

  // Boolean to indicate whether data is currently being fetched
  bool isLoading = false;              

  // Function to search books based on user query
  Future<void> search(String query) async {
    // Construct the URL for the Google Books API with the query string
    final url =
        'https://www.googleapis.com/books/v1/volumes?q=$query';

    // Set loading state to true to indicate data fetching has started
    isLoading = true;
    // Notify listeners (e.g., UI) to update the loading state
    notifyListeners();   

    try {
      // Make an HTTP GET request to the Google Books API
      final response = await http.get(Uri.parse(url));

      // Log the response status code for debugging purposes
      print("response status code ${response.statusCode}");

      // Check if the request was successful (HTTP status code 200)
      if (response.statusCode == 200) {
        // Parse the JSON response body
        final data = json.decode(response.body);   
        // Extract the 'items' field from the response, or set to an empty list if null
        books = data['items'] ?? [];  
      } else {
        // If the request fails, clear the books list
        books = [];  
      }
    } catch (e) {
      // Handle any exceptions that occur during the HTTP request
      // Clear the books list in case of an error
      books = [];
    }

    // Set loading state to false to indicate data fetching is complete
    isLoading = false;
    // Notify listeners (e.g., UI) to update the loading state and display results
    notifyListeners();   
  }
}

import 'package:flutter/material.dart';
import 'package:provider/provider.dart';
import '../services/google_books_api.dart';
import './book_details.dart';

// HomeScreen is the main screen of the application where users can search for books
class HomeScreen extends StatelessWidget {
  const HomeScreen({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // Access the GoogleBooksApi provider
    final bookProvider = Provider.of<GoogleBooksApi>(context);
    // Controller for the search input field
    TextEditingController searchController = TextEditingController();

    return Scaffold(
      appBar: AppBar(
        centerTitle: true,
        title: const Text(
          'EBook reader Application',
          style: TextStyle(fontSize: 25),
        ),
        backgroundColor: Colors.green[700],
        foregroundColor: Colors.white,
        toolbarHeight: 70,
        elevation: 5,
        shadowColor: Colors.green[700],
        shape: RoundedRectangleBorder(borderRadius: BorderRadius.circular(20)),
      ),
      body: Column(
        children: [
          const SizedBox(height: 10), // Adds spacing at the top
          Padding(
            padding: const EdgeInsets.all(10.0),
            child: TextField(
              // Binds the controller to the TextField
              controller: searchController,
              // Triggers search on submission
              onSubmitted:
                  (value) => bookProvider.search(searchController.text),
              decoration: InputDecoration(
                border: OutlineInputBorder(),
                focusedBorder: OutlineInputBorder(
                  borderSide: const BorderSide(
                    color: Color.fromARGB(255, 3, 131, 29),
                  ),
                  borderRadius: BorderRadius.circular(10.0),
                ),
                // Placeholder text
                labelText: 'Search for books',
                labelStyle: TextStyle(color: Color.fromARGB(255, 3, 131, 29)),
                suffixIcon: IconButton(
                  icon: const Icon(
                    Icons.search,
                    size: 30,
                    color: Color.fromARGB(255, 3, 131, 29),
                  ),
                  onPressed: () {
                    // Triggers search on button press
                    bookProvider.search(searchController.text);
                  },
                ),
              ),
            ),
          ),
          Expanded(
            // Checks if data is still loading
            child:
                bookProvider.isLoading
                    ? const Center(
                      child: CircularProgressIndicator(
                        color: Color.fromARGB(255, 3, 131, 29),
                      ),
                    )
                    : ListView.builder(
                      // Number of books to display
                      itemCount: bookProvider.books.length,
                      itemBuilder: (context, index) {
                        // Current book data
                        final book = bookProvider.books[index];
                        return ListTile(
                          // Book title
                          title: Text(
                            book['volumeInfo']['title'] ?? 'No Title',
                          ),
                          // Authors list
                          subtitle: Text(
                            book['volumeInfo']['authors'] != null
                                ? book['volumeInfo']['authors'].join(', ')
                                : 'Unknown Author', // Fallback if no authors are available
                          ),
                          onTap: () {
                            // Navigate to the BookDetail screen when a book is tapped
                            Navigator.push(
                              context,
                              MaterialPageRoute(
                                builder: (context) => BookDetail(book: book),
                              ),
                            );
                          },
                        );
                      },
                    ),
          ),
        ],
      ),
    );
  }
}

import 'package:flutter/material.dart';
import 'package:url_launcher/url_launcher.dart';

class BookDetail extends StatelessWidget {
  final Map book;

  const BookDetail({Key? key, required this.book}) : super(key: key);
  // Function to open URLs in the browser
  Future<void> _launchURL(String url) async {
    try {
      // Encode the URL to handle special characters
      final Uri uri = Uri.parse(url);
      if (!await launchUrl(uri)) {
        throw Exception('Could not launch $uri');
      }
    } catch (e) {
      // Show a snackbar with the error message
      debugPrint('Error launching URL: $e');
      // You might want to show this error to the user through a SnackBar
      // or other UI element
    }
  }

  @override
  Widget build(BuildContext context) {
    final volumeInfo = book['volumeInfo'];

    // Extract URLs
    final thumbnail =
        volumeInfo['imageLinks'] != null
            ? volumeInfo['imageLinks']['thumbnail']
            : null;

    final previewLink = volumeInfo['previewLink'];
    final downloadLink =
        book['accessInfo'] != null
            ? book['accessInfo']['pdf'] != null &&
                    book['accessInfo']['pdf']['isAvailable']
                ? book['accessInfo']['pdf']['acsTokenLink']
                : null
            : null;

    final buyLink = volumeInfo['infoLink'];

    return Scaffold(
      appBar: AppBar(title: Text(volumeInfo['title'] ?? 'No Title')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(8.0),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // Display the image with a placeholder and error handling
            thumbnail != null
                ? Center(
                  child: Image.network(
                    thumbnail,
                    fit: BoxFit.cover,
                    loadingBuilder: (context, child, loadingProgress) {
                      if (loadingProgress == null) {
                        return child;
                      }
                      return const Center(child: CircularProgressIndicator());
                    },
                    errorBuilder: (context, error, stackTrace) {
                      return const Icon(Icons.error, size: 100);
                    },
                  ),
                )
                : const Icon(Icons.book, size: 100),
            const SizedBox(height: 16),
            Text(
              volumeInfo['title'] ?? 'No Title',
              style: const TextStyle(fontSize: 15, fontWeight: FontWeight.bold),
            ),
            const SizedBox(height: 8),
            Text(
              'Author(s): ' +
                  (volumeInfo['authors'] != null
                      ? volumeInfo['authors'].join(', ')
                      : 'Unknown'),
            ),
            const SizedBox(height: 8),
            Text(volumeInfo['description'] ?? 'No Description'),
            const SizedBox(height: 16),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                // Preview Button
                if (previewLink != null)
                  ElevatedButton(
                    onPressed: () {
                      _launchURL(previewLink);
                    },
                    child: const Text(
                      'Preview',
                      style: TextStyle(
                        fontSize: 10,
                        letterSpacing: 1.0,
                        fontWeight: FontWeight.bold,
                      ),
                      textAlign: TextAlign.center,
                    ),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.green[700],
                      foregroundColor: Colors.white,
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(10),
                      ),
                      padding: EdgeInsets.only(
                        right: 20,
                        left: 25,
                        top: 15,
                        bottom: 15,
                      ),
                    ),
                  ),
                const SizedBox(width: 10),
                // Download Button
                if (downloadLink != null)
                  ElevatedButton(
                    onPressed: () {
                      _launchURL(downloadLink);
                    },
                    child: const Text(
                      'Download',
                      style: TextStyle(
                        fontSize: 10,
                        letterSpacing: 1.0,
                        fontWeight: FontWeight.bold,
                      ),
                      textAlign: TextAlign.center,
                    ),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.green[700],
                      foregroundColor: Colors.white,
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(10),
                      ),
                      padding: EdgeInsets.only(
                        right: 20,
                        left: 25,
                        top: 15,
                        bottom: 15,
                      ),
                    ),
                  )
                else
                  ElevatedButton(
                    onPressed: () {
                      _launchURL(buyLink);
                    },
                    child: const Text(
                      'More Info',
                      style: TextStyle(
                        fontSize: 10,
                        letterSpacing: 1.0,
                        fontWeight: FontWeight.bold,
                      ),
                      textAlign: TextAlign.center,
                    ),
                    style: ElevatedButton.styleFrom(
                      backgroundColor: Colors.green[700],
                      foregroundColor: Colors.white,
                      shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(10),
                      ),
                      padding: EdgeInsets.only(
                        right: 20,
                        left: 25,
                        top: 15,
                        bottom: 15,
                      ),
                    ),
                  ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}