plagiarism_checker_plus 1.0.3

A Flutter package that checks plagiarism using Cosine Similarity and Jaccard Similarity algorithms.

example/main.dart

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

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Plagiarism Checker Plus',
      theme: ThemeData(
        useMaterial3: true,
        colorScheme: ColorScheme.fromSeed(
          seedColor: const Color(0xFF6750A4),
          brightness: Brightness.light,
        ),
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  final checker = PlagiarismCheckerPlus();
  final TextEditingController text1Controller = TextEditingController();
  final TextEditingController text2Controller = TextEditingController();
  double threshold = 0.7;
  Algorithm selectedAlgorithm = Algorithm.average;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text(
          'Plagiarism Checker Plus',
          style: TextStyle(fontWeight: FontWeight.w600),
        ),
        elevation: 0,
        centerTitle: true,
      ),
      body: Container(
        width: MediaQuery.sizeOf(context).width,
        height: MediaQuery.sizeOf(context).height,
        decoration: BoxDecoration(
          gradient: LinearGradient(
            begin: Alignment.topCenter,
            end: Alignment.bottomCenter,
            colors: [
              Theme.of(context).colorScheme.surface,
              Theme.of(context).colorScheme.surface.withOpacity(0.8),
            ],
          ),
        ),
        child: Column(
          children: [
            Expanded(
              flex: 4,
              child: Column(
                children: [
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.all(8.0),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          _buildSectionTitle('Original Text'),
                          const SizedBox(height: 8),
                          Expanded(
                            child: _buildTextArea(
                              text1Controller,
                              'Enter or paste original text here...',
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.all(8.0),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.start,
                        children: [
                          _buildSectionTitle('Comparison Text'),
                          const SizedBox(height: 8),
                          Expanded(
                            child: _buildTextArea(
                              text2Controller,
                              'Enter or paste text to compare...',
                            ),
                          ),
                        ],
                      ),
                    ),
                  ),
                ],
              ),
            ),
            Expanded(
              flex: 2,
              child: Padding(
                padding: const EdgeInsets.all(8.0),
                child: Column(
                  children: [
                    _buildSettingsSection(),
                    const SizedBox(height: 16),
                    ElevatedButton.icon(
                      onPressed: _checkPlagiarism,
                      style: ElevatedButton.styleFrom(
                        padding: const EdgeInsets.symmetric(
                          horizontal: 32,
                          vertical: 16,
                        ),
                        shape: RoundedRectangleBorder(
                          borderRadius: BorderRadius.circular(30),
                          side: BorderSide(
                            color: Theme.of(context).colorScheme.primary,
                          ),
                        ),
                      ),
                      icon: const Icon(Icons.compare_arrows),
                      label: const Text('Analyze Similarity'),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  Widget _buildSectionTitle(String title) {
    return Text(
      title,
      style: TextStyle(
        fontSize: 16,
        fontWeight: FontWeight.w600,
        color: Theme.of(context).colorScheme.primary,
      ),
    );
  }

  Widget _buildTextArea(TextEditingController controller, String hint) {
    return Container(
      decoration: BoxDecoration(
        color: Theme.of(context).colorScheme.surface,
        borderRadius: BorderRadius.circular(12),
        boxShadow: [
          BoxShadow(
            color: Colors.black.withOpacity(0.05),
            blurRadius: 10,
            offset: const Offset(0, 2),
          ),
        ],
      ),
      child: TextField(
        controller: controller,
        decoration: InputDecoration(
          hintText: hint,
          hintStyle: TextStyle(color: Colors.grey.shade400),
          border: OutlineInputBorder(
            borderRadius: BorderRadius.circular(12),
            borderSide: BorderSide.none,
          ),
          filled: true,
          fillColor: Colors.white,
          contentPadding: const EdgeInsets.all(16),
        ),
        maxLines: null,
        expands: true,
        textAlignVertical: TextAlignVertical.top,
        style: const TextStyle(fontSize: 14),
      ),
    );
  }

  Widget _buildSettingsSection() {
    return Container(
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: Theme.of(context).colorScheme.surface,
        borderRadius: BorderRadius.circular(12),
        border: Border.all(
          color: Theme.of(context).colorScheme.outline.withOpacity(0.1),
        ),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          const Text(
            'Analysis Settings',
            style: TextStyle(
              fontSize: 14,
              fontWeight: FontWeight.w600,
            ),
          ),
          const SizedBox(height: 8),
          Row(
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Algorithm',
                      style: TextStyle(
                        fontSize: 12,
                        color: Colors.grey.shade600,
                      ),
                    ),
                    const SizedBox(height: 4),
                    DropdownButtonFormField<Algorithm>(
                      value: selectedAlgorithm,
                      decoration: InputDecoration(
                        contentPadding: const EdgeInsets.symmetric(
                          horizontal: 12,
                          vertical: 4,
                        ),
                        border: OutlineInputBorder(
                          borderRadius: BorderRadius.circular(8),
                          borderSide: BorderSide(
                            color: Theme.of(context).colorScheme.outline,
                          ),
                        ),
                      ),
                      onChanged: (Algorithm? newValue) {
                        setState(() {
                          selectedAlgorithm = newValue!;
                        });
                      },
                      items: Algorithm.values.map((Algorithm algorithm) {
                        return DropdownMenuItem<Algorithm>(
                          value: algorithm,
                          child: Text(
                            algorithm.toString().split('.').last,
                            style: const TextStyle(fontSize: 12),
                          ),
                        );
                      }).toList(),
                    ),
                  ],
                ),
              ),
              const SizedBox(width: 16),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Threshold: ${threshold.toStringAsFixed(1)}',
                      style: TextStyle(
                        fontSize: 12,
                        color: Colors.grey.shade600,
                      ),
                    ),
                    Slider(
                      value: threshold,
                      min: 0.0,
                      max: 1.0,
                      divisions: 10,
                      label: threshold.toStringAsFixed(1),
                      onChanged: (double value) {
                        setState(() {
                          threshold = value;
                        });
                      },
                    ),
                  ],
                ),
              ),
            ],
          ),
        ],
      ),
    );
  }

  void _checkPlagiarism() {
    final text1 = text1Controller.text;
    final text2 = text2Controller.text;

    if (text1.isEmpty || text2.isEmpty) {
      _showDialog(
        'Input Required',
        'Please enter both texts to compare.',
        isError: true,
      );
      return;
    }

    final result = checker.check(
      text1,
      text2,
      algorithm: selectedAlgorithm,
      threshold: threshold,
    );

    _showResultDialog(result);
  }

  void _showDialog(String title, String content, {bool isError = false}) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(16),
          ),
          title: Text(
            title,
            style: const TextStyle(fontWeight: FontWeight.w600),
          ),
          content: Text(
            content,
            style: const TextStyle(),
          ),
          actions: [
            TextButton(
              child: Text(
                'OK',
                style: TextStyle(
                  color: isError
                      ? Theme.of(context).colorScheme.error
                      : Theme.of(context).colorScheme.primary,
                ),
              ),
              onPressed: () => Navigator.of(context).pop(),
            ),
          ],
        );
      },
    );
  }

  void _showResultDialog(PlagiarismResult result) {
    showDialog(
      context: context,
      builder: (BuildContext context) {
        return AlertDialog(
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(16),
          ),
          title: const Text(
            'Analysis Results',
            style: TextStyle(fontWeight: FontWeight.w600),
          ),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              _buildResultItem(
                'Similarity Score',
                '${(result.similarityScore * 100).toStringAsFixed(1)}%',
                result.similarityScore > threshold ? Colors.red : Colors.green,
              ),
              const SizedBox(height: 16),
              _buildResultItem(
                'Algorithm Used',
                result.algorithm.toString().split('.').last,
                Theme.of(context).colorScheme.primary,
              ),
              const SizedBox(height: 16),
              _buildResultItem(
                'Status',
                result.isPlagiarized
                    ? 'Potential Plagiarism Detected'
                    : 'Original Content',
                result.isPlagiarized ? Colors.red : Colors.green,
              ),
            ],
          ),
          actions: [
            TextButton(
              child: Text(
                'Close',
                style: TextStyle(
                  color: Theme.of(context).colorScheme.primary,
                ),
              ),
              onPressed: () => Navigator.of(context).pop(),
            ),
          ],
        );
      },
    );
  }

  Widget _buildResultItem(String label, String value, Color valueColor) {
    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        Text(
          label,
          style: TextStyle(
            fontSize: 14,
            color: Colors.grey.shade600,
          ),
        ),
        const SizedBox(height: 4),
        Text(
          value,
          style: TextStyle(
            fontSize: 16,
            fontWeight: FontWeight.w600,
            color: valueColor,
          ),
        ),
      ],
    );
  }
}