flutter_decision_making 1.0.5

Dart package for multi-criteria decision making. Currently supports Analytic Hierarchy Process (AHP) with plans to add other popular algorithms like SAW and TOPSIS.

example/lib/main.dart

import 'package:example/helper.dart';
import 'package:example/show_pairwise_comparison_scale_dialog.dart';
import 'package:flutter/material.dart';
import 'package:flutter_decision_making/flutter_decision_making.dart';

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

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

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.blue),
      ),

      home: const AHPPage(title: 'Flutter Decision Making Example'),
    );
  }
}

class AHPPage extends StatefulWidget {
  const AHPPage({super.key, required this.title});

  final String title;

  @override
  State<AHPPage> createState() => _AHPPageState();
}

class _AHPPageState extends State<AHPPage> {
  final _criteriaController = TextEditingController();
  final _alternativeController = TextEditingController();
  late TextStyle _textStyle;
  late AHP _ahp;
  late List<AhpItem> _listCriteria;
  late List<AhpItem> _listAlternative;
  late List<PairwiseComparisonInput> _inputCriteria;
  late List<PairwiseAlternativeInput> _inputAlternative;
  late Helper _helper;

  @override
  void initState() {
    super.initState();
    _ahp = AHP();
    _textStyle = TextStyle(fontSize: 18);
    _listAlternative = [];
    _listCriteria = [];
    _inputCriteria = [];
    _inputAlternative = [];
    _helper = Helper();
  }

  @override
  void dispose() {
    super.dispose();
    _criteriaController.dispose();
    _alternativeController.dispose();
  }

  @override
  Widget build(BuildContext context) {
    final paddingBottom = MediaQuery.of(context).viewInsets.bottom;
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: SafeArea(
        child: Padding(
          padding: EdgeInsets.symmetric(vertical: 10, horizontal: 10),
          child: ListView(
            children: [
              /// CRITERIA YOU WANT
              _buildInputWidget(
                title: 'Criteria',
                controller: _criteriaController,
                onPressed:
                    () => _addItem(
                      _criteriaController,
                      _listCriteria,
                      (name) => AhpItem(name: name),
                    ),
              ),

              /// LIST CRITERIA
              _listCriteria.isNotEmpty
                  ? Container(
                    constraints: BoxConstraints(maxHeight: 100),
                    margin: EdgeInsets.only(bottom: 10, top: 10),
                    padding: EdgeInsets.symmetric(vertical: 5, horizontal: 5),
                    decoration: BoxDecoration(
                      border: Border.all(color: Colors.black),
                    ),
                    width: double.infinity,
                    child: Scrollbar(
                      child: ListView.builder(
                        itemCount: _listCriteria.length,
                        itemBuilder: (context, index) {
                          var data = _listCriteria[index];
                          return Text(
                            '${index + 1}. ${data.name}',
                            style: _textStyle,
                          );
                        },
                      ),
                    ),
                  )
                  : SizedBox(height: 10),

              const Divider(),

              /// ALTERNATIVE YOU HAVE
              _buildInputWidget(
                title: 'Alternative',
                controller: _alternativeController,
                onPressed:
                    () => _addItem(
                      _alternativeController,
                      _listAlternative,
                      (name) => AhpItem(name: name),
                    ),
              ),

              /// LIST ALTERNATIVE
              _listAlternative.isNotEmpty
                  ? Container(
                    constraints: BoxConstraints(maxHeight: 100),
                    margin: EdgeInsets.only(bottom: 40, top: 10),
                    padding: EdgeInsets.symmetric(vertical: 5, horizontal: 5),
                    decoration: BoxDecoration(
                      border: Border.all(color: Colors.black),
                    ),
                    width: double.infinity,
                    child: Scrollbar(
                      child: ListView.builder(
                        itemCount: _listAlternative.length,
                        itemBuilder: (context, index) {
                          var data = _listAlternative[index];
                          return Text(
                            '${index + 1}. ${data.name}',
                            style: _textStyle,
                          );
                        },
                      ),
                    ),
                  )
                  : SizedBox(height: 40),

              /// GENERATE HIERARCHY STRUCTURE & PAIRWISE MATRIX TEMPLATE
              Center(
                child: ElevatedButton(
                  onPressed: () async {
                    await _ahp
                        .generateHierarchyAndPairwiseTemplate(
                          listCriteria: _listCriteria,
                          listAlternative: _listAlternative,
                        )
                        .catchError((e) {
                          if (context.mounted) {
                            _helper.showScaffoldMessenger(
                              context: context,
                              message: e.toString(),
                            );
                          }
                        });

                    setState(() {
                      /// COPY RESULT TO LIST
                      _inputCriteria = _ahp.listPairwiseCriteriaInput;
                      _inputAlternative = _ahp.listPairwiseAlternativeInput;
                    });
                  },
                  child: Text(
                    'Generate Hierarchy Structure and Pairwise Matrix Template',
                    style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold),
                    textAlign: TextAlign.center,
                  ),
                ),
              ),

              /// PAIRWISE CRITERIA
              _inputCriteria.isNotEmpty
                  ? Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Padding(
                        padding: EdgeInsets.symmetric(vertical: 10),
                        child: Divider(),
                      ),

                      Text(
                        'Pairwise Criteria',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 20,
                        ),
                      ),

                      /// CRITERIA ITEMS
                      SizedBox(
                        height: 200,
                        child: Scrollbar(
                          child: ListView.builder(
                            itemCount: _inputCriteria.length,
                            padding: EdgeInsets.only(right: 10),
                            itemBuilder: (context, index) {
                              var criteria = _inputCriteria[index];
                              return Row(
                                children: [
                                  /// NAME
                                  Text(criteria.left.name, style: _textStyle),

                                  /// SELECT VALUE COMPARISON
                                  Expanded(
                                    child: InkWell(
                                      onTap: () {
                                        /// SHOW COMPARISON SCALE DIALOG
                                        showPairwiseComparisonScaleDialog(
                                          context,
                                          comparison:
                                              _ahp.listPairwiseComparisonScale,
                                          leftItemName: criteria.left.name,
                                          rightItemName: criteria.right.name,
                                          onSelected: (scale, important) {
                                            if (scale != null &&
                                                important != null) {
                                              /// UPDATE CRITERIA VALUE
                                              _ahp.updatePairwiseCriteriaValue(
                                                id: criteria.id,
                                                scale: scale.value,
                                                isLeftMoreImportant: important,
                                              );

                                              setState(() {
                                                /// COPY UPDATED CRITERIA VALUE
                                                _inputCriteria =
                                                    _ahp.listPairwiseCriteriaInput;
                                              });
                                            }
                                          },
                                        );
                                      },
                                      child: Container(
                                        height: 40,
                                        width: double.infinity,
                                        alignment: Alignment.centerLeft,
                                        padding: EdgeInsets.symmetric(
                                          horizontal: 5,
                                        ),
                                        margin: EdgeInsets.symmetric(
                                          horizontal: 10,
                                          vertical: 5,
                                        ),
                                        decoration: BoxDecoration(
                                          border: Border.all(
                                            color: Colors.black,
                                          ),
                                        ),
                                        child: Text(
                                          criteria.preferenceValue != null
                                              ? '${criteria.preferenceValue} - ${criteria.isLeftMoreImportant == true ? 'left item is more important' : 'right item is more important'}'
                                              : 'please select scale comparison',
                                          style: _textStyle,
                                        ),
                                      ),
                                    ),
                                  ),

                                  /// NAME
                                  Text(criteria.right.name, style: _textStyle),
                                ],
                              );
                            },
                          ),
                        ),
                      ),
                    ],
                  )
                  : const SizedBox(),

              /// PAIRWISE ALTERNATIVE
              _inputAlternative.isNotEmpty
                  ? Column(
                    mainAxisSize: MainAxisSize.min,
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Padding(
                        padding: EdgeInsets.symmetric(vertical: 10),
                        child: Divider(),
                      ),

                      /// TITLE
                      Text(
                        'Pairwise Alternative',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 20,
                        ),
                      ),

                      /// ALTERNATIVE ITEMS
                      SizedBox(
                        height: 200,
                        child: Scrollbar(
                          child: ListView.builder(
                            itemCount: _inputAlternative.length,
                            padding: EdgeInsets.only(right: 10),
                            itemBuilder: (context, index) {
                              final data = _inputAlternative[index];
                              return Column(
                                mainAxisSize: MainAxisSize.min,
                                crossAxisAlignment: CrossAxisAlignment.start,
                                children: [
                                  Text(
                                    data.criteria.name,
                                    style: _textStyle.copyWith(
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),

                                  ...data.alternative.map(
                                    (e) => Row(
                                      children: [
                                        /// NAME
                                        Text(e.left.name, style: _textStyle),

                                        /// SELECT VALUE COMPARISON
                                        Expanded(
                                          child: InkWell(
                                            onTap: () {
                                              /// SHOW COMPARISON SCALE DIALOG
                                              showPairwiseComparisonScaleDialog(
                                                context,
                                                comparison:
                                                    _ahp.listPairwiseComparisonScale,
                                                leftItemName: e.left.name,
                                                rightItemName: e.right.name,
                                                onSelected: (scale, important) {
                                                  if (scale != null &&
                                                      important != null) {
                                                    /// UPDATE ALTERNATIVE VALUE
                                                    _ahp.updatePairwiseAlternativeValue(
                                                      id: data.criteria.id,
                                                      alternativeId: e.id,
                                                      scale: scale.value,
                                                      isLeftMoreImportant:
                                                          important,
                                                    );

                                                    setState(() {
                                                      /// COPY UPDATED ALTERNATIVE VALUE
                                                      _inputAlternative =
                                                          _ahp.listPairwiseAlternativeInput;
                                                    });
                                                  }
                                                },
                                              );
                                            },
                                            child: Container(
                                              height: 40,
                                              width: double.infinity,
                                              alignment: Alignment.centerLeft,
                                              padding: EdgeInsets.symmetric(
                                                horizontal: 5,
                                              ),
                                              margin: EdgeInsets.symmetric(
                                                horizontal: 10,
                                                vertical: 5,
                                              ),
                                              decoration: BoxDecoration(
                                                border: Border.all(
                                                  color: Colors.black,
                                                ),
                                              ),
                                              child: Text(
                                                e.preferenceValue != null
                                                    ? '${e.preferenceValue} - ${e.isLeftMoreImportant == true ? 'left item is more important' : 'right item is more important'}'
                                                    : 'please select scale comparison',
                                                style: _textStyle,
                                              ),
                                            ),
                                          ),
                                        ),

                                        /// NAME
                                        Text(e.right.name, style: _textStyle),
                                      ],
                                    ),
                                  ),
                                ],
                              );
                            },
                          ),
                        ),
                      ),
                    ],
                  )
                  : const SizedBox(),

              /// GENERATE PAIRWISE MATRIX
              _ahp.listPairwiseAlternativeInput.isNotEmpty &&
                      _ahp.listPairwiseCriteriaInput.isNotEmpty
                  ? Padding(
                    padding: EdgeInsets.only(top: 20),
                    child: Center(
                      child: ElevatedButton(
                        onPressed: () async {
                          /// GET RESULT AHP
                          await _ahp.generateResult().catchError((e) {
                            if (context.mounted) {
                              /// SHOW MESSAGE IF CATCH EXCEPTION
                              _helper.showScaffoldMessenger(
                                context: context,
                                message: e.toString(),
                              );
                            }
                          });

                          setState(() {});
                        },
                        child: Text(
                          'Generate Result',
                          style: TextStyle(
                            fontSize: 18,
                            fontWeight: FontWeight.bold,
                          ),
                          textAlign: TextAlign.center,
                        ),
                      ),
                    ),
                  )
                  : const SizedBox(),

              /// RESULT
              _ahp.ahpResult != null
                  ? Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Padding(
                        padding: EdgeInsets.symmetric(vertical: 10),
                        child: Divider(),
                      ),

                      Text(
                        'Result',
                        style: TextStyle(
                          fontWeight: FontWeight.bold,
                          fontSize: 20,
                        ),
                      ),

                      /// RESULT ITEMS
                      ListView.builder(
                        shrinkWrap: true,
                        physics: const NeverScrollableScrollPhysics(),
                        padding: EdgeInsets.only(top: 10),
                        itemCount: _ahp.ahpResult?.results.length ?? 0,
                        itemBuilder: (context, index) {
                          var data = _ahp.ahpResult?.results[index];
                          return Text(
                            '${data?.name}: ${data?.value}',
                            style: _textStyle,
                          );
                        },
                      ),

                      const Divider(),

                      /// RESULT CONSISTENCY CRITERIA RATIO
                      Text(
                        'criteria consistency ratio: ${_ahp.ahpResult?.consistencyCriteriaRatio}',
                        style: _textStyle,
                      ),

                      const Divider(),

                      /// IS VALID CRITERIA?
                      Text(
                        'is criteria consistent: ${_ahp.ahpResult?.isConsistentCriteria}',
                        style: _textStyle,
                      ),

                      const Divider(),

                      /// RESULT ALTERNATIVE RATIO
                      Text(
                        'alternative consistency ratio: ${_ahp.ahpResult?.consistencyAlternativeRatio}',
                        style: _textStyle,
                      ),

                      const Divider(),

                      /// IS VALID ALTERNATIVE?
                      Text(
                        'is alternative consistent: ${_ahp.ahpResult?.isConsistentAlternative}',
                        style: _textStyle,
                      ),

                      const Divider(),

                      /// NOTE WILL BE DISPLAYED IF THE CRITERIA OR ALTERNATIVES ARE INVALID
                      _ahp.ahpResult?.note != null
                          ? Text(_ahp.ahpResult!.note!, style: _textStyle)
                          : const SizedBox(),
                    ],
                  )
                  : const SizedBox(),

              SizedBox(height: paddingBottom),
            ],
          ),
        ),
      ),
    );
  }

  /// INPUT FOR CRITERIA OR ALTERNATIVE
  Widget _buildInputWidget({
    required String title,
    required TextEditingController controller,
    required Function() onPressed,
  }) {
    return Row(
      children: [
        Text(title, style: _textStyle),

        Expanded(
          child: Padding(
            padding: EdgeInsets.symmetric(horizontal: 10),
            child: TextFormField(
              controller: controller,
              decoration: InputDecoration(border: OutlineInputBorder()),
            ),
          ),
        ),

        ElevatedButton(onPressed: onPressed, child: Text('Add')),
      ],
    );
  }

  /// ADD ITEM TO CRITERIA OR ALTERNATIVE
  void _addItem<T>(
    TextEditingController controller,
    List<T> items,
    T Function(String name) createItem,
  ) {
    final value = controller.text.trim();
    if (value.isNotEmpty) {
      setState(() {
        items.add(createItem(value));
        controller.clear();
      });
    }
  }
}