magnifying_glass 1.0.2

Flutter real-time magnifying glass lens widget with Barrel/Pincushion distortion.

example/lib/main.dart

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

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

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({Key? key}) : super(key: key);

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  ValueNotifier<int> diameter = ValueNotifier(150);
  ValueNotifier<double> distortion = ValueNotifier(1.0);
  ValueNotifier<double> magnification = ValueNotifier(1.2);
  ValueNotifier<GlassPosition> glassPosition =
      ValueNotifier(GlassPosition.touchPosition);

  @override
  Widget build(BuildContext context) {
    MagnifyingGlassController magnifyingGlassController =
        MagnifyingGlassController();
    return MagnifyingGlass(
      controller: magnifyingGlassController,
      glassPosition: glassPosition.value,
      glassParams: GlassParams(
        // startingPosition: Offset(150, 150),
        diameter: diameter.value,
        distortion: distortion.value,
        magnification: magnification.value,
        padding: EdgeInsets.all(10),
      ),
      child: Scaffold(
        body: Padding(
          padding: const EdgeInsets.all(16.0),
          child: Column(children: [
            Image.asset('assets/dash.png'),

            /// Diameter
            Row(
              children: [
                Text('Diameter'),
                ValueListenableBuilder<int>(
                    valueListenable: diameter,
                    builder: (_, _diameter, __) {
                      return Expanded(
                        child: Slider(
                            value: _diameter.toDouble(),
                            min: 10,
                            max: 300,
                            divisions: 29,
                            label: diameter.value.toString(),
                            onChanged: (value) {
                              diameter.value = value.toInt();
                              magnifyingGlassController
                                  .setDiameter(diameter.value);
                            }),
                      );
                    }),
              ],
            ),

            /// Distortion
            Row(
              children: [
                Text('Distortion'),
                ValueListenableBuilder<double>(
                    valueListenable: distortion,
                    builder: (_, _distortion, __) {
                      return Expanded(
                        child: Slider(
                            value: _distortion,
                            min: -3.0,
                            max: 3.0,
                            divisions: 60,
                            label: distortion.value.toStringAsFixed(2),
                            onChanged: (value) {
                              distortion.value = value;
                              magnifyingGlassController.setDistortion(
                                  distortion.value, magnification.value);
                            }),
                      );
                    }),
              ],
            ),

            /// Magnification
            Row(
              children: [
                Text('Magnification'),
                ValueListenableBuilder<double>(
                    valueListenable: magnification,
                    builder: (_, _magnification, __) {
                      return Expanded(
                        child: Slider(
                            value: _magnification,
                            min: -2.0,
                            max: 2.0,
                            divisions: 100,
                            label: magnification.value.toStringAsFixed(2),
                            onChanged: (value) {
                              magnification.value = value;
                              magnifyingGlassController.setDistortion(
                                  distortion.value, magnification.value);
                            }),
                      );
                    }),
              ],
            ),

            /// Glass Position top
            ValueListenableBuilder<GlassPosition>(
                valueListenable: glassPosition,
                builder: (_, _glassPosition, __) {
                  return Row(
                    mainAxisSize: MainAxisSize.max,
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Checkbox(
                        value: _glassPosition == GlassPosition.topLeft,
                        onChanged: (bool? value) {
                          glassPosition.value = GlassPosition.topLeft;
                          setState(() {});
                        },
                      ),
                      Checkbox(
                        value: _glassPosition == GlassPosition.topRight,
                        onChanged: (bool? value) {
                          glassPosition.value = GlassPosition.topRight;
                          setState(() {});
                        },
                      ),
                    ],
                  );
                }),

            /// Glass Position touch
            ValueListenableBuilder<GlassPosition>(
                valueListenable: glassPosition,
                builder: (_, _glassPosition, __) {
                  return Checkbox(
                    value: _glassPosition == GlassPosition.touchPosition,
                    onChanged: (bool? value) {
                      glassPosition.value = GlassPosition.touchPosition;
                      setState(() {});
                    },
                  );
                }),

            /// Glass Position top
            ValueListenableBuilder<GlassPosition>(
                valueListenable: glassPosition,
                builder: (_, _glassPosition, __) {
                  return Row(
                    mainAxisSize: MainAxisSize.max,
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      Checkbox(
                        value: _glassPosition == GlassPosition.bottomLeft,
                        onChanged: (bool? value) {
                          glassPosition.value = GlassPosition.bottomLeft;
                          setState(() {});
                        },
                      ),
                      Checkbox(
                        value: _glassPosition == GlassPosition.bottomRight,
                        onChanged: (bool? value) {
                          glassPosition.value = GlassPosition.bottomRight;
                          setState(() {});
                        },
                      ),
                    ],
                  );
                }),

            const Text(
              'Lorem ipsum dolor sit amet, consectetur adipiscing elit. '
              'Phasellus dictum maximus tortor ac porta. Aenean aliquet '
              'erat eu mi commodo, ut feugiat enim consectetur. ',
              textScaleFactor: 1.3,
              textAlign: TextAlign.justify,
            ),
          ]),
        ),
        floatingActionButton: FloatingActionButton(
          onPressed: () => magnifyingGlassController.openGlass(),
          child: const Icon(Icons.search),
        ),
      ),
    );
  }
}