DynamicScreen.dart

import 'package:flutter/material.dart';

abstract class FieldRenderer {
    Widget render(FormField field);
}

class FieldRendererFactory {
    static FieldRenderer? getRenderer(String type) {
        switch (type) {
            case "input":
                return InputFieldRenderer();
            case "select":
                return SelectFieldRenderer();
            case "textarea":
                return TextAreaRenderer();
            case "text":
                return TextRenderer();
            default:
                return null;
        }
    }
}

class InputFieldRenderer implements FieldRenderer {
    @override
    Widget render(FormField field) {
        return Padding(
            padding: const EdgeInsets.symmetric(vertical: 8.0),
            child: TextField(
                decoration: InputDecoration(
                    hintText: field.props.placeholder ?? "",
                ),
            ),
        );
    }
}

class SelectFieldRenderer implements FieldRenderer {
    @override
    Widget render(FormField field) {
        return Padding(
            padding: const EdgeInsets.all(8.0),
            child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                    Text(field.label),
                    DropdownButtonFormField<String>(
                        value: field.props.options?.first.value ?? "",
                        items: field.props.options?.map((option) {
                            return DropdownMenuItem<String>(
                                value: option.value,
                                child: Text(option.label),
                            );
                        }).toList() ?? [],
                        onChanged: (value) {},
                    ),
                ],
            ),
        );
    }
}

class TextAreaRenderer implements FieldRenderer {
    @override
    Widget render(FormField field) {
        return Padding(
            padding: const EdgeInsets.symmetric(vertical: 8.0),
            child: TextField(
                decoration: InputDecoration(
                    labelText: field.label,
                    hintText: field.props.placeholder ?? "",
                ),
                maxLines: field.props.rows ?? 4,
                minLines: 3,
            ),
        );
    }
}

class TextRenderer implements FieldRenderer {
    @override
    Widget render(FormField field) {
        return Padding(
            padding: EdgeInsets.all(field.style.padding ?? 0),
            child: Text(
                field.label,
                textAlign: _getTextAlign(field.style.alignment),
            ),
        );
    }

    TextAlign _getTextAlign(String? alignment) {
        switch (alignment) {
            case "center":
                return TextAlign.center;
            case "right":
                return TextAlign.right;
            default:
                return TextAlign.start;
        }
    }
}

class FieldComposer extends StatelessWidget {
    final FormModel formModel;

    const FieldComposer({
        Key? key,
        required this.formModel,
    }) : super(key: key);

    @override
    Widget build(BuildContext context) {
        return Padding(
            padding: const EdgeInsets.all(16.0),
            child: Column(
                children: formModel.fields.map((field) {
                    final renderer = FieldRendererFactory.getRenderer(field.type);
                    return renderer?.render(field) ?? const SizedBox.shrink();
                }).toList(),
            ),
        );
    }
}

class DynamicScreen extends StatelessWidget {
    final FormModel state;

    const DynamicScreen({
        Key? key,
        this.state = const FormModel(),
    }) : super(key: key);

    @override
    Widget build(BuildContext context) {
        return FieldComposer(formModel: state);
    }
}