mobile_nebula/lib/components/CIDRFormField.dart

import 'package:flutter/cupertino.dart';
import 'package:mobile_nebula/components/CIDRField.dart';
import 'package:mobile_nebula/models/CIDR.dart';
import 'package:mobile_nebula/validators/ipValidator.dart';

class CIDRFormField extends FormField<CIDR> {
  //TODO: onSaved, validator, auto-validate, enabled?
  CIDRFormField({
    super.key,
    autoFocus = false,
    enableIPV6 = false,
    focusNode,
    nextFocusNode,
    ValueChanged<CIDR>? onChanged,
    super.onSaved,
    textInputAction,
    super.initialValue,
    this.ipController,
    this.bitsController,
  }) : super(
         validator: (cidr) {
           if (cidr == null) {
             return "Please fill out this field";
           }

           if (!ipValidator(cidr.ip, enableIPV6)) {
             return 'Please enter a valid ip address';
           }

           if (cidr.bits > 32 || cidr.bits < 0) {
             return "Please enter a valid number of bits";
           }

           return null;
         },
         builder: (FormFieldState<CIDR> field) {
           final _CIDRFormField state = field as _CIDRFormField;

           void onChangedHandler(CIDR value) {
             if (onChanged != null) {
               onChanged(value);
             }
             field.didChange(value);
           }

           return Column(
             crossAxisAlignment: CrossAxisAlignment.end,
             children: <Widget>[
               CIDRField(
                 autoFocus: autoFocus,
                 focusNode: focusNode,
                 nextFocusNode: nextFocusNode,
                 onChanged: onChangedHandler,
                 textInputAction: textInputAction,
                 ipController: state._effectiveIPController,
                 bitsController: state._effectiveBitsController,
               ),
               field.hasError
                   ? Text(
                     field.errorText ?? "Unknown error",
                     style: TextStyle(color: CupertinoColors.systemRed.resolveFrom(field.context), fontSize: 13),
                     textAlign: TextAlign.end,
                   )
                   : Container(height: 0),
             ],
           );
         },
       );

  final TextEditingController? ipController;
  final TextEditingController? bitsController;

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

class _CIDRFormField extends FormFieldState<CIDR> {
  TextEditingController? _ipController = TextEditingController();
  TextEditingController? _bitsController = TextEditingController();

  TextEditingController get _effectiveIPController => widget.ipController ?? _ipController!;
  TextEditingController get _effectiveBitsController => widget.bitsController ?? _bitsController!;

  @override
  CIDRFormField get widget => super.widget as CIDRFormField;

  @override
  void initState() {
    super.initState();
    if (widget.ipController == null) {
      _ipController = TextEditingController(text: widget.initialValue?.ip);
    } else {
      widget.ipController!.addListener(_handleControllerChanged);
    }

    if (widget.bitsController == null) {
      _bitsController = TextEditingController(text: widget.initialValue?.bits.toString() ?? "");
    } else {
      widget.bitsController!.addListener(_handleControllerChanged);
    }
  }

  @override
  void didUpdateWidget(CIDRFormField oldWidget) {
    super.didUpdateWidget(oldWidget);
    var update = CIDR(ip: widget.ipController?.text ?? "", bits: int.tryParse(widget.bitsController?.text ?? "") ?? 0);
    bool shouldUpdate = false;

    if (widget.ipController != oldWidget.ipController) {
      oldWidget.ipController?.removeListener(_handleControllerChanged);
      widget.ipController?.addListener(_handleControllerChanged);

      if (oldWidget.ipController != null && widget.ipController == null) {
        _ipController = TextEditingController.fromValue(oldWidget.ipController!.value);
      }

      if (widget.ipController != null) {
        shouldUpdate = true;
        update.ip = widget.ipController!.text;
        if (oldWidget.ipController == null) _ipController = null;
      }
    }

    if (widget.bitsController != oldWidget.bitsController) {
      oldWidget.bitsController?.removeListener(_handleControllerChanged);
      widget.bitsController?.addListener(_handleControllerChanged);

      if (oldWidget.bitsController != null && widget.bitsController == null) {
        _bitsController = TextEditingController.fromValue(oldWidget.bitsController!.value);
      }

      if (widget.bitsController != null) {
        shouldUpdate = true;
        update.bits = int.parse(widget.bitsController!.text);
        if (oldWidget.bitsController == null) _bitsController = null;
      }
    }

    if (shouldUpdate) {
      setValue(update);
    }
  }

  @override
  void dispose() {
    widget.ipController?.removeListener(_handleControllerChanged);
    widget.bitsController?.removeListener(_handleControllerChanged);
    super.dispose();
  }

  @override
  void reset() {
    super.reset();
    setState(() {
      _effectiveIPController.text = widget.initialValue?.ip ?? "";
      _effectiveBitsController.text = widget.initialValue?.bits.toString() ?? "";
    });
  }

  void _handleControllerChanged() {
    // Suppress changes that originated from within this class.
    //
    // In the case where a controller has been passed in to this widget, we
    // register this change listener. In these cases, we'll also receive change
    // notifications for changes originating from within this class -- for
    // example, the reset() method. In such cases, the FormField value will
    // already have been set.
    final effectiveBits = int.parse(_effectiveBitsController.text);
    if (value == null) {
      return;
    }

    if (_effectiveIPController.text != value!.ip || effectiveBits != value!.bits) {
      didChange(CIDR(ip: _effectiveIPController.text, bits: effectiveBits));
    }
  }
}