mobile_nebula/lib/components/IPAndPortFormField.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/widgets.dart';
import 'package:mobile_nebula/models/IPAndPort.dart';
import 'package:mobile_nebula/validators/dnsValidator.dart';
import 'package:mobile_nebula/validators/ipValidator.dart';

import 'IPAndPortField.dart';

class IPAndPortFormField extends FormField<IPAndPort> {
  //TODO: onSaved, validator, autovalidate, enabled?
  IPAndPortFormField({
    Key key,
    ipOnly = false,
    ipHelp = "ip address",
    autoFocus = false,
    focusNode,
    nextFocusNode,
    ValueChanged<IPAndPort> onChanged,
    FormFieldSetter<IPAndPort> onSaved,
    textInputAction,
    IPAndPort initialValue,
    noBorder,
    ipTextAlign = TextAlign.center,
    this.ipController,
    this.portController,
  }) : super(
            key: key,
            initialValue: initialValue,
            onSaved: onSaved,
            validator: (ipAndPort) {
              if (ipAndPort == null) {
                return "Please fill out this field";
              }

              if (!ipValidator(ipAndPort.ip) && (!ipOnly && !dnsValidator(ipAndPort.ip))) {
                return ipOnly ? 'Please enter a valid ip address' : 'Please enter a valid ip address or dns name';
              }

              if (ipAndPort.port == null || ipAndPort.port > 65535 || ipAndPort.port < 0) {
                return "Please enter a valid port";
              }

              return null;
            },
            builder: (FormFieldState<IPAndPort> field) {
              final _IPAndPortFormField state = field;

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

              return Column(children: <Widget>[
                IPAndPortField(
                  ipOnly: ipOnly,
                  ipHelp: ipHelp,
                  autoFocus: autoFocus,
                  focusNode: focusNode,
                  nextFocusNode: nextFocusNode,
                  onChanged: onChangedHandler,
                  textInputAction: textInputAction,
                  ipController: state._effectiveIPController,
                  portController: state._effectivePortController,
                  noBorder: noBorder,
                  ipTextAlign: ipTextAlign,
                ),
                field.hasError
                    ? Text(field.errorText,
                        style: TextStyle(color: CupertinoColors.systemRed.resolveFrom(field.context), fontSize: 13))
                    : Container(height: 0)
              ]);
            });

  final TextEditingController ipController;
  final TextEditingController portController;

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

class _IPAndPortFormField extends FormFieldState<IPAndPort> {
  TextEditingController _ipController;
  TextEditingController _portController;

  TextEditingController get _effectiveIPController => widget.ipController ?? _ipController;
  TextEditingController get _effectivePortController => widget.portController ?? _portController;

  @override
  IPAndPortFormField get widget => super.widget;

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

    if (widget.portController == null) {
      _portController = TextEditingController(text: widget.initialValue?.port?.toString() ?? "");
    } else {
      widget.portController.addListener(_handleControllerChanged);
    }
  }

  @override
  void didUpdateWidget(IPAndPortFormField oldWidget) {
    super.didUpdateWidget(oldWidget);
    var update =
        IPAndPort(ip: widget.ipController?.text, port: int.tryParse(widget.portController?.text ?? "") ?? null);
    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.portController != oldWidget.portController) {
      oldWidget.portController?.removeListener(_handleControllerChanged);
      widget.portController?.addListener(_handleControllerChanged);

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

      if (widget.portController != null) {
        shouldUpdate = true;
        update.port = int.parse(widget.portController.text);
        if (oldWidget.portController == null) _portController = null;
      }
    }

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

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

  @override
  void reset() {
    super.reset();
    setState(() {
      _effectiveIPController.text = widget.initialValue.ip;
      _effectivePortController.text = widget.initialValue.port.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 effectivePort = int.parse(_effectivePortController.text);
    if (_effectiveIPController.text != value.ip || effectivePort != value.port) {
      didChange(IPAndPort(ip: _effectiveIPController.text, port: effectivePort));
    }
  }
}