stadtbote-app/lib/popups/tasks_popups/signature_popup.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:signature/signature.dart';
import 'package:stadtbote/model/task_info.dart';
import 'package:stadtbote/tools/app_localizations.dart';
import 'package:stadtbote/tools/util.dart';

showSignaturePopup(BuildContext context, TaskInfo taskInfo, Function(String?) onFinished) async {
  await showDialog(
      context: context,
      builder: (BuildContext context) {
        return PopScope(
            canPop: false,
            onPopInvokedWithResult: (bool didPop, dynamic result) async {
              if (!didPop) {
                final shouldPop = await taskDialogSecurityException(context, language: AppLanguage.german);
                if (shouldPop) {
                  SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
                  if (context.mounted) {
                    Navigator.of(context).pop();
                  }
                }
              }
            },
            child: AlertDialog(
                contentPadding: EdgeInsets.zero,
                shadowColor: Colors.transparent,
                backgroundColor: Colors.white,
                content: StatefulBuilder(
                  builder: (BuildContext context, StateSetter setState) {
                    final SignatureController controller = SignatureController();

                    var popupHeight = MediaQuery.of(context).size.height * 0.85;
                    var popupWidth = MediaQuery.of(context).size.width * 0.85;

                    String convertPoints(List<Point> points) {
                      if (points.isNotEmpty) {
                        String result = "";

                        for (var point in points) {
                          if (point.type != PointType.tap) {
                            result += "${point.offset.dx.toInt()},${point.offset.dy.toInt()};";
                          } else {
                            result += "A";
                          }
                        }

                        return result.replaceAll("AA", "A");
                      }

                      return "";
                    }

                    return SizedBox(
                        key: GlobalKey(),
                        height: popupHeight,
                        width: popupWidth,
                        child: Container(
                          decoration: BoxDecoration(
                            borderRadius: BorderRadius.circular(10),
                            color: Colors.white,
                            border: Border.all(
                              color: Colors.grey,
                              width: 0.5,
                            ),
                          ),
                          child: Padding(
                            padding: const EdgeInsets.all(20.0),
                            child: Column(
                              children: [
                                Text(taskInfo.task?.topic ?? ''),
                                const SizedBox(height: 20),
                                Expanded(
                                  child: Signature(
                                    controller: controller,
                                    width: 500,
                                    height: 200,
                                    backgroundColor: Colors.lightBlueAccent,
                                  ),
                                ),
                                getDefaultButton(
                                    AppLocalizations.tr('apply', language: AppLanguage.german),
                                    buttonHeight: 50,
                                    () => {
                                          if (controller.points.length > 50)
                                            {Navigator.of(context).pop(), onFinished(convertPoints(controller.points))}
                                          else
                                            {
                                              showAlertDialog(
                                                AppLocalizations.tr('error', language: AppLanguage.german),
                                                AppLocalizations.tr('signature_too_short', language: AppLanguage.german),
                                              )
                                            }
                                        })
                              ],
                            ),
                          ),
                        ));
                  },
                )));
      });
}