Some improvements

lib/screens/settings/encryption/encryption_functions.dart

@@ -0,0 +1,106 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+String? validateDomain(BuildContext context, String domain) {
+  RegExp regExp = RegExp(r'^([a-z0-9|-]+\.)*[a-z0-9|-]+\.[a-z]+$');
+  if (regExp.hasMatch(domain)) {
+    return null;
+  }
+  else {
+    return AppLocalizations.of(context)!.domainNotValid;
+  }
+}
+
+String? validatePort(BuildContext context, String value) {
+  if (int.tryParse(value) != null && int.parse(value) <= 65535) {
+    return null;
+  }
+  else {
+    return AppLocalizations.of(context)!.invalidPort;
+  } 
+}
+
+String? validateCertificate(BuildContext context, String cert) {
+  final regExp = RegExp(r'(-{3,}(\bBEGIN CERTIFICATE\b))|(-{3,}-{3,}(\END CERTIFICATE\b)-{3,})', multiLine: true);
+  if (regExp.hasMatch(cert.replaceAll('\n', ''))) {
+    return AppLocalizations.of(context)!.invalidCertificate;
+  }
+  else {
+    return null;
+  }
+}
+
+String? validatePrivateKey(BuildContext context, String cert) {
+  final regExp = RegExp(r'(-{3,}(\bBEGIN\b).*(PRIVATE KEY\b))|(-{3,}-{3,}(\bEND\b).*(PRIVATE KEY\b)-{3,})', multiLine: true);
+  if (regExp.hasMatch(cert.replaceAll('\n', ''))) {
+    return AppLocalizations.of(context)!.invalidPrivateKey;
+  }
+  else {
+    return null;
+  }
+}
+
+String? validatePath(BuildContext context, String cert) {
+  final regExp = RegExp(r'^(\/{0,1}(?!\/))[A-Za-z0-9\/\-_]+(\.([a-zA-Z]+))?$');
+  if (regExp.hasMatch(cert)) {
+    return null;
+  }
+  else {
+    return AppLocalizations.of(context)!.invalidPath;
+  }
+}
+
+Widget generateStatus(bool localValidation, int dataValidApi) {
+  if (localValidation == true) {
+    if (dataValidApi == 0) {
+      return const SizedBox(
+        height: 25,
+        width: 25,
+        child: CircularProgressIndicator(
+          strokeWidth: 3,
+        )
+      );
+    }
+    else if (dataValidApi == 1) {
+      return const Icon(
+        Icons.check_circle_rounded,
+        color: Colors.green,
+      );
+    }
+    else if (dataValidApi == 2) {
+      return const Icon(
+        Icons.cancel_rounded,
+        color: Colors.red,
+      );
+    }
+    else {
+      return const SizedBox();
+    }
+  }
+  else {
+    return const Icon(
+      Icons.error_rounded,
+      color: Colors.grey,
+    );
+  }
+}
+
+String generateStatusString(BuildContext context, bool localValidation, int dataValidApi) {
+  if (localValidation == true) {
+    if (dataValidApi == 0) {
+      return AppLocalizations.of(context)!.validatingData;
+    }
+    else if (dataValidApi == 1) {
+      return AppLocalizations.of(context)!.dataValid;
+    }
+    else if (dataValidApi == 2) {
+      return AppLocalizations.of(context)!.dataNotValid;
+    }
+    else {
+      return "";
+    }
+  }
+  else {
+    return AppLocalizations.of(context)!.dataNotValid;
+  }
+}