refactor: move dialog to widgets

lib/widgets/dialog_rename.dart

@@ -0,0 +1,41 @@
+import 'package:flutter/material.dart';
+
+showRenameDialog(
+  BuildContext context,
+  String dialogTitle,
+  String? name,
+  Function(String) onRename,
+) {
+  showDialog(
+      context: context,
+      builder: (context) {
+        final controller = TextEditingController(text: name ?? "");
+        controller.selection =
+            TextSelection(baseOffset: 0, extentOffset: controller.text.length);
+        return AlertDialog(
+          title: Text(dialogTitle),
+          content: TextField(
+            autofocus: true,
+            controller: controller,
+            decoration: const InputDecoration(hintText: "Enter new name"),
+          ),
+          actions: <Widget>[
+            OutlinedButton(
+                onPressed: () {
+                  Navigator.pop(context);
+                },
+                child: const Text('CANCEL')),
+            FilledButton(
+                onPressed: () {
+                  final val = controller.text.trim();
+                  onRename(val);
+                  Navigator.pop(context);
+                  Future.delayed(const Duration(milliseconds: 100), () {
+                    controller.dispose();
+                  });
+                },
+                child: const Text('OK')),
+          ],
+        );
+      });
+}