login and keys manage

lib/component/user/user_name_component.dart

@@ -0,0 +1,31 @@
+import 'package:flutter/material.dart';
+import 'package:nostr_sdk/nip19/nip19.dart';
+
+class UserNameComponent extends StatefulWidget {
+  String pubkey;
+
+  bool fullNpubName;
+
+  UserNameComponent(this.pubkey, {this.fullNpubName = false});
+
+  @override
+  State<StatefulWidget> createState() {
+    return _UserNameComponent();
+  }
+}
+
+class _UserNameComponent extends State<UserNameComponent> {
+  @override
+  Widget build(BuildContext context) {
+    var npub = Nip19.encodePubKey(widget.pubkey);
+    if (!widget.fullNpubName) {
+      npub = Nip19.encodeSimplePubKey(widget.pubkey);
+    }
+
+    return Text(
+      npub,
+      maxLines: 1,
+      overflow: TextOverflow.ellipsis,
+    );
+  }
+}