feat: add list file search listener

flutter/lib/desktop/widgets/list_search_action_listener.dart

@@ -0,0 +1,75 @@
+import 'package:flutter/material.dart';
+
+class ListSearchActionListener extends StatelessWidget {
+  final FocusNode node;
+  final TimeoutStringBuffer buffer;
+  final Widget child;
+  final Function(String) onNext;
+  final Function(String) onSearch;
+
+  const ListSearchActionListener(
+      {super.key,
+      required this.node,
+      required this.buffer,
+      required this.child,
+      required this.onNext,
+      required this.onSearch});
+
+  @mustCallSuper
+  @override
+  Widget build(BuildContext context) {
+    return KeyboardListener(
+        autofocus: true,
+        onKeyEvent: (kv) {
+          final ch = kv.character;
+          if (ch == null) {
+            return;
+          }
+          final action = buffer.input(ch);
+          switch (action) {
+            case ListSearchAction.search:
+              onSearch(buffer.buffer);
+              break;
+            case ListSearchAction.next:
+              onNext(buffer.buffer);
+              break;
+          }
+        },
+        focusNode: node,
+        child: child);
+  }
+}
+
+enum ListSearchAction { search, next }
+
+class TimeoutStringBuffer {
+  var _buffer = "";
+  late DateTime _duration;
+
+  static int timeoutMilliSec = 1500;
+
+  String get buffer => _buffer;
+
+  TimeoutStringBuffer() {
+    _duration = DateTime.now();
+  }
+
+  ListSearchAction input(String ch) {
+    final curr = DateTime.now();
+    try {
+      if (curr.difference(_duration).inMilliseconds > timeoutMilliSec) {
+        _buffer = ch;
+        return ListSearchAction.search;
+      } else {
+        if (ch == _buffer) {
+          return ListSearchAction.next;
+        } else {
+          _buffer += ch;
+          return ListSearchAction.search;
+        }
+      }
+    } finally {
+      _duration = curr;
+    }
+  }
+}