fix sz session abort

lib/core.dart

@@ -34,7 +34,32 @@ class ZModemCore {
 
   final ZModemTextHandler? onPlainText;
 
+  bool _findSubSeq(Uint8List origin, Uint8List subSeq) {
+    // 如果 b 是空数组，直接返回 true
+    if (subSeq.isEmpty) return true;
+
+    // 如果 a 的长度小于 b 的长度，直接返回 false
+    if (origin.length < subSeq.length) return false;
+
+    // 遍历 a 数组，检查是否存在连续的子序列与 b 相等
+    for (int i = 0; i <= origin.length - subSeq.length; i++) {
+      bool match = true;
+      for (int j = 0; j < subSeq.length; j++) {
+        if (origin[i + j] != subSeq[j]) {
+          match = false;
+          break;
+        }
+      }
+      if (match) return true;
+    }
+
+    return false;
+  }
+
   Iterable<ZModemEvent> receive(Uint8List data) sync* {
+    if (_findSubSeq(data, ZModemAbortSequence.abortSequence)) {
+      yield ZSessionAbortedEvent();
+    }
     _parser.addData(data);
     // print('data: ${data.map((e) => e.toRadixString(16)).toList()}');
 

lib/src/zmodem_event.dart

@@ -46,6 +46,13 @@ class ZSessionFinishedEvent implements ZModemEvent {
     return 'ZSessionFinishedEvent()';
   }
 }
+/// The event fired when the ZModem aborted
+class ZSessionAbortedEvent implements ZModemEvent {
+  @override
+  String toString() {
+    return 'ZSessionAbortedEvent()';
+  }
+}
 
 /// The other side is ready to receive a file.
 class ZReadyToSendEvent implements ZModemEvent {

lib/src/zmodem_parser.dart

@@ -55,7 +55,6 @@ class ZModemParser implements Iterator<ZModemPacket> {
   /// and it's impossible to distinguish between plain text and a data subpacket
   /// without this prompt....
   void expectDataSubpacket() {
-    print('expectDataSubpacket');
     _expectDataSubpacket = true;
   }