gui: add File source type to connection tab

- ConnectionConfig: new file_path and delay fields
- ConnectionRow: File page with path input, Browse button, delay
  spinner (0–10 s), and auto-fill of receiver-ID from filename
- ReceiverManager.connect_receiver: FileBackend wired for 'file' type;
  UBX poll timer skipped for file sources
- FileBackend.register_xcvr: fallback to first unoccupied entry when
  name does not match filename pattern

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

backend/file_backend.py

@@ -35,7 +35,12 @@ class FileBackend(ABackend):
                 e['xcvr'] = xcvr
                 xcvr.on_register(self)
                 return
-        raise Exception(f"No log file found for source \"{xcvr.name}\"")
+        for e in self._entries:
+            if e['xcvr'] is None:
+                e['xcvr'] = xcvr
+                xcvr.on_register(self)
+                return
+        raise Exception(f"No available log file entry for \"{xcvr.name}\"")
 
     def connect(self):
         for e in self._entries:

gui/connection_tab.py

@@ -8,12 +8,13 @@ for _p in [_root, _gui]:
 
 from PyQt5.QtWidgets import (
     QWidget, QHBoxLayout, QVBoxLayout, QPushButton, QLabel,
-    QLineEdit, QComboBox, QSpinBox, QStackedWidget, QScrollArea,
+    QLineEdit, QComboBox, QSpinBox, QDoubleSpinBox, QStackedWidget,
-    QFrame, QMessageBox, QSizePolicy,
+    QScrollArea, QFrame, QMessageBox, QSizePolicy, QFileDialog,
 )
 from PyQt5.QtCore import pyqtSignal, Qt
 
 from data_model import ReceiverManager, ConnectionConfig
+from backend.file_backend import source_id_from_path
 
 BAUD_RATES = ['4800', '9600', '19200', '38400', '57600', '115200',
               '230400', '460800', '921600']
@@ -53,7 +54,7 @@ class ConnectionRow(QWidget):
 
         # ── Connection type ──────────────────────────────────────────────────
         self._type_combo = QComboBox()
-        self._type_combo.addItems(['TCP', 'Serial'])
+        self._type_combo.addItems(['TCP', 'Serial', 'File'])
         self._type_combo.currentIndexChanged.connect(self._on_type_changed)
         layout.addWidget(self._type_combo)
 
@@ -95,6 +96,32 @@ class ConnectionRow(QWidget):
         ser_l.addWidget(self._baud_combo)
         self._stack.addWidget(ser_w)
 
+        # File page
+        file_w = QWidget()
+        file_l = QHBoxLayout(file_w)
+        file_l.setContentsMargins(0, 0, 0, 0)
+        file_l.setSpacing(4)
+        file_l.addWidget(QLabel("Path:"))
+        self._file_edit = QLineEdit()
+        self._file_edit.setPlaceholderText("log file path…")
+        self._file_edit.setMinimumWidth(200)
+        self._file_edit.textChanged.connect(self._on_file_path_changed)
+        file_l.addWidget(self._file_edit)
+        browse_btn = QPushButton("Browse")
+        browse_btn.setFixedWidth(60)
+        browse_btn.clicked.connect(self._browse_file)
+        file_l.addWidget(browse_btn)
+        file_l.addWidget(QLabel("Delay:"))
+        self._delay_spin = QDoubleSpinBox()
+        self._delay_spin.setRange(0.0, 10.0)
+        self._delay_spin.setSingleStep(0.1)
+        self._delay_spin.setDecimals(1)
+        self._delay_spin.setValue(1.0)
+        self._delay_spin.setSuffix(" s")
+        self._delay_spin.setFixedWidth(72)
+        file_l.addWidget(self._delay_spin)
+        self._stack.addWidget(file_w)
+
         layout.addWidget(self._stack)
         layout.addStretch()
 
@@ -115,6 +142,17 @@ class ConnectionRow(QWidget):
         if config:
             self.apply_config(config)
 
+    # ── File browse ──────────────────────────────────────────────────────────
+
+    def _browse_file(self):
+        path, _ = QFileDialog.getOpenFileName(
+            self, "Select log file", "", "Log files (*.log);;All files (*)")
+        if path:
+            self._file_edit.setText(path)
+
+    def _on_file_path_changed(self, path: str):
+        self._id_edit.setText(source_id_from_path(path) or '')
+
     # ── Serial port detection ────────────────────────────────────────────────
 
     def _populate_serial_ports(self):
@@ -129,7 +167,8 @@ class ConnectionRow(QWidget):
 
     def apply_config(self, config: ConnectionConfig):
         self._id_edit.setText(config.receiver_id)
-        self._type_combo.setCurrentIndex(0 if config.conn_type == 'tcp' else 1)
+        self._type_combo.setCurrentIndex(
+            {'tcp': 0, 'serial': 1, 'file': 2}.get(config.conn_type, 0))
         self._host_edit.setText(config.host)
         self._port_spin.setValue(config.port)
         if config.serial_port:
@@ -137,9 +176,11 @@ class ConnectionRow(QWidget):
             self._ser_combo.setCurrentIndex(idx) if idx >= 0 \
                 else self._ser_combo.setCurrentText(config.serial_port)
         self._baud_combo.setCurrentText(str(config.baud_rate))
+        self._file_edit.setText(config.file_path)
+        self._delay_spin.setValue(config.delay)
 
     def get_config(self) -> ConnectionConfig:
-        t = 'tcp' if self._type_combo.currentIndex() == 0 else 'serial'
+        t = ['tcp', 'serial', 'file'][self._type_combo.currentIndex()]
         return ConnectionConfig(
             receiver_id = self._id_edit.text().strip(),
             conn_type   = t,
@@ -147,6 +188,8 @@ class ConnectionRow(QWidget):
             port        = self._port_spin.value(),
             serial_port = self._ser_combo.currentText().strip(),
             baud_rate   = int(self._baud_combo.currentText()),
+            file_path   = self._file_edit.text().strip(),
+            delay       = self._delay_spin.value(),
         )
 
     def get_receiver_id(self) -> str:
@@ -157,7 +200,8 @@ class ConnectionRow(QWidget):
         self._dot.set_connected(connected)
         self._conn_btn.setText("Disconnect" if connected else "Connect")
         for w in [self._id_edit, self._type_combo, self._host_edit,
-                  self._port_spin, self._ser_combo, self._baud_combo]:
+                  self._port_spin, self._ser_combo, self._baud_combo,
+                  self._file_edit, self._delay_spin]:
             w.setEnabled(not connected)
 
     # ── Slots ────────────────────────────────────────────────────────────────
@@ -180,6 +224,10 @@ class ConnectionRow(QWidget):
             QMessageBox.warning(self, "GNSS Monitor",
                                 f"ID '{config.receiver_id}' wird bereits verwendet.")
             return
+        if config.conn_type == 'file' and not config.file_path:
+            QMessageBox.warning(self, "GNSS Monitor",
+                                "Bitte eine Log-Datei auswählen.")
+            return
 
         self._model.add_receiver(config)
         self._rid = config.receiver_id

gui/data_model.py

@@ -52,16 +52,20 @@ class SatelliteData:
 @dataclass
 class ConnectionConfig:
     receiver_id: str
-    conn_type:   str = 'tcp'
+    conn_type:   str   = 'tcp'
-    host:        str = ''
+    host:        str   = ''
-    port:        int = 8721
+    port:        int   = 8721
-    serial_port: str = ''
+    serial_port: str   = ''
-    baud_rate:   int = 115200
+    baud_rate:   int   = 115200
+    file_path:   str   = ''
+    delay:       float = 1.0
 
     def display_str(self) -> str:
         if self.conn_type == 'tcp':
             return f"{self.receiver_id}  [{self.host}:{self.port}]"
-        return f"{self.receiver_id}  [{self.serial_port} @ {self.baud_rate}]"
+        if self.conn_type == 'serial':
+            return f"{self.receiver_id}  [{self.serial_port} @ {self.baud_rate}]"
+        return f"{self.receiver_id}  [file: {os.path.basename(self.file_path)}]"
 
     def to_dict(self):
         return dataclasses.asdict(self)
@@ -148,6 +152,7 @@ class ReceiverManager(QObject):
     def connect_receiver(self, rid: str):
         from listeners import NavSatQtListener, GsaQtListener
         from backend.serial_backend import SerialBackend
+        from backend.file_backend   import FileBackend
 
         config = self._configs.get(rid)
         state  = self._states.get(rid)
@@ -160,8 +165,10 @@ class ReceiverManager(QObject):
             backend = NetworkBackend(
                 [{'name': rid, 'host': config.host, 'port': config.port}]
             )
-        else:
+        elif config.conn_type == 'serial':
             backend = SerialBackend(config.serial_port, config.baud_rate)
+        else:
+            backend = FileBackend([config.file_path], delay=config.delay)
 
         backend.register_xcvr(xcvr)
 
@@ -184,12 +191,12 @@ class ReceiverManager(QObject):
         state.transceiver = xcvr
         state.connected   = True
 
-        # Poll UBX messages every second (receiver only sends on request by default)
+        if config.conn_type != 'file':
-        timer = QTimer(self)
+            timer = QTimer(self)
-        timer.setInterval(1000)
+            timer.setInterval(1000)
-        timer.timeout.connect(lambda r=rid: self._poll_ubx(r))
+            timer.timeout.connect(lambda r=rid: self._poll_ubx(r))
-        timer.start()
+            timer.start()
-        state.poll_timer = timer
+            state.poll_timer = timer
 
         self._push_lru(config)
         self.connection_changed.emit(rid, True)