new GPR parameters and some UI fixes

python_app/workflows/sequential_capture_workflow.py

@@ -24,6 +24,8 @@ class SequentialCaptureState:
     captured_count: int
     total_count: int
     current_combo: ComboModel | None
+    can_undo: bool
+    is_complete: bool
 
 
 class SequentialCaptureSession:
@@ -112,6 +114,8 @@ class SequentialCaptureSession:
             captured_count=len(self._traces),
             total_count=len(self._combos),
             current_combo=current_combo,
+            can_undo=bool(self._traces),
+            is_complete=self.is_complete(),
         )
 
     def capture_current_combo(self) -> TraceData:
@@ -138,6 +142,34 @@ class SequentialCaptureSession:
         self._next_index += 1
         return trace
 
+    def undo_last_capture(self) -> TraceData:
+        """Remove the most recently captured trace and rewind cursor by one combo."""
+        if not self._opened:
+            raise RuntimeError("Capture session is not opened")
+        if not self._traces or self._next_index <= 0:
+            raise RuntimeError("No captured combo is available to undo")
+
+        expected_combo = self._combos[self._next_index - 1]
+        removed_trace = self._traces[-1]
+        if (
+            int(removed_trace.combo.input_pos) != int(expected_combo.input)
+            or int(removed_trace.combo.output_pos) != int(expected_combo.output)
+        ):
+            raise RuntimeError("Capture session state is inconsistent; last trace does not match rewind combo")
+        self._next_index -= 1
+        self._traces.pop()
+        return removed_trace
+
+    def last_captured_trace(self) -> TraceData | None:
+        """Return the most recently captured trace, if any."""
+        if not self._traces:
+            return None
+        return self._traces[-1]
+
+    def captured_traces(self) -> list[TraceData]:
+        """Return captured traces in acquisition order."""
+        return list(self._traces)
+
     def is_complete(self) -> bool:
         """Return `True` when all combos were captured."""
         return self._next_index >= len(self._combos)