fix graph and white background added

python_app/gui/controllers/pipeline_controller.py

@@ -80,6 +80,9 @@ class PipelineController:
         self._raw_reader: ShmRingReader | None = None
         self._pre_reader: ShmRingReader | None = None
         self._result_reader: ShmRingReader | None = None
+        # Results read anywhere (polling, Stop/pause drains, snapshots) await display;
+        # the next poll shows the newest acquisition, not merely the last one read.
+        self._display_pending = False
         self.active_config: RunConfigModel | None = None
         self.active_config_path: Path | None = None
         self.stop_generation = 0
@@ -203,6 +206,7 @@ class PipelineController:
                 raise error
             if not operation.valid:
                 raise InterruptedError("Pipeline operation cancelled")
+            self._display_pending = False  # the pausing operation owns the display
             return operation
         except BaseException:
             operation.finish(resume=False)
@@ -478,11 +482,14 @@ class PipelineController:
                 finally:
                     if self.single_capture_active:
                         self._check_single_capture_deadline()
-            elif latest[2] is not None:
-                self._restart_count = 0
-                started = time.monotonic_ns()
-                self.plots.draw(latest[2])
-                self.metrics.record("rendering", time.monotonic_ns() - started)
+            elif self._display_pending:
+                if latest[2] is not None:
+                    self._restart_count = 0  # results flow again
+                self._display_pending = False
+                if self.history.results:
+                    started = time.monotonic_ns()
+                    self.plots.draw(self.history.results[-1])
+                    self.metrics.record("rendering", time.monotonic_ns() - started)
         except Exception as exc:
             self._report_ui_error("Result display", exc)
 
@@ -634,6 +641,7 @@ class PipelineController:
                 self.metrics.record("processing", collection.processing_duration_ns)
                 if self.history.record_result(collection):
                     self.recording.record("results", collection)
+                self._display_pending = True
                 latest = collection
         return latest
 
@@ -662,17 +670,20 @@ class PipelineController:
             stable = 0 if self.drain_once() else stable + 1
             self.pump_events(poll_s)
 
-    def drain_results(self, *, timeout_s: float, poll_s: float) -> ResultCollection | None:
-        deadline, stable = time.monotonic() + timeout_s, 0
-        latest_seen = None
-        while self._result_reader is not None and time.monotonic() < deadline and (latest_seen is None or stable < 2):
-            latest = self.read_results()
-            if latest is not None:
-                latest_seen, stable = latest, 0
-            elif latest_seen is not None:
+    def drain_results(self, *, timeout_s: float, poll_s: float, revision: int | None = None) -> None:
+        """Read results until the timeout; stop two quiet polls after results arrive or,
+        given a revision, as soon as the newest result carries it."""
+        deadline, seen, stable = time.monotonic() + timeout_s, False, 0
+        while self._result_reader is not None and time.monotonic() < deadline:
+            if self.read_results() is not None:
+                seen, stable = True, 0
+            elif seen:
                 stable += 1
+            if revision is None and stable >= 2:
+                return
+            if revision is not None and self.history.results and self.history.results[-1].settings_revision == revision:
+                return
             self.pump_events(poll_s)
-        return latest_seen
 
     def drain_snapshot(self) -> None:
         initial_readers = self.readers