Mean is calculated in separate thread, spectrum updated in Main thread

mantidimaging/gui/windows/live_viewer/model.py

@@ -6,7 +6,6 @@
 from typing import TYPE_CHECKING
 from pathlib import Path
 from logging import getLogger
-from threading import Thread
 
 import numpy as np
 from PyQt5.QtCore import QFileSystemWatcher, QObject, pyqtSignal, QTimer
@@ -251,14 +250,9 @@ def calc_mean_chunk(self, chunk_size: int) -> None:
                     buffer_mean = np.mean(self.image_cache.load_image(self.images[ind])[top:bottom, left:right])
                     np.put(self.mean, ind, buffer_mean)
 
-    def create_new_calc_mean_all_chunks_thread(self, chunk_size: int) -> None:
-        self.calc_mean_all_chunks_thread = Thread(target=self.calc_mean_all_chunks, args=[chunk_size])
-
     def calc_mean_all_chunks(self, chunk_size: int) -> None:
         while np.isnan(self.mean).any():
             self.calc_mean_chunk(chunk_size)
-            self.presenter.update_spectrum(self.mean)
-
 
 
 class ImageWatcher(QObject):

mantidimaging/gui/windows/live_viewer/presenter.py

@@ -8,6 +8,7 @@
 from logging import getLogger
 
 import numpy as np
+from PyQt5.QtCore import pyqtSignal, QObject, QThread
 
 from imagecodecs._deflate import DeflateError
 
@@ -23,6 +24,18 @@
 logger = getLogger(__name__)
 
 
+class Worker(QObject):
+    finished = pyqtSignal()
+
+    def __init__(self, presenter: LiveViewerWindowPresenter):
+        super().__init__()
+        self.presenter = presenter
+
+    def run(self):
+        self.presenter.model.calc_mean_all_chunks(100)
+        self.finished.emit()
+
+
 class LiveViewerWindowPresenter(BasePresenter):
     """
     The presenter for the Live Viewer window.
@@ -166,13 +179,25 @@ def handle_roi_moved(self, force_new_spectrums: bool = False):
         roi = self.view.live_viewer.get_roi()
         self.model.set_roi(roi)
         self.model.clear_mean_partial()
-        if self.model.calc_mean_all_chunks_thread is not None:
-            self.model.calc_mean_all_chunks_thread.join()
-        self.model.create_new_calc_mean_all_chunks_thread(100)
-        self.model.calc_mean_all_chunks_thread.start()
+        self.run_mean_chunk_calc()
         self.roi_moving = False
 
+    def run_mean_chunk_calc(self):
+        self.thread = QThread()
+        self.worker = Worker(self)
+        self.worker.moveToThread(self.thread)
+        self.thread.started.connect(self.worker.run)
+        self.worker.finished.connect(self.update_spectrum_with_mean)
+        self.worker.finished.connect(self.thread.quit)
+        self.worker.finished.connect(self.worker.deleteLater)
+        self.thread.finished.connect(self.thread.deleteLater)
+        self.thread.start()
+
     def handle_roi_moved_start(self):
         self.roi_moving = True
         self.model.clear_mean_partial()
         self.update_spectrum(self.model.mean)
+
+    def update_spectrum_with_mean(self):
+        self.view.spectrum.clearPlots()
+        self.view.spectrum.plot(self.model.mean)