Merge branch '2143_Settings_Menu_Themes' of https://github.com/mantid…

…project/mantidimaging into 2143_Settings_Menu_Themes

docs/release_notes/next/dev-2035-process-count

@@ -0,0 +1 @@
+#2035: Add setting for number of processes to start in multiprocessing pool (default to 8)

docs/release_notes/next/fix-2076-ROI-speed

@@ -0,0 +1 @@
+#2076: ROI speed up

mantidimaging/core/parallel/manager.py

@@ -28,13 +28,16 @@
 pool: Pool | None = None
 
 
-def create_and_start_pool():
-    LOG.info('Creating process pool')
+def create_and_start_pool(process_count: int) -> None:
     t0 = time.monotonic()
     context = get_context('spawn')
     global cores
-    cores = context.cpu_count()
+    if process_count == 0:
+        cores = context.cpu_count()
+    else:
+        cores = process_count
     global pool
+    LOG.info(f'Creating process pool with {cores} processes')
     pool = context.Pool(cores, initializer=worker_setup)
 
     if perf_logger.isEnabledFor(1):

mantidimaging/gui/windows/spectrum_viewer/spectrum_widget.py

@@ -175,9 +175,6 @@ def set_roi_visibility_flags(self, name: str, visible: bool) -> None:
         for handle in handles:
             handle.setVisible(visible)
         self.roi_dict[name].setVisible(visible)
-        self.roi_dict[name].setAcceptedMouseButtons(Qt.MouseButton.LeftButton)
-        self.roi_dict[name].sigRegionChanged.connect(self.roi_changed.emit)
-        self.roi_dict[name].sigClicked.connect(self.roi_clicked.emit)
 
     def set_roi_alpha(self, name: str, alpha: float) -> None:
         """
@@ -205,7 +202,7 @@ def add_roi(self, roi: SensibleROI, name: str) -> None:
 
         self.roi_dict[name] = roi_object.roi
         self.max_roi_size = roi_object.size()
-        self.roi_dict[name].sigRegionChanged.connect(self.roi_changed.emit)
+        self.roi_dict[name].sigRegionChangeFinished.connect(self.roi_changed.emit)
         self.roi_dict[name].sigClicked.connect(self.roi_clicked.emit)
         self.image.vb.addItem(self.roi_dict[name])
         self.roi_dict[name].hoverPen = mkPen(self.roi_dict[name].colour, width=3)
@@ -276,7 +273,7 @@ def __init__(self) -> None:
         self.nextRow()
         self._tof_range_label = self.addLabel()
         self.range_control = LinearRegionItem()
-        self.range_control.sigRegionChanged.connect(self._handle_tof_range_changed)
+        self.range_control.sigRegionChangeFinished.connect(self._handle_tof_range_changed)
         self.ci.layout.setRowStretchFactor(0, 1)
 
     def get_tof_range(self) -> tuple[int, int]:

mantidimaging/main.py

@@ -9,6 +9,7 @@
 import os
 
 import darkdetect
+from PyQt5.QtCore import QSettings
 from PyQt5.QtWidgets import QApplication
 from PyQt5 import QtCore
 from PyQt5.QtGui import QGuiApplication, QFont, QFontInfo
@@ -112,9 +113,12 @@ def main() -> None:
 
     h.initialise_logging(args.log_level)
 
+    settings = QSettings()
+    process_count = settings.value("multiprocessing/process_count", 8, type=int)
+
     from mantidimaging import gui
     try:
-        pm.create_and_start_pool()
+        pm.create_and_start_pool(process_count)
         gui.execute()
         result = q_application.exec_()
     except BaseException as e:

mantidimaging/test_helpers/start_qapplication.py

@@ -85,7 +85,7 @@ def tearDownClass():
 def start_multiprocessing_pool(cls):
 
     def setUpClass():
-        create_and_start_pool()
+        create_and_start_pool(0)
 
     def tearDownClass():
         end_pool()