Fix non-responding widgets for multi indexing runs

The previous design pattern created a list of `QSignalBlocker` objects,
and it relied on Python to perform reference counting and delete this list
at the end of the function, so that the widgets would become unblocked.

For some reason, if you run indexing multiple times, it appears that this
list is sometimes not deleted at the end of the function.

Instead of relying on Python to perform reference counting correctly,
let's use a context manager so that we can be sure the widgets get
unblocked.

This fixes an issue where widgets were not emitting signals in the eta
omega maps viewer when running the HEDM workflow multiple times.

We should also go back and fix any other cases of the design pattern, since
it appears to be error-prone.

Signed-off-by: Patrick Avery <[email protected]>

hexrd/ui/indexing/ome_maps_viewer_dialog.py

@@ -6,7 +6,7 @@
 import numpy as np
 import yaml
 
-from PySide2.QtCore import Signal, QObject, QSignalBlocker, QTimer, Qt
+from PySide2.QtCore import Signal, QObject, QTimer, Qt
 from PySide2.QtWidgets import (
     QCheckBox, QComboBox, QDoubleSpinBox, QFileDialog, QMessageBox,
     QSizePolicy, QSpinBox
@@ -699,57 +699,60 @@ def all_widgets(self):
     def update_gui(self):
         # Updates all of the widgets with their settings from the config
         self.update_hkl_options()
-        blockers = [QSignalBlocker(x) for x in self.all_widgets]  # noqa: F841
 
-        def setter(w):
-            if isinstance(w, QComboBox):
-                return lambda x: w.setCurrentIndex(w.findData(x))
+        with block_signals(*self.all_widgets):
 
-            # Assume it is a spin box of some kind
-            return w.setValue
+            def setter(w):
+                if isinstance(w, QComboBox):
+                    return lambda x: w.setCurrentIndex(w.findData(x))
 
-        config = self.config
+                # Assume it is a spin box of some kind
+                return w.setValue
 
-        def set_val(w, path):
-            cur = config
-            for x in path:
-                if x not in cur:
-                    # If it's not in the config, skip over it
-                    return
-                cur = cur[x]
+            config = self.config
 
-            setter(w)(cur)
+            def set_val(w, path):
+                cur = config
+                for x in path:
+                    if x not in cur:
+                        # If it's not in the config, skip over it
+                        return
+                    cur = cur[x]
 
-        for w, path in self.widget_paths.items():
-            w = getattr(self.ui, w)
-            set_val(w, path)
+                setter(w)(cur)
 
-        find_orientations = config['find_orientations']
+            for w, path in self.widget_paths.items():
+                w = getattr(self.ui, w)
+                set_val(w, path)
 
-        if find_orientations.get('_hand_picked_quaternions', False):
-            self.quaternion_method_name = 'hand_picked'
-        elif find_orientations['use_quaternion_grid']:
-            self.quaternion_method_name = 'grid_search'
-        else:
-            self.quaternion_method_name = 'seed_search'
+            find_orientations = config['find_orientations']
 
-        self.quaternion_grid_file = find_orientations.get('_quat_file', '')
+            if find_orientations.get('_hand_picked_quaternions', False):
+                self.quaternion_method_name = 'hand_picked'
+            elif find_orientations['use_quaternion_grid']:
+                self.quaternion_method_name = 'grid_search'
+            else:
+                self.quaternion_method_name = 'seed_search'
 
-        # Update the method name
-        method = find_orientations['seed_search']['method']
-        self.seed_search_method_name = next(iter(method))
+            self.quaternion_grid_file = find_orientations.get('_quat_file', '')
 
-        # Also set the color map minimum to the threshold value...
-        self.threshold = find_orientations['threshold']
+            # Update the method name
+            method = find_orientations['seed_search']['method']
+            self.seed_search_method_name = next(iter(method))
 
-        self.filter_maps = find_orientations['orientation_maps']['filter_maps']
+            # Also set the color map minimum to the threshold value...
+            self.threshold = find_orientations['threshold']
 
-        key = '_write_scored_orientations'
-        self.write_scored_orientations = find_orientations.get(key, False)
+            orientation_maps = find_orientations['orientation_maps']
+            self.filter_maps = orientation_maps['filter_maps']
+
+            key = '_write_scored_orientations'
+            self.write_scored_orientations = find_orientations.get(key, False)
 
-        self.working_dir = config.get('working_dir', HexrdConfig().working_dir)
+            self.working_dir = config.get('working_dir',
+                                          HexrdConfig().working_dir)
 
-        self.synchronize_fiber_step_boxes(self.ui.fiber_step.value())
+            self.synchronize_fiber_step_boxes(self.ui.fiber_step.value())
 
     def update_config(self):
         # Update all of the config with their settings from the widgets