Remove use of QSignalBlocker in most code

It appears that we can't always rely on python's reference counting
system to delete `QSignalBlocker` (or lists of `QSignalBlocker`) at
the end of method calls. As such, we should convert over to using the
`block_signals()` context manager from `hexrd.ui.utils`.

This commit moves all code over to that.

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

hexrd/ui/calibration_crystal_editor.py

@@ -2,7 +2,7 @@
 import numpy as np
 from numpy.linalg import LinAlgError
 
-from PySide2.QtCore import QObject, QSignalBlocker, Signal
+from PySide2.QtCore import QObject, Signal
 from PySide2.QtWidgets import QFileDialog
 
 from hexrd import instrument, matrixutil
@@ -16,7 +16,7 @@
 from hexrd.ui.select_grains_dialog import SelectGrainsDialog
 from hexrd.ui.select_items_widget import SelectItemsWidget
 from hexrd.ui.ui_loader import UiLoader
-from hexrd.ui.utils import convert_angle_convention
+from hexrd.ui.utils import block_signals, convert_angle_convention
 
 
 class CalibrationCrystalEditor(QObject):
@@ -171,8 +171,8 @@ def update_duplicate(self, w):
         dup_ind = self.stretch_matrix_duplicates.get(ind)
         if dup_ind is not None:
             dup = getattr(self.ui, f'stretch_matrix_{dup_ind}')
-            blocker = QSignalBlocker(dup)  # noqa: F841
-            dup.setValue(w.value())
+            with block_signals(dup):
+                dup.setValue(w.value())
 
     def set_matrix_valid(self):
         self.set_matrix_style_sheet('background-color: white')
@@ -215,8 +215,8 @@ def orientation(self, v):
             v = np.degrees(v)
 
         for i, w in enumerate(self.orientation_widgets):
-            blocker = QSignalBlocker(w)  # noqa: F841
-            w.setValue(v[i])
+            with block_signals(w):
+                w.setValue(v[i])
 
     @property
     def position(self):
@@ -225,8 +225,8 @@ def position(self):
     @position.setter
     def position(self, v):
         for i, w in enumerate(self.position_widgets):
-            blocker = QSignalBlocker(w)  # noqa: F841
-            w.setValue(v[i])
+            with block_signals(w):
+                w.setValue(v[i])
 
     @property
     def inverse_stretch(self):
@@ -245,8 +245,8 @@ def stretch_matrix(self):
     @stretch_matrix.setter
     def stretch_matrix(self, v):
         for i, w in enumerate(self.stretch_matrix_widgets):
-            blocker = QSignalBlocker(w)  # noqa: F841
-            w.setValue(v[i])
+            with block_signals(w):
+                w.setValue(v[i])
 
     @property
     def orientation_widgets(self):

hexrd/ui/calibration_crystal_slider_widget.py

@@ -1,9 +1,10 @@
 from enum import IntEnum
 
-from PySide2.QtCore import QObject, QSignalBlocker, Signal
+from PySide2.QtCore import QObject, Signal
 from PySide2.QtWidgets import QProxyStyle, QStyle
 
 from hexrd.ui.ui_loader import UiLoader
+from hexrd.ui.utils import block_signals
 
 
 class SpinBoxStyle(QProxyStyle):
@@ -90,9 +91,9 @@ def on_mode_changed(self):
 
         # Update spinbox values
         for i, w in enumerate(self.spinbox_widgets):
-            blocker = QSignalBlocker(w)  # noqa: F841
-            w.setSuffix(suffix)
-            w.setValue(data[i])
+            with block_signals(w):
+                w.setSuffix(suffix)
+                w.setValue(data[i])
 
         # Update slider positions
         self.ui.slider_range.setValue(srange)
@@ -123,10 +124,9 @@ def on_spinbox_changed(self, value):
         slider_value = value * self.CONF_VAL_TO_SLIDER_VAL
         w_name = f'slider_{index}'
         w = getattr(self.ui, w_name)
-        blocker = QSignalBlocker(w)  # noqa: F841
-        w.setValue(slider_value)
-
-        self.changed.emit(mode.value, index, value)
+        with block_signals(w):
+            w.setValue(slider_value)
+            self.changed.emit(mode.value, index, value)
 
     def reset_ranges(self):
         self._orientation_range = self.DEFAULT_SLIDER_RANGE
@@ -156,8 +156,8 @@ def update_gui(self, orientation, position):
         data = self._orientation if self.mode == WidgetMode.ORIENTATION \
             else self._position
         for i, w in enumerate(self.spinbox_widgets):
-            blocker = QSignalBlocker(w)  # noqa: F841
-            w.setValue(data[i])
+            with block_signals(w):
+                w.setValue(data[i])
         self.update_ranges()
 
     def update_ranges(self):
@@ -169,6 +169,6 @@ def update_ranges(self):
         sliders = self.slider_widgets
         for i, slider in enumerate(sliders):
             val = data[i] * self.CONF_VAL_TO_SLIDER_VAL
-            blocker = QSignalBlocker(slider)  # noqa: F841
-            slider.setRange(val - delta, val + delta)
-            slider.setValue(val)
+            with block_signals(slider):
+                slider.setRange(val - delta, val + delta)
+                slider.setValue(val)

hexrd/ui/dev-guide.md

@@ -109,6 +109,10 @@ class SomeWidget(QObject):
 For updating the GUI with internal config, the design pattern we typically
 use is as follows:
 ```
+from hexrd.ui.utils import block_signals
+
+...
+
     @property
     def all_widgets(self):
         return [
@@ -118,16 +122,14 @@ use is as follows:
         ]
 
     def update_gui(self):
-        blockers = [QSignalBlocker(x) for x in self.all_widgets]  # noqa: F841
-        self.ui.widget1.setValue(...)
-        ...
+        with block_signals(*self.all_widgets):
+            self.ui.widget1.setValue(...)
+            ...
 ```
 
 We need to block the widget signals when we are updating the values, so that
-they do not modify the config as well. The reason we use a list of
-QSignalBlockers is so that if an exception is raised, they will be unblocked
-automatically. `# noqa: F841` is necessary to tell `flake8` to ignore the
-fact that we don't use `blockers` (it is only being used in an RAII fashion).
+they do not modify the config as well. The reason we use a context manager
+is so that if an exception is raised, they will be unblocked automatically.
 
 Resources
 ---------

hexrd/ui/image_mode_widget.py

@@ -3,13 +3,14 @@
 import multiprocessing
 import numpy as np
 
-from PySide2.QtCore import QObject, QSignalBlocker, Signal
+from PySide2.QtCore import QObject, Signal
 
 from hexrd.ui.constants import ViewType
 from hexrd.ui.create_hedm_instrument import create_hedm_instrument
 from hexrd.ui.create_raw_mask import apply_threshold_mask, remove_threshold_mask
 from hexrd.ui.hexrd_config import HexrdConfig
 from hexrd.ui.ui_loader import UiLoader
+from hexrd.ui.utils import block_signals
 
 
 class ImageModeWidget(QObject):
@@ -133,45 +134,45 @@ def all_widgets(self):
         return widgets
 
     def update_gui_from_config(self):
-        blocked = [QSignalBlocker(x) for x in self.all_widgets()]  # noqa: F841
-        self.ui.raw_threshold_comparison.setCurrentIndex(
-            HexrdConfig().threshold_comparison)
-        self.ui.raw_threshold_value.setValue(
-            HexrdConfig().threshold_value)
-        self.ui.raw_threshold_mask.setChecked(
-            HexrdConfig().threshold_mask_status)
-        self.ui.cartesian_pixel_size.setValue(
-            HexrdConfig().cartesian_pixel_size)
-        self.ui.cartesian_virtual_plane_distance.setValue(
-            HexrdConfig().cartesian_virtual_plane_distance)
-        self.ui.cartesian_plane_normal_rotate_x.setValue(
-            HexrdConfig().cartesian_plane_normal_rotate_x)
-        self.ui.cartesian_plane_normal_rotate_y.setValue(
-            HexrdConfig().cartesian_plane_normal_rotate_y)
-        self.ui.polar_pixel_size_tth.setValue(
-            HexrdConfig().polar_pixel_size_tth)
-        self.ui.polar_pixel_size_eta.setValue(
-            HexrdConfig().polar_pixel_size_eta)
-        self.ui.polar_res_tth_min.setValue(
-            HexrdConfig().polar_res_tth_min)
-        self.ui.polar_res_tth_max.setValue(
-            HexrdConfig().polar_res_tth_max)
-        self.ui.polar_res_eta_min.setValue(
-            HexrdConfig().polar_res_eta_min)
-        self.ui.polar_res_eta_max.setValue(
-            HexrdConfig().polar_res_eta_max)
-        self.ui.polar_snip1d_algorithm.setCurrentIndex(
-            HexrdConfig().polar_snip1d_algorithm)
-        self.ui.polar_apply_snip1d.setChecked(
-            HexrdConfig().polar_apply_snip1d)
-        self.ui.polar_snip1d_width.setValue(
-            HexrdConfig().polar_snip1d_width)
-        self.ui.polar_snip1d_numiter.setValue(
-            HexrdConfig().polar_snip1d_numiter)
-        self.ui.polar_apply_erosion.setChecked(
-            HexrdConfig().polar_apply_erosion)
-
-        self.update_enable_states()
+        with block_signals(*self.all_widgets()):
+            self.ui.raw_threshold_comparison.setCurrentIndex(
+                HexrdConfig().threshold_comparison)
+            self.ui.raw_threshold_value.setValue(
+                HexrdConfig().threshold_value)
+            self.ui.raw_threshold_mask.setChecked(
+                HexrdConfig().threshold_mask_status)
+            self.ui.cartesian_pixel_size.setValue(
+                HexrdConfig().cartesian_pixel_size)
+            self.ui.cartesian_virtual_plane_distance.setValue(
+                HexrdConfig().cartesian_virtual_plane_distance)
+            self.ui.cartesian_plane_normal_rotate_x.setValue(
+                HexrdConfig().cartesian_plane_normal_rotate_x)
+            self.ui.cartesian_plane_normal_rotate_y.setValue(
+                HexrdConfig().cartesian_plane_normal_rotate_y)
+            self.ui.polar_pixel_size_tth.setValue(
+                HexrdConfig().polar_pixel_size_tth)
+            self.ui.polar_pixel_size_eta.setValue(
+                HexrdConfig().polar_pixel_size_eta)
+            self.ui.polar_res_tth_min.setValue(
+                HexrdConfig().polar_res_tth_min)
+            self.ui.polar_res_tth_max.setValue(
+                HexrdConfig().polar_res_tth_max)
+            self.ui.polar_res_eta_min.setValue(
+                HexrdConfig().polar_res_eta_min)
+            self.ui.polar_res_eta_max.setValue(
+                HexrdConfig().polar_res_eta_max)
+            self.ui.polar_snip1d_algorithm.setCurrentIndex(
+                HexrdConfig().polar_snip1d_algorithm)
+            self.ui.polar_apply_snip1d.setChecked(
+                HexrdConfig().polar_apply_snip1d)
+            self.ui.polar_snip1d_width.setValue(
+                HexrdConfig().polar_snip1d_width)
+            self.ui.polar_snip1d_numiter.setValue(
+                HexrdConfig().polar_snip1d_numiter)
+            self.ui.polar_apply_erosion.setChecked(
+                HexrdConfig().polar_apply_erosion)
+
+            self.update_enable_states()
 
     def update_enable_states(self):
         apply_snip1d = self.ui.polar_apply_snip1d.isChecked()
@@ -280,9 +281,9 @@ def on_eta_min_changed(self, min_value):
             max_value = min_value + 360.0
             update_max = True
         if update_max:
-            blocked = QSignalBlocker(self.ui.polar_res_eta_max)  # noqa: F841
-            self.ui.polar_res_eta_max.setValue(max_value)
-            HexrdConfig().set_polar_res_eta_max(max_value, rerender=False)
+            with block_signals(self.ui.polar_res_eta_max):
+                self.ui.polar_res_eta_max.setValue(max_value)
+                HexrdConfig().set_polar_res_eta_max(max_value, rerender=False)
         HexrdConfig().polar_res_eta_min = min_value
 
     def on_eta_max_changed(self, max_value):
@@ -296,9 +297,9 @@ def on_eta_max_changed(self, max_value):
             min_value = max_value - 360.0
             update_min = True
         if update_min:
-            blocked = QSignalBlocker(self.ui.polar_res_eta_min)  # noqa: F841
-            self.ui.polar_res_eta_min.setValue(min_value)
-            HexrdConfig().set_polar_res_eta_min(min_value, rerender=False)
+            with block_signals(self.ui.polar_res_eta_min):
+                self.ui.polar_res_eta_min.setValue(min_value)
+                HexrdConfig().set_polar_res_eta_min(min_value, rerender=False)
         HexrdConfig().polar_res_eta_max = max_value
 
 

hexrd/ui/indexing/fit_grains_options_dialog.py

@@ -1,11 +1,12 @@
 from PySide2.QtCore import (
-    QItemSelectionModel, QModelIndex, QObject, QSignalBlocker, Qt, Signal)
+    QItemSelectionModel, QModelIndex, QObject, Qt, Signal)
 from PySide2.QtWidgets import QDialogButtonBox, QFileDialog, QHeaderView
 
 from hexrd.ui.hexrd_config import HexrdConfig
 from hexrd.ui.indexing.grains_table_model import GrainsTableModel
 from hexrd.ui.reflections_table import ReflectionsTable
 from hexrd.ui.ui_loader import UiLoader
+from hexrd.ui.utils import block_signals
 
 from hexrd.ui.indexing.fit_grains_tolerances_model import (
     FitGrainsToleranceModel)
@@ -221,47 +222,47 @@ def update_config(self):
         indexing_config['_write_spots'] = self.ui.write_out_spots.isChecked()
 
     def update_gui_from_config(self, config):
-        blocked = [QSignalBlocker(x) for x in self.all_widgets()]
-        self.ui.npdiv.setValue(config.get('npdiv'))
-        self.ui.refit_pixel_scale.setValue(config.get('refit')[0])
-        self.ui.refit_ome_step_scale.setValue(config.get('refit')[1])
-        self.ui.threshold.setValue(config.get('threshold'))
-
-        tth_max = config.get('tth_max')
-        if isinstance(tth_max, bool):
-            enabled = tth_max
-            instrument = tth_max
-            value = 0.0
-        else:
-            enabled = True
-            instrument = False
-            value = tth_max
-
-        self.ui.tth_max_enable.setChecked(enabled)
-
-        self.ui.tth_max_instrument.setEnabled(enabled)
-        self.ui.tth_max_instrument.setChecked(instrument)
-
-        self.ui.tth_max_specify.setEnabled(enabled)
-        self.ui.tth_max_specify.setChecked(not instrument)
-
-        self.ui.tth_max_value.setEnabled(enabled and (not instrument))
-        self.ui.tth_max_value.setValue(value)
-
-        tolerances = config.get('tolerance')
-        self.tolerances_model.update_from_config(tolerances)
-
-        indexing_config = HexrdConfig().indexing_config
-        self.selected_material = indexing_config.get('_selected_material')
-        working_dir = indexing_config.get(
-            'working_dir', str(Path(HexrdConfig().working_dir).parent))
-        analysis_name = indexing_config.get(
-            'analysis_name', Path(HexrdConfig().working_dir).stem)
-        self.spots_path = str(Path(working_dir) / analysis_name)
-        write_spots = indexing_config.get('_write_spots', False)
-        self.ui.write_out_spots.setChecked(write_spots)
-
-        self.update_num_hkls()
+        with block_signals(*self.all_widgets()):
+            self.ui.npdiv.setValue(config.get('npdiv'))
+            self.ui.refit_pixel_scale.setValue(config.get('refit')[0])
+            self.ui.refit_ome_step_scale.setValue(config.get('refit')[1])
+            self.ui.threshold.setValue(config.get('threshold'))
+
+            tth_max = config.get('tth_max')
+            if isinstance(tth_max, bool):
+                enabled = tth_max
+                instrument = tth_max
+                value = 0.0
+            else:
+                enabled = True
+                instrument = False
+                value = tth_max
+
+            self.ui.tth_max_enable.setChecked(enabled)
+
+            self.ui.tth_max_instrument.setEnabled(enabled)
+            self.ui.tth_max_instrument.setChecked(instrument)
+
+            self.ui.tth_max_specify.setEnabled(enabled)
+            self.ui.tth_max_specify.setChecked(not instrument)
+
+            self.ui.tth_max_value.setEnabled(enabled and (not instrument))
+            self.ui.tth_max_value.setValue(value)
+
+            tolerances = config.get('tolerance')
+            self.tolerances_model.update_from_config(tolerances)
+
+            indexing_config = HexrdConfig().indexing_config
+            self.selected_material = indexing_config.get('_selected_material')
+            working_dir = indexing_config.get(
+                'working_dir', str(Path(HexrdConfig().working_dir).parent))
+            analysis_name = indexing_config.get(
+                'analysis_name', Path(HexrdConfig().working_dir).stem)
+            self.spots_path = str(Path(working_dir) / analysis_name)
+            write_spots = indexing_config.get('_write_spots', False)
+            self.ui.write_out_spots.setChecked(write_spots)
+
+            self.update_num_hkls()
 
     def run(self):
         self.ui.show()