Fix leaky QT widgets

pyproject.toml

@@ -36,6 +36,7 @@ fix = true
 convention = "numpy"
 
 [tool.mypy]
+python_version = "3.8"
 # Block below are checks that form part of mypy 'strict' mode
 warn_unused_configs = true
 warn_redundant_casts = true
@@ -51,6 +52,7 @@ disallow_incomplete_defs = true
 disallow_untyped_defs = true
 no_implicit_reexport = true
 warn_return_any = false # TODO: fix
+ignore_missing_imports = true
 
 [[tool.mypy.overrides]]
 module = [

src/napari_matplotlib/base.py

@@ -1,6 +1,6 @@
 import os
 from pathlib import Path
-from typing import List, Tuple
+from typing import List, Optional, Tuple
 
 import napari
 from matplotlib.axes import Axes
@@ -43,16 +43,20 @@ class NapariMPLWidget(QWidget):
         List of currently selected napari layers.
     """
 
-    def __init__(self, napari_viewer: napari.viewer.Viewer):
-        super().__init__()
+    def __init__(
+        self,
+        napari_viewer: napari.viewer.Viewer,
+        parent: Optional[QWidget] = None,
+    ):
+        super().__init__(parent=parent)
 
         self.viewer = napari_viewer
         self.canvas = FigureCanvas()
 
         self.canvas.figure.patch.set_facecolor("none")
         self.canvas.figure.set_layout_engine("constrained")
         self.toolbar = NapariNavigationToolbar(
-            self.canvas, self
+            self.canvas, parent=self
         )  # type: ignore[no-untyped-call]
         self._replace_toolbar_icons()
 

src/napari_matplotlib/histogram.py

@@ -1,13 +1,14 @@
+from typing import Optional
+
+import napari
 import numpy as np
+from qtpy.QtWidgets import QWidget
 
 from .base import NapariMPLWidget
+from .util import Interval
 
 __all__ = ["HistogramWidget"]
 
-import napari
-
-from .util import Interval
-
 _COLORS = {"r": "tab:red", "g": "tab:green", "b": "tab:blue"}
 
 
@@ -19,8 +20,12 @@ class HistogramWidget(NapariMPLWidget):
     n_layers_input = Interval(1, 1)
     input_layer_types = (napari.layers.Image,)
 
-    def __init__(self, napari_viewer: napari.viewer.Viewer):
-        super().__init__(napari_viewer)
+    def __init__(
+        self,
+        napari_viewer: napari.viewer.Viewer,
+        parent: Optional[QWidget] = None,
+    ):
+        super().__init__(napari_viewer, parent=parent)
         self.add_single_axes()
         self.update_layers(None)
 

src/napari_matplotlib/scatter.py

@@ -1,9 +1,8 @@
-from typing import Any, List, Optional, Tuple
+from typing import Any, Dict, List, Optional, Tuple, Union
 
 import napari
 import numpy.typing as npt
-from magicgui import magicgui
-from magicgui.widgets import ComboBox
+from qtpy.QtWidgets import QComboBox, QLabel, QVBoxLayout, QWidget
 
 from .base import NapariMPLWidget
 from .util import Interval
@@ -20,11 +19,13 @@ class ScatterBaseWidget(NapariMPLWidget):
     # the scatter is plotted as a 2D histogram
     _threshold_to_switch_to_histogram = 500
 
-    def __init__(self, napari_viewer: napari.viewer.Viewer):
-        super().__init__(napari_viewer)
-
+    def __init__(
+        self,
+        napari_viewer: napari.viewer.Viewer,
+        parent: Optional[QWidget] = None,
+    ):
+        super().__init__(napari_viewer, parent=parent)
         self.add_single_axes()
-        self.update_layers(None)
 
     def clear(self) -> None:
         """
@@ -113,55 +114,57 @@ class FeaturesScatterWidget(ScatterBaseWidget):
         napari.layers.Vectors,
     )
 
-    def __init__(self, napari_viewer: napari.viewer.Viewer):
-        super().__init__(napari_viewer)
-        self._key_selection_widget = magicgui(
-            self._set_axis_keys,
-            x_axis_key={"choices": self._get_valid_axis_keys},
-            y_axis_key={"choices": self._get_valid_axis_keys},
-            call_button="plot",
-        )
+    def __init__(
+        self,
+        napari_viewer: napari.viewer.Viewer,
+        parent: Optional[QWidget] = None,
+    ):
+        super().__init__(napari_viewer, parent=parent)
+
+        self.layout().addLayout(QVBoxLayout())
 
-        self.layout().addWidget(self._key_selection_widget.native)
+        self._selectors: Dict[str, QComboBox] = {}
+        for dim in ["x", "y"]:
+            self._selectors[dim] = QComboBox()
+            # Re-draw when combo boxes are updated
+            self._selectors[dim].currentTextChanged.connect(self._draw)
+
+            self.layout().addWidget(QLabel(f"{dim}-axis:"))
+            self.layout().addWidget(self._selectors[dim])
+
+        self.update_layers(None)
 
     @property
-    def x_axis_key(self) -> Optional[str]:
+    def x_axis_key(self) -> Union[str, None]:
         """
         Key to access x axis data from the FeaturesTable.
         """
-        return self._x_axis_key
+        if self._selectors["x"].count() == 0:
+            return None
+        else:
+            return self._selectors["x"].currentText()
 
     @x_axis_key.setter
-    def x_axis_key(self, key: Optional[str]) -> None:
-        self._x_axis_key = key
+    def x_axis_key(self, key: str) -> None:
+        self._selectors["x"].setCurrentText(key)
         self._draw()
 
     @property
-    def y_axis_key(self) -> Optional[str]:
+    def y_axis_key(self) -> Union[str, None]:
         """
         Key to access y axis data from the FeaturesTable.
         """
-        return self._y_axis_key
+        if self._selectors["y"].count() == 0:
+            return None
+        else:
+            return self._selectors["y"].currentText()
 
     @y_axis_key.setter
-    def y_axis_key(self, key: Optional[str]) -> None:
-        """
-        Set the y-axis key.
-        """
-        self._y_axis_key = key
-        self._draw()
-
-    def _set_axis_keys(self, x_axis_key: str, y_axis_key: str) -> None:
-        """
-        Set both axis keys and then redraw the plot.
-        """
-        self._x_axis_key = x_axis_key
-        self._y_axis_key = y_axis_key
+    def y_axis_key(self, key: str) -> None:
+        self._selectors["y"].setCurrentText(key)
         self._draw()
 
-    def _get_valid_axis_keys(
-        self, combo_widget: Optional[ComboBox] = None
-    ) -> List[str]:
+    def _get_valid_axis_keys(self) -> List[str]:
         """
         Get the valid axis keys from the layer FeatureTable.
 
@@ -185,11 +188,12 @@ def _ready_to_scatter(self) -> bool:
             return False
 
         feature_table = self.layers[0].features
+        valid_keys = self._get_valid_axis_keys()
         return (
             feature_table is not None
             and len(feature_table) > 0
-            and self.x_axis_key is not None
-            and self.y_axis_key is not None
+            and self.x_axis_key in valid_keys
+            and self.y_axis_key in valid_keys
         )
 
     def draw(self) -> None:
@@ -230,9 +234,9 @@ def _on_update_layers(self) -> None:
         """
         Called when the layer selection changes by ``self.update_layers()``.
         """
-        if hasattr(self, "_key_selection_widget"):
-            self._key_selection_widget.reset_choices()
-
-        # reset the axis keys
-        self._x_axis_key = None
-        self._y_axis_key = None
+        # Clear combobox
+        for dim in ["x", "y"]:
+            while self._selectors[dim].count() > 0:
+                self._selectors[dim].removeItem(0)
+            # Add keys for newly selected layer
+            self._selectors[dim].addItems(self._get_valid_axis_keys())

src/napari_matplotlib/slice.py

@@ -1,9 +1,9 @@
-from typing import Any, Dict, Tuple
+from typing import Any, Dict, Optional, Tuple
 
 import napari
 import numpy as np
 import numpy.typing as npt
-from qtpy.QtWidgets import QComboBox, QHBoxLayout, QLabel, QSpinBox
+from qtpy.QtWidgets import QComboBox, QHBoxLayout, QLabel, QSpinBox, QWidget
 
 from .base import NapariMPLWidget
 from .util import Interval
@@ -22,9 +22,13 @@ class SliceWidget(NapariMPLWidget):
     n_layers_input = Interval(1, 1)
     input_layer_types = (napari.layers.Image,)
 
-    def __init__(self, napari_viewer: napari.viewer.Viewer):
+    def __init__(
+        self,
+        napari_viewer: napari.viewer.Viewer,
+        parent: Optional[QWidget] = None,
+    ):
         # Setup figure/axes
-        super().__init__(napari_viewer)
+        super().__init__(napari_viewer, parent=parent)
         self.add_single_axes()
 
         button_layout = QHBoxLayout()

src/napari_matplotlib/tests/conftest.py

@@ -1,3 +1,5 @@
+import os
+
 import numpy as np
 import pytest
 from skimage import data
@@ -22,3 +24,17 @@ def astronaut_data():
 @pytest.fixture
 def brain_data():
     return data.brain(), {"rgb": False}
+
+
+@pytest.fixture(autouse=True, scope="session")
+def set_strict_qt():
+    env_var = "NAPARI_STRICT_QT"
+    old_val = os.environ.get(env_var)
+    os.environ[env_var] = "1"
+    # Run tests
+    yield
+    # Reset to original value
+    if old_val is not None:
+        os.environ[env_var] = old_val
+    else:
+        del os.environ[env_var]

tox.ini

@@ -12,5 +12,5 @@ python =
 [testenv]
 extras = testing
 commands =
-    - python -c 'from skimage import data; data.brain()'
-    - python -m pytest --mpl -v --color=yes --cov=napari_matplotlib --cov-report=xml
+    python -c 'from skimage import data; data.brain()'
+    python -m pytest --mpl -v --color=yes --cov=napari_matplotlib --cov-report=xml