Merge pull request #47 from matplotlib/scatter-tidy

Tidy up scatter code

Author: dstansby

Diff for: src/napari_matplotlib/scatter.py

@@ -1,4 +1,4 @@
-from typing import List, Tuple, Union
+from typing import List, Optional, Tuple
 
 import matplotlib.colors as mcolor
 import napari
@@ -22,21 +22,21 @@ class ScatterBaseWidget(NapariMPLWidget):
     # the scatter is plotted as a 2dhist
     _threshold_to_switch_to_histogram = 500
 
-    def __init__(
-        self,
-        napari_viewer: napari.viewer.Viewer,
-    ):
+    def __init__(self, napari_viewer: napari.viewer.Viewer):
         super().__init__(napari_viewer)
 
         self.axes = self.canvas.figure.subplots()
         self.update_layers(None)
 
     def clear(self) -> None:
+        """
+        Clear the axes.
+        """
         self.axes.clear()
 
     def draw(self) -> None:
         """
-        Clear the axes and scatter the currently selected layers.
+        Scatter the currently selected layers.
         """
         data, x_axis_name, y_axis_name = self._get_data()
 
@@ -86,14 +86,6 @@ class ScatterWidget(ScatterBaseWidget):
 
     n_layers_input = 2
 
-    def __init__(
-        self,
-        napari_viewer: napari.viewer.Viewer,
-    ):
-        super().__init__(
-            napari_viewer,
-        )
-
     def _get_data(self) -> Tuple[List[np.ndarray], str, str]:
         """Get the plot data.
 
@@ -116,42 +108,34 @@ def _get_data(self) -> Tuple[List[np.ndarray], str, str]:
 class FeaturesScatterWidget(ScatterBaseWidget):
     n_layers_input = 1
 
-    def __init__(
-        self,
-        napari_viewer: napari.viewer.Viewer,
-        key_selection_gui: bool = True,
-    ):
-        self._key_selection_widget = None
-        super().__init__(
-            napari_viewer,
+    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",
         )
 
-        if key_selection_gui is True:
-            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",
-            )
-            self.layout().addWidget(self._key_selection_widget.native)
+        self.layout().addWidget(self._key_selection_widget.native)
 
     @property
-    def x_axis_key(self) -> Union[None, str]:
+    def x_axis_key(self) -> Optional[str]:
         """Key to access x axis data from the FeaturesTable"""
         return self._x_axis_key
 
     @x_axis_key.setter
-    def x_axis_key(self, key: Union[None, str]):
+    def x_axis_key(self, key: Optional[str]):
         self._x_axis_key = key
         self._draw()
 
     @property
-    def y_axis_key(self) -> Union[None, str]:
+    def y_axis_key(self) -> Optional[str]:
         """Key to access y axis data from the FeaturesTable"""
         return self._y_axis_key
 
     @y_axis_key.setter
-    def y_axis_key(self, key: Union[None, str]):
+    def y_axis_key(self, key: Optional[str]):
         self._y_axis_key = key
         self._draw()
 
@@ -214,10 +198,11 @@ def _get_data(self) -> Tuple[List[np.ndarray], str, str]:
         return data, x_axis_name, y_axis_name
 
     def _on_update_layers(self) -> None:
-        """This is called when the layer selection changes
-        by self.update_layers().
         """
-        if self._key_selection_widget is not None:
+        This is 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