Add widgets for Java Number implementations

src/napari_imagej/types/widget_mappings.py

@@ -15,6 +15,7 @@
 from napari_imagej.widgets.parameter_widgets import (
     ShapeWidget,
     file_widget_for,
+    number_widget_for,
     numeric_type_widget_for,
 )
 
@@ -71,6 +72,14 @@ def _numeric_type_preference(
         return numeric_type_widget_for(item.getType())
 
 
+@_widget_preference
+def _number_preference(
+    item: "jc.ModuleItem", type_hint: Union[type, str]
+) -> Optional[Union[type, str]]:
+    if issubclass(item.getType(), jc.Number):
+        return number_widget_for(item.getType())
+
+
 @_widget_preference
 def _mutable_output_preference(
     item: "jc.ModuleItem", type_hint: Union[type, str]

src/napari_imagej/widgets/parameter_widgets.py

@@ -27,6 +27,7 @@
 from napari.layers import Layer
 from napari.utils._magicgui import get_layers
 from numpy import dtype
+from scyjava import numeric_bounds
 
 from napari_imagej.java import jc
 
@@ -83,6 +84,52 @@ def value(self):
     return Widget
 
 
+@lru_cache(maxsize=None)
+def number_widget_for(cls: type):
+    if not issubclass(cls, jc.Number):
+        return None
+    # Sensible default for Number iface
+    if cls == jc.Number:
+        cls = jc.Double
+
+    # NB cls in this instance is jc.Byte.class_, NOT jc.Byte
+    # We want the latter for use in numeric_bounds and in the widget subclass
+    if cls == jc.Byte:
+        cls = jc.Byte
+    if cls == jc.Short:
+        cls = jc.Short
+    if cls == jc.Integer:
+        cls = jc.Integer
+    if cls == jc.Long:
+        cls = jc.Long
+    if cls == jc.Float:
+        cls = jc.Float
+    if cls == jc.Double:
+        cls = jc.Double
+
+    extra_args = {}
+    extra_args["min"], extra_args["max"] = numeric_bounds(cls)
+    # Case logic for implementation-specific attributes
+    parent = FloatSpinBox if issubclass(cls, (jc.Double, jc.Float)) else SpinBox
+
+    # Define the new widget
+    class Widget(parent):
+        def __init__(self, **kwargs):
+            for k, v in extra_args.items():
+                kwargs.setdefault(k, v)
+            super().__init__(**kwargs)
+
+        @property
+        def value(self):
+            return cls(parent.value.fget(self))
+
+        @value.setter
+        def value(self, value: Any):
+            parent.value.fset(self, value)
+
+    return Widget
+
+
 class MutableOutputWidget(Container):
     """
     A ComboBox widget combined with a button that creates new layers.

tests/widgets/test_parameter_widgets.py

@@ -19,13 +19,15 @@
 )
 from napari import current_viewer
 from napari.layers import Image
+from scyjava import numeric_bounds
 
 from napari_imagej.widgets.parameter_widgets import (
     DirectoryWidget,
     MutableOutputWidget,
     OpenFileWidget,
     SaveFileWidget,
     ShapeWidget,
+    number_widget_for,
     numeric_type_widget_for,
 )
 from tests.utils import jc
@@ -164,6 +166,23 @@ def test_mutable_output_add_new_image(
     assert foo is output_widget.value
 
 
+def test_numbers():
+    numbers = [
+        (jc.Byte),
+        (jc.Short),
+        (jc.Integer),
+        (jc.Long),
+        (jc.Float),
+        (jc.Double),
+    ]
+    for number in numbers:
+        widget = number_widget_for(number.class_)()
+        min_val, max_val = numeric_bounds(number)
+        assert min_val == widget.min
+        assert max_val == widget.max
+        assert isinstance(widget.value, number)
+
+
 def test_realType():
     real_types = [
         (jc.BitType),