[ENH] Allow specification of union types in input/output meta defintions

orangecanvas/document/editlinksdialog.py

@@ -31,6 +31,7 @@
 from ..registry import InputSignal, OutputSignal
 
 from ..resources import icon_loader
+from ..utils import type_str
 
 if typing.TYPE_CHECKING:
     from ..scheme import SchemeNode
@@ -42,9 +43,9 @@ class EditLinksDialog(QDialog):
     A dialog for editing links.
 
     >>> dlg = EditLinksDialog()
-    >>> dlg.setNodes(file_node, test_learners_node)
-    >>> dlg.setLinks([(file_node.output_channel("Data"),
-    ...                test_learners_node.input_channel("Data")])
+    >>> dlg.setNodes(source_node, sink_node)
+    >>> dlg.setLinks([(source_node.output_channel("Data"),
+    ...                sink_node.input_channel("Data"))])
     >>> if dlg.exec_() == EditLinksDialog.Accepted:
     ...     new_links = dlg.links()
     ...
@@ -662,7 +663,8 @@ def setSchemeNode(self, node):
             text_item.setHtml(text)
             text_item.setSizePolicy(QSizePolicy.Fixed, QSizePolicy.Fixed)
             text_item.setToolTip(
-                escape(getattr(channel, 'description', channel.type)))
+                escape(getattr(channel, 'description', type_str(channel.type)))
+            )
 
             grid.addItem(text_item, i, label_row,
                          alignment=label_alignment)

orangecanvas/registry/base.py

@@ -22,7 +22,7 @@
 log = logging.getLogger(__name__)
 
 # Registry hex version
-VERSION_HEX = 0x000104
+VERSION_HEX = 0x000105
 
 
 class WidgetRegistry(object):

orangecanvas/registry/description.py

@@ -9,7 +9,7 @@
 import warnings
 
 import typing
-from typing import Union, Optional, List, Iterable
+from typing import Union, Optional, List, Tuple, Iterable
 
 from orangecanvas.utils import qualified_name
 
@@ -72,10 +72,13 @@ class CategorySpecificationError(DescriptionError):
 
 # Input/output signal (channel) description
 
-
 if typing.TYPE_CHECKING:
+    #: A simple single type spec (a fully qualified name or a type instance)
+    TypeSpecSimple = Union[str, type]
+    #: A tuple of simple type specs indicating a union type.
+    TypeSpecUnion = Tuple[TypeSpecSimple, ...]
     #: Specification of a input/output type
-    TypeSpec = Union[type, str]
+    TypeSpec = Union[TypeSpecSimple, TypeSpecUnion]
 
 
 class InputSignal(object):
@@ -86,8 +89,13 @@ class InputSignal(object):
     ----------
     name : str
         Name of the channel.
-    type : str or `type`
-        Type of the accepted signals.
+    type : Union[str, type] or Tuple[Union[str, type]]
+        Specify the type of the accepted input. This can be a `type` instance,
+        a fully qualified type name or a tuple of such. If a tuple then the
+        input type is a union of the passed types.
+
+        .. versionchanged:: 0.1.5
+            Added `Union` type support.
     handler : str
         Name of the handler method for the signal.
     flags : int
@@ -132,6 +140,19 @@ def __init__(self, name, type, handler, flags=Single + NonDefault,
         self.explicit = bool(flags & Explicit)
         self.flags = flags
 
+    @property
+    def types(self):
+        # type: () -> Tuple[str, ...]
+        """
+        The normalized type specification. This is a tuple of qualified
+        type names that were passed to the constructor.
+
+        .. versionadded:: 0.1.5
+
+        :type: Tuple[str, ...]
+        """
+        return normalize_type(self.type)
+
     def __str__(self):
         fmt = ("{0.__name__}(name={name!r}, type={type!r}, "
                "handler={handler!r}, ...)")
@@ -160,8 +181,13 @@ class OutputSignal(object):
     ----------
     name : str
         Name of the channel.
-    type : str or `type`
-        Type of the output signals.
+    type : Union[str, type] or Tuple[Union[str, type]]
+        Specify the type of the output. This can be a `type` instance,
+        a fully qualified type name or a tuple of such. If a tuple then the
+        output type is a union of the passed types.
+
+        .. versionchanged:: 0.1.5
+            Added `Union` type support.
     flags : int, optional
         Channel flags.
     id : str
@@ -209,6 +235,19 @@ def __init__(self, name, type, flags=Single + NonDefault,
                 "Output signal can not be 'Multiple' and 'Dynamic'."
             )
 
+    @property
+    def types(self):
+        # type: () -> Tuple[str, ...]
+        """
+        The normalized type specification. This is a tuple of qualified
+        type names that were passed to the constructor.
+
+        .. versionadded:: 0.1.5
+
+        :type: Tuple[str, ...]
+        """
+        return normalize_type(self.type)
+
     def __str__(self):
         fmt = ("{0.__name__}(name={name!r}, type={type!r}, "
                "...)")
@@ -230,8 +269,8 @@ def output_channel_from_args(args):
                         "(got {0!r})".format(type(args)))
 
 
-def normalize_type(type_):
-    # type: (TypeSpec) -> str
+def normalize_type_simple(type_):
+    # type: (TypeSpecSimple) -> str
     if isinstance(type_, type):
         return qualified_name(type_)
     elif isinstance(type_, str):
@@ -240,6 +279,14 @@ def normalize_type(type_):
         raise TypeError
 
 
+def normalize_type(type_):
+    # type: (TypeSpec) -> Tuple[str, ...]
+    if isinstance(type_, (type, str)):
+        return (normalize_type_simple(type_), )
+    else:
+        return tuple(map(normalize_type_simple, type_))
+
+
 class WidgetDescription(object):
     """
     Description of a widget.

orangecanvas/registry/qt.py

@@ -15,6 +15,7 @@
 from AnyQt.QtCore import QObject, Qt
 from AnyQt.QtCore import pyqtSignal as Signal
 
+from ..utils import type_str
 from .discovery import WidgetDiscovery
 from .description import WidgetDescription, CategoryDescription
 from .base import WidgetRegistry
@@ -309,26 +310,17 @@ def tooltip_helper(desc):
 
     inputs_fmt = "<li>{name} ({class_name})</li>"
 
-    def type_str(type_name):
-        # type: (Union[str, type]) -> str
-        if isinstance(type_name, type):
-            return type_str("{0.__module__}.{0.__qualname__}".format(type_name))
-        elif type_name.startswith("builtins."):
-            return type_name[len("builtins."):]
-        else:
-            return type_name
-
     if desc.inputs:
         inputs = "".join(inputs_fmt.format(name=inp.name,
-                                           class_name=type_str(inp.type))
+                                           class_name=type_str(inp.types))
                          for inp in desc.inputs)
         tooltip.append("Inputs:<ul>{0}</ul>".format(inputs))
     else:
         tooltip.append("No inputs")
 
     if desc.outputs:
         outputs = "".join(inputs_fmt.format(name=out.name,
-                                            class_name=type_str(out.type))
+                                            class_name=type_str(out.types))
                           for out in desc.outputs)
         tooltip.append("Outputs:<ul>{0}</ul>".format(outputs))
     else:

orangecanvas/registry/tests/test_base.py

@@ -5,6 +5,7 @@
 from operator import attrgetter
 
 import unittest
+from orangecanvas.registry import InputSignal, OutputSignal
 
 from ..base import WidgetRegistry
 from .. import description
@@ -97,3 +98,24 @@ def test_registry_const(self):
                             for desc in [one_desc, zero_desc, sub_desc,
                                          add_desc])
                         )
+
+    def test_input_signal(self):
+        isig_1 = InputSignal("A", str, "aa", id="sig-a")
+        isig_2 = InputSignal("A", 'builtins.str', "aa", id="sig-a")
+        self.assertTupleEqual(isig_1.types, isig_2.types)
+        self.assertTupleEqual(isig_1.types, ('builtins.str',))
+        isig_1 = InputSignal("A", (str, int), "aa", id="sig-a")
+        isig_2 = InputSignal("A", ('builtins.str', "builtins.int",), "aa",
+                             id="sig-a")
+        self.assertTupleEqual(isig_1.types, isig_2.types)
+
+    def test_output_signal(self):
+        osig_1 = OutputSignal("A", str, id="sig-a")
+        osig_2 = OutputSignal("A", 'builtins.str', id="sig-a")
+        self.assertTupleEqual(osig_1.types, osig_2.types)
+        self.assertTupleEqual(osig_1.types, ('builtins.str',))
+        osig_1 = OutputSignal("A", (str, int), id="sig-a")
+        osig_2 = OutputSignal("A", ('builtins.str', "builtins.int",),
+                              id="sig-a")
+        self.assertTupleEqual(osig_1.types, osig_2.types)
+        self.assertTupleEqual(osig_1.types, ('builtins.str', "builtins.int",))