PR: Add utility functions that convert between ints and Qt Enums (compat.py) (#481)

Author: dalthviz

qtpy/compat.py

@@ -5,6 +5,7 @@
 """
 Compatibility functions
 """
+import enum
 import sys
 
 from . import (
@@ -200,3 +201,26 @@ def isalive(obj):
 
         return shiboken.isValid(obj)
     return None
+
+
+# =============================================================================
+def getenumasint(enum_value):
+    """Get the integer value of a Qt enum
+    For example:
+        Qt.AlignmentFlag.AlignBaseline -> 256
+        Qt.WidgetAttribute.WA_AcceptDrops -> 78
+    If an integer is passed in, simply return it.
+    PySide2's enums are themselves classes, not enum values per se, so if
+    we get an integer or a class, return the class.
+    """
+    if isinstance(enum_value, enum.Enum):
+        if PYSIDE2 or PYQT5:
+            return int(enum_value)
+        return enum_value.value
+    return enum_value
+
+
+# =============================================================================
+def getenumfromint(enum_class, i):
+    """Get the Qt enum value from an integer"""
+    return enum_class(i)

qtpy/tests/test_compat.py

@@ -1,9 +1,11 @@
 """Test the compat module."""
+
 import sys
 
 import pytest
+from packaging import version
 
-from qtpy import QtWidgets, compat
+from qtpy import PYQT5, PYQT_VERSION, QtWidgets, compat
 from qtpy.tests.utils import not_using_conda
 
 
@@ -22,3 +24,21 @@ def test_isalive(qtbot):
     with qtbot.waitSignal(test_widget.destroyed):
         test_widget.deleteLater()
     assert compat.isalive(test_widget) is False
+
+
+def test_getenumasint():
+    """Test compat.getenumasint"""
+    if PYQT5 and version.parse(PYQT_VERSION) <= version.parse("5.9.2"):
+        assert compat.getenumasint(QtWidgets.QSizePolicy.Maximum) == 4
+    else:
+        assert compat.getenumasint(QtWidgets.QSizePolicy.Policy.Maximum) == 4
+    assert compat.getenumasint(5) == 5
+
+
+def test_getenumfromint():
+    """Test compat.getenumfromint"""
+    enum_value = compat.getenumfromint(QtWidgets.QSizePolicy.Policy, 7)
+    if PYQT5 and version.parse(PYQT_VERSION) <= version.parse("5.9.2"):
+        assert enum_value == QtWidgets.QSizePolicy.Expanding
+    else:
+        assert enum_value == QtWidgets.QSizePolicy.Policy.Expanding