shr: add DescribeLength

Steve Canny · Steve Canny · commit 226b69956f83 · 2014-12-27T22:07:12.000-08:00
diff --git a/docx/shared.py b/docx/shared.py
@@ -17,7 +17,7 @@ class Length(int):
     _EMUS_PER_INCH = 914400
     _EMUS_PER_CM = 360000
     _EMUS_PER_MM = 36000
-    _EMUS_PER_PX = 12700
+    _EMUS_PER_PT = 12700
     _EMUS_PER_TWIP = 635
 
     def __new__(cls, emu):
@@ -52,10 +52,11 @@ def mm(self):
         return self / float(self._EMUS_PER_MM)
 
     @property
-    def px(self):
-        # round can somtimes return values like x.999999 which are truncated
-        # to x by int(); adding the 0.1 prevents this
-        return int(round(self / float(self._EMUS_PER_PX)) + 0.1)
+    def pt(self):
+        """
+        Floating point length in points
+        """
+        return self / float(self._EMUS_PER_PT)
 
     @property
     def twips(self):
@@ -104,23 +105,12 @@ def __new__(cls, mm):
         return Length.__new__(cls, emu)
 
 
-class Pt(int):
-    """
-    Convenience class for setting font sizes in points
-    """
-    _UNITS_PER_POINT = 100
-
-    def __new__(cls, pts):
-        units = int(pts * Pt._UNITS_PER_POINT)
-        return int.__new__(cls, units)
-
-
-class Px(Length):
+class Pt(Length):
     """
-    Convenience constructor for length in pixels.
+    Convenience value class for specifying a length in points
     """
-    def __new__(cls, px):
-        emu = int(px * Length._EMUS_PER_PX)
+    def __new__(cls, points):
+        emu = int(points * Length._EMUS_PER_PT)
         return Length.__new__(cls, emu)
 
 
diff --git a/tests/test_shared.py b/tests/test_shared.py
@@ -11,7 +11,7 @@
 import pytest
 
 from docx.opc.part import XmlPart
-from docx.shared import ElementProxy
+from docx.shared import ElementProxy, Length, Cm, Emu, Inches, Mm, Pt, Twips
 
 from .unitutil.cxml import element
 from .unitutil.mock import instance_mock
@@ -70,3 +70,46 @@ def other_proxy_(self, request):
     @pytest.fixture
     def part_(self, request):
         return instance_mock(request, XmlPart)
+
+
+class DescribeLength(object):
+
+    def it_can_construct_from_convenient_units(self, construct_fixture):
+        UnitCls, units_val, emu = construct_fixture
+        length = UnitCls(units_val)
+        assert isinstance(length, Length)
+        assert length == emu
+
+    def it_can_self_convert_to_convenient_units(self, units_fixture):
+        emu, units_prop_name, expected_length_in_units, type_ = units_fixture
+        length = Length(emu)
+        length_in_units = getattr(length, units_prop_name)
+        assert length_in_units == expected_length_in_units
+        assert isinstance(length_in_units, type_)
+
+    # fixtures -------------------------------------------------------
+
+    @pytest.fixture(params=[
+        (Length,      914400,  914400),
+        (Inches,      1.1,    1005840),
+        (Cm,          2.53,    910799),
+        (Emu,         9144.9,    9144),
+        (Mm,          13.8,    496800),
+        (Pt,          24.5,    311150),
+        (Twips,       360,     228600),
+    ])
+    def construct_fixture(self, request):
+        UnitCls, units_val, emu = request.param
+        return UnitCls, units_val, emu
+
+    @pytest.fixture(params=[
+        (914400, 'inches', 1.0,    float),
+        (914400, 'cm',     2.54,   float),
+        (914400, 'emu',    914400, int),
+        (914400, 'mm',     25.4,   float),
+        (914400, 'pt',     72.0,   float),
+        (914400, 'twips',  1440,   int),
+    ])
+    def units_fixture(self, request):
+        emu, units_prop_name, expected_length_in_units, type_ = request.param
+        return emu, units_prop_name, expected_length_in_units, type_
