tabs: add TabStop.position setter

Author: DKWoods

docx/oxml/text/parfmt.py

@@ -333,3 +333,16 @@ class CT_TabStops(BaseOxmlElement):
     ``<w:tabs>`` element, container for a sorted sequence of tab stops.
     """
     tab = OneOrMore('w:tab', successors=())
+
+    def insert_tab_in_order(self, pos, align, leader):
+        """
+        Insert a newly created `w:tab` child element in *pos* order.
+        """
+        new_tab = self._new_tab()
+        new_tab.pos, new_tab.val, new_tab.leader = pos, align, leader
+        for tab in self.tab_lst:
+            if new_tab.pos < tab.pos:
+                tab.addprevious(new_tab)
+                return new_tab
+        self.append(new_tab)
+        return new_tab

docx/text/tabstops.py

@@ -88,3 +88,10 @@ def position(self):
         paragraph. May be positive or negative.
         """
         return self._tab.pos
+
+    @position.setter
+    def position(self, value):
+        tab = self._tab
+        tabs = tab.getparent()
+        self._tab = tabs.insert_tab_in_order(value, tab.val, tab.leader)
+        tabs.remove(tab)

features/tab-tabstop-props.feature

@@ -14,7 +14,6 @@ Feature: Tab stop properties
       |    out    | -457200  |
 
 
-  @wip
   Scenario Outline: Set TabStop.position
     Given a tab stop 0.5 inches in from the paragraph left edge
      When I assign <value> to tab_stop.position

tests/text/test_tabstops.py

@@ -15,7 +15,7 @@
 
 import pytest
 
-from ..unitutil.cxml import element
+from ..unitutil.cxml import element, xml
 from ..unitutil.mock import call, class_mock, instance_mock
 
 
@@ -25,6 +25,12 @@ def it_knows_its_position(self, position_get_fixture):
         tab_stop, expected_value = position_get_fixture
         assert tab_stop.position == expected_value
 
+    def it_can_change_its_position(self, position_set_fixture):
+        tab_stop, value, tabs, new_idx, expected_xml = position_set_fixture
+        tab_stop.position = value
+        assert tab_stop._tab is tabs[new_idx]
+        assert tabs.xml == expected_xml
+
     def it_knows_its_alignment(self, alignment_get_fixture):
         tab_stop, expected_value = alignment_get_fixture
         assert tab_stop.alignment == expected_value
@@ -61,6 +67,31 @@ def position_get_fixture(self, request):
         tab_stop = TabStop(element('w:tab{w:pos=720}'))
         return tab_stop, Twips(720)
 
+    @pytest.fixture(params=[
+        ('w:tabs/w:tab{w:pos=360,w:val=left}',
+         Twips(720), 0,
+         'w:tabs/w:tab{w:pos=720,w:val=left}'),
+        ('w:tabs/(w:tab{w:pos=360,w:val=left},w:tab{w:pos=720,w:val=left})',
+         Twips(180), 0,
+         'w:tabs/(w:tab{w:pos=180,w:val=left},w:tab{w:pos=720,w:val=left})'),
+        ('w:tabs/(w:tab{w:pos=360,w:val=left},w:tab{w:pos=720,w:val=left})',
+         Twips(960), 1,
+         'w:tabs/(w:tab{w:pos=720,w:val=left},w:tab{w:pos=960,w:val=left})'),
+        ('w:tabs/(w:tab{w:pos=-72,w:val=left},w:tab{w:pos=-36,w:val=left})',
+         Twips(-48), 0,
+         'w:tabs/(w:tab{w:pos=-48,w:val=left},w:tab{w:pos=-36,w:val=left})'),
+        ('w:tabs/(w:tab{w:pos=-72,w:val=left},w:tab{w:pos=-36,w:val=left})',
+         Twips(-16), 1,
+         'w:tabs/(w:tab{w:pos=-36,w:val=left},w:tab{w:pos=-16,w:val=left})'),
+    ])
+    def position_set_fixture(self, request):
+        tabs_cxml, value, new_idx, expected_cxml = request.param
+        tabs = element(tabs_cxml)
+        tab = tabs.tab_lst[0]
+        tab_stop = TabStop(tab)
+        expected_xml = xml(expected_cxml)
+        return tab_stop, value, tabs, new_idx, expected_xml
+
 
 class DescribeTabStops(object):