Add table cell background color

Author: botzill

pydocx/constants.py

@@ -25,6 +25,11 @@
 # https://en.wikipedia.org/wiki/Twip
 TWIPS_PER_POINT = 20
 
+# According to this: http://alienryderflex.com/hsp.html
+BRIGHTNESS_DARK_COLOR = 50
+
+COLOR_FOR_DARK_BACKGROUND = 'FFFFFF'
+
 # TODO These alignment values are for traditional conformance. Strict
 # conformance uses different values
 JUSTIFY_CENTER = 'center'

pydocx/export/base.py

@@ -359,6 +359,7 @@ def get_run_styles_to_apply(self, run):
             (properties.hidden, self.export_run_property_hidden),
             (properties.vertical_align, self.export_run_property_vertical_align),
             (properties.color, self.export_run_property_color),
+            (not properties.color, self.export_run_property_parent_background_color),
         ]
         for actual_value, handler in property_rules:
             if actual_value:
@@ -407,6 +408,9 @@ def export_run_property_vertical_align(self, run, results):
     def export_run_property_color(self, run, results):
         return results
 
+    def export_run_property_parent_background_color(self, run, results):
+        return results
+
     def export_hyperlink(self, hyperlink):
         return self.yield_nested(hyperlink.children, self.export_node)
 

pydocx/export/html.py

@@ -17,11 +17,16 @@
     POINTS_PER_EM,
     PYDOCX_STYLES,
     TWIPS_PER_POINT,
-    EMUS_PER_PIXEL
+    EMUS_PER_PIXEL,
+    BRIGHTNESS_DARK_COLOR,
+    COLOR_FOR_DARK_BACKGROUND
 )
 from pydocx.export.base import PyDocXExporter
 from pydocx.export.numbering_span import NumberingItem
 from pydocx.openxml import wordprocessing
+from pydocx.openxml.wordprocessing.paragraph import Paragraph
+from pydocx.openxml.wordprocessing.table_cell import TableCell
+from pydocx.util import color
 from pydocx.util.uri import uri_is_external
 from pydocx.util.xml import (
     convert_dictionary_to_html_attributes,
@@ -572,6 +577,29 @@ def export_run_property_color(self, run, results):
         tag = HtmlTag('span', **attrs)
         return self.export_run_property(tag, run, results)
 
+    def export_run_property_parent_background_color(self, run, results):
+        background_color = None
+
+        if isinstance(run.parent, (Paragraph,)):
+            paragraph = run.parent
+            if isinstance(paragraph.parent, (TableCell,)) and paragraph.parent.properties:
+                table_cell_prop = paragraph.parent.properties
+                background_color = table_cell_prop.background_color
+
+        if background_color:
+            brightness = color.brightness(background_color)
+            # We need to change the text color if background color is dark
+            # and text run does not have custom color.
+            # Office Word does this automatically.
+            if brightness < BRIGHTNESS_DARK_COLOR:
+                attrs = {
+                    'style': 'color: #%s' % COLOR_FOR_DARK_BACKGROUND
+                }
+                tag = HtmlTag('span', **attrs)
+                results = self.export_run_property(tag, run, results)
+
+        return results
+
     def export_text(self, text):
         results = super(PyDocXHTMLExporter, self).export_text(text)
         for result in results:
@@ -668,6 +696,12 @@ def export_table_cell(self, table_cell):
                 attrs['colspan'] = colspan
             if rowspan > 1:
                 attrs['rowspan'] = rowspan
+
+            if table_cell.properties:
+                background_color = table_cell.properties.background_color
+                if background_color:
+                    attrs['style'] = 'background-color: #%s' % background_color
+
             tag = HtmlTag('td', **attrs)
 
         numbering_spans = self.yield_numbering_spans(table_cell.children)

pydocx/openxml/wordprocessing/table_cell_properties.py

@@ -13,6 +13,8 @@ class TableCellProperties(XmlModel):
 
     grid_span = XmlChild(name='gridSpan', attrname='val')
 
+    background_fill = XmlChild(name='shd', attrname='fill')
+
     vertical_merge = XmlChild(name='vMerge', type=lambda el: dict(el.attrib))  # noqa
 
     def should_close_previous_vertical_merge(self):
@@ -25,3 +27,13 @@ def should_close_previous_vertical_merge(self):
         if merge != 'continue':
             return True
         return False
+
+    @property
+    def background_color(self):
+        background_fill = getattr(self, 'background_fill', None)
+
+        # There is no need to set white background color
+        if background_fill not in ('auto', 'FFFFFF'):
+            return background_fill
+
+        return None

pydocx/test/document_builder.py

@@ -206,13 +206,14 @@ def li(self, text, ilvl, numId, bold=False):
         )
 
     @classmethod
-    def table_cell(self, paragraph, merge=False, merge_continue=False):
+    def table_cell(self, paragraph, merge=False, merge_continue=False, fill_color='auto'):
         template = env.get_template(templates['tc'])
         return template_render(
             template,
             paragraph=paragraph,
             merge=merge,
             merge_continue=merge_continue,
+            fill_color=fill_color
         )
 
     @classmethod

pydocx/util/color.py

@@ -0,0 +1,26 @@
+# coding: utf-8
+from __future__ import (
+    absolute_import,
+    print_function,
+    unicode_literals,
+)
+
+import math
+
+
+def hex_to_rgb(value):
+    """Return (red, green, blue) for the color given as #rrggbb."""
+
+    value = value.lstrip('#')
+    lv = len(value)
+    return tuple(int(value[i:i + lv // 3], 16) for i in range(0, lv, lv // 3))
+
+
+def brightness(hex_color):
+    """A trick to determine the brightness of the color.
+    More info about this here: http://alienryderflex.com/hsp.html
+    """
+
+    r, g, b = hex_to_rgb(hex_color)
+
+    return math.sqrt(math.pow(r, 2) * .241 + math.pow(g, 2) * .691 + math.pow(b, 2) * .068)

tests/export/test_xml.py

@@ -296,6 +296,35 @@ def get_xml(self):
         return xml
 
 
+class TableWithCellBackgroundColor(TranslationTestCase):
+    expected_output = '''
+        <table border="1">
+            <tr>
+                <td style="background-color: #FF00FF">AAA</td>
+                <td>BBB</td>
+            </tr>
+            <tr>
+                <td>CCC</td>
+                <td style="background-color: #000000">
+                    <span style="color: #FFFFFF">DDD</span>
+                </td>
+            </tr>
+        </table>
+    '''
+
+    def get_xml(self):
+        cell1 = DXB.table_cell(paragraph=DXB.p_tag('AAA'), fill_color='FF00FF')
+        cell2 = DXB.table_cell(paragraph=DXB.p_tag('BBB'), fill_color='FFFFFF')
+        cell3 = DXB.table_cell(paragraph=DXB.p_tag('CCC'), fill_color='auto')
+        # for dark color we get white text color
+        cell4 = DXB.table_cell(paragraph=DXB.p_tag('DDD'), fill_color='000000')
+        rows = [DXB.table_row([cell1, cell2]), DXB.table_row([cell3, cell4])]
+        table = DXB.table(rows)
+        body = table
+        xml = DXB.xml(body)
+        return xml
+
+
 class SimpleListTestCase(TranslationTestCase):
     expected_output = '''
         <ol class="pydocx-list-style-type-lowerLetter">

tests/fixtures/styled_color.html

@@ -2,7 +2,7 @@
 <p><span style="color:#31849B">BBB</span></p>
 <table border="1">
   <tr>
-    <td>CCC</td>
+    <td style="background-color: #5F497A">CCC</td>
   </tr>
 </table>
 <p>DDD</p>

tests/templates/tc.xml

@@ -14,7 +14,7 @@
 			<w:left w:color="000000" w:space="0" w:sz="2" w:val="single"/>
 			<w:bottom w:color="000000" w:space="0" w:sz="2" w:val="single"/>
 		</w:tcBorders>
-		<w:shd w:fill="auto" w:val="clear"/>
+		<w:shd w:fill="{{ fill_color }}" w:val="clear"/>
 		<w:tcMar>
 			<w:top w:type="dxa" w:w="55"/>
 			<w:left w:type="dxa" w:w="55"/>