adding support for strikethrough (#538)

* adding support for strikethrough

 + doc test

* remove warning

this is called internally to get and set formattedstring attributes

docs/content/text/textProperties.rst

@@ -5,6 +5,7 @@ Text Properties
 .. autofunction:: drawBot.fontSize
 .. autofunction:: drawBot.fallbackFont
 .. autofunction:: drawBot.underline
+.. autofunction:: drawBot.strikethrough
 .. autofunction:: drawBot.hyphenation
 .. autofunction:: drawBot.lineHeight
 .. autofunction:: drawBot.tracking

drawBot/context/baseContext.py

@@ -1049,6 +1049,18 @@ class FormattedString(SVGContextPropertyMixin, ContextPropertyMixin):
         # byWord=0x8000 # AppKit.NSUnderlineByWord,
     )
 
+    _textstrikethroughMap = dict(
+        single=AppKit.NSUnderlineStyleSingle,
+        thick=AppKit.NSUnderlineStyleThick,
+        double=AppKit.NSUnderlineStyleDouble,
+        # solid=AppKit.NSUnderlinePatternSolid,
+        # dotted=AppKit.NSUnderlinePatternDot,
+        # dashed=AppKit.NSUnderlinePatternDash,
+        # dotDashed=AppKit.NSUnderlinePatternDashDot,
+        # dotDotted=AppKit.NSUnderlinePatternDashDotDot,
+        # byWord=0x8000 # AppKit.NSUnderlineByWord,
+    )
+
     _formattedAttributes = dict(
         font=_FALLBACKFONT,
         fallbackFont=None,
@@ -1067,6 +1079,7 @@ class FormattedString(SVGContextPropertyMixin, ContextPropertyMixin):
         tracking=None,
         baselineShift=None,
         underline=None,
+        strikethrough=None,
         url=None,
         openTypeFeatures=dict(),
         fontVariations=dict(),
@@ -1339,6 +1352,8 @@ def append(self, txt, **kwargs):
             attributes[AppKit.NSBaselineOffsetAttributeName] = self._baselineShift
         if self._underline in self._textUnderlineMap:
             attributes[AppKit.NSUnderlineStyleAttributeName] = self._textUnderlineMap[self._underline]
+        if self._strikethrough in self._textstrikethroughMap:
+            attributes[AppKit.NSStrikethroughStyleAttributeName] = self._textstrikethroughMap[self._strikethrough]
         if self._url is not None:
             attributes[AppKit.NSLinkAttributeName] = AppKit.NSURL.URLWithString_(self._url)
         if self._language:
@@ -1551,6 +1566,13 @@ def underline(self, underline):
         """
         self._underline = underline
 
+    def strikethrough(self, strikethrough):
+        """
+        Set the strikethrough value.
+        Underline must be `single`, `thick`, `double` or `None`.
+        """
+        self._strikethrough = strikethrough
+
     def url(self, url):
         """
         set the url value.
@@ -2091,6 +2113,7 @@ class BaseContext(object):
     _textAlignMap = FormattedString._textAlignMap
     _textTabAlignMap = FormattedString._textTabAlignMap
     _textUnderlineMap = FormattedString._textUnderlineMap
+    _textstrikethroughMap = FormattedString._textstrikethroughMap
 
     _colorSpaceMap = dict(
         genericRGB=AppKit.NSColorSpace.genericRGBColorSpace(),
@@ -2435,6 +2458,9 @@ def baselineShift(self, baselineShift):
     def underline(self, underline):
         self._state.text.underline(underline)
 
+    def strikethrough(self, strikethrough):
+        self._state.text.strikethrough(strikethrough)
+
     def url(self, value):
         self._state.text.url(value)
 

drawBot/context/svgContext.py

@@ -260,6 +260,12 @@ class SVGContext(BaseContext):
         AppKit.NSUnderlineStyleDouble: "double",
     }
 
+    _svgStrikethroughStylesMap = {
+        AppKit.NSUnderlineStyleSingle: "",
+        AppKit.NSUnderlineStyleThick: "",
+        AppKit.NSUnderlineStyleDouble: "double",
+    }
+
     indentation = " "
     fileExtensions = ["svg"]
     saveImageOptions = [
@@ -440,6 +446,7 @@ def _textBox(self, rawTxt, box, align):
                 baselineShift = attributes.get(AppKit.NSBaselineOffsetAttributeName, 0)
                 openTypeFeatures = attributes.get("drawBot.formattedString.properties", dict()).get("openTypeFeatures")
                 underline = attributes.get(AppKit.NSUnderlineStyleAttributeName)
+                strikethrough = attributes.get(AppKit.NSStrikethroughStyleAttributeName)
                 url = attributes.get(AppKit.NSLinkAttributeName)
 
                 fontName = font.fontName()
@@ -477,6 +484,12 @@ def _textBox(self, rawTxt, box, align):
                     if underlineStyle:
                         style["text-decoration-style"] = underlineStyle
 
+                if strikethrough is not None:
+                    style["text-decoration"] = "line-through"
+                    strikethroughStyle = self._svgStrikethroughStylesMap.get(strikethrough)
+                    if strikethroughStyle:
+                        style["text-decoration-style"] = strikethroughStyle
+
                 if style:
                     spanData["style"] = self._svgStyle(**style)
                 self._save()

drawBot/drawBotDrawingTools.py

@@ -1438,6 +1438,23 @@ def underline(self, value):
         self._dummyContext.underline(value)
         self._addInstruction("underline", value)
 
+    def strikethrough(self, value):
+        """
+        Set the strikethrough value.
+        Underline must be `single`, `thick`, `double` or `None`.
+
+        .. downloadcode:: strikethrough.py
+
+            size(1000, 200)
+            strikethrough("single")
+            fontSize(100)
+            text("hello strikethrough", (40, 60))
+        """
+        if value is not None and value not in self._dummyContext._textstrikethroughMap:
+            raise DrawBotError("strikethrough must be %s" % (", ".join(sorted(self._dummyContext._textstrikethroughMap.keys()))))
+        self._dummyContext.strikethrough(value)
+        self._addInstruction("strikethrough", value)
+
     def url(self, value):
         """
         Set the url value for text.