Add mask attribute to image tag and allow mask to be set to "auto" ev…

…erywhere it's used

src/z3c/rml/attr.py

@@ -443,13 +443,16 @@ class Color(RMLAttribute):
     specification.
     """
 
-    def __init__(self, acceptNone=False, *args, **kw):
+    def __init__(self, acceptNone=False, acceptAuto=False, *args, **kw):
         super(Color, self).__init__(*args, **kw)
         self.acceptNone = acceptNone
+        self.acceptAuto = acceptAuto
 
     def fromUnicode(self, value):
         if self.acceptNone and value.lower() == 'none':
             return None
+        if self.acceptAuto and value.lower() == 'auto':
+            return 'auto'
         manager = getManager(self.context)
 
         if value.startswith('rml:'):

src/z3c/rml/canvas.py

@@ -341,6 +341,12 @@ class IImage(interfaces.IRMLDirectiveSignature):
         default=False,
         required=False)
 
+    mask = attr.Color(
+        title=u'Mask',
+        description=u'The color mask used to render the image.',
+        required=False,
+        acceptAuto=True)
+
 class Image(CanvasRMLDirective):
     signature = IImage
     callable = 'drawImage'

src/z3c/rml/flowable.py

@@ -904,7 +904,8 @@ class IImage(interfaces.IRMLDirectiveSignature):
     mask = attr.Color(
         title=u'Mask',
         description=u'The color mask used to render the image.',
-        required=False)
+        required=False,
+        acceptAuto=True)
 
     align = attr.Choice(
         title=u'Alignment',
@@ -980,7 +981,8 @@ class IImageAndFlowables(interfaces.IRMLDirectiveSignature):
     imageMask = attr.Color(
         title=u'Mask',
         description=u'The height the image.',
-        required=False)
+        required=False,
+        acceptAuto=True)
 
     imageLeftPadding = attr.Measurement(
         title=u'Image Left Padding',

src/z3c/rml/tests/input/tag-image-mask.rml

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<!DOCTYPE document SYSTEM "rml.dtd">
+
+<document
+    filename="tag-image-svg.pdf"
+    xmlns:doc="http://namespaces.zope.org/rml/doc">
+  <pageDrawing>
+
+    <image file="[z3c.rml.tests]/input/images/cylinder.png"
+        x="10mm" y="10mm" mask="auto" />
+
+  </pageDrawing>
+</document>

src/z3c/rml/tests/test_rml.py

@@ -134,6 +134,9 @@ def test_suite():
        if not filename.endswith(".rml"):
            continue
 
+       if 'image-mask' not in filename:
+           continue
+
        inPath = os.path.join(inputDir, filename)
        outPath = os.path.join(outputDir, filename[:-4] + '.pdf')
        expectPath = os.path.join(expectDir, filename[:-4] + '.pdf')