Added line cap style and line join style attributes.

Includes support as state variables, arguments to the constructor,
getters and setters in the BezierPath class and shortcut properties (for
join style: MITER, ROUND and BEVEL; for cap style: BUTT, ROUND and
SQUARE).  Closes issue #1.

Author: Frederik De Bleser

nodebox/graphics/__init__.py

@@ -41,6 +41,8 @@ def _resetContext(self):
         self._fillcolor = self.Color()
         self._strokecolor = None
         self._strokewidth = 1.0
+        self._capstyle = BUTT
+        self._joinstyle = MITER
         self.canvas.background = self.Color(1.0)
         self._path = None
         self._autoclosepath = True
@@ -409,6 +411,20 @@ def strokewidth(self, width=None):
         if width is not None:
             self._strokewidth = max(width, 0.0001)
         return self._strokewidth
+        
+    def capstyle(self, style=None):
+        if style is not None:
+            if style not in (BUTT, ROUND, SQUARE):
+                raise NodeBoxError, 'Line cap style should be BUTT, ROUND or SQUARE.'
+            self._capstyle = style
+        return self._capstyle
+
+    def joinstyle(self, style=None):
+        if style is not None:
+            if style not in (MITER, ROUND, BEVEL):
+                raise NodeBoxError, 'Line join style should be MITER, ROUND or BEVEL.'
+            self._joinstyle = style
+        return self._joinstyle
 
     ### Font Commands ###
 

nodebox/graphics/cocoa.py

@@ -13,6 +13,7 @@
         "RGB", "HSB", "CMYK",
         "CENTER", "CORNER",
         "MOVETO", "LINETO", "CURVETO", "CLOSE",
+        "MITER", "ROUND", "BEVEL", "BUTT", "SQUARE",
         "LEFT", "RIGHT", "CENTER", "JUSTIFY",
         "NORMAL","FORTYFIVE",
         "NUMBER", "TEXT", "BOOLEAN","BUTTON",
@@ -39,6 +40,12 @@
 CURVETO = NSCurveToBezierPathElement
 CLOSE = NSClosePathBezierPathElement
 
+MITER = NSMiterLineJoinStyle
+ROUND = NSRoundLineJoinStyle # Also used for NSRoundLineCapStyle, same value.
+BEVEL = NSBevelLineJoinStyle
+BUTT = NSButtLineCapStyle
+SQUARE = NSSquareLineCapStyle
+
 LEFT = NSLeftTextAlignment
 RIGHT = NSRightTextAlignment
 CENTER = NSCenterTextAlignment
@@ -66,6 +73,8 @@
     '_fillcolor':     'fill',
     '_strokecolor':   'stroke',
     '_strokewidth':   'strokewidth',
+    '_capstyle':      'capstyle',
+    '_joinstyle':     'joinstyle',
     '_transform':     'transform',
     '_transformmode': 'transformmode',
     '_fontname':      'font',
@@ -210,13 +219,15 @@ def _set_strokewidth(self, strokewidth):
 class BezierPath(Grob, TransformMixin, ColorMixin):
     """A BezierPath provides a wrapper around NSBezierPath."""
 
-    stateAttributes = ('_fillcolor', '_strokecolor', '_strokewidth', '_transform', '_transformmode')
-    kwargs = ('fill', 'stroke', 'strokewidth')
+    stateAttributes = ('_fillcolor', '_strokecolor', '_strokewidth', '_capstyle', '_joinstyle', '_transform', '_transformmode')
+    kwargs = ('fill', 'stroke', 'strokewidth', 'capstyle', 'joinstyle')
 
     def __init__(self, ctx, path=None, **kwargs):
         super(BezierPath, self).__init__(ctx)
         TransformMixin.__init__(self)
         ColorMixin.__init__(self, **kwargs)
+        self.capstyle = kwargs.get('capstyle', BUTT)
+        self.joinstyle = kwargs.get('joinstyle', MITER)
         self._segment_cache = None
         if path is None:
             self._nsBezierPath = NSBezierPath.bezierPath()
@@ -238,6 +249,24 @@ def _get_path(self):
 
     def copy(self):
         return self.__class__(self._ctx, self)
+    
+    ### Cap and Join style ###
+    
+    def _get_capstyle(self):
+        return self._capstyle
+    def _set_capstyle(self, style):
+        if style not in (BUTT, ROUND, SQUARE):
+            raise NodeBoxError, 'Line cap style should be BUTT, ROUND or SQUARE.'
+        self._capstyle = style
+    capstyle = property(_get_capstyle, _set_capstyle)
+
+    def _get_joinstyle(self):
+        return self._joinstyle
+    def _set_joinstyle(self, style):
+        if style not in (MITER, ROUND, BEVEL):
+            raise NodeBoxError, 'Line join style should be MITER, ROUND or BEVEL.'
+        self._joinstyle = style
+    joinstyle = property(_get_joinstyle, _set_joinstyle)
 
     ### Path methods ###
 
@@ -256,7 +285,7 @@ def curveto(self, x1, y1, x2, y2, x3, y3):
     def closepath(self):
         self._segment_cache = None
         self._nsBezierPath.closePath()
-
+        
     def setlinewidth(self, width):
         self.linewidth = width
 
@@ -359,6 +388,8 @@ def _draw(self):
         if (self._strokecolor):
             self._strokecolor.set()
             self._nsBezierPath.setLineWidth_(self._strokewidth)
+            self._nsBezierPath.setLineCapStyle_(self._capstyle)
+            self._nsBezierPath.setLineJoinStyle_(self._joinstyle)
             self._nsBezierPath.stroke()
         _restore()
 

tests/graphics.py

@@ -11,31 +11,69 @@
 
 class GraphicsTestCase(unittest.TestCase):
 
+    def setUp(self):
+        self.ctx = Context()
+
     def test_arrow_type_error(self):
         """Test if passing a wrong arrow type raises an error."""
-        ctx = Context()
-        self.assertRaises(NodeBoxError, ctx.arrow, 0, 0, 100, type=42)
+        self.assertRaises(NodeBoxError, self.ctx.arrow, 0, 0, 100, type=42)
 
     def test_too_many_pops(self):
         """Test if popping too many times raises an error."""
-        ctx = Context()
-        self.assertRaises(NodeBoxError, ctx.pop)
+        self.assertRaises(NodeBoxError, self.ctx.pop)
 
     def test_font_not_found(self):
         """Test if setting an unexisting font raises an error."""
-        ctx = Context()
-        old_font = ctx.font()
-        self.assertRaises(NodeBoxError, ctx.font, "THIS_FONT_DOES_NOT_EXIST")
-        self.assertEquals(ctx.font(), old_font, "Current font has not changed.")
+        old_font = self.ctx.font()
+        self.assertRaises(NodeBoxError, self.ctx.font, "THIS_FONT_DOES_NOT_EXIST")
+        self.assertEquals(self.ctx.font(), old_font, "Current font has not changed.")
 
     def test_ellipse(self):
         """Test if ellipse is an alias for oval."""
-        ctx = Context()
-        self.assertTrue(hasattr(ctx, "ellipse"))
-        self.assertTrue(ctx.ellipse == ctx.oval)
-        p = BezierPath(ctx)
+        self.assertTrue(hasattr(self.ctx, "ellipse"))
+        self.assertTrue(self.ctx.ellipse == self.ctx.oval)
+        p = BezierPath(self.ctx)
         self.assertTrue(hasattr(p, "ellipse"))
         self.assertTrue(p.ellipse == p.oval)
+        
+class BezierPathTestCase(unittest.TestCase):
+    
+    def setUp(self):
+        self.ctx = Context()
+    
+    def test_capstyle_context(self):
+        self.ctx.capstyle(SQUARE)
+        p = BezierPath(self.ctx)
+        self.assertEquals(p.capstyle, BUTT, "Default line cap style is butt.")
+        p.inheritFromContext()
+        self.assertEquals(p.capstyle, SQUARE)
+        
+    def test_capstyle_constructor(self):
+        p = BezierPath(self.ctx, capstyle=ROUND)
+        self.assertEquals(p.capstyle, ROUND)
+        
+    def test_capstyle_validation(self):
+        self.assertRaises(NodeBoxError, self.ctx.capstyle, 42)
+        self.assertRaises(NodeBoxError, BezierPath, self.ctx, capstyle=42)
+        p = BezierPath(self.ctx)
+        self.assertRaises(NodeBoxError, p._set_capstyle, 42)
+        
+    def test_joinstyle_context(self):
+        self.ctx.joinstyle(ROUND)
+        p = BezierPath(self.ctx)
+        self.assertEquals(p.joinstyle, MITER, "Default line join style is miter.")
+        p.inheritFromContext()
+        self.assertEquals(p.joinstyle, ROUND)
+        
+    def test_joinstyle_constructor(self):
+        p = BezierPath(self.ctx, joinstyle=ROUND)
+        self.assertEquals(p.joinstyle, ROUND)
+
+    def test_joinstyle_validation(self):
+        self.assertRaises(NodeBoxError, self.ctx.joinstyle, 42)
+        self.assertRaises(NodeBoxError, BezierPath, self.ctx, joinstyle=42)
+        p = BezierPath(self.ctx)
+        self.assertRaises(NodeBoxError, p._set_joinstyle, 42)
 
 if __name__=='__main__':
     unittest.main()