Add edgecolor parameter

Allow user to set the polygons edge color.

examples/pColorMeshItem.py

@@ -33,7 +33,9 @@ y = np.tile(np.arange(1, yn+1), xn).reshape(xn, yn)
 z = np.exp(-(x*xn)**2/1000)[:-1,:-1]
 
 ## Create image item
-pcmi = pg.PColorMeshItem()
+edgecolors = None
+# edgecolors = {'color':'w', 'width':2} # May be uncommened to see edgecolor effect
+pcmi = pg.PColorMeshItem(edgecolors=edgecolors)
 view.addItem(pcmi)
 
 

pyqtgraph/graphicsItems/PColorMeshItem.py

@@ -31,7 +31,7 @@ class PColorMeshItem(GraphicsObject):
 
 
     def __init__(self, x=None, y=None, z=None,
-                 cmap='viridis'):
+                 cmap='viridis', edgecolors=None):
         """
 
 
@@ -44,8 +44,13 @@ class PColorMeshItem(GraphicsObject):
             colors.
         cmap : str, default 'viridis
             Colormap used to map the z value to colors.
+        edgecolors : dict , default None
+            The color of the edges of the polygons.
+            Default None means no edges.
+            The dict may contains any arguments accepted by :func:`mkColor() <pyqtgraph.mkColor>.
+            Example:
+                mkPen(color='w', width=2)
         """
-
         GraphicsObject.__init__(self)
 
         self.x = x
@@ -56,6 +61,7 @@ class PColorMeshItem(GraphicsObject):
         
         self.axisOrder = getConfigOption('imageAxisOrder')
 
+        self.edgecolors = edgecolors
         if cmap in Gradients.keys():
             self.cmap = cmap
         else:
@@ -84,7 +90,10 @@ class PColorMeshItem(GraphicsObject):
         p = QtGui.QPainter(self.qpicture)
         
         # We set the pen of all polygons once
-        p.setPen(QtGui.QColor(0, 0, 0, 0))
+        if self.edgecolors is None:
+            p.setPen(QtGui.QColor(0, 0, 0, 0))
+        else:
+            p.setPen(fn.mkPen(self.edgecolors))
 
         ## Prepare colormap
         # First we get the LookupTable