Add GrippingEdge

Still needs to replace Boxes.grip()

boxes/__init__.py

@@ -297,6 +297,8 @@ class Boxes:
         self.edges = {}
         self.addPart(edges.Edge(self, None))
         self.addPart(edges.OutSetEdge(self, None))
+        s = edges.GripSettings(self.thickness)
+        self.addPart(edges.GrippingEdge(self, s))
 
         # Finger joints
         # Share settings object

boxes/edges.py

@@ -211,6 +211,79 @@ class OutSetEdge(BaseEdge):
     def startwidth(self):
         return self.boxes.thickness
 
+#############################################################################
+####     Gripping Edge
+#############################################################################
+
+class GripSettings(Settings):
+    """Settings for GrippingEdge
+Values:
+
+* absolute_params
+
+ * style : A : "A" (wiggly line) or "B" (bumps)
+ * outset : True : extend outward the straight edge
+
+* relative (in multiples of thickness)
+
+ * depth : 0.3 : depth of the grooves
+
+"""
+
+    absolute_params = {
+        "style" : "A",
+        "outset" : True,
+    }
+
+    relative_params = {
+        "depth" : 0.3,
+    }
+
+class GrippingEdge(BaseEdge):
+    description = """Corrugated edge useful as an gipping area"""
+    char = 'g'
+
+
+    def A(self, length):
+        depth = self.settings.depth
+        grooves = int(length // (depth*2.0)) + 1
+        depth = length / grooves / 4.0
+
+        o = 1 if self.settings.outset else -1
+        for groove in range(grooves):
+            self.corner(o * -90, depth)
+            self.corner(o * 180, depth)
+            self.corner(o * -90, depth)
+
+    def B(self, length):
+        depth = self.settings.depth
+        grooves = int(length // (depth*2.0)) + 1
+        depth = length / grooves / 2.0
+        o = 1 if self.settings.outset else -1
+        if self.settings.outset:
+            self.corner(-90)
+        else:
+            self.corner(90)
+            self.edge(depth)
+            self.corner(-180)
+        for groove in range(grooves):
+            self.corner(180, depth)
+            self.corner(-180, 0)
+        if self.settings.outset:
+            self.corner(90)
+        else:
+            self.edge(depth)
+            self.corner(90)
+
+    def margin(self):
+        if self.settings.outset:
+            return self.settings.depth + self.boxes.spacing
+        else:
+            return self.boxes.spacing
+
+    def __call__(self, length, **kw):
+        getattr(self, self.settings.style)(length)
+
 class CompoundEdge(BaseEdge):
     """Edge composed of multiple different Edges"""
     description = "Compound Edge"

documentation/src/edges.rst

@@ -5,17 +5,18 @@ As edges started out as methods of the main Boxes class they still are
 callables. A set of instances are kept the ``.edges`` attribute of the
 ``Boxes`` class. It is a dict with strings of length one as keys:
 
-* e : Edge
-* E : OutSetEdge
-* s : StackableEdge
-* S : StackableEdgeTop
-* f : FingerJointEdge
-* F : FingerJointEdgeCounterPart
-* h : FingerHoleEdge
 * d : DoveTailJoint
 * D : DoveTailJointCounterPart
+* e : Edge
+* E : OutSetEdge
+* f : FingerJointEdge
+* F : FingerJointEdgeCounterPart
+* g : GrippingEdge
+* h : FingerHoleEdge
 * ijk : Hinge (start, end, both sides)
 * IJK : HingePin (start, end, both sides)
+* s : StackableEdge
+* S : StackableEdgeTop
 
 Edges of the same type share a settings instance to make sure both
 sides match (when the same length is given).
@@ -41,6 +42,12 @@ Straight Edges
 .. autoclass:: boxes.edges.Edge
 .. autoclass:: boxes.edges.OutSetEdge
 
+Grip
+----
+
+.. autoclass:: boxes.edges.GripSettings
+.. autoclass:: boxes.edges.GrippingEdge
+
 Stackable Edges
 ---------------