add XDistance constraint to test Sketch

Window.py

@@ -7,6 +7,7 @@ from SketchWidget import SketchWidget
 from Line import Line
 from Circle import Circle
 from Connect import Connect
+from XDistance import XDistance
 
 class Window:
     def __init__(self, title):
@@ -35,8 +36,9 @@ class Window:
         s.constraints.append(Connect(c, 1, l2, 0))
         s.constraints.append(Connect(c, 4, l3, 1))
 
-        s.solve()
+        s.constraints.append(XDistance(l1, 0, l1, 1, 0.4))
 
+        s.solve()
 
         sw = SketchWidget(s)
         self.window.add(sw.widget)