add Horiz/Vert contraint buttons and drawing modes

SketchWidget.py

@@ -26,6 +26,8 @@ class SketchWidget(object):
                 'line': LineMode(),
                 'circle': CircleMode(),
                 'connect': ConnectMode(),
+                'horizontal': HorizontalMode(),
+                'vertical': VerticalMode(),
                 }
         self.mode_name = 'select'
         self.mode = self.modes[self.mode_name]
@@ -635,3 +637,57 @@ class ConnectMode(Mode):
             self.first_ptref = None
         else:
             sw.window.set_mode('')
+
+class HorizontalMode(Mode):
+    def start_mode(self, sw):
+        self.first_ptref = None
+
+    def get_cursor(self):
+        return 'crosshair'
+
+    def do_motion(self, sw, x, y):
+        sw.update_hover_snap_point(x, y)
+
+    def do_left_click(self, sw, x, y):
+        if sw.hover_snap_ptref is not None:
+            if self.first_ptref is None:
+                self.first_ptref = sw.hover_snap_ptref
+            else:
+                c = Horizontal(self.first_ptref.shape, self.first_ptref.ptNum,
+                        sw.hover_snap_ptref.shape, sw.hover_snap_ptref.ptNum)
+                sw.sketch.constraints.append(c)
+                self.first_ptref = None
+                sw.invalidate()
+
+    def do_right_click(self, sw, x, y):
+        if self.first_ptref is not None:
+            self.first_ptref = None
+        else:
+            sw.window.set_mode('')
+
+class VerticalMode(Mode):
+    def start_mode(self, sw):
+        self.first_ptref = None
+
+    def get_cursor(self):
+        return 'crosshair'
+
+    def do_motion(self, sw, x, y):
+        sw.update_hover_snap_point(x, y)
+
+    def do_left_click(self, sw, x, y):
+        if sw.hover_snap_ptref is not None:
+            if self.first_ptref is None:
+                self.first_ptref = sw.hover_snap_ptref
+            else:
+                c = Vertical(self.first_ptref.shape, self.first_ptref.ptNum,
+                        sw.hover_snap_ptref.shape, sw.hover_snap_ptref.ptNum)
+                sw.sketch.constraints.append(c)
+                self.first_ptref = None
+                sw.invalidate()
+
+    def do_right_click(self, sw, x, y):
+        if self.first_ptref is not None:
+            self.first_ptref = None
+        else:
+            sw.window.set_mode('')

Window.py

@@ -34,6 +34,8 @@ class Window(object):
         addButton('line', 'Line')
         addButton('circle', 'Circle')
         addButton('connect', 'Connect')
+        addButton('horizontal', 'Horiz')
+        addButton('vertical', 'Vert')
 
         self.status_lbl = gtk.Label()
         self.status_lbl.set_alignment(0.0, 0.5)