Extract some other constants (labels and icons placement).

diff --git a/qwerty.py b/qwerty.py
index 687ced0..ba38160 100755
--- a/qwerty.py
+++ b/qwerty.py
@@ -18,6 +18,14 @@ SECTION = 1
 KEY = 2

 PADDING = 4
+ICON_TOP_MARGIN = 40
+LABEL_LEFT, LABEL_TOP = 20,25
+LABEL_FONT_SIZE = 16
+DESC_TOP = 120
+DESC_FONT_SIZE = 14
+KEY_BOTTOM = 45
+KEY_FONT_SIZE = 40
+
 LINEHEIGHT = 1.2

 KEYS = [ "QWERTYUIOP",
@@ -84,8 +92,7 @@ class SuperButton(gtk.DrawingArea):
                 s = s + ' ' + word
             else:
                 s = word
-            o,n = size(old), size(s)
-            if o < self.width and n >= self.width:
+            if size(s) >= self.width - LABEL_LEFT:
                 lines.append(old)
                 s = word
             else:
@@ -109,9 +116,8 @@ class SuperButton(gtk.DrawingArea):
         cr2.paint()

         x = (self.width - w)/2
-        y = 45

-        cr.set_source_surface(IS,x,y)
+        cr.set_source_surface(IS,x,ICON_TOP_MARGIN)
         cr.paint()

     def draw_button(self,cr):
@@ -128,12 +134,12 @@ class SuperButton(gtk.DrawingArea):
     def draw_label(self,cr):
         if self.active:
             cr.set_source_rgb(*BUTTON_BORDER_ACTIVE)
-            cr.move_to(20,30)
-            cr.set_font_size(16)
+            cr.move_to(LABEL_LEFT, LABEL_TOP)
+            cr.set_font_size(LABEL_FONT_SIZE)
             cr.show_text(self.label)

     def draw_desc(self,cr):
-        self.show_text_wrap(cr,20,130, 14, self.desc)
+        self.show_text_wrap(cr,LABEL_LEFT,DESC_TOP, DESC_FONT_SIZE, self.desc)

     def on_expose(self,widget,event):
         x,y,self.width,self.height,b = widget.window.get_geometry()
@@ -145,8 +151,8 @@ class SuperButton(gtk.DrawingArea):
             cr.set_source_rgb(*BUTTON_BORDER_ACTIVE)

         # Draw key
-        cr.move_to(20, self.height-50)
-        cr.set_font_size(40)
+        cr.move_to(LABEL_LEFT, self.height-KEY_BOTTOM)
+        cr.set_font_size(KEY_FONT_SIZE)
         cr.show_text(self.key)

         self.draw_label(cr)