1 files changed, 35 insertions, 0 deletions
diff --git a/pysamples/uturn.py b/pysamples/uturn.py
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+++ b/pysamples/uturn.py
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+#Copyright (c) 2011, Walter Bender
+
+# This procedure is invoked when the user-definable block on the
+# "extras" palette is selected.
+
+# Usage: Import this code into a Python (user-definable) block; when
+# it is run, a u-turn block will be added to the Turtle Palette. You
+# can use the u-turn block as you would any other block.
+
+
+def myblock(tw, arg):
+    ''' Add a uturn block to the 'turtle' palette '''
+
+    from TurtleArt.tapalette import make_palette, palette_name_to_index
+    from TurtleArt.talogo import primitive_dictionary
+    from gettext import gettext as _
+
+    # Choose a palette for the new block.
+    palette = make_palette('turtle')
+
+    # Create a new block prototype.
+    palette.add_block('uturn',
+                      style='basic-style-extended-vertical',
+                      label=_('uturn'),
+                      prim_name='uturn',
+                      help_string=_('make a uturn'))
+
+    # Add its primitive to the LogoCode dictionary.
+    tw.lc.def_prim('uturn', 0,
+                   lambda self: primitive_dictionary['set'](
+            'heading', tw.canvas.seth, tw.canvas.heading + 180))
+
+    # Regenerate the palette, which will now include the new block.
+    tw.show_toolbar_palette(palette_name_to_index('turtle'),
+                                   regenerate=True)