Hi Gregor, I tried it out on OS X and it works great. There are some very beautiful demos. I will try to dig under the hood at some point and see if it would be feasible to replace Tinker with Cocoa (conditionally, if the user has PyObjC installed, otherwise it could fall back to Tkinter). Putting it into Javascript would probably be possible, and there is even a workaround for <canvas> in IE, but the performance would definitely take a hit. Great work. I should take a look at Rur-ple now... --Dethe

Hi Gregor, The more I play with the new xturtle the more I like it. Thanks! I've been thinking about the following extension to TurtleScreenBase and I wonder what you and others think of the idea. I like the fact that the turtle starts out in a coordinate system with 0,0 in the middle of the window, and I like the fact that for beginning students 1 unit == 1 pixel on the screen. But, I think that after a student has used the turtle to plot a sin or cos curve and learned about scaling the values to make the plot visible in the window it would be nice to place the turtle in a world coordinate system that matched whatever application the student was working on. For example the gravitaion examples could be done in meters. Let TurtleScreenBase take care of the translation and scaling after for you. The API could be extended by a single call setWorldCoordinates(llx,lly,ulx,uly) that specifies the world coordinates of the lower left corner of the screen and the upper right. (This is very similar to the ortho2 call in openGL. Note, if the student does not call setWorldCoordinates then the turtle functions just as it does now. I've already added this capability to the turtle.py that Vern wrote for Python 2.5 and I don't think it would be too hard to add to TurtleScreenBase. What do you all think? Would this be a useful addition? Gregor, is this something you already have on your todo list? Would you be interested? Thanks, Brad On Jun 22, 2006, at 5:37 PM, Gregor Lingl wrote:

Hi educators!

One of the hardest problems I've encountered upto now is to decide, when a piece of software is ready to be be published.

I've decided, that my new turtle graphics module ready now. A package, which additionally contains some example scripts. a tiny demoViewer and some documentation can be downloaded from:

http://ada.rg16.asn-wien.ac.at/~python/xturtle

From now on it's the user community, which will largely determine the future development of the module. I hope that it will grow to more than one user (which is me) soon. (*) And I'm willing to continue development (preferably in cooperation with others) until it's considered a really useful tool by the community.

In my opinion it should replace the current turtle.py in the standard distribution. We will see if others join me in this respect ...

(Please note, that xturtle.py is a complete reimplementation of what I've shown to you some ten weeks ago.)

For now I'll not write too much about it, but ask you for feedback and contributions to a discussion about the module. (You'll find some more information on the webpage mentioned above!)

However, I'll give a talk at Europython 2006 on July 5th about:

xturtle - an extended turtle module for Python as a vehicle for teaching programming concepts.

For this, too, your feedback will be welcome. And you'll get back the slides of the talk ;-)

Regards, Gregor Lingl

(*) This hope seems reasonable since I intend to use it in the forthcoming 2nd edition of "Python für Kids"

_______________________________________________ Edu-sig mailing list Edu-sig@python.org http://mail.python.org/mailman/listinfo/edu-sig

Brad Miller, PhD Assistant Professor Luther College http://www.cs.luther.edu/~bmiller jabber: bnmnetp@jabber.org

Gregor Lingl wrote:

I've decided, that my new turtle graphics module ready now.

Gregor- Nice work! Just for fun, I've integrated xturle.py with PataPata as a component, and here are a few changes I made to it (in diff format, at the end of this message), in case you are interested. Using PataPata, I was able to interactively build a xturtle script which took parameters, where the parameters were entered via Morphs I made as I needed them (like iterations, or color). I have an example world file with two widgets. Now, obviously, such an activity is not for the beginner user -- but more advanced ones might like being able to make parameterized xturtle functions. Since I use Python2.3 mainly as it is the default install for Debian, I made xturtle.py run with Python2.3 by changing the static methods and the use of sorted(). There might be more Python2.3 issues, but those were the only ones I've come across so far. I also added a line of code to reset TurtleScreen._RUNNING before throwing the Terminator exception, as otherwise you can't restart the turtle if you are using the library in a long running application. When I started playing around with it, that was a big issue for me, so that motivated my adding a BREAK interrupt key response to PataPata (though it only works for the xturtle XTurtleCanvas -- an endless loop doing nothing or just printing will still hang TK and PataPata). Now, whether you want to make it run with Python2.3 may be debatable, and you may well use those static methods in other code, so making them instance methods may well break other demos. But you most probably want to reset the _Running flag in any case. PataPata 0.1.19 has the XTurtleCanvas.py component in it, but the extra BREAK handling code is only in the latest stuff I've been adding to SVN here: http://svn.sourceforge.net/viewcvs.cgi/patapata/trunk/PataPata/ By the way, here is a simple world file written by PataPata that uses an XTurtleCanvas: http://svn.sourceforge.net/viewcvs.cgi/patapata/trunk/PataPata/WorldWithXTur... Note how the color and iterations are taken from GUI widget Morphs in the section: def mouseClick(self): reset() down() color(self.components.colorEntry.text) for i in range(int(self.components.iterationsEntry.text)): forward(100) right(91) forward(50) This is the file that defines the XTurtleCanvas (among other things): http://svn.sourceforge.net/viewcvs.cgi/patapata/trunk/PataPata/WorldCommonPC... This is the relevant xturtle specific code to make an XTurtleCanvas: XTurtleCanvas = world.newPrototype("Morph") XTurtleCanvas.size = (200, 200) XTurtleCanvas.pen = None def _newWidget(self): xturtle._root = self.world.widget newCanvas = xturtle.ScrolledCanvas(self.container.widget) xturtle._canvas = newCanvas self.setAttributeWithoutSideEffects("pen", xturtle.Pen()) xturtle._pen = self.pen return newCanvas XTurtleCanvas._newWidget = _newWidget def _destroyEmbeddedWidget(self): if self.widget: if xturtle._canvas == self.widget: xturtle._canvas = None if xturtle.pen == self.pen: xturtle._pen = None self.widget.destroy() self.widget = None self.setAttributeWithoutSideEffects("pen", None) XTurtleCanvas._destroyEmbeddedWidget = _destroyEmbeddedWidget def windowFocusIn(self): if self.widget: xturtle._canvas = self.widget xturtle._pen = self.pen XTurtleCanvas.windowFocusIn = windowFocusIn XTurtleCanvas.localProperty("pen").writeFunction = "_store_None" XTurtleCanvas.localProperty("pen").copyFunction = "_store_None" XTurtleCanvas.localProperty("pen").setFunction = None world.worldGlobals["XTurtleCanvas"] = XTurtleCanvas (The bit at the end with properties just ensures the pen is read only and is stored as None when the world is saved to a Python file). It was a bit tricky to get the thing to work right with those global functions when you have multiple canvases! I'm still not sure I'm quite satisfied with the result, but basically I swap in _pen and _canvas into the loaded xturtle module from the window's xturtle canvas whenever a TK window gets focus (I had to add that window focus handling too). This would be a problem if there was more than one xturtle canvas on a window, but by then for multiple canvases on one window I assume one could write code that accessed the each canvas's pen directly instead of using those globals functions. Good luck with your talk. Thanks for making such a nice library. --Paul Fernhout $ diff xturtle.py ~/workspace/PataPata/xturtle.py 20a21,22

# PDF -- Modified to work with Python2.3 instead of 2.4 (removed static methods use and sorted() use) # PDF -- added "TurtleScreen._RUNNING = True" before raised Terminator. 292,294c294,297 < < @staticmethod < def _blankimage():

# pdf modified next two methods to not be static so coudl run with

Python 2.3

#@staticmethod def _blankimage(self):

301,302c304,305 < @staticmethod < def _image(filename): ---

#@staticmethod def _image(self, filename):

795a799

TurtleScreen._RUNNING = True

864,865c868,872 < """ < return sorted(self._shapes.keys()) ---

""" # PDF MODIFIED work with Python 2.3 keys = self._shapes.keys() keys.sort() return keys