[etoys-dev] Re: Fwd: How can I tell if a Scripting Tile is
moved into a script?
yoshiki at vpri.org
Tue Jan 19 22:08:31 EST 2010
At Tue, 19 Jan 2010 15:11:19 -0500,
Steve Thomas wrote:
> Stephen wrote:
> >> Folks,
> >> I am working on a Etoys Tutorial similar to Etoys Challange and I want to be able to detect if certain tiles were
> >>(or not used), so that I can provide "pop up" hints to users.
> >> I tried creating a script on a "Scripting Tile Holder", but as soon as I move the "Scripting Tile Holder" the script
> >> disappears (literally, off the screen and it is removed from the object).
> >> To recreate: Open Etoys Challenge, then create a script for one the Scripting Tiles (ex:Car forward by 10), then move
> >> the Scripting Tile with you mouse and the script disappears.
> >> Another possible solution would be to somehow use reflection to see what is in a particular script, but I would need
> >> help in figuring out how to do that.
> Yoshiki responded:
> > I think this is a tricky one. As you found out, Scripting Tile
> >Holder is transient. As soon as you pick it up, the green fringe
> >around the tile goes away; it means that the Scripting Tile Holder for
> >that tile goes away along with the scripts and tiles. One may think
> >that the Phrase Tile (inside the Scripting Tile Holder) may retain the
> >identity, but once it is dropped into a scriptor, it results in a copy
> >of original and also loses scripts.
> > - One approach is to look at the scriptor and visit recursively the
> > tree structure of tiles in there and found out what kind of
> > commands (and Test) are used. If you want to go this way, I or
> > somebody should be able to provide a short code snippet that does
> > it.
> > - Another approach would be to make the playfield that contains these
> > phrases intelligent, and whenever a phrase is taken out from it, it
> > assumes that it is "used". (Not perfect because it may be just moved
> > to the world). Again, if you want to go this way, I or somebody should
> > be able to provide a short code snippet that looks at the elements
> > in the playfield and tells you what kind of tiles inside.
> >I would guess that the first approach would be more "faithful" in
> >guiding the user, but still there is a mechanism to compare the
> >current situation and the goal and decide what kind of information to
> >provide to the user...
> >-- Yoshiki
> Yes I would definitely prefer the more "faithful" solution.
> If you would be kind enough to provide the code snippet (preferably inside an Etoys Challenge project so I can see how
> it works) I will work on learning squeak enough to modify it for my needs and work on the mechanism's to compare current
> to goal and provide the information based on results and timing.
I created a "proof of concept" version and uploaded it to:
and also squeakland.org showcase.
What I did was:
- Wrote a little bit of code so that readable text representation
of phrases in a script can be obtained. (This only handles
phrases with no complex expression as the argument, and Test
tile). Add variables called currentScriptor and result to the
world. "forward by: 10" is rendered as "forward:10" and "turn by
-10" is rendered as "turn:-10".
- Add a couple of Etoys scripts that take the text representation
and see if the specified condition is met. One of such scripts
is "includesInCurrentScriptor:", which checks if the tile given
as its argument is in the currentScriptor. The other one is
"includesInCurrentScriptorTrueClause:", which checks if the tile
specified by the argument is in the Yes part of Test. (You can
think of more variations but this is a start.)
- Attach some scripts to the page objects for "step 1" and "step
2". The "step1Setup" script for example sets up the
currentScriptor variable of the world, and start ticking
- The checkstep1 script for example checks if "forward:10" is in
the Yes part of a test tile. The result is stored in the
"result" variable of world so you can see it.
- When you flip the page to "step 2", proper test script will be
You probably need a bit more elaborated checks for giving meaningful
feedback to the user... You would want to have a script that checks
the condition part of a test and yes part for example (I'm happy to
write it if you need). But I hope this illustrates the concept.
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