Thread Subject: Aborting a set in a PropertyPreSet listener callback

Is there a way to abort a requested SET call in a
PropertyPreSet listener callback?

schema.prop objects have an access flag called 'AbortSet'
that would suggest this is possible, but I haven't found
anything digging through Mathworks' code.

I know I COULD create a corresponding PropertyPostSet
listener to 'undo' whatever was done, but this gets pretty
unwieldy with linked properties (i.e. setting the XLim
property of an axes changes the XLimMode, XTick, etc.)

"Darik " <dgambleDEL@uwaterlooDEL.caDEL> wrote in message
<ff86su$p1i$1@fred.mathworks.com>...
> Is there a way to abort a requested SET call in a
> PropertyPreSet listener callback?
>
> schema.prop objects have an access flag called 'AbortSet'
> that would suggest this is possible, but I haven't found
> anything digging through Mathworks' code.
>
> I know I COULD create a corresponding PropertyPostSet
> listener to 'undo' whatever was done, but this gets pretty
> unwieldy with linked properties (i.e. setting the XLim
> property of an axes changes the XLimMode, XTick, etc.)


I never tried it myself, but you can try one of two ways:

1) set the schema.prop's SetFunction to your own callback,
in which you can abort or return the original value. Note
that SetFunction is unsupported in Matlab 6, but is in 7
(unsure about 6.5). See usage example in my uicomponent
submission:
http://www.mathworks.com/matlabcentral/fileexchange/loadFile.do?objectId=14583

2) within your PropertyPreSet callback, retrieve the
original value and use it to modify the suggestedValue back
to the original value. This will effectively abort the
property's modification.

...or ask Mathworks how to use AbortSet (ha ha...)

Yair Altman
http://ymasoftware.com

"Yair Altman" <altmanyDEL@gmailDEL.comDEL> wrote in message
<ff8r0h$gdq$1@fred.mathworks.com>...
>
> I never tried it myself, but you can try one of two ways:
>
> 1) set the schema.prop's SetFunction to your own callback,
> in which you can abort or return the original value. Note
> that SetFunction is unsupported in Matlab 6, but is in 7
> (unsure about 6.5). See usage example in my uicomponent
> submission:
>
http://www.mathworks.com/matlabcentral/fileexchange/loadFile
.do?objectId=14583
>

Yeah, this would definitely be the easiest route, but
unfortunately most of the interesting properties seem to be
read-only.

E.g.

>> p = findprop(handle(gca), 'XLim');
>> p.SetFunction = @mySetFunction;

Returns:

??? The SetFunction for this property can not be modified.

Any way around this?

> 2) within your PropertyPreSet callback, retrieve the
> original value and use it to modify the suggestedValue
back
> to the original value. This will effectively abort the
> property's modification.

This actually doesn't work, oddly enough. As far as I can
tell, any set calls in the PropertyPreSet callback are
overridden by the set call that triggered the listener
callback in the first place. I can create a property to
temporarily store the original value, which can then be
replaced by a corresponding PropertyPostSet function, but
as I said, this gets a bit hairy with multiple linked
properties.

> ...or ask Mathworks how to use AbortSet (ha ha...)

Hah, I wish.