LiveCode Forums.

I recently discovered cardWidth and cardHeight when learning how to maintain the position of controls when resizing the card.

Now I want to use cardWidth and cardHeight to position an image at a random position on the card, even when the card has been resized.
Say my object is 100x100 I wanted to do something like this:
when I try to run this code I get the error:

button "START":execution error at line 25 (Operators-:error in left operand), char11

Line 25 mentioned in the error is actually line 1 of the code snippet I posted.

The only thing I can think of is when I use cardWidth and cardHeight for resizing I first have a line like:
Do I need to add a similar line of code to tell LiveCode to "get" the cardWidth and cardHeight?

Thanks for any ideas or suggestions,

TJ.

Hi Tj,

I recently discovered cardWidth and cardHeight

Where ?
As far I know "cardWidth" doesn't exist. One card have the width and height of the stack
Try this Kind regards
Jean-Marc

Hi TJ,

the example resizestack handler in the docs just has some arbitrary, yet meaningful names for the parameters it comes with!
Could also be:
on resizeStack James, Harold, Bill, Carl


cardHeight and cardWidth are not valid/built-in Livecode constants or properties!
So you need to "roll" your own:
...
put the width of this cd into cardWidth
put the height of this cd into cardHeight
put cardWidth-100 into cwidth
...

Best

Klaus

All.

This happens often. A new user will see these sorts of things in a lesson, or even in a handler that someone has written, and consider them native. As Klaus said, "roll your own", but somebody else already did. The new user assumes these are part of the language.

It is an important lesson in its own right that the newbie sees how this is done, that in a sense, those new words are now, indeed part of the language, but that they were engineered outside that language.

So TJ, where did you see these "cardWidth, etc" properties?

Craig Newman

Yes; this can be a problem.
I recently made a prototype code block stack: http://andregarzia.on-rev.com/richmond/GR.zip

with a whole lot of groups with scripts of this sort

on ACTION
do something
end ACTION

and a kid I sent the stack to came back within half-an-hour asking my why "action" wasn't in the LC Dictionary.

So, maybe, we should be kind and label our "personal funnies" as such to avoid confusion.
ALWAYS read the label!

Thanks for the help everyone. Yes, Craig I did see this in a tutorial on resizing cards found here:
http://lessons.runrev.com/s/lessons/m/4 ... is-resized

In the tutorial cardWidth/cardHeight was just used with the on resizeStack, I was thinking these were native, but obviously it's pretty easy to get the effect I am looking for by "rolling my own" and using something like:
Thanks again everyone for all the help. Very much appreciated.

TJ.