Scrollbardrag drag

[hamlynart]

Hi,

I'm a bit confused - why doesn't this work:

Code: Select all

on scrollbarDrag
   if myVariable <=1 then
      add 1 to fld "myField"
      put 1 into myVariable
   end if
   put the thumbPosition of me into fld "Data"
end scrollbarDrag

Basically I'd like to use the "if" statement to execute a command just once at the beginning of the scrollbardrag but to continue with other stuff.

Any thoughts much appreciated.

Jim H

[bn]

Jim,

myVariable is not initialised and it does not persist. So nothing is in myVariable that could trigger your if structure (<=). In your script myVariable = "myVariable"

you can see this if you change your code to

Code: Select all

if myVariable = "myVariable" then

but
since scrollbardrag is send repeatedly you will get many calls to your if structure. Just put it into a mousedown handler which is invoked at the click on the scrollbar once.
If I understand you correctly something like

Code: Select all

on scrollbarDrag
    put the thumbposition of me into fld "Data"
end scrollbarDrag

on mouseDown
        add 1 to field "myField"
end mouseDown

should do what you want. It counts how many times the scrollbar was clicked and gives you continously the thumbposition. (provided field "myField" was initialised to 0)

regards
Bernd

[hamlynart]

Bernd,

Wow - that works perfectly! I've been struggling with this for hours. You're right, it was the repeating that was causing the problem.

Many Thanks

Jim H

[Klaus]

Hi Jim,

hint:
The "scrollbardrag" message will also have a parameter that you can use:

Code: Select all

on scrollbardrag tValue 
## this will be the current real-time value of the scrollbar = thumbpos)
  put tValue into fld "Data"
end scrollbardrag

This is a tiny bit more efficient than additionally querying the thumbposition in the handler


Best

Klaus