TEXT

My edit field is resizeable (tied to a window) and is styled. The challenge is to find the number of visible lines in the field, and then set the 5ht parameter in SCROLL BUTTON accordingly within a _wndRefresh event.

I had the same problem (my page scroll was fixed to 16 lines, I don't know why), so every time I resize a window I call this function, I think you can drop it as is in your code, and call it every _wndRefresh event:

CLEAR LOCAL MODE
LOCAL FN adjustScroll(id)                         'fixes the page scroll  
  teHndle1& = TEHANDLE(id)                        'get handle to edit
field
  LONG IF teHndle1&
    CALL TECALTEXT(teHndle1&)
    fontH% = FN TEGETHEIGHT (1,1,teHndle1&)
    efTop% = teHndle1&..teViewRect.top%
    efBottom% = teHndle1&..teViewRect.bottom%
    efVisLines%=((efBottom%-efTop%)/fontH%)-1
    SCROLL BUTTON -id,,,,efVisLines%,,_scrollOther
  END IF
END FN

Someone will correct me if I am wrong, but when I have fiddled with scrollbars, I could never get them to change size when doing a window refresh. I had to write my own code to handle the Window Grow and resize before the refresh.

I resize my windows with both methods (standard window grow box and "hand-made" FN windowGrow) and always resize the edit field and its scrollbar with the attached function. FN ResizeField is called in the _wndSized event for standard windows, and directly inside FN windowGrow for the custom ones.

CLEAR LOCAL MODE
LOCAL FN ResizeField
  w=WINDOW(_width)-15
  h=WINDOW(_height)-15
    EDIT FIELD -1,,(4,79)-(w-5,h-4),
    SCROLL BUTTON -1,,,,,(w-5,78)-(w+11,h-3),_scrollOther
    FN adjustScroll(1)
END FN