getscroll(3Tk)

NAME
     Tk_GetScrollInfo - parse arguments for scrolling commands

SYNOPSIS
     #include <tk.h>

     int
     Tk_GetScrollInfo(interp, argc, argv, dblPtr, intPtr)

ARGUMENTS
     Tcl_Interp   *interp   (in)      Interpreter to use for error reporting.

     int          argc      (in)      Number of strings in argv array.

     char         *argv[]   (in)      Argument strings.  These represent the
                                      entire widget command, of which the
                                      first word is typically the widget name
                                      and the second word is typically xview
                                      or yview.  This procedure parses
                                      arguments starting with argv[2].

     double       *dblPtr   (out)     Filled in with fraction from moveto
                                      option, if any.

     int          *intPtr   (out)     Filled in with line or page count from
                                      scroll option, if any.  The value may be
                                      negative.


DESCRIPTION
     Tk_GetScrollInfo parses the arguments expected by widget scrolling
     commands such as xview and yview.  It receives the entire list of words
     that make up a widget command and parses the words starting with argv[2].
     The words starting with argv[2] must have one of the following forms:

          moveto fraction

          scroll number units

          scroll number pages

     Any of the moveto, scroll, units, and pages keywords may be abbreviated.
     If argv has the moveto form, TK_SCROLL_MOVETO is returned as result and
     *dblPtr is filled in with the fraction argument to the command, which
     must be a proper real value.  If argv has the scroll form,
     TK_SCROLL_UNITS or TK_SCROLL_PAGES is returned and *intPtr is filled in
     with the number value, which must be a proper integer.  If an error
     occurs in parsing the arguments, TK_SCROLL_ERROR is returned and an error
     message is left in interp->result.
KEYWORDS
     parse, scrollbar, scrolling command, xview, yview