trusty (3) Tk_GetScrollInfo.3tk.gz

NAME

       Tk_GetScrollInfo, Tk_GetScrollInfoObj - parse arguments for scrolling commands

SYNOPSIS

       #include <tk.h>

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

       int
       Tk_GetScrollInfoObj(interp, objc, objv, dblPtr, intPtr)

ARGUMENTS

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

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

       const 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.

       int objc (in)                    Number of Tcl_Obj's in objv array.

       Tcl_Obj *const objv[] (in)       Argument  objects.   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.

       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.
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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.

       Tk_GetScrollInfoObj  is  identical in function to Tk_GetScrollInfo.  However, Tk_GetScrollInfoObj accepts
       Tcl_Obj style arguments, making it more appropriate for use with new development.

KEYWORDS

       parse, scrollbar, scrolling command, xview, yview