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Tk_GetScrollInfo(3tk) Tk Library Procedures Tk_GetScrollInfo(3tk) 





NAME


Tk_GetScrollInfoObj, Tk_GetScrollInfo - parse arguments for
    scrolling commands






SYNOPSIS


#include <tk.h>

int
Tk_GetScrollInfoObj(interp, objc, objv, fractionPtr, stepsPtr)

int
Tk_GetScrollInfo(interp, argc, argv, fractionPtr, stepsPtr)






ARGUMENTS



  
Tcl_Interp *interp (in)

  
Interpreter to use for error reporting.

  
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.

  
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.

  
double *fractionPtr (out)

  
Filled in with fraction from moveto option, if any.

  
int *stepsPtr (out)

  
Filled in with line or page count from scroll option, if any. The
      value may be negative.
    
    

    

  








DESCRIPTION


Tk_GetScrollInfoObj 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 objv[2]. The words starting with objv[2] must
    have one of the following forms:




moveto fraction
scroll number pages
scroll number units




Any of the moveto, scroll, pages, and
    units keywords may be abbreviated. If objv has the
    moveto form, TK_SCROLL_MOVETO is returned as result and
    *fractionPtr is filled in with the fraction argument to the
    command, which must be a proper real value. If objv has the
    scroll form, TK_SCROLL_PAGES or TK_SCROLL_UNITS is
    returned and *stepsPtr is filled in with the number value,
    which must be a integer or a float, but if it is a float then it is
    converted to an integer, rounded away from 0. If an error occurs in parsing
    the arguments, TK_SCROLL_ERROR is returned and an error message is
    left in interpreter interp's result.


Tk_GetScrollInfo is identical in function to
    Tk_GetScrollInfoObj. However, Tk_GetScrollInfo accepts string
    arguments, making it more appropriate for use with legacy widgets.






KEYWORDS


parse, scrollbar, scrolling command, xview, yview







  

    8.0
    Tk