Tk_GetScrollInfo(3) Tk Library Procedures Tk_GetScrollInfo(3)

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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.
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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 units
scroll number pages

Any of the moveto, scroll, units, and pages 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_UNITS or TK_SCROLL_PAGES is returned
and *stepsPtr 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
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

Tk 8.0 Tk_GetScrollInfo(3)