Tk_GetScrollInfo manual page - Tk Library Procedures

Tcl8.5.19/Tk8.5.19 Documentation > TkLib > GetScroll

Tcl/Tk Applications | Tcl Commands | Tk Commands | Tcl Library | Tk Library

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

DESCRIPTION

KEYWORDS

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.

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