Tk_GetScrollInfo - parse arguments for scrolling commands


#include <tk.h>

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


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 method, 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.


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 method 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.


parse, scrollbar, scrolling command, xview, yview