|Tk_GetScrollInfo(3tk)||Tk Library Procedures||Tk_GetScrollInfo(3tk)|
Tk_GetScrollInfoObj, Tk_GetScrollInfo - parse arguments for scrolling commands
#include <tk.h> int Tk_GetScrollInfoObj(interp, objc, objv, fractionPtr, stepsPtr) int Tk_GetScrollInfo(interp, argc, argv, fractionPtr, stepsPtr)
- 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.
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. The words starting with objv 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.
parse, scrollbar, scrolling command, xview, yview