table of contents
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.
- Tcl_Size 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 |