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curs_window(3X) Library calls curs_window(3X) NAME newwin, delwin, mvwin, subwin, derwin, mvderwin, dupwin, wsyncup, syncok, wcursyncup, wsyncdown - create and manipulate curses windows SYNOPSIS #include <curses.h> WINDOW *newwin( int nlines, int ncols, int begin_y, int begin_x); int delwin(WINDOW *win); int mvwin(WINDOW *win, int y, int x); WINDOW *subwin(WINDOW *orig, int nlines, int ncols, int begin_y, int begin_x); WINDOW *derwin(WINDOW *orig, int nlines, int ncols, int begin_y, int begin_x); int mvderwin(WINDOW *win, int par_y, int par_x); WINDOW *dupwin(WINDOW *win); void wsyncup(WINDOW *win); int syncok(WINDOW *win, bool bf); void wcursyncup(WINDOW *win); void wsyncdown(WINDOW *win); DESCRIPTION newwin Calling newwin creates and returns a pointer to a new window with the given number of lines and columns. The upper left-hand corner of the window is at line begin_y, column begin_x If either nlines or ncols is zero, they default to LINES - begin_y and COLS - begin_x. A new full-screen window is created by calling newwin(0,0,0,0). Regardless of the function used for creating a new window (e.g., newwin, subwin, derwin, newpad), rather than a duplicate (with dupwin), all of the window modes are initialized to the default values. These functions set window modes after a window is created: idcok idlok immedok keypad leaveok nodelay scrollok setscrreg syncok wbkgdset wbkgrndset and wtimeout. delwin Calling delwin deletes the named window, freeing all memory associated with it (it does not actually erase the window's screen image). Sub- windows must be deleted before the main window can be deleted. mvwin Calling mvwin moves the window so that the upper left-hand corner is at position (x, y). If the move would cause the window to be off the screen, it is an error and the window is not moved. Moving subwindows is allowed, but should be avoided. subwin Calling subwin creates and returns a pointer to a new window with the given number of lines, nlines, and columns, ncols. The window is at position (begin_y, begin_x) on the screen. The subwindow shares memory with the window orig, its ancestor, so that changes made to one window will affect both windows. When using this routine, it is necessary to call touchwin or touchline on orig before calling wrefresh on the sub- window. derwin Calling derwin is the same as calling subwin, except that begin_y and begin_x are relative to the origin of the window orig rather than the screen. There is no difference between the subwindows and the derived windows. mvderwin Calling mvderwin moves a derived window (or subwindow) inside its par- ent window. The screen-relative parameters of the window are not changed. This routine is used to display different parts of the parent window at the same physical position on the screen. dupwin Calling dupwin creates an exact duplicate of the window win. wsyncup Calling wsyncup touches all locations in ancestors of win that are changed in win. If syncok is called with second argument TRUE then wsyncup is called automatically whenever there is a change in the win- dow. wsyncdown The wsyncdown routine touches each location in win that has been touched in any of its ancestor windows. This routine is called by wre- fresh, so it should almost never be necessary to call it manually. wcursyncup The routine wcursyncup updates the current cursor position of all the ancestors of the window to reflect the current cursor position of the window. RETURN VALUE Routines that return an integer return the integer ERR upon failure and OK (SVr4 only specifies "an integer value other than ERR") upon suc- cessful completion. Routines that return pointers return NULL on error. X/Open defines no error conditions. In this implementation delwin returns an error if the window pointer is null, or if the window is the parent of another window. derwin returns an error if the parent window pointer is null, or if any of its ordinates or dimensions is negative, or if the resulting window does not fit inside the parent window. dupwin returns an error if the window pointer is null. This implementation also maintains a list of windows, and checks that the pointer passed to delwin is one that it created, return- ing an error if it was not.. mvderwin returns an error if the window pointer is null, or if some part of the window would be placed off-screen. mvwin returns an error if the window pointer is null, or if the window is really a pad, or if some part of the window would be placed off-screen. newwin will fail if either of its beginning ordinates is negative, or if either the number of lines or columns is negative. syncok returns an error if the window pointer is null. subwin returns an error if the parent window pointer is null, or if any of its ordinates or dimensions is negative, or if the resulting window does not fit inside the parent window. The functions which return a window pointer may also fail if there is insufficient memory for its data structures. Any of these functions will fail if the screen has not been initialized, i.e., with initscr or newterm. NOTES If many small changes are made to the window, the wsyncup option could degrade performance. Note that syncok may be a macro. PORTABILITY X/Open Curses, Issue 4 describes these functions. X/Open Curses states regarding delwin: • It must delete subwindows before deleting their parent. • If delwin is asked to delete a parent window, it can only succeed if the curses library keeps a list of the subwindows. SVr4 curses kept a count of the number of subwindows rather than a list. It simply returned ERR when asked to delete a subwindow. Solaris X/Open curses does not even make that check, and will delete a par- ent window which still has subwindows. • Since release 4.0 (1996), ncurses maintains a list of windows for each screen, to ensure that a window has no subwindows before al- lowing deletion. • NetBSD copied this feature of ncurses in 2003. PDCurses follows the scheme used in Solaris X/Open curses. BUGS The subwindow functions subwin, derwin, mvderwin, wsyncup, wsyncdown, wcursyncup, and syncok are flaky, incompletely implemented, and not well tested. System V's curses documentation is unclear about what wsyncup and wsyncdown actually do. It seems to imply that they are supposed to touch only those lines that are affected by changes to a window's an- cestors. The language here, and behavior of ncurses, is patterned on the X/Open Curses standard; this approach may result in slower updates. SEE ALSO curses(3X), curs_initscr(3X), curs_refresh(3X), curs_touch(3X), curs_variables(3X) ncurses 6.5 2024-04-20 curs_window(3X)
NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | NOTES | PORTABILITY | BUGS | SEE ALSO
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