1curs_window(3X) curs_window(3X)
2
6 newwin, delwin, mvwin, subwin, derwin, mvderwin, dupwin, wsyncup,
7 syncok, wcursyncup, wsyncdown - create curses windows
8
10 #include <curses.h>
11 WINDOW *newwin(
13 int nlines, int ncols,
14 int begin_y, int begin_x);
15 int delwin(WINDOW *win);
16 int mvwin(WINDOW *win, int y, int x);
17 WINDOW *subwin(WINDOW *orig,
18 int nlines, int ncols,
19 int begin_y, int begin_x);
20 WINDOW *derwin(WINDOW *orig,
21 int nlines, int ncols,
22 int begin_y, int begin_x);
23 int mvderwin(WINDOW *win, int par_y, int par_x);
24 WINDOW *dupwin(WINDOW *win);
25 void wsyncup(WINDOW *win);
26 int syncok(WINDOW *win, bool bf);
27 void wcursyncup(WINDOW *win);
28 void wsyncdown(WINDOW *win);
29
31 newwin
32 Calling newwin creates and returns a pointer to a new window with the
33 given number of lines and columns. The upper left-hand corner of the
34 window is at
35 line begin_y,
36 column begin_x
37 If either nlines or ncols is zero, they default to
39 LINES - begin_y and
40 COLS - begin_x.
41 A new full-screen window is created by calling newwin(0,0,0,0).
43 Regardless of the function used for creating a new window (e.g.,
45 newwin, subwin, derwin, newpad), rather than a duplicate (with dupwin),
46 all of the window modes are initialized to the default values. These
47 functions set window modes after a window is created:
48 idcok, idlok, immedok, keypad, leaveok, nodelay, scrollok,
50 setscrreg, syncok, wbkgdset, wbkgrndset, and wtimeout
51 delwin
53 Calling delwin deletes the named window, freeing all memory associated
54 with it (it does not actually erase the window's screen image). Sub‐
55 windows must be deleted before the main window can be deleted.
56 mvwin
58 Calling mvwin moves the window so that the upper left-hand corner is at
59 position (x, y). If the move would cause the window to be off the
60 screen, it is an error and the window is not moved. Moving subwindows
61 is allowed, but should be avoided.
62 subwin
64 Calling subwin creates and returns a pointer to a new window with the
65 given number of lines, nlines, and columns, ncols. The window is at
66 position (begin_y, begin_x) on the screen. The subwindow shares memory
67 with the window orig, so that changes made to one window will affect
68 both windows. When using this routine, it is necessary to call touch‐
69 win or touchline on orig before calling wrefresh on the subwindow.
70 derwin
72 Calling derwin is the same as calling subwin, except that begin_y and
73 begin_x are relative to the origin of the window orig rather than the
74 screen. There is no difference between the subwindows and the derived
75 windows.
76 Calling mvderwin moves a derived window (or subwindow) inside its par‐
78 ent window. The screen-relative parameters of the window are not
79 changed. This routine is used to display different parts of the parent
80 window at the same physical position on the screen.
81 dupwin
83 Calling dupwin creates an exact duplicate of the window win.
84 wsyncup
86 Calling wsyncup touches all locations in ancestors of win that are
87 changed in win. If syncok is called with second argument TRUE then
88 wsyncup is called automatically whenever there is a change in the win‐
89 dow.
90 wsyncdown
92 The wsyncdown routine touches each location in win that has been
93 touched in any of its ancestor windows. This routine is called by wre‐
94 fresh, so it should almost never be necessary to call it manually.
95 wcursyncup
97 The routine wcursyncup updates the current cursor position of all the
98 ancestors of the window to reflect the current cursor position of the
99 window.
100
102 Routines that return an integer return the integer ERR upon failure and
103 OK (SVr4 only specifies "an integer value other than ERR") upon suc‐
104 cessful completion.
105 Routines that return pointers return NULL on error.
107 X/Open defines no error conditions. In this implementation
109 delwin
111 returns an error if the window pointer is null, or if the window
112 is the parent of another window.
113 derwin
115 returns an error if the parent window pointer is null, or if any
116 of its ordinates or dimensions is negative, or if the resulting
117 window does not fit inside the parent window.
118 dupwin
120 returns an error if the window pointer is null.
121 This implementation also maintains a list of windows, and checks
123 that the pointer passed to delwin is one that it created, return‐
124 ing an error if it was not..
125 mvderwin
127 returns an error if the window pointer is null, or if some part of
128 the window would be placed off-screen.
129 mvwin
131 returns an error if the window pointer is null, or if the window
132 is really a pad, or if some part of the window would be placed
133 off-screen.
134 newwin
136 will fail if either of its beginning ordinates is negative, or if
137 either the number of lines or columns is negative.
138 syncok
140 returns an error if the window pointer is null.
141 subwin
143 returns an error if the parent window pointer is null, or if any
144 of its ordinates or dimensions is negative, or if the resulting
145 window does not fit inside the parent window.
146 The functions which return a window pointer may also fail if there is
148 insufficient memory for its data structures. Any of these functions
149 will fail if the screen has not been initialized, i.e., with initscr or
150 newterm.
151
153 If many small changes are made to the window, the wsyncup option could
154 degrade performance.
155 Note that syncok may be a macro.
157
159 The subwindow functions (subwin, derwin, mvderwin, wsyncup, wsyncdown,
160 wcursyncup, syncok) are flaky, incompletely implemented, and not well
161 tested.
162 The System V curses documentation is very unclear about what wsyncup
164 and wsyncdown actually do. It seems to imply that they are only sup‐
165 posed to touch exactly those lines that are affected by ancestor
166 changes. The language here, and the behavior of the curses implementa‐
167 tion, is patterned on the XPG4 curses standard. The weaker XPG4 spec
168 may result in slower updates.
169
171 The XSI Curses standard, Issue 4 describes these functions.
172 X/Open Curses states regarding delwin:
174 • It must delete subwindows before deleting their parent.
176 • If delwin is asked to delete a parent window, it can only succeed
178 if the curses library keeps a list of the subwindows. SVr4 curses
179 kept a count of the number of subwindows rather than a list. It
180 simply returned ERR when asked to delete a subwindow. Solaris
181 X/Open curses does not even make that check, and will delete a par‐
182 ent window which still has subwindows.
183 • Since release 4.0 (1996), ncurses maintains a list of windows for
185 each screen, to ensure that a window has no subwindows before al‐
186 lowing deletion.
187 • NetBSD copied this feature of ncurses in 2003.
189 PDCurses follows the scheme used in Solaris X/Open curses.
190
192 curses(3X), curs_initscr(3X), curs_refresh(3X), curs_touch(3X),
193 curs_variables(3X)
194 curs_window(3X)