xref: /original-bsd/lib/libcurses/PSD.doc/appen.B (revision c3e32dec)
Copyright (c) 1980, 1993
The Regents of the University of California. All rights reserved.

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@(#)appen.B 8.1 (Berkeley) 06/08/93

.eh 'PS1:19-%''\*(Ln Appendix B' .bp .(x .b "Appendix B" .)x .nr $1 0 .sh 1 "The WINDOW structure" .pp The WINDOW structure is defined as follows: .(l I .so win_st.gr .)l .pp .Vn \*_cury \® .(f \** All variables not normally accessed directly by the user are named with an initial q \*_ to avoid conflicts with the user's variables. .)f and .Vn \*_curx are the current \*y for the window. New characters added to the screen are added at this point. .Vn \*_maxy and .Vn \*_maxx are the maximum values allowed for .Vn \*_cury\*,\*_curx ). ( .Vn \*_begy and .Vn \*_begx are the starting \*y on the terminal for the window, .i i.e. , the window's home. .Vn \*_cury , .Vn \*_curx , .Vn \*_maxy , and .Vn \*_maxx are measured relative to .Vn \*_begy\*,\*_begx ), ( not the terminal's home. .pp .Vn \*_clear tells if a clear-screen sequence is to be generated on the next .Fn refresh call. This is only meaningful for screens. The initial clear-screen for the first .Fn refresh call is generated by initially setting clear to be TRUE for .Vn curscr , which always generates a clear-screen if set, irrelevant of the dimensions of the window involved. .Vn \*_leave is TRUE if the current \*y and the cursor are to be left after the last character changed on the terminal, or not moved if there is no change. .Vn \*_scroll is TRUE if scrolling is allowed. .pp .Vn \*_y is a pointer to an array of lines which describe the terminal. Thus: .(l \*_y[i] .)l .lp is a pointer to the .Vn i th line, and .(l \*_y[i][j] .)l .lp is the .Vn j th character on the .Vn i th line. .Vn \*_flags can have one or more values or'd into it. .pp For windows that are not subwindows, .Vn \*_orig is NULL . For subwindows, it points to the main window to which the window is subsidiary. .Vn \*_nextp is a pointer in a circularly linked list of all the windows which are subwindows of the same main window, plus the main window itself. .pp .Vn \*_firstch and .Vn \*_lastch are .Fn malloc ed arrays which contain the index of the first and last changed characters on the line. .Vn \*_ch\*_off is the x offset for the window in the .Vn \*_firstch and .Vn \*_lastch arrays for this window. For main windows, this is always 0; for subwindows it is the difference between the starting point of the main window and that of the subindow, so that change markers can be set relative to the main window. This makes these markers global in scope. .pp All subwindows share the appropriate portions of .Vn _y , .Vn _firstch , .Vn _lastch , and .Vn _insdel with their main window. .pp .b \*_ENDLINE says that the end of the line for this window is also the end of a screen. .b \*_FULLWIN says that this window is a screen. .b \*_SCROLLWIN indicates that the last character of this screen is at the lower right-hand corner of the terminal; .i i.e. , if a character was put there, the terminal would scroll. .b \*_FULLLINE says that the width of a line is the same as the width of the terminal. If .b \*_FLUSH is set, it says that .Fn fflush "" "" stdout should be called at the end of each .Fn refresh .b \*_STANDOUT says that all characters added to the screen are in standout mode. .b \*_INSDEL is reserved for future use, and is set by .Fn idlok . .Vn \*_firstch is set to .b \*_NOCHANGE for lines on which there has been no change since the last .Fn refresh .