phr@anuck.UUCP (12/04/87)
I need help from people who have used Curses and are familiar with
terminfo. Recently I have been using curses and have noted some
strange behavior. I am not sure if the problems represent "features"
of curses or are indicating that I am using curses incorrectly. Any
help on the following is appreciated.
1. I have noticed that cursors can not create a box around a window
which is the size of the entire screen. The last row, last column
position remains "unboxed".
2. The screen cursor often flickers across the screen as I enter
text when using getstr or getch. This flickering seems to be
worse if I have used reverse video for displaying any text or boxes
on the screen.
3. If I define a boxed window, with a reverse video border, which starts
in column 2 of the screen, the border appears in column 1 and 2, except
for the very first row and column which does not contain the border.
Has anyone else experienced this strange behavior with Curses? Is it a
problem with the tool or with the application using curses?
Thanks for any suggestions.
L. Hilliard
8-245-4595
MV 3E-11
anuck!phr or mvuxn!lah
allbery@ncoast.UUCP (Brandon Allbery) (12/08/87)
As quoted from <409@anuck.UUCP> by phr@anuck.UUCP (p.h.reed): +--------------- | 1. I have noticed that cursors can not create a box around a window | which is the size of the entire screen. The last row, last column | position remains "unboxed". +--------------- Curses won't write that last column, since most terminals will scroll the first line off the screen if it does. See also #3. +--------------- | 2. The screen cursor often flickers across the screen as I enter | text when using getstr or getch. This flickering seems to be | worse if I have used reverse video for displaying any text or boxes | on the screen. +--------------- Especially when screen attributes are used, refresh() does some fancy repainting when only a single character is being updated. V.3 terminfo has a call "echochar()" which avoids this in many cases. +--------------- | 3. If I define a boxed window, with a reverse video border, which starts | in column 2 of the screen, the border appears in column 1 and 2, except | for the very first row and column which does not contain the border. +--------------- Sounds like it might be a problem with your terminfo description. Check the description; if displaying a character in the last column of the screen makes the cursor move to the next line, you should add the "am" boolean to the description and re-"tic" it. I have a bug to report in V.3 terminfo; maybe someone else already knows about it, but.... The bug is that wsetscrreg() doesn't check to insure that its arguments are in range. If they aren't, curses won't scroll; moreover, the cursor will move outside the window when attempting to scroll. (It doesn't display anything, but the window's cursor ends up *outside* the window.) The fix: since wsetscrreg() is a macro, anyone (including binary sites) can change it. The values to be set should be tested against 0 and (w)->_maxy, and also checked so that the second value is >= the first. -- Brandon S. Allbery necntc!ncoast!allbery@harvard.harvard.edu {hoptoad,harvard!necntc,cbosgd,sun!mandrill!hal,uunet!hnsurg3}!ncoast!allbery Moderator of comp.sources.misc