Re: [Fwd: FW: Problems with pads]

[jonw]

Hi Morris;

I am relatively new to pads with ncurses, but the problem you describe is
similar to something I just dealt with.  If I understand your situation, you
would like to display both the string in the pad and outside of the pad at
the same time, without the pad message being deleted.  I found that calling
refresh at initialization time causes alot of unexpected behaviour to go
away.  Two points BTW;

1. The man page for ripoffline states;

Inside this initialization routine, the integer variables LINES and COLS
(defined  in  <curses.h>)  are  not guaranteed  to be accurate and wrefresh
or doupdate must not be called.  It is allowable to call wnoutrefresh during
the initialization routine.

I did call wrefresh inside the init routine and it did seem to work.

2.  I did use libncurses-5.3 so the problem you are experiencing may be
version related.

Here is the modified program;

#include <stdio.h>
#include <stdlib.h>
#include <ncurses/curses.h> /* ensure ncurses is being used, jonw */

WINDOW * pad, * line;

static void curses_close( void )
{
  clear(); refresh(); endwin();
}
static int do_line( WINDOW * w, int cols )
{
  line = w;
  waddstr( w, "Rip off!" );
  wrefresh( line );  // This causes an end to all keyboard input
/* worked for me, jonw */
  return 0;
}
int
main( int argc, char ** argv )
{
  ripoffline( 1, do_line );
  initscr();
  cbreak();
  noecho();
  refresh( ); /* this seems to always help, jonw */
  atexit( curses_close );
  // Refresh the ripped-off line.  This causes an end to all keyboard
  // input if placed in do_line()
  // wrefresh( line );

  pad = newpad( 100, 100 );
  //trace( TRACE_MAXIMUM );

  // Write some text into the pad and display it. pnoutrefresh does
  // nothing so use prefresh instead
  mvwaddstr( pad, 3, 3, "Text in pad added with mvwaddstr" );
  prefresh( pad, 0,0,0,0,10,60 );

  // Wait for input.  If this is just getch(), pad text does not appear.
  getch( ); /* pad test appeared for me, jonw */
  //wgetch( line );

  // Add some text ouside the pad view area.  Pad text now disappears!
  /* pad text did not disappear, I hope this is what you want William, jonw
*/
  move( 12, 12 );
  addstr( "Text in main area added with addstr" );
  getch();

  // Put the pad text back.  Now we have both text areas!
/* yes, I agree, jonw */
  // (pnotrefresh() does nothing here)
  prefresh( pad, 0,0,0,0,10,60 );

  // getch() doesn't obliterate pad this time.
  getch();
  return 0;
}

Hope this helps.  It all depends if I understood your situation.  Let me know
how well it worked for you.

Thanks,
jonw


> -----Original Message-----
> From: address@hidden
> [mailto:address@hidden Behalf Of
> Morris, William
> Sent: December 17, 2002 6:09 AM
> To: address@hidden
> Subject: Problems with pads
>
> Hello
>
> Can anyone put me right in the use of "pads"?
>
> I added a pad to a program which needs to show a portion of some data.
> The data in the pad never appeared.  So I have the simple code below
> which tries to make a pad do what I expect.  The comments in the code
> explain what happens.  I would like to be able to:
>
>  1. get input from the main window or other windows
>  2. use addstr/waddstr (and variants) to add to areas inside and outside
>     the pad view area.
>
> I'm running QNX6.2 (realtime OS with POSIX features) curses version-5.2.
> I tried compiling up the 5.3 release.  The library (libncurses.a)
> compiled, but other components failed.  After compiling/linking against
> the 5.3 library, text strings were printed in a garbled fashion and the
> pad text appeared in the rip-off line.
>
> Thanks in advance
> William Morris
>
> -------------------------------------
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <curses.h>
>
> WINDOW * pad, * line;
>
> static void curses_close( void )
> {
>   clear(); refresh(); endwin();
> }
> static int do_line( WINDOW * w, int cols )
> {
>   line = w;
>   waddstr( w, "Rip off!" );
>   //wrefresh( line );  This causes an end to all keyboard input
>   return 0;
> }
> int
> main( int argc, char ** argv )
> {
>   ripoffline( 1, do_line );
>   initscr();
>   cbreak();
>   noecho();
>   atexit( curses_close );
>   // Refresh the ripped-off line.  This causes an end to all keyboard
>   // input if placed in do_line()
>   wrefresh( line );
>
>   pad = newpad( 100, 100 );
>   //trace( TRACE_MAXIMUM );
>
>   // Write some text into the pad and display it. pnoutrefresh does
>   // nothing so use prefresh instead
>   mvwaddstr( pad, 3, 3, "Text in pad added with mvwaddstr" );
>   prefresh( pad, 0,0,0,0,10,60 );
>
>   // Wait for input.  If this is just getch(), pad text does not appear.
>   wgetch( line );
>   // getch();
>
>   // Add some text ouside the pad view area.  Pad text now disappears!
>   move( 12, 12 );
>   addstr( "Text in main area added with addstr" );
>   getch();
>
>   // Put the pad text back.  Now we have both text areas!
>   // (pnotrefresh() does nothing here)
>   prefresh( pad, 0,0,0,0,10,60 );
>
>   // getch() doesn't obliterate pad this time.
>   getch();
>   return 0;
> }
>
> ---
> William Morris
> address@hidden
>
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