Device busy problem

[Haseen I. Alam]

I am relatively new in SunView environment.  I wrote a program to do edge
linking on Unix systems in C.  Next I added three procedures called
open_display, put_pixel, and close_display.  open_display is passed in the
x and y dimensions and it opens up a window of that size.  put_pixel is
passed in the x,y coordinates and a gray level value.  I use this same
procedure to turn pixels on and off.  Then at the end I call close_display
to close the display window.  At some point or other I would like to port
this program to X-windows as well.

These procedures are defined in a file (included below) that I link via
makefile with my actual program.  Everything works fine, almost!  One
problem is if I open up aother window that overlaps the display window,
then it does not refresh anymore.  The other problem is serious: at the
end of the program it pops up a little dialog box saying "Use left button
to quit" (something similar to that).  If by mistake I use any of the
other two buttons then I get a DEVICE BUSY error. then I either have to
use CTRL-C or pull down a menu from the title bar and exit.  Also I saw a
call that I can add to bring the display window in front of all the other
windows at the end, but I forgot its name.  May be someone can point me in
the right direction.  My edge linking program does a lot of calculations
to enhance, detect and link the edges.  Everytime it finds a decent edge
that it wants to write out, It will call put_pixel to do so.  This shows
the actual linking on screen as it is done.  But depending on the
complexity of the edge and the noise level, the calls to draw to
consecutive edges may have some time gap when I do a lot of computation
but no sunview calls to refresh the screen.  Do I need to do that myself?
or is there a way that will auto refresh after some time interval till I
quit the program?

I would appreciate if any kind soul will help me with the above mentioned
problems of (1) window refresh, (2) Device busy error, (3) making it the
top most window at the end, and (4) some code/pointer to implement the
above mentioned operations in X-windows.

 The code follows.  Thanks in advance.

 Haseen.

/* This is intdisp.c   note this is not a main program */

#include <suntool/sunview.h>
#include <suntool/canvas.h>

#define BUFSIZ 1024

Frame      base_frame ;
Canvas     canvas ;
Cursor     cursor ;
Pixwin    *pw, *fpw ;
Pixrect   *mem_create() ;
char       cmsname[BUFSIZ] ;
u_char     red[256], green[256], blue[256] ;
colormap_t colormap ;
int        X_size, Y_size;


static void canvas_event_proc() ;
void open_display () ;
void put_pixel () ;
void close_display () ;


void open_display (x,y)
    int x,y ;
{
    base_frame = window_create (NULL, FRAME,
				FRAME_LABEL,	"Display",
				WIN_HEIGHT,   y+20,
				WIN_WIDTH,    x+20,
				0 ) ;

    create_show_popup () ;
    window_set (base_frame,WIN_SHOW,TRUE,0) ;
    notify_dispatch () ;

    X_size = x ;
    Y_size = y ;

}

void close_display()
{
     window_destroy(base_frame);
     window_main_loop(base_frame);
}


create_show_popup()
{
        setup_colourmap();
	cursor = cursor_create(
		    CURSOR_OP, PIX_SRC ^ PIX_DST,
		    CURSOR_CROSSHAIR_LENGTH, 20,
		    CURSOR_SHOW_CROSSHAIRS, TRUE,0);
	canvas = window_create(base_frame, CANVAS,
		    WIN_CURSOR, cursor,
		    CANVAS_HEIGHT, 768,
		    CANVAS_WIDTH,  768,
		    CANVAS_AUTO_SHRINK, FALSE,
		    WIN_EVENT_PROC,  canvas_event_proc,
		    WIN_CONSUME_PICK_EVENT, WIN_IN_TRANSIT_EVENTS,
		    0);
	pw = canvas_pixwin(canvas);

}



setup_colourmap()
{
	register int i;

	for (i = 0; i < 256; i++) {
		red[i] = green[i] = blue[i] = -1;
	}
	fpw = (Pixwin *) window_get(base_frame, WIN_PIXWIN);

	if (colormap.type == RMT_NONE || colormap.length == 0) {
		sprintf(cmsname, "greyscale%d", 8);

		pw_setcmsname(fpw, cmsname);

		for (i = 1; i < 255; i++) {
			red[i] = i;
			green[i] = i;
			blue[i] = i;
		}
		pw_putcolormap(fpw, 0, 256, red, green, blue);
	}
	window_set(base_frame, FRAME_INHERIT_COLORS, TRUE, 0);
}


static void canvas_event_proc (canvas, event, arg)
	Canvas  canvas;
	Event  *event;
	caddr_t arg;
{
    ;
}

void put_pixel(x,y,value)
    int x,y,value;
{
    pw_put(pw,x,y,value);
    notify_dispatch();
}