Correction de efface.c
/* a chaque clic, affiche la position du Button presse, la precedente est
effacee */
#include <stdio.h>
#include <X11/Xlib.h>
GC gc;
Display *display;
int screen;
Window win, root;
unsigned long white_pixel, black_pixel;
char buf[100];
main() {
if ((display = XOpenDisplay ("")) == NULL) {
fprintf (stderr, "Can't open Display\n");
exit (1);
}
gc = DefaultGC (display, screen);
screen = DefaultScreen (display);
root = RootWindow (display, screen);
white_pixel = WhitePixel (display, screen);
black_pixel = BlackPixel (display, screen);
win = XCreateSimpleWindow (display, root,
0, 0, 200, 150, 2, black_pixel, white_pixel);
XSelectInput (display, win, ExposureMask | ButtonPressMask);
XStoreName (display, win, "efface");
XMapWindow (display, win);
for (;;) {
XEvent ev;
XNextEvent (display, &ev);
switch (ev.type) {
case Expose :
XDrawString (display, win, gc, 10, 30, "coucou !", 8);
break;
case ButtonPress :
XClearWindow (display, win);
XDrawString (display, win, gc, 10, 30, "coucou !", 8);
sprintf(buf,"x=%3d,y=%3d", ev.xbutton.x, ev.xbutton.y);
XDrawString (display, win, gc, ev.xbutton.x, ev.xbutton.y,
buf, strlen(buf));
break;
default :
break;
}
}
}