--- HELLO.C START --- /* HelloX.C ======== (c) Copyright Paul Griffiths 1999 Email: paulgriffiths@cwcom.net "Hello, World!", X Window System style. */ #include #include #include #include #include #include #include /* Global variables */ Display * display; int screen_num; static char * appname; /* main() function */ int main( int argc, char * argv[] ) { /* Window variables */ Window win; int x, y; unsigned int width, height; unsigned int border_width; char * window_name = "Hello, X Window System!"; char * icon_name = "HelloX"; /* Display variables */ char * display_name = NULL; unsigned int display_width, display_height; /* Miscellaneous X variables */ XSizeHints * size_hints; XWMHints * wm_hints; XClassHint * class_hints; XTextProperty windowName, iconName; XEvent report; XFontStruct * font_info; XGCValues values; GC gc; appname = argv[0]; /* Allocate memory for our structures */ if ( !( size_hints = XAllocSizeHints() ) || !( wm_hints = XAllocWMHints() ) || !( class_hints = XAllocClassHint() ) ) { fprintf(stderr, "%s: couldn't allocate memory.\n", appname); exit(EXIT_FAILURE); } /* Connect to X server */ if ( (display = XOpenDisplay(display_name)) == NULL ) { fprintf(stderr, "%s: couldn't connect to X server %s\n", appname, display_name); exit(EXIT_FAILURE); } /* Get screen size from display structure macro */ screen_num = DefaultScreen(display); display_width = DisplayWidth(display, screen_num); display_height = DisplayHeight(display, screen_num); /* Set initial window size and position, and create it */ x = y = 0; width = display_width / 3; height = display_width / 3; win = XCreateSimpleWindow(display, RootWindow(display, screen_num), x, y, width, height, border_width, BlackPixel(display, screen_num), WhitePixel(display, screen_num)); /* Set hints for window manager before mapping window */ if ( XStringListToTextProperty(&window_name, 1, &windowName) == 0 ) { fprintf(stderr, "%s: structure allocation for windowName failed.\n", appname); exit(EXIT_FAILURE); } if ( XStringListToTextProperty(&icon_name, 1, &iconName) == 0 ) { fprintf(stderr, "%s: structure allocation for iconName failed.\n", appname); exit(EXIT_FAILURE); } size_hints->flags = PPosition | PSize | PMinSize; size_hints->min_width = 200; size_hints->min_height = 100; wm_hints->flags = StateHint | InputHint; wm_hints->initial_state = NormalState; wm_hints->input = True; class_hints->res_name = appname; class_hints->res_class = "hellox"; XSetWMProperties(display, win, &windowName, &iconName, argv, argc, size_hints, wm_hints, class_hints); /* Choose which events we want to handle */ XSelectInput(display, win, ExposureMask | KeyPressMask | ButtonPressMask | StructureNotifyMask); /* Load a font called "9x15" */ if ( (font_info = XLoadQueryFont(display, "9x15")) == NULL ) { fprintf(stderr, "%s: cannot open 9x15 font.\n", appname); exit(EXIT_FAILURE); } /* Create graphics context */ gc = XCreateGC(display, win, 0, &values); XSetFont(display, gc, font_info->fid); XSetForeground(display, gc, BlackPixel(display, screen_num)); /* Display Window */ XMapWindow(display, win); /* Enter event loop */ while ( 1 ) { static char * message = "Hello, X Window System!"; static int length; static int font_height; static int msg_x, msg_y; XNextEvent(display, &report); switch ( report.type ) { case Expose: if ( report.xexpose.count != 0 ) break; /* Output message centrally in window */ length = XTextWidth(font_info, message, strlen(message)); msg_x = (width - length) / 2; font_height = font_info->ascent + font_info->descent; msg_y = (height + font_height) / 2; XDrawString(display, win, gc, msg_x, msg_y, message, strlen(message)); break; case ConfigureNotify: /* Store new window width & height */ width = report.xconfigure.width; height = report.xconfigure.height; break; case ButtonPress: /* Fall through */ case KeyPress: /* Clean up and exit */ XUnloadFont(display, font_info->fid); XFreeGC(display, gc); XCloseDisplay(display); exit(EXIT_SUCCESS); } } return EXIT_SUCCESS; /* We shouldn't get here */ } --- HELLO.C END --- --- Makefile START --- HelloX: HelloX.o gcc -o HelloX HelloX.o -Wall -L/usr/X11R6/lib -lX11 HelloX.o: HelloX.c gcc -o HelloX.o HelloX.c -c -ansi -pedantic -Wall --- Makefile END ---