Data update

Task/Draw-a-pixel/C/draw-a-pixel-2.c

@@ -0,0 +1,71 @@
+// dotrosetta.c - https://rosettacode.org/wiki/Draw_a_pixel
+
+#include <X11/Xutil.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+int
+main(void)
+	{
+	Atom wm_both_protocols[1];
+	Atom wm_delete;
+	Atom wm_protocols;
+	Display *display;
+	GC gc;
+	Window root;
+	Window window;
+	XEvent event;
+	XSetWindowAttributes attr;
+	int more = 1;
+
+	display = XOpenDisplay(NULL);
+	if(display == NULL)
+		{
+		fprintf(stderr,"Error: The display cannot be opened\n");
+		exit(1);
+		}
+	root = DefaultRootWindow(display);
+	wm_delete = XInternAtom(display, "WM_DELETE_WINDOW", False);
+	wm_protocols = XInternAtom(display, "WM_PROTOCOLS", False);
+	attr.background_pixel = 0x000000;
+	attr.event_mask = ExposureMask;
+	window = XCreateWindow(display, root,
+		0, 0, 320, 240, 0,
+		CopyFromParent, InputOutput, CopyFromParent,
+		CWBackPixel | CWEventMask,
+		&attr
+		);
+	XStoreName(display, window, "Draw a Pixel");
+	wm_both_protocols[0] = wm_delete;
+	XSetWMProtocols(display, window, wm_both_protocols, 1);
+	gc = XCreateGC(display, window, 0, NULL);
+	XSetForeground(display, gc, 0xFF0000);
+	XMapWindow(display, window);
+
+	while(more)
+		{
+		XNextEvent(display, &event);
+		switch(event.type)
+			{
+		case Expose:
+			XDrawPoint(display, window, gc, 100, 100);
+			break;
+
+		case ClientMessage: // for close request from WM
+			if(event.xclient.window == window &&
+				event.xclient.message_type == wm_protocols &&
+				event.xclient.format == 32 &&
+				event.xclient.data.l[0] == wm_delete)
+				{
+				more = 0;
+				}
+			break;
+
+		default:
+			printf("unexpected event.type %d\n", event.type);;
+			}
+		}
+
+	XCloseDisplay(display);
+	exit(0);
+	}