Update datetime

atoms.c

@@ -26,6 +26,7 @@ AtomValues atoms_create(Display *const dpy)
 	atom_values->netatom[NetWMWindowType] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False);
 	atom_values->netatom[NetWMWindowTypeDialog] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DIALOG", False);
 	atom_values->netatom[NetClientList] = XInternAtom(dpy, "_NET_CLIENT_LIST", False);
+	atom_values->netatom[NetDateTime] = XInternAtom(dpy, "_NET_DATE_TIME", False);
 
 	atom_values->xatom[Manager] = XInternAtom(dpy, "MANAGER", False);
 	atom_values->xatom[Xembed] = XInternAtom(dpy, "_XEMBED", False);

atoms.h

@@ -8,7 +8,7 @@ enum {
 	NetSupported, NetWMName, NetWMState, NetWMCheck, NetSystemTray,
 	NetSystemTrayOP, NetSystemTrayOrientation, NetSystemTrayOrientationHorz,
 	NetWMFullscreen, NetActiveWindow, NetWMWindowType, NetWMWindowTypeDialog,
-	NetClientList, NetLast,
+	NetClientList, NetDateTime, NetLast,
 };
 
 /* Xembed atoms */

datetime.c

@@ -1,10 +1,12 @@
 #include "datetime.h"
 
+#include "atoms.h"
+
 #include <pthread.h>
-#include <stdbool.h>
 #include <string.h>
 #include <time.h>
 #include <unistd.h>
+#include <X11/Xlib.h>
 
 #define BUFFER_SIZE 32
 
@@ -12,20 +14,33 @@ static void *run(void *vargp);
 
 static const char *const default_text = "date & time";
 
+static Display *display = None;
+static AtomValues atom_values = NULL;
 static bool running = true;
 static pthread_t thread;
 static pthread_mutex_t mutex;
 static char buffer[BUFFER_SIZE];
 
-void datetime_start()
+bool datetime_start()
 {
 	strcpy(buffer, default_text);
+
+	if ((display = XOpenDisplay(NULL)) == NULL) {
+		return false;
+	}
+
+	atom_values = atoms_create(display);
+
 	pthread_create(&thread, NULL, run, NULL);
+
+	return true;
 }
 
 void datetime_stop()
 {
 	running = false;
+	atoms_destroy(atom_values);
+	XCloseDisplay(display);
 	pthread_join(thread, NULL);
 }
 
@@ -41,6 +56,24 @@ void *run(void *vargp)
 		strftime(buffer, sizeof(buffer), "%a, %e %b %Y, %H:%M:%S", time_info);
 		datetime_unlock();
 
+		XEvent event;
+		memset(&event, 0, sizeof(event));
+		event.xclient.type = ClientMessage;
+		event.xclient.serial = 0;
+		event.xclient.send_event = True;
+		event.xclient.display = display; // TODO: was undefined in xclimsg
+		event.xclient.window = DefaultRootWindow(display);
+		event.xclient.message_type = atom_values->netatom[NetDateTime];
+		event.xclient.format = 32;
+		XSendEvent(
+			display,
+			event.xclient.window,
+			False,
+			SubstructureRedirectMask | SubstructureNotifyMask,
+			&event
+		);
+		XFlush(display);
+
 		sleep(1);
 	}
 

datetime.h

@@ -1,7 +1,9 @@
 #ifndef _DATETIME_H
 #define _DATETIME_H
 
-void datetime_start();
+#include <stdbool.h>
+
+bool datetime_start();
 void datetime_stop();
 
 void datetime_lock();

dwm.c

@@ -601,6 +601,12 @@ clientmessage(XEvent *e)
 		}
 		return;
 	}
+
+	if (cme->message_type == atom_values->netatom[NetDateTime]) {
+		updatestatus(); // TODO: maybe we need some filtering
+		return;
+	}
+
 	if (!c)
 		return;
 	if (cme->message_type == atom_values->netatom[NetWMState]) {
@@ -2476,7 +2482,8 @@ main(int argc, char *argv[])
 	if (!(dpy = XOpenDisplay(NULL)))
 		die("dwm: cannot open display");
 	checkotherwm();
-	datetime_start();
+	if (!datetime_start())
+		die("dwm: cannot start datetime service");
 	setup();
 #ifdef __OpenBSD__
 	if (pledge("stdio rpath proc exec", NULL) == -1)