Attempt to fix #62

ChangeLog

@@ -1,3 +1,14 @@
+2025-12-18 Richard Frith-Macdonald <[email protected]>
+
+	* Source/x11/XGServer.m:
+	* Source/x11/XGServerWindow.m:
+	If DESKTOP_STARTUP_ID environment variable is present, set it as the
+	_NET_STARTUP_ID property of the first window we make visible (to tell
+	the WM we are starting up) and, when launch completes, send a message
+	to the root window to tell it that startup is over.
+	This is an attempt to fix issue  #62 on github by implementing the
+	XDG startup notification mechanism.
+
 2025-05-21 Fred Kiefer <[email protected]>
 
 	* Source/x11/scale.c,

Source/x11/XGServer.m

@@ -382,6 +382,48 @@ + (Display *) xDisplay
   return [(XGServer*)GSCurrentServer() xDisplay];
 }
 
+static NSString	*startupID = nil;
+
+- (void) _didFinishLaunching: (NSNotification*)n
+{
+  /* To tell the window manager that we have completed launching we must
+   * send a _NET_STARTUP_INFO_END message telling it that startup has ended
+   * for the DESKTOP_STARTUP_ID (issue #62 on github)
+   */
+  if (startupID)
+    {
+      const char	*startup_id = [startupID UTF8String];
+      Window		root = RootWindow(dpy, defScreen);
+      Atom 		atom = XInternAtom(dpy, "_NET_STARTUP_INFO_END", False);
+      int		len = strlen(startup_id);
+      char 		*msg = malloc(len + 12);
+      int		pos = 0;
+
+      snprintf(msg, len+12, "remove: ID=%s", startup_id);
+      len = strlen(msg) + 1;
+
+      while (pos < len)
+	{
+	  int		chunk;
+	  XEvent	ev = {0};
+
+	  ev.xclient.type = ClientMessage;
+	  ev.xclient.window = root;
+	  ev.xclient.message_type = atom;
+	  ev.xclient.format = 8;
+
+	  chunk = (len - pos > 20) ? 20 : (len - pos);
+	  memcpy(ev.xclient.data.b, msg + pos, chunk);
+
+	  XSendEvent(dpy, root, False, PropertyChangeMask, &ev);
+	  pos += chunk;
+	}
+      XFlush(dpy);
+
+      DESTROY(startupID);
+    }
+}
+
 - (id) _initXContext
 {
   int screen_id, display_id;
@@ -490,6 +532,17 @@ - (id) initWithAttributes: (NSDictionary *)info
   [super initWithAttributes: info];
   [self _initXContext];
 
+  ASSIGN(startupID, [[[NSProcessInfo processInfo] environment]
+    objectForKey: @"DESKTOP_STARTUP_ID"]);
+  if (startupID)
+    {
+      [[NSNotificationCenter defaultCenter]
+	    addObserver: self
+	       selector: @selector(_didFinishLaunching:)
+		   name: NSApplicationDidFinishLaunchingNotification
+		 object: nil];
+    }
+
   [self setupRunLoopInputSourcesForMode: NSDefaultRunLoopMode]; 
   [self setupRunLoopInputSourcesForMode: NSConnectionReplyMode]; 
   [self setupRunLoopInputSourcesForMode: NSModalPanelRunLoopMode]; 

Source/x11/XGServerWindow.m

@@ -89,7 +89,7 @@
 static NSMapTable *windowtags = NULL;
 
 /* Track used window numbers */
-static int		last_win_num = 0;
+static int	last_win_num = 0;
 
 @interface NSCursor (BackendPrivate)
 - (void *)_cid;
@@ -1439,14 +1439,16 @@ - (void) _setupRootWindow
    * Set up standard atoms.
    */
 #ifdef HAVE_XINTERNATOMS
-   XInternAtoms(dpy, atom_names, sizeof(atom_names)/sizeof(char*),
-                False, generic.atoms);
+  XInternAtoms(dpy, atom_names, sizeof(atom_names)/sizeof(char*),
+    False, generic.atoms);
 #else
-   {
-     int atomCount;
+  {
+    int count;
 
-     for (atomCount = 0; atomCount < sizeof(atom_names)/sizeof(char*); atomCount++)
-       generic.atoms[atomCount] = XInternAtom(dpy, atom_names[atomCount], False);
+    for (count = 0; count < sizeof(atom_names)/sizeof(char*); count++)
+      {
+        generic.atoms[count] = XInternAtom(dpy, atom_names[count], False);
+      }
    }
 #endif
 
@@ -1580,9 +1582,9 @@ - (void) _setupRootWindow
  * hold 64bit values.
  */
     XChangeProperty(dpy, ROOT,
-                    generic._GNUSTEP_WM_ATTR_ATOM, generic._GNUSTEP_WM_ATTR_ATOM,
-                    32, PropModeReplace, (unsigned char *)&win_attrs,
-                    sizeof(GNUstepWMAttributes)/sizeof(CARD32));
+      generic._GNUSTEP_WM_ATTR_ATOM, generic._GNUSTEP_WM_ATTR_ATOM,
+      32, PropModeReplace, (unsigned char *)&win_attrs,
+      sizeof(GNUstepWMAttributes)/sizeof(CARD32));
   }
 
   if ((generic.wm & XGWM_EWMH) != 0)
@@ -1595,12 +1597,13 @@ - (void) _setupRootWindow
  * hold 64bit values.
  */
       XChangeProperty(dpy, ROOT,
-		      generic._NET_WM_PID_ATOM, XA_CARDINAL,
-		      32, PropModeReplace,
-		      (unsigned char*)&pid, 1);
+	generic._NET_WM_PID_ATOM, XA_CARDINAL,
+	32, PropModeReplace,
+	(unsigned char*)&pid, 1);
       // FIXME: Need to set WM_CLIENT_MACHINE as well.
     }
 
+
   /* We need to determine the offsets between the actual decorated window
    * and the window we draw into.
    */
@@ -1632,9 +1635,9 @@ - (void) _setupRootWindow
         }
       else
         {
-          offsets = (uint16_t *)PropGetCheckProperty(dpy, DefaultRootWindow(dpy),
-                                                     generic._GNUSTEP_FRAME_OFFSETS_ATOM,
-                                                     XA_CARDINAL, 16, 60, &count);
+          offsets = (uint16_t *)PropGetCheckProperty(dpy,
+	    DefaultRootWindow(dpy), generic._GNUSTEP_FRAME_OFFSETS_ATOM,
+	    XA_CARDINAL, 16, 60, &count);
         }
 
       if (offsets == 0)
@@ -1924,6 +1927,7 @@ - (int) window: (NSRect)frame : (NSBackingStoreType)type : (unsigned int)style
    * It could be done for popup windows, but at this point we don't know
    * about the usage of the window.
    */
+
   window->xwn_attrs.override_redirect = False;
 
   window->ident = XCreateWindow(dpy, window->root,
@@ -2869,6 +2873,37 @@ - (void) orderwindow: (int)op : (int)otherWin : (int)winNum
 
   if (op != NSWindowOut)
     {
+      static BOOL	beenHere = NO;
+
+      /* To tell the window manager that our window corresponds to
+       * a particular task we must pass it the DESKTOP_STARTUP_ID
+       * by setting it as a property of the first toplevel window
+       * made visible.
+       * (issue #62 on github)
+       */
+      if (NO == beenHere)
+	{
+	  NSProcessInfo	*p = [NSProcessInfo processInfo];
+	  NSDictionary	*e = [p environment];
+	  NSString	*s = [e objectForKey: @"DESKTOP_STARTUP_ID"];
+
+	  beenHere = YES;
+	  if ([s length] > 0)
+	    {
+	      const char	*ptr = [s UTF8String];
+
+	      XChangeProperty(dpy, window->ident,
+		XInternAtom(dpy, "_NET_STARTUP_ID", False),
+		generic.UTF8_STRING_ATOM,
+		8,
+		PropModeReplace,
+		(unsigned char *)ptr,
+		strlen(ptr)
+	      );
+	      [p setValue: nil inEnvironment: @"DESKTOP_STARTUP_ID"];
+	    }
+	}
+
       /*
        * Some window managers ignore any hints and properties until the
        * window is actually mapped, so we need to set them all up