add an obscured flag that tracks if the frame is at all obscured

openbox/event.c

@@ -621,6 +621,9 @@ static void event_handle_client(ObClient *client, XEvent *e)
     ObFrameContext con;
      
     switch (e->type) {
+    case VisibilityNotify:
+        client->frame->obscured = e->xvisibility.state != VisibilityUnobscured;
+        break;
     case ButtonPress:
     case ButtonRelease:
         /* Wheel buttons don't draw because they are an instant click, so it

openbox/frame.c

@@ -8,7 +8,8 @@
 
 #define PLATE_EVENTMASK (SubstructureRedirectMask | ButtonPressMask)
 #define FRAME_EVENTMASK (EnterWindowMask | LeaveWindowMask | \
-                         ButtonPressMask | ButtonReleaseMask)
+                         ButtonPressMask | ButtonReleaseMask | \
+                         VisibilityChangeMask)
 #define ELEMENT_EVENTMASK (ButtonPressMask | ButtonReleaseMask | \
                            ButtonMotionMask | ExposureMask | \
                            EnterWindowMask | LeaveWindowMask)
@@ -36,6 +37,7 @@ ObFrame *frame_new()
     self = g_new(ObFrame, 1);
 
     self->visible = FALSE;
+    self->obscured = TRUE;
     self->decorations = 0;
 
     /* create all of the decor windows */

openbox/frame.h

@@ -54,6 +54,10 @@ struct _ObFrame
     Strut     size;
     Rect      area;
     gboolean  visible;
+
+    /*! Whether the window is obscured at all or fully visible. */
+    gboolean obscured;
+
     guint     decorations;
 
     Window    title;