new experimental updategeom() additions that should avoid several problems with Xiner...

diff --git a/dwm.c b/dwm.c
index 1cb07d3..2b4d6b0 100644 (file)
--- a/dwm.c
+++ b/dwm.c
@@ -221,7 +221,7 @@ static void toggleview(const Arg *arg);
 static void unfocus(Client *c);
 static void unmanage(Client *c, Bool destroyed);
 static void unmapnotify(XEvent *e);
-static void updategeom(void);
+static Bool updategeom(void);
 static void updatebarpos(Monitor *m);
 static void updatebars(void);
 static void updatenumlockmask(void);
@@ -535,14 +535,15 @@ configurenotify(XEvent *e) {
        if(ev->window == root) {
                sw = ev->width;
                sh = ev->height;
-               updategeom();
-               if(dc.drawable != 0)
-                       XFreePixmap(dpy, dc.drawable);
-               dc.drawable = XCreatePixmap(dpy, root, sw, bh, DefaultDepth(dpy, screen));
-               updatebars();
-               for(m = mons; m; m = m->next)
-                       XMoveResizeWindow(dpy, m->barwin, m->wx, m->by, m->ww, bh);
-               arrange();
+               if(updategeom()) {
+                       if(dc.drawable != 0)
+                               XFreePixmap(dpy, dc.drawable);
+                       dc.drawable = XCreatePixmap(dpy, root, sw, bh, DefaultDepth(dpy, screen));
+                       updatebars();
+                       for(m = mons; m; m = m->next)
+                               XMoveResizeWindow(dpy, m->barwin, m->wx, m->by, m->ww, bh);
+                       arrange();
+               }
        }
 }
 
@@ -1692,26 +1693,73 @@ updatebarpos(Monitor *m) {
                m->by = -bh;
 }
 
-void
+Bool
 updategeom(void) {
-       int i, n = 1;
+       int i, j, nn = 1, n = 1;
        Client *c;
        Monitor *newmons = NULL, *m = NULL, *tm;
 
 #ifdef XINERAMA
-       int nn;
        XineramaScreenInfo *info = NULL;
+       Bool *flags = NULL;
 
        if(XineramaIsActive(dpy))
                info = XineramaQueryScreens(dpy, &n);
-       for(i = 1, nn = n; i < n; i++)
-               if(info[i - 1].x_org == info[i].x_org && info[i - 1].y_org == info[i].y_org
-               && info[i - 1].width == info[i].width && info[i - 1].height == info[i].height)
-                       --nn;
-       n = nn; /* we only consider unique geometries as separate screens */
+       flags = (Bool *)malloc(sizeof(Bool) * n);
+       for(i = 0; i < n; i++)
+               flags[i] = False;
+       /* next double-loop seeks any combination of retrieved Xinerama info
+        * with existing monitors, this is used to avoid unnecessary
+        * re-allocations of monitor structs */
+       for(i = 0, nn = n; i < n; i++)
+               for(j = 0, m = mons; m; m = m->next, j++)
+                       if(!flags[j]) {
+                               if((flags[j] = (
+                                       info[i].x_org == m->mx
+                                       && info[i].y_org == m->my
+                                       && info[i].width == m->mw
+                                       && info[i].height == m->mh)
+                               ))
+                                       --nn;
+                       }
+       if(nn == 0) { /* no need to re-allocate monitors */
+               j = 0;
+               for(i = 0, m = mons; m; m = m->next, i++) {
+                       m->num = info[i].screen_number;
+                       if(info[i].x_org != m->mx
+                       || info[i].y_org != m->my
+                       || info[i].width != m->mw
+                       || info[i].height != m->mh)
+                       {
+                               m->mx = m->wx = info[i].x_org;
+                               m->my = m->wy = info[i].y_org;
+                               m->mw = m->ww = info[i].width;
+                               m->mh = m->wh = info[i].height;
+                               updatebarpos(m);
+                               j++;
+                       }
+               }
+               XFree(info);
+               free(flags);
+               return j > 0;
+       }
+       /* next algorithm only considers unique geometries as separate screens */
+       for(i = 0; i < n; i++)
+               flags[i] = False; /* used for ignoring certain monitors */
+       for(i = 0, nn = n; i < n; i++)
+               for(j = 0; j < n; j++)
+                       if(i != j && !flags[i]) {
+                               if((flags[i] = (
+                                       info[i].x_org == info[j].x_org
+                                       && info[i].y_org == info[j].y_org
+                                       && info[i].width == info[j].width
+                                       && info[i].height == info[j].height)
+                               ))
+                                       --nn;
+                       }
 #endif /* XINERAMA */
        /* allocate monitor(s) for the new geometry setup */
-       for(i = 0; i < n; i++) {
+       for(i = 0; i < nn; i++) {
                if(!(m = (Monitor *)malloc(sizeof(Monitor))))
                        die("fatal: could not malloc() %u bytes\n", sizeof(Monitor));
                m->next = newmons;
@@ -1720,14 +1768,18 @@ updategeom(void) {
        /* initialise monitor(s) */
 #ifdef XINERAMA
        if(XineramaIsActive(dpy)) {
-               for(i = 0, m = newmons; m; m = m->next, i++) {
-                       m->num = info[i].screen_number;
-                       m->mx = m->wx = info[i].x_org;
-                       m->my = m->wy = info[i].y_org;
-                       m->mw = m->ww = info[i].width;
-                       m->mh = m->wh = info[i].height;
+               for(i = 0, m = newmons; m && i < n; i++) {
+                       if(!flags[i]) { /* only use screens that aren't dublettes */
+                               m->num = info[i].screen_number;
+                               m->mx = m->wx = info[i].x_org;
+                               m->my = m->wy = info[i].y_org;
+                               m->mw = m->ww = info[i].width;
+                               m->mh = m->wh = info[i].height;
+                               m = m->next;
+                       }
                }
                XFree(info);
+               free(flags);
        }
        else
 #endif /* XINERAMA */
@@ -1767,6 +1819,7 @@ updategeom(void) {
        cleanupmons();
        selmon = mons = newmons;
        selmon = wintomon(root);
+       return True;
 }
 
 void