@@ -26,13 +26,13 @@ openbox3_SOURCES=parse.tab.c parse.lex.c action.c client.c config.c \
                  extensions.c focus.c frame.c grab.c menu.c menu_render.c \
                  openbox.c framerender.c parse.c plugin.c prop.c screen.c \
                  stacking.c dispatch.c event.c group.c timer.c xerror.c \
-                 moveresize.c startup.c popup.c slit.c
+                 moveresize.c startup.c popup.c slit.c window.c
 
 noinst_HEADERS=action.h client.h config.h dispatch.h event.h extensions.h \
                focus.h frame.h framerender.h geom.h gettext.h grab.h group.h \
                menu.h openbox.h parse.h parse.tab.h plugin.h prop.h screen.h \
                stacking.h timer.h xerror.h moveresize.h startup.h popup.h \
-               slit.h
+               slit.h window.h
 
 # kill the implicit .c.y rule
 %.c: %.y

@@ -222,14 +222,14 @@ void action_focusraise(union ActionData *data)
 {
     if (data->client.c) {
         client_focus(data->client.c);
-        stacking_raise(data->client.c);
+        stacking_raise(CLIENT_AS_WINDOW(data->client.c));
     }
 }
 
 void action_raise(union ActionData *data)
 {
     if (data->client.c)
-        stacking_raise(data->client.c);
+        stacking_raise(CLIENT_AS_WINDOW(data->client.c));
 }
 
 void action_unshaderaise(union ActionData *data)
@@ -238,7 +238,7 @@ if (data->client.c) {
         if (data->client.c->shaded)
             client_shade(data->client.c, FALSE);
         else
-            stacking_raise(data->client.c);
+            stacking_raise(CLIENT_AS_WINDOW(data->client.c));
     }
 }
 
@@ -246,7 +246,7 @@ void action_shadelower(union ActionData *data)
 {
     if (data->client.c) {
         if (data->client.c->shaded)
-            stacking_lower(data->client.c);
+            stacking_lower(CLIENT_AS_WINDOW(data->client.c));
         else
             client_shade(data->client.c, TRUE);
     }
@@ -255,7 +255,7 @@ 
 void action_lower(union ActionData *data)
 {
     if (data->client.c)
-        stacking_lower(data->client.c);
+        stacking_lower(CLIENT_AS_WINDOW(data->client.c));
 }
 
 void action_close(union ActionData *data)

@@ -158,7 +158,7 @@ Client *c;
 
         w = startup_stack_order[i-1];
         c = g_hash_table_lookup(client_map, &w);
-        if (c) stacking_lower(c);
+        if (c) stacking_lower(CLIENT_AS_WINDOW(c));
     }
     g_free(startup_stack_order);
     startup_stack_order = NULL;
@@ -222,6 +222,7 @@ 
     /* create the Client struct, and populate it from the hints on the
        window */
     self = g_new(Client, 1);
+    self->obwin.type = Window_Client;
     self->window = window;
     client_get_all(self);
 
@@ -242,14 +243,14 @@ 
     grab_server(FALSE);
      
     client_list = g_list_append(client_list, self);
-    stacking_list = g_list_append(stacking_list, self);
+    stacking_add(self);
     g_assert(!g_hash_table_lookup(client_map, &self->window));
     g_hash_table_insert(client_map, &self->window, self);
 
     /* update the focus lists */
     focus_order_add_new(self);
 
-    stacking_raise(self);
+    stacking_raise(CLIENT_AS_WINDOW(self));
 
     screen_update_struts();
 
@@ -336,7 +337,7 @@ 
     frame_hide(self->frame);
 
     client_list = g_list_remove(client_list, self);
-    stacking_list = g_list_remove(stacking_list, self);
+    stacking_remove(self);
     g_hash_table_remove(client_map, &self->window);
 
     /* update the focus lists */
@@ -1455,8 +1456,7 @@ static StackLayer calc_layer(Client *self)
 {
     StackLayer l;
 
-    if (self->iconic) l = Layer_Icon;
-    else if (self->fullscreen) l = Layer_Fullscreen;
+    if (self->fullscreen) l = Layer_Fullscreen;
     else if (self->type == Type_Desktop) l = Layer_Desktop;
     else if (self->type == Type_Dock) {
         if (!self->below) l = Layer_Top;
@@ -1484,7 +1484,7 @@ calc_recursive(it->data, orig, l, raised ? raised : l != old);
 
     if (!raised && l != old)
 	if (orig->frame) /* only restack if the original window is managed */
-	    stacking_raise(self);
+	    stacking_raise(CLIENT_AS_WINDOW(self));
 }
 
 void client_calc_layer(Client *self)
@@ -2028,7 +2028,7 @@ if (!donthide)
         client_showhide(self);
     /* raise if it was not already on the desktop */
     if (old != DESKTOP_ALL)
-        stacking_raise(self);
+        stacking_raise(CLIENT_AS_WINDOW(self));
     screen_update_struts();
 
     /* add to the new desktop(s) */
@@ -2310,7 +2310,7 @@ return;
     if (self->shaded)
         client_shade(self, FALSE);
     client_focus(self);
-    stacking_raise(self);
+    stacking_raise(CLIENT_AS_WINDOW(self));
 }
 
 gboolean client_focused(Client *self)

@@ -110,6 +110,8 @@ } Decoration;
 
 
 typedef struct Client {
+    ObWindow obwin;
+
     Window  window;
 
     /*! The window's decorations. NULL while the window is being managed! */

@@ -13,6 +13,8 @@ /*! Focus the last focused window as a fallback when switching desktops */
 extern gboolean config_focus_last_on_desktop;
 /*! Show a popup dialog while cycling focus */
 extern gboolean config_focus_popup;
+/*! The number of slits to create */
+extern int config_slit_number;
 
 /* The name of the theme */
 char *config_theme;

@@ -916,6 +916,8 @@ 
 static void event_handle_slit(Slit *s, XEvent *e)
 {
     switch (e->type) {
+    case ButtonPress:
+        stacking_raise(SLIT_AS_WINDOW(s));
     case EnterNotify:
         slit_hide(s, FALSE);
         break;

@@ -40,8 +40,7 @@ focus_backup = XCreateWindow(ob_display, ob_root,
 				 -100, -100, 1, 1, 0,
                                  CopyFromParent, InputOutput, CopyFromParent,
                                  CWOverrideRedirect, &attrib);
-    XMapWindow(ob_display, focus_backup);
-    stacking_raise_internal(focus_backup);
+    XMapRaised(ob_display, focus_backup);
 
     /* start with nothing focused */
     focus_set_client(NULL);

@@ -154,6 +154,7 @@ XSetWindowAttributes attrib;
     Menu *self;
 
     self = g_new0(Menu, 1);
+    self->obwin.type = Window_Menu;
     self->label = g_strdup(label);
     self->name = g_strdup(name);
     self->parent = parent;
@@ -350,7 +351,9 @@ MIN(x, screen_physical_size.width - self->size.width),
 	      MIN(y, screen_physical_size.height - self->size.height));
 
     if (!self->shown) {
-	stacking_raise_internal(self->frame);
+        /* XXX gotta add to the stacking list first!
+           stacking_raise(MENU_AS_WINDOW(self));
+        */
 	XMapWindow(ob_display, self->frame);
 	self->shown = TRUE;
     } else if (self->shown && self->open_submenu) {

@@ -18,6 +18,8 @@ typedef void(*menu_controller_mouseover)(struct MenuEntry *self,
                                          gboolean enter);
 
 typedef struct Menu {
+    ObWindow obwin;
+
     char *label;
     char *name;
     

@@ -186,7 +186,6 @@ if (!theme) return 1;
 
         menu_startup();
         frame_startup();
-        stacking_startup();
         moveresize_startup();
 	focus_startup();
 	screen_startup();
@@ -215,7 +214,6 @@ group_shutdown();
 	screen_shutdown();
 	focus_shutdown();
         moveresize_shutdown();
-        stacking_shutdown();
         frame_shutdown();
         menu_shutdown();
         grab_shutdown();

@@ -1,38 +1,13 @@ 
 #include "slit.h"
 #include "screen.h"
 #include "grab.h"
-#include "timer.h"
 #include "openbox.h"
 #include "render/theme.h"
-#include "render/render.h"
 
 #define SLIT_EVENT_MASK (ButtonPressMask | ButtonReleaseMask | \
                          EnterWindowMask | LeaveWindowMask)
 #define SLITAPP_EVENT_MASK (StructureNotifyMask)
 
-struct Slit {
-    Window frame;
-
-    /* user-requested position stuff */
-    SlitPosition pos;
-    int gravity;
-    int user_x, user_y;
-
-    /* actual position (when not auto-hidden) */
-    int x, y;
-    int w, h;
-
-    gboolean horz;
-    gboolean hide;
-    gboolean hidden;
-
-    Appearance *a_frame;
-
-    Timer *hide_timer;
-
-    GList *slit_apps;
-};
-
 GHashTable *slit_map = NULL;
 GHashTable *slit_app_map = NULL;
 
@@ -53,12 +28,14 @@ slit_app_map = g_hash_table_new(g_int_hash, g_int_equal);
 
     nslits = 1;
     slit = g_new0(struct Slit, nslits);
+    slit->obwin.type = Window_Slit;
 
     for (i = 0; i < nslits; ++i) {
         slit[i].horz = FALSE;
         slit[i].hide = FALSE;
         slit[i].hidden = TRUE;
         slit[i].pos = SlitPos_TopRight;
+        slit[i].layer = Layer_Top;
 
         attrib.event_mask = SLIT_EVENT_MASK;
         attrib.override_redirect = True;
@@ -71,6 +48,8 @@ XSetWindowBorder(ob_display, slit[i].frame, theme_b_color->pixel);
         XSetWindowBorderWidth(ob_display, slit[i].frame, theme_bwidth);
 
         g_hash_table_insert(slit_map, &slit[i].frame, &slit[i]);
+        stacking_add(&slit[i]);
+        stacking_raise(SLIT_AS_WINDOW(&slit[i]));
     }
 }
 
@@ -82,6 +61,7 @@ for (i = 0; i < nslits; ++i) {
         XDestroyWindow(ob_display, slit[i].frame);
         appearance_free(slit[i].a_frame);
         g_hash_table_remove(slit_map, &slit[i].frame);
+        stacking_remove(&slit[i]);
     }
     g_hash_table_destroy(slit_app_map);
     g_hash_table_destroy(slit_map);

@@ -1,11 +1,52 @@ 
 #ifndef __slit_h
 #define __slit_h
 
+#include "timer.h"
+#include "render/render.h"
+#include "window.h"
+#include "stacking.h"
+
 #include <glib.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
 
-typedef struct Slit Slit;
+typedef enum {
+    SlitPos_Floating,
+    SlitPos_TopLeft,
+    SlitPos_Top,
+    SlitPos_TopRight,
+    SlitPos_Right,
+    SlitPos_BottomRight,
+    SlitPos_Bottom,
+    SlitPos_BottomLeft,
+    SlitPos_Left
+} SlitPosition;
+
+typedef struct Slit {
+    ObWindow obwin;
+
+    Window frame;
+    StackLayer layer;
+
+    /* user-requested position stuff */
+    SlitPosition pos;
+    int gravity;
+    int user_x, user_y;
+
+    /* actual position (when not auto-hidden) */
+    int x, y;
+    int w, h;
+
+    gboolean horz;
+    gboolean hide;
+    gboolean hidden;
+
+    Appearance *a_frame;
+
+    Timer *hide_timer;
+
+    GList *slit_apps;
+} Slit;
 
 typedef struct SlitApp {
     int ignore_unmaps;
@@ -18,18 +59,6 @@ int y;
     int w;
     int h;
 } SlitApp;
-
-typedef enum {
-    SlitPos_Floating,
-    SlitPos_TopLeft,
-    SlitPos_Top,
-    SlitPos_TopRight,
-    SlitPos_Right,
-    SlitPos_BottomRight,
-    SlitPos_Bottom,
-    SlitPos_BottomLeft,
-    SlitPos_Left
-} SlitPosition;
 
 extern GHashTable *slit_map;
 extern GHashTable *slit_app_map;

@@ -4,28 +4,11 @@ #include "focus.h"
 #include "client.h"
 #include "group.h"
 #include "frame.h"
+#include "window.h"
 #include <glib.h>
 
 GList  *stacking_list = NULL;
 
-static Window top_window = None;
-
-void stacking_startup()
-{
-    XSetWindowAttributes attrib;
-    attrib.override_redirect = TRUE;
-    top_window =  XCreateWindow(ob_display, ob_root,
-                                -100, -100, 1, 1, 0,
-                                CopyFromParent, InputOutput, CopyFromParent,
-                                CWOverrideRedirect, &attrib);
-    XMapWindow(ob_display, top_window);
-}
-
-void stacking_shutdown()
-{
-    XDestroyWindow(ob_display, top_window);
-}
-
 void stacking_set_list()
 {
     Window *windows, *win_it;
@@ -44,7 +27,8 @@ windows = g_new(Window, size);
 	win_it = windows;
 	for (it = g_list_last(stacking_list); it != NULL;
              it = it->prev, ++win_it)
-	    *win_it = ((Client*)it->data)->window;
+            if (WINDOW_IS_CLIENT(it->data))
+                *win_it = window_top(it->data);
     } else
 	windows = NULL;
 
@@ -67,7 +51,7 @@ return it;
     return NULL;
 }
 
-static void raise_recursive(Client *client)
+static void raise_recursive(ObWindow *window)
 {
     Window wins[2];  /* only ever restack 2 windows. */
     GList *it, *low;
@@ -75,21 +59,27 @@ GSList *sit;
 
     g_assert(stacking_list != NULL); /* this would be bad */
 
-    /* remove the client before looking so we can't run into ourselves and our
+    /* remove the window before looking so we can't run into ourselves and our
        transients can't either. */
-    stacking_list = g_list_remove(stacking_list, client);
+    stacking_list = g_list_remove(stacking_list, window);
 
     /* raise transients first */
-    for (sit = client->transients; sit; sit = sit->next)
-        raise_recursive(sit->data);
+    if (WINDOW_IS_CLIENT(window)) {
+        Client *client = WINDOW_AS_CLIENT(window);
+        for (sit = client->transients; sit; sit = sit->next)
+            raise_recursive(sit->data);
+    }
 
     /* find 'it' where it is the positiion in the stacking order where
-       'client' will be inserted *before* */
+       'window' will be inserted *before* */
 
-    low = find_lowest_transient(client);
+    if (WINDOW_IS_CLIENT(window))
+        low = find_lowest_transient(WINDOW_AS_CLIENT(window));
+    else
+        low = NULL;
     /* the stacking list is from highest to lowest */
     for (it = g_list_last(stacking_list); it; it = it->prev) {
-        if (it == low || client->layer < ((Client*)it->data)->layer) {
+        if (it == low || window_layer(window) < window_layer(it->data)) {
             it = it->next;
             break;
         }
@@ -104,110 +94,112 @@ */
     if (it == stacking_list)
 	wins[0] = focus_backup;
     else if (it != NULL)
-	wins[0] = ((Client*)it->prev->data)->frame->window;
+	wins[0] = window_top(it->prev->data);
     else
-	wins[0] = ((Client*)g_list_last(stacking_list)->data)->frame->window;
-    wins[1] = client->frame->window;
+	wins[0] = window_top(g_list_last(stacking_list)->data);
+    wins[1] = window_top(window);
 
-    stacking_list = g_list_insert_before(stacking_list, it, client);
+    stacking_list = g_list_insert_before(stacking_list, it, window);
 
     XRestackWindows(ob_display, wins, 2);
 }
 
-void stacking_raise(Client *client)
+void stacking_raise(ObWindow *window)
 {
     g_assert(stacking_list != NULL); /* this would be bad */
 
-    /* move up the transient chain as far as possible first */
-    while (client->transient_for) {
-        if (client->transient_for != TRAN_GROUP) {
-            client = client->transient_for;
-        } else {
-            GSList *it;
+    if (WINDOW_IS_CLIENT(window)) {
+        Client *client = WINDOW_AS_CLIENT(window);
+        /* move up the transient chain as far as possible first */
+        while (client->transient_for) {
+            if (client->transient_for != TRAN_GROUP) {
+                client = client->transient_for;
+            } else {
+                GSList *it;
 
-            /* the check for TRAN_GROUP is to prevent an infinate loop with
-               2 transients of the same group at the head of the group's
-               members list */
-            for (it = client->group->members; it; it = it->next) {
-                Client *c = it->data;
+                /* the check for TRAN_GROUP is to prevent an infinate loop with
+                   2 transients of the same group at the head of the group's
+                   members list */
+                for (it = client->group->members; it; it = it->next) {
+                    Client *c = it->data;
 
-                if (c != client && c->transient_for != TRAN_GROUP) {
-                    client = it->data;
-                    break;
+                    if (c != client && c->transient_for != TRAN_GROUP) {
+                        client = it->data;
+                        break;
+                    }
                 }
+                if (it == NULL) break;
             }
-            if (it == NULL) break;
         }
+        window = CLIENT_AS_WINDOW(client);
     }
 
-    raise_recursive(client);
+    raise_recursive(window);
 
     stacking_set_list();
 }
 
-static void lower_recursive(Client *client, Client *above)
+static void lower_recursive(ObWindow *window, ObWindow *above)
 {
     Window wins[2];  /* only ever restack 2 windows. */
     GList *it;
     GSList *sit;
 
     /* find 'it' where 'it' is the position in the stacking_list where the
-       'client' will be placed *after* */
+       'window' will be placed *after* */
 
     for (it = g_list_last(stacking_list); it != stacking_list; it = it->prev)
-        if (client->layer <= ((Client*)it->data)->layer && it->data != above)
+        if (window_layer(window) <= window_layer(it->data) &&
+            it->data != above)
             break;
 
-    if (it->data != client) { /* not already the bottom */
-        wins[0] = ((Client*)it->data)->frame->window;
-        wins[1] = client->frame->window;
+    if (it->data != window) { /* not already the bottom */
+        wins[0] = window_top(it->data);
+        wins[1] = window_top(window);
 
-        stacking_list = g_list_remove(stacking_list, client);
-        stacking_list = g_list_insert_before(stacking_list, it->next, client);
+        stacking_list = g_list_remove(stacking_list, window);
+        stacking_list = g_list_insert_before(stacking_list, it->next, window);
         XRestackWindows(ob_display, wins, 2);
     }
 
-    for (sit = client->transients; sit; sit = sit->next)
-        lower_recursive(sit->data, client);
+    if (WINDOW_IS_CLIENT(window)) {
+        Client *client = WINDOW_AS_CLIENT(window);
+        for (sit = client->transients; sit; sit = sit->next)
+            lower_recursive(CLIENT_AS_WINDOW(sit->data), window);
+    }
 }
 
-void stacking_lower(Client *client)
+void stacking_lower(ObWindow *window)
 {
     g_assert(stacking_list != NULL); /* this would be bad */
 
-    /* move up the transient chain as far as possible first */
-    while (client->transient_for) {
-        if (client->transient_for != TRAN_GROUP) {
-            client = client->transient_for;
-        } else {
-            GSList *it;
+    if (WINDOW_IS_CLIENT(window)) {
+        Client *client = WINDOW_AS_CLIENT(window);
+        /* move up the transient chain as far as possible first */
+        while (client->transient_for) {
+            if (client->transient_for != TRAN_GROUP) {
+                client = client->transient_for;
+            } else {
+                GSList *it;
 
-            /* the check for TRAN_GROUP is to prevent an infinate loop with
-               2 transients of the same group at the head of the group's
-               members list */
-            for (it = client->group->members; it; it = it->next) {
-                Client *c = it->data;
+                /* the check for TRAN_GROUP is to prevent an infinate loop with
+                   2 transients of the same group at the head of the group's
+                   members list */
+                for (it = client->group->members; it; it = it->next) {
+                    Client *c = it->data;
 
-                if (c != client && c->transient_for != TRAN_GROUP) {
-                    client = it->data;
-                    break;
+                    if (c != client && c->transient_for != TRAN_GROUP) {
+                        client = it->data;
+                        break;
+                    }
                 }
+                if (it == NULL) break;
             }
-            if (it == NULL) break;
         }
+        window = CLIENT_AS_WINDOW(client);
     }
 
-    lower_recursive(client, NULL);
+    lower_recursive(window, NULL);
 
     stacking_set_list();
 }
-
-void stacking_raise_internal(Window win)
-{
-    Window wins[2];  /* only ever restack 2 windows. */
-
-    wins[0] = top_window;
-    wins[1] = win;
-
-    XRestackWindows(ob_display, wins, 2);
-}

@@ -1,46 +1,42 @@ 
 #ifndef __stacking_h
 #define __stacking_h
 
+#include "window.h"
+
 #include <glib.h>
 #include <X11/Xlib.h>
 
-struct Client;
-
 /*! The possible stacking layers a client window can be a part of */
 typedef enum {
-    Layer_Icon,       /*!< 0 - iconified windows, in any order at all */
-    Layer_Desktop,    /*!< 1 - desktop windows */
-    Layer_Below,      /*!< 2 - normal windows w/ below */
-    Layer_Normal,     /*!< 3 - normal windows */
-    Layer_Above,      /*!< 4 - normal windows w/ above */
-    Layer_Top,        /*!< 5 - always-on-top-windows (docks?) */
-    Layer_Fullscreen, /*!< 6 - fullscreeen windows */
-    Layer_Internal    /*!< 7 - openbox windows/menus */
+    Layer_Desktop,    /*!< 0 - desktop windows */
+    Layer_Below,      /*!< 1 - normal windows w/ below */
+    Layer_Normal,     /*!< 2 - normal windows */
+    Layer_Above,      /*!< 3 - normal windows w/ above */
+    Layer_Top,        /*!< 4 - always-on-top-windows (docks?) */
+    Layer_Fullscreen, /*!< 5 - fullscreeen windows */
+    Layer_Internal    /*!< 6 - openbox windows/menus */
 } StackLayer;
 
-/* list of Client*s in stacking order from highest to lowest */
+/* list of ObWindow*s in stacking order from highest to lowest */
 extern GList  *stacking_list;
 
-void stacking_startup();
-void stacking_shutdown();
+/*! Sets the window stacking list on the root window from the
+  stacking_list */
+void stacking_set_list();
 
-/*! Sets the client stacking list on the root window from the
-  stacking_clientlist */
-void stacking_set_list();
+#define stacking_add(win) stacking_list = g_list_append(stacking_list, win);
+#define stacking_remove(win) stacking_list = g_list_remove(stacking_list, win);
 
-/*! Raises a client window above all others in its stacking layer
+/*! Raises a window above all others in its stacking layer
   raiseWindow has a couple of constraints that lowerWindow does not.<br>
-  1) raiseWindow can be called after changing a Client's stack layer, and
+  1) raiseWindow can be called after changing a Window's stack layer, and
      the list will be reorganized properly.<br>
   2) raiseWindow guarantees that XRestackWindows() will <i>always</i> be
-     called for the specified client.
+     called for the specified window.
 */
-void stacking_raise(struct Client *client);
+void stacking_raise(ObWindow *window);
 
 /*! Lowers a client window below all others in its stacking layer */
-void stacking_lower(struct Client *client);
-
-/*! Raises an internal window (e.g. menus) */
-void stacking_raise_internal(Window win);
+void stacking_lower(ObWindow *window);
 
 #endif

@@ -0,0 +1,33 @@ 
+#include "window.h"
+#include "menu.h"
+#include "slit.h"
+#include "client.h"
+#include "frame.h"
+
+Window window_top(ObWindow *self)
+{
+    switch (self->type) {
+    case Window_Menu:
+        return ((Menu*)self)->frame;
+    case Window_Slit:
+        return ((Slit*)self)->frame;
+    case Window_Client:
+        return ((Client*)self)->frame->window;
+    }
+    g_assert_not_reached();
+    return None;
+}
+
+Window window_layer(ObWindow *self)
+{
+    switch (self->type) {
+    case Window_Menu:
+        return Layer_Internal;
+    case Window_Slit:
+        return ((Slit*)self)->layer;
+    case Window_Client:
+        return ((Client*)self)->layer;
+    }
+    g_assert_not_reached();
+    return None;
+}

@@ -0,0 +1,35 @@ 
+#ifndef __window_h
+#define __window_h
+
+#include <X11/Xlib.h>
+
+typedef enum {
+    Window_Menu,
+    Window_Slit,
+    Window_Client
+} Window_InternalType;
+
+typedef struct ObWindow {
+    Window_InternalType type;
+} ObWindow;
+
+#define WINDOW_IS_MENU(win) (((ObWindow*)win)->type == Window_Menu)
+#define WINDOW_IS_SLIT(win) (((ObWindow*)win)->type == Window_Slit)
+#define WINDOW_IS_CLIENT(win) (((ObWindow*)win)->type == Window_Client)
+
+struct Menu;
+struct Slit;
+struct Client;
+
+#define WINDOW_AS_MENU(win) ((struct Menu*)win)
+#define WINDOW_AS_SLIT(win) ((struct Slit*)win)
+#define WINDOW_AS_CLIENT(win) ((struct Client*)win)
+
+#define MENU_AS_WINDOW(menu) ((ObWindow*)menu)
+#define SLIT_AS_WINDOW(slit) ((ObWindow*)slit)
+#define CLIENT_AS_WINDOW(client) ((ObWindow*)client)
+
+Window window_top(ObWindow *self);
+Window window_layer(ObWindow *self);
+
+#endif

@@ -65,6 +65,8 @@ for (it = stacking_list; it != NULL; it = it->next) {
             Client *target;
             int tl, tt, tr, tb; /* 1 past the target's edges on each side */
 
+            if (!WINDOW_IS_CLIENT(it->data))
+                continue;
             target = it->data;
             /* don't snap to self or non-visibles */
             if (!target->frame->visible || target == c) continue;