screen: make tags array overwritable

Signed-off-by: Julien Danjou <julien@danjou.info>

lua.c

@@ -645,7 +645,8 @@ luaA_parserc(const char *confpatharg)
     /* Assure there's at least one tag */
     for(screen = 0; screen < globalconf.screens_info->nscreen; screen++)
         if(!globalconf.screens[screen].tags.len)
-            tag_append_to_screen(tag_new("default", sizeof("default")-1, layout_tile, 0.5, 1, 0), screen);
+            tag_append_to_screen(tag_new("default", sizeof("default")-1, layout_tile, 0.5, 1, 0),
+                                 &globalconf.screens[screen]);
 
     p_delete(&confpath);
 }

screen.c

@@ -308,6 +308,8 @@ luaA_screen_newindex(lua_State *L)
     size_t len;
     const char *buf = luaL_checklstring(L, 2, &len);
     screen_t *s;
+    tag_t **tag;
+    int i;
 
     s = lua_touserdata(L, 1);
 
@@ -322,6 +324,27 @@ luaA_screen_newindex(lua_State *L)
 
         ewmh_update_workarea(screen_virttophys(s->index));
 
+        break;
+      case A_TK_TAGS:
+        luaA_checktable(L, 3);
+
+        /* remove current tags */
+        for(i = 0; i < s->tags.len; i++)
+            s->tags.tab[i]->screen = SCREEN_UNDEF;
+
+        tag_array_wipe(&s->tags);
+        tag_array_init(&s->tags);
+
+        s->need_arrange = true;
+
+        /* push new tags */
+        lua_pushnil(L);
+        while(lua_next(L, 3))
+        {
+            tag = luaA_checkudata(L, -1, "tag");
+            tag_append_to_screen(*tag, s);
+            lua_pop(L, 1);
+        }
         break;
       default:
         return 0;

tag.c

@@ -91,16 +91,16 @@ tag_new(const char *name, ssize_t len, layout_t *layout, double mwfact, int nmas
  * \param screen the screen id
  */
 void
-tag_append_to_screen(tag_t *tag, int screen)
+tag_append_to_screen(tag_t *tag, screen_t *s)
 {
-    int phys_screen = screen_virttophys(screen);
+    int phys_screen = screen_virttophys(s->index);
 
-    tag->screen = screen;
+    tag->screen = s->index;
-    tag_array_append(&globalconf.screens[screen].tags, tag_ref(&tag));
+    tag_array_append(&s->tags, tag_ref(&tag));
     ewmh_update_net_numbers_of_desktop(phys_screen);
     ewmh_update_net_desktop_names(phys_screen);
     ewmh_update_workarea(phys_screen);
-    widget_invalidate_cache(screen, WIDGET_CACHE_TAGS);
+    widget_invalidate_cache(s->index, WIDGET_CACHE_TAGS);
 }
 
 /** Remove a tag from screen. Tag must be on a screen and have no clients.
@@ -137,6 +137,7 @@ tag_client(client_t *c, tag_t *t)
     if(is_client_tagged(c, t))
         return;
 
+    tag_ref(&t);
     client_array_append(&t->clients, c);
     client_saveprops(c);
     widget_invalidate_cache(c->screen, WIDGET_CACHE_CLIENTS);
@@ -153,6 +154,7 @@ untag_client(client_t *c, tag_t *t)
     for(int i = 0; i < t->clients.len; i++)
         if(t->clients.tab[i] == c)
         {
+            tag_unref(&t);
             client_array_take(&t->clients, i);
             client_saveprops(c);
             widget_invalidate_cache(c->screen, WIDGET_CACHE_CLIENTS);
@@ -401,13 +403,7 @@ luaA_tag_newindex(lua_State *L)
             screen = SCREEN_UNDEF;
 
         if((*tag)->screen != SCREEN_UNDEF)
-        {
+            tag_remove_from_screen(*tag);
-            if((*tag)->clients.len)
-                luaL_error(L, "unable to remove tag %s from screen %d, it still has clients",
-                           (*tag)->name, (*tag)->screen);
-            else
-                tag_remove_from_screen(*tag);
-        }
 
         if(screen != SCREEN_UNDEF)
         {
@@ -415,7 +411,7 @@ luaA_tag_newindex(lua_State *L)
                 luaL_error(L, "a tag with the name `%s' is already on screen %d",
                            (*tag)->name, screen);
 
-            tag_append_to_screen(*tag, screen);
+            tag_append_to_screen(*tag, &globalconf.screens[screen]);
         }
         break;
       case A_TK_LAYOUT:

tag.h

@@ -44,7 +44,7 @@ void tag_client(client_t *, tag_t *);
 void untag_client(client_t *, tag_t *);
 bool is_client_tagged(client_t *, tag_t *);
 void tag_view_only_byindex(int, int);
-void tag_append_to_screen(tag_t *, int);
+void tag_append_to_screen(tag_t *, screen_t *);
 int luaA_tag_userdata_new(lua_State *, tag_t *);
 
 DO_RCNT(tag_t, tag, tag_delete)