Add screen.primary

Right now this just always returns the first screens, but this can easily be
implemented properly later.

Signed-off-by: Uli Schlachter <psychon@znc.in>

globalconf.h

@@ -80,6 +80,8 @@ typedef struct
     xcb_key_symbols_t *keysyms;
     /** Logical screens */
     screen_array_t screens;
+    /** The primary screen, access through screen_get_primary() */
+    screen_t *primary_screen;
     /** Root window key bindings */
     key_array_t keys;
     /** Root window mouse bindings */

mouse.c

@@ -135,7 +135,7 @@ luaA_mouse_index(lua_State *L)
         if (globalconf.focus.client)
             luaA_pushscreen(L, globalconf.focus.client->screen);
         else
-            luaA_pushscreen(L, globalconf.screens.tab[0]);
+            luaA_pushscreen(L, screen_get_primary());
         return 1;
     }
 

objects/screen.c

@@ -44,6 +44,7 @@
 /** Screen is a table where indexes are screen numbers. You can use `screen[1]`
  * to get access to the first screen, etc. Alternatively, if RANDR information
  * is available, you can use output names for finding screen objects.
+ * The primary screen can be accessed as `screen.primary`.
  * Each screen has a set of properties.
  *
  * @tfield table geometry The screen coordinates. Immutable.
@@ -536,6 +537,14 @@ screen_get_index(screen_t *s)
     return 0;
 }
 
+screen_t *
+screen_get_primary(void)
+{
+    if (!globalconf.primary_screen && globalconf.screens.len > 0)
+        globalconf.primary_screen = globalconf.screens.tab[0];
+    return globalconf.primary_screen;
+}
+
 /** Screen module.
  * \param L The Lua VM state.
  * \return The number of elements pushed on stack.
@@ -548,10 +557,15 @@ luaA_screen_module_index(lua_State *L)
     const char *name;
 
     if(lua_type(L, 2) == LUA_TSTRING && (name = lua_tostring(L, 2)))
+    {
+        if(A_STREQ(name, "primary"))
+            return luaA_object_push(L, screen_get_primary());
+
         foreach(screen, globalconf.screens)
             foreach(output, (*screen)->outputs)
                 if(A_STREQ(output->name, name))
                     return luaA_object_push(L, screen);
+    }
 
     return luaA_object_push(L, luaA_checkscreen(L, 2));
 }

objects/screen.h

@@ -47,6 +47,7 @@ bool screen_coord_in_screen(screen_t *, int, int);
 int screen_get_index(screen_t *);
 area_t display_area_get(void);
 void screen_client_moveto(client_t *, screen_t *, bool);
+screen_t *screen_get_primary(void);
 
 void luaA_pushscreen(lua_State *, screen_t *);
 screen_t *luaA_checkscreen(lua_State *, int);