root: Add support for setting a miss handler.

This will allow to port some functions from C to Lua, such as supporting
`awful.key` directly when setting the buttons.

luaa.c

@@ -80,9 +80,10 @@ extern const struct luaL_Reg awesome_dbus_lib[];
 #endif
 extern const struct luaL_Reg awesome_keygrabber_lib[];
 extern const struct luaL_Reg awesome_mousegrabber_lib[];
-extern const struct luaL_Reg awesome_root_lib[];
 extern const struct luaL_Reg awesome_mouse_methods[];
 extern const struct luaL_Reg awesome_mouse_meta[];
+extern const struct luaL_Reg awesome_root_methods[];
+extern const struct luaL_Reg awesome_root_meta[];
 
 /** A call into the Lua code aborted with an error.
  *
@@ -995,8 +996,7 @@ luaA_init(xdgHandle* xdg, string_array_t *searchpath)
     setup_awesome_signals(L);
 
     /* Export root lib */
-    luaA_registerlib(L, "root", awesome_root_lib);
+    luaA_openlib(L, "root", awesome_root_methods, awesome_root_meta);
-    lua_pop(L, 1); /* luaA_registerlib() leaves the table on stack */
 
 #ifdef WITH_DBUS
     /* Export D-Bus lib */

root.c

@@ -31,6 +31,7 @@
 #include "common/xcursor.h"
 #include "common/xutil.h"
 #include "objects/button.h"
+#include "common/luaclass.h"
 #include "xwindow.h"
 
 #include "math.h"
@@ -39,6 +40,10 @@
 #include <xcb/xcb_aux.h>
 #include <cairo-xcb.h>
 
+static int miss_index_handler    = LUA_REFNIL;
+static int miss_newindex_handler = LUA_REFNIL;
+static int miss_call_handler     = LUA_REFNIL;
+
 static void
 root_set_wallpaper_pixmap(xcb_connection_t *c, xcb_pixmap_t p)
 {
@@ -525,7 +530,62 @@ luaA_root_tags(lua_State *L)
     return 1;
 }
 
-const struct luaL_Reg awesome_root_lib[] =
+/**
+* Add a custom call handler.
+*/
+static int
+luaA_root_set_call_handler(lua_State *L)
+{
+    return luaA_registerfct(L, 1, &miss_call_handler);
+}
+
+/**
+* Add a custom property handler (getter).
+*/
+static int
+luaA_root_set_index_miss_handler(lua_State *L)
+{
+    return luaA_registerfct(L, 1, &miss_index_handler);
+}
+
+/**
+* Add a custom property handler (setter).
+*/
+static int
+luaA_root_set_newindex_miss_handler(lua_State *L)
+{
+    return luaA_registerfct(L, 1, &miss_newindex_handler);
+}
+
+/** Root library.
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ * \luastack
+ */
+static int
+luaA_root_index(lua_State *L)
+{
+    if (miss_index_handler != LUA_REFNIL)
+        return luaA_call_handler(L, miss_index_handler);
+
+    return luaA_default_index(L);
+}
+
+/** Newindex for root.
+ * \param L The Lua VM state.
+ * \return The number of elements pushed on stack.
+ */
+static int
+luaA_root_newindex(lua_State *L)
+{
+    /* Call the lua root property handler */
+    if (miss_newindex_handler != LUA_REFNIL)
+        return luaA_call_handler(L, miss_newindex_handler);
+
+    return luaA_default_newindex(L);
+}
+
+const struct luaL_Reg awesome_root_methods[] =
 {
     { "buttons", luaA_root_buttons },
     { "keys", luaA_root_keys },
@@ -536,8 +596,17 @@ const struct luaL_Reg awesome_root_lib[] =
     { "size", luaA_root_size },
     { "size_mm", luaA_root_size_mm },
     { "tags", luaA_root_tags },
-    { "__index", luaA_default_index },
+    { "__index", luaA_root_index },
-    { "__newindex", luaA_default_newindex },
+    { "__newindex", luaA_root_newindex },
+    { "set_index_miss_handler", luaA_root_set_index_miss_handler},
+    { "set_call_handler", luaA_root_set_call_handler},
+    { "set_newindex_miss_handler", luaA_root_set_newindex_miss_handler},
+
+    { NULL, NULL }
+};
+
+const struct luaL_Reg awesome_root_meta[] =
+{
     { NULL, NULL }
 };
 

tests/examples/shims/root.lua

@@ -174,6 +174,15 @@ function root._write_string(string, c)
     end
 end
 
+
+function root.set_newindex_miss_handler(h)
+    rawset(mouse, "_ni_handler", h)
+end
+
+function root.set_index_miss_handler(h)
+    rawset(mouse, "_i_handler", h)
+end
+
 return root
 
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