client: Add API to query all icons

This adds c.icon_sizes which is a table containing the width and height
of each available icon. With c:get_icon(i), Lua can query the i-th icon
as a lightuserdata.

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

objects/client.c

@@ -381,6 +381,19 @@
  * @param surface
  */
 
+/**
+ * The available sizes of client icons. This is a table where each entry
+ * contains the width and height of an icon.
+ *
+ * **Signal:**
+ *
+ *  * *property::icon*
+ *
+ * @property icon_sizes
+ * @tparam table sizes
+ * @see `get_icon`
+ */
+
 /**
  * Client screen.
  *
@@ -3425,6 +3438,50 @@ luaA_client_keys(lua_State *L)
     return luaA_key_array_get(L, 1, keys);
 }
 
+static int
+luaA_client_get_icon_sizes(lua_State *L)
+{
+    int index = 1;
+    client_t *c = luaA_checkudata(L, 1, &client_class);
+
+    lua_newtable(L);
+    foreach (s, c->icons) {
+        /* Create a table { width, height } and append it to the table */
+        lua_createtable(L, 2, 0);
+
+        lua_pushinteger(L, cairo_image_surface_get_width(*s));
+        lua_rawseti(L, -2, 1);
+
+        lua_pushinteger(L, cairo_image_surface_get_height(*s));
+        lua_rawseti(L, -2, 2);
+
+        lua_rawseti(L, -2, index++);
+    }
+    return 1;
+}
+
+/** Get the client's n-th icon.
+ *
+ * **Signal:**
+ *
+ *  * *property::icon*
+ *
+ * @tparam interger index The index in the list of icons to get.
+ * @treturn surface A lightuserdata for a cairo surface. This reference must be
+ * destroyed!
+ * @function get_icon
+ */
+static int
+luaA_client_get_some_icon(lua_State *L)
+{
+    client_t *c = luaA_checkudata(L, 1, &client_class);
+    int index = luaL_checkinteger(L, 2);
+    luaL_argcheck(L, (index >= 1 && index <= c->icons.len), 2,
+            "invalid icon index");
+    lua_pushlightuserdata(L, cairo_surface_reference(c->icons.tab[index-1]));
+    return 1;
+}
+
 static int
 client_tostring(lua_State *L, client_t *c)
 {
@@ -3510,6 +3567,7 @@ client_class_setup(lua_State *L)
         { "titlebar_right", luaA_client_titlebar_right },
         { "titlebar_bottom", luaA_client_titlebar_bottom },
         { "titlebar_left", luaA_client_titlebar_left },
+        { "get_icon", luaA_client_get_some_icon },
         { NULL, NULL }
     };
 
@@ -3608,6 +3666,10 @@ client_class_setup(lua_State *L)
                             (lua_class_propfunc_t) luaA_client_set_icon,
                             (lua_class_propfunc_t) luaA_client_get_icon,
                             (lua_class_propfunc_t) luaA_client_set_icon);
+    luaA_class_add_property(&client_class, "icon_sizes",
+                            NULL,
+                            (lua_class_propfunc_t) luaA_client_get_icon_sizes,
+                            NULL);
     luaA_class_add_property(&client_class, "ontop",
                             (lua_class_propfunc_t) luaA_client_set_ontop,
                             (lua_class_propfunc_t) luaA_client_get_ontop,