Add awesome.pixbuf_to_surface

This function takes a GdkPixbuf, copies it to a cairo image surface and
returns the image surface.

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

draw.c

@@ -81,7 +81,7 @@ draw_surface_from_data(int width, int height, uint32_t *data)
  * \param buf The pixbuf
  * \return Number of items pushed on the lua stack.
  */
-static cairo_surface_t *
+cairo_surface_t *
 draw_surface_from_pixbuf(GdkPixbuf *buf)
 {
     int width = gdk_pixbuf_get_width(buf);

draw.h

@@ -30,6 +30,9 @@
 #include "common/array.h"
 #include "common/util.h"
 
+/* Forward definition */
+typedef struct _GdkPixbuf GdkPixbuf;
+
 typedef struct area_t area_t;
 struct area_t
 {
@@ -57,6 +60,7 @@ DO_ARRAY(cairo_surface_t *, cairo_surface, cairo_surface_array_destroy_surface)
 cairo_surface_t *draw_surface_from_data(int width, int height, uint32_t *data);
 cairo_surface_t *draw_dup_image_surface(cairo_surface_t *surface);
 cairo_surface_t *draw_load_image(lua_State *L, const char *path, GError **error);
+cairo_surface_t *draw_surface_from_pixbuf(GdkPixbuf *buf);
 
 xcb_visualtype_t *draw_find_visual(const xcb_screen_t *s, xcb_visualid_t visual);
 xcb_visualtype_t *draw_default_visual(const xcb_screen_t *s);

luaa.c

@@ -281,6 +281,23 @@ luaA_sync(lua_State *L)
     return 0;
 }
 
+/** Translate a GdkPixbuf to a cairo image surface..
+ *
+ * @param pixbuf The pixbuf as a light user datum.
+ * @return A cairo surface as light user datum.
+ * @function pixbuf_to_surface
+ */
+static int
+luaA_pixbuf_to_surface(lua_State *L)
+{
+    GdkPixbuf *pixbuf = (GdkPixbuf *) lua_touserdata(L, 1);
+    cairo_surface_t *surface = draw_surface_from_pixbuf(pixbuf);
+
+    /* lua has to make sure to free the ref or we have a leak */
+    lua_pushlightuserdata(L, surface);
+    return 1;
+}
+
 /** Load an image from a given path.
  *
  * @param name The file name.
@@ -292,6 +309,10 @@ luaA_sync(lua_State *L)
 static int
 luaA_load_image(lua_State *L)
 {
+    /* TODO: Deprecate this function, Lua can use GdkPixbuf directly plus
+     * awesome.pixbuf_to_surface
+     */
+
     GError *error = NULL;
     const char *filename = luaL_checkstring(L, 1);
     cairo_surface_t *surface = draw_load_image(L, filename, &error);
@@ -776,6 +797,7 @@ luaA_init(xdgHandle* xdg, string_array_t *searchpath)
         { "emit_signal", luaA_awesome_emit_signal },
         { "systray", luaA_systray },
         { "load_image", luaA_load_image },
+        { "pixbuf_to_surface", luaA_pixbuf_to_surface },
         { "set_preferred_icon_size", luaA_set_preferred_icon_size },
         { "register_xproperty", luaA_register_xproperty },
         { "set_xproperty", luaA_set_xproperty },