gears.surface: Use GdkPixbuf

This now does directly what previously awesome.load_image() did. Also,
this commit removes the only caller of awesome.load_image(), so that
function could (in theory) be removed now.

Fixes: https://github.com/awesomeWM/awesome/issues/1235
Signed-off-by: Uli Schlachter <psychon@znc.in>

build-utils/lgi-check.c

@@ -35,7 +35,7 @@ const char commands[] =
 "        '0.8.0', require('lgi.version')))\n"
 "end\n"
 "lgi = require('lgi')\n"
-"assert(lgi.cairo, lgi.Pango, lgi.PangoCairo, lgi.GLib, lgi.Gio)\n"
+"assert(lgi.cairo, lgi.Pango, lgi.PangoCairo, lgi.GLib, lgi.Gio, lgi.GdkPixbuf)\n"
 ;
 
 int main()

lib/gears/surface.lua

@@ -8,6 +8,7 @@ local setmetatable = setmetatable
 local type = type
 local capi = { awesome = awesome }
 local cairo = require("lgi").cairo
+local GdkPixbuf = require("lgi").GdkPixbuf
 local color = nil
 local gdebug = require("gears.debug")
 local hierarchy = require("wibox.hierarchy")
@@ -36,7 +37,6 @@ end
 -- @return The loaded surface, or the replacement default
 -- @return An error message, or nil on success
 function surface.load_uncached_silently(_surface, default)
-    local file
     -- On nil, return some sane default
     if not _surface then
         return get_default(default)
@@ -47,12 +47,11 @@ function surface.load_uncached_silently(_surface, default)
     end
     -- Strings are assumed to be file names and get loaded
     if type(_surface) == "string" then
-        local err
-        file = _surface
-        _surface, err = capi.awesome.load_image(file)
-        if not _surface then
-            return get_default(default), err
+        local pixbuf, err = GdkPixbuf.Pixbuf.new_from_file(_surface)
+        if not pixbuf then
+            return get_default(default), tostring(err)
         end
+        _surface = capi.awesome.pixbuf_to_surface(pixbuf._native)
     end
     -- Everything else gets forced into a surface
     return cairo.Surface(_surface, true)