ui.backend.gtk: default-icon-path considers install-prefix

basis/ui/backend/gtk/gtk.factor

@@ -4,13 +4,13 @@ USING: accessors alien.accessors alien.c-types alien.data
 alien.strings arrays assocs classes.struct combinators continuations
 destructors environment gdk.ffi gdk.gl.ffi gdk.pixbuf.ffi glib.ffi
 gobject-introspection.standard-types gobject.ffi gtk.ffi gtk.gl.ffi
-io.encodings.binary io.encodings.utf8 io.files io.pathnames kernel libc literals
-locals math math.bitwise math.vectors namespaces sequences strings
-system threads ui ui.backend ui.backend.gtk.input-methods
-ui.backend.gtk.io ui.clipboards ui.event-loop ui.gadgets
-ui.gadgets.private ui.gadgets.worlds ui.gestures
-ui.pixel-formats ui.pixel-formats.private ui.private
-vocabs.loader ;
+io.encodings.binary io.encodings.utf8 io.files io.pathnames kernel
+libc literals locals math math.bitwise math.vectors namespaces
+sequences strings system threads ui ui.backend
+ui.backend.gtk.input-methods ui.backend.gtk.io ui.backend.x11.keys
+ui.clipboards ui.event-loop ui.gadgets ui.gadgets.private
+ui.gadgets.worlds ui.gestures ui.pixel-formats
+ui.pixel-formats.private ui.private vocabs.loader ;
 IN: ui.backend.gtk
 
 SINGLETON: gtk-ui-backend
@@ -171,7 +171,11 @@ CONSTANT: events-mask
 : on-focus-out ( win event user-data -- ? )
     2drop window unfocus-world t ;
 
-CONSTANT: default-icon-path "resource:misc/icons/Factor_128x128.png"
+: default-icon-path ( -- path )
+    install-prefix dup "." =
+    [ drop "resource:misc/icons/Factor_128x128.png" ] [
+        "share/factor/icons/Factor_128x128.png" append-path
+    ] if ;
 
 : default-icon-data ( -- byte-array/f )
     [