Removed ui.gadgets.lines

with-lines moves to ui.tools.common, white-interior moves to
ui.gadgets.colors

basis/ui/gadgets/colors/colors.factor

@@ -38,3 +38,8 @@ T{ rgba { red 0.9295 } { green 0.9569 } { blue 0.8510 } { alpha 1.0 } } inline
 
 CONSTANT: error-summary-background
 T{ rgba { red 0.9568 } { green 0.8509 } { blue 0.8509 } { alpha 1.0 } } inline
+
+CONSTANT: content-background COLOR: white
+
+: white-interior ( track -- track )
+    content-background <solid> >>interior ;

basis/ui/gadgets/lines/lines.factor

@@ -1,11 +0,0 @@
-! Copyright (C) 2015 Nicolas Pénet.
-! See http://factorcode.org/license.txt for BSD license.
-USING: accessors colors.constants kernel ui.gadgets.colors ui.pens.solid ;
-IN: ui.gadgets.lines
-
-: with-lines ( track -- track )
-    dup orientation>> >>gap 
-    line-color <solid> >>interior ;
-
-: white-interior ( track -- track )
-    COLOR: white <solid> >>interior ;

basis/ui/tools/common/common.factor

@@ -41,3 +41,7 @@ SLOT: scroller
 
 : margins ( child -- border ) 
     { 9 9 } <filled-border> ;
+
+: with-lines ( track -- track )
+    dup orientation>> >>gap 
+    line-color <solid> >>interior ;