diff --git a/basis/ui/gadgets/tracks/tracks-tests.factor b/basis/ui/gadgets/tracks/tracks-tests.factor
index ab9de3c238..9abe70bfaa 100644
--- a/basis/ui/gadgets/tracks/tracks-tests.factor
+++ b/basis/ui/gadgets/tracks/tracks-tests.factor
@@ -1,5 +1,5 @@
 USING: kernel ui.gadgets ui.gadgets.tracks tools.test
-       math.rectangles accessors ;
+math.rectangles accessors sequences ;
 IN: ui.gadgets.tracks.tests
 
 [ { 100 100 } ] [
@@ -37,4 +37,26 @@ IN: ui.gadgets.tracks.tests
         <gadget> { 10 10 } >>dim f track-add
         <gadget> { 10 10 } >>dim f track-add
     pref-dim
+] unit-test
+
+[ V{ { 10 10 } { 10 80 } { 10 10 } } ] [
+    vertical <track>
+        0 >>fill
+        <gadget> { 10 10 } >>dim f track-add
+        <gadget> { 10 10 } >>dim 1 track-add
+        <gadget> { 10 10 } >>dim f track-add
+    { 10 100 } >>dim
+    [ layout ] [ children>> [ dim>> ] map ] bi
+] unit-test
+
+[ V{ { 10 10 } { 10 35 } { 10 10 } { 10 35 } { 10 10 } } ] [
+    vertical <track>
+        0 >>fill
+        <gadget> { 10 10 } >>dim f track-add
+        <gadget> { 10 10 } >>dim 1/2 track-add
+        <gadget> { 10 10 } >>dim f track-add
+        <gadget> { 10 10 } >>dim 1/2 track-add
+        <gadget> { 10 10 } >>dim f track-add
+    { 10 100 } >>dim
+    [ layout ] [ children>> [ dim>> ] map ] bi
 ] unit-test
\ No newline at end of file
diff --git a/basis/ui/gadgets/tracks/tracks.factor b/basis/ui/gadgets/tracks/tracks.factor
index fb43ceaa78..bf86c7f34e 100644
--- a/basis/ui/gadgets/tracks/tracks.factor
+++ b/basis/ui/gadgets/tracks/tracks.factor
@@ -1,40 +1,40 @@
-! Copyright (C) 2006, 2008 Slava Pestov.
+! Copyright (C) 2006, 2009 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors io kernel namespaces fry
-math math.vectors math.rectangles math.order
-sequences words ui.gadgets ui.gadgets.packs ;
+USING: accessors io kernel namespaces fry math math.vectors
+math.rectangles math.order sequences words ui.gadgets ui.gadgets.packs
+ui.gadgets.packs.private combinators ;
 IN: ui.gadgets.tracks
 
 TUPLE: track < pack sizes ;
 
-: normalized-sizes ( track -- seq )
-    sizes>> dup sift sum '[ dup [ _ / ] when ] map ;
-
-: init-track ( track -- track )
-    V{ } clone >>sizes
-    1 >>fill ; inline
-
 : new-track ( orientation class -- track )
-    new-gadget
-        init-track
+    new
+        1 >>fill
+        V{ } clone >>sizes
         swap >>orientation ; inline
 
 : <track> ( orientation -- track ) track new-track ;
 
+<PRIVATE
+
+: normalized-sizes ( track -- seq )
+    sizes>> dup sift sum '[ dup [ _ / ] when ] map ;
+
 : alloted-dim ( track -- dim )
     [ children>> ] [ sizes>> ] bi { 0 0 }
-    [ [ drop { 0 0 } ] [ pref-dim ] if v+ ] 2reduce ;
-
-: gap-dim ( track -- dim )
-    [ gap>> ] [ children>> length 1 [-] ] bi v*n ;
+    [ [ drop ] [ pref-dim v+ ] if ] 2reduce ;
 
 : available-dim ( track -- dim )
     [ dim>> ] [ alloted-dim ] bi v- ;
 
 : track-layout ( track -- sizes )
-    [ [ available-dim ] [ gap-dim ] bi v- ]
-    [ children>> ] [ normalized-sizes ] tri
-    [ [ over n*v ] [ pref-dim ] ?if ] 2map nip ;
+    {
+        [ children>> pref-dims ]
+        [ normalized-sizes ]
+        [ [ available-dim ] [ gap-dim ] bi v- ]
+        [ orientation>> ]
+    } cleave
+    '[ [ _ n*v _ set-axis ] when* ] 2map ;
 
 M: track layout* ( track -- ) dup track-layout pack-layout ;
 
@@ -55,14 +55,17 @@ M: track pref-dim* ( gadget -- dim )
     tri
     set-axis ;
 
+PRIVATE>
+
 : track-add ( track gadget constraint -- track )
     pick sizes>> push add-gadget ;
 
 : track-remove ( track gadget -- track )
-    dupd dup [
+    [ drop ] [
         [ swap children>> index ]
-        [ unparent sizes>> ] 2bi
-        delete-nth 
-    ] [ 2drop ] if ;
+        [ drop sizes>> ]
+        [ nip unparent ]
+        2tri delete-nth
+    ] 2bi ;
 
 : clear-track ( track -- ) [ sizes>> delete-all ] [ clear-gadget ] bi ;