Better slider rounding

TODO.FACTOR.txt

@@ -4,7 +4,6 @@
 
 + day after:
 
-- roundoff is still not quite right with tracks
 - httpd search tools
 [2:45pm] tathi: Factor's text display is a bit odd sometimes, until you mouse over (or click, if there's no "live" text)
 [2:48pm] tathi: it appears to be using the font metrics from the sprite tuple, but re-using the texture from the previous letter
@@ -20,6 +19,8 @@
 
 + ui:
 
+- integrated error documentation
+- roundoff is still not quite right with tracks and sliders
 - 'show' doesn't work if invoked from a listener on an object which is
   itself inspected in the listener
 - ui uses too much cpu time idling
@@ -56,6 +57,7 @@
 
 + compiler/ffi:
 
+- mach_signal: fault address reporting is not reliable
 - mac intel: struct returns from objc methods
 - see if alien calls can be made faster
 - faster sequence= for UI

library/ui/gadgets/sliders.factor

@@ -97,19 +97,20 @@ C: elevator ( vector -- elevator )
     [ set-gadget-orientation ] keep ;
 
 : (layout-thumb) ( slider n -- n thumb )
-    over gadget-orientation n*v [ >fixnum ] map
-    swap slider-thumb ;
+    over gadget-orientation n*v swap slider-thumb ;
 
 : thumb-loc ( slider -- loc )
     dup slider-value swap slider>screen ;
 
 : layout-thumb-loc ( slider -- )
-    dup thumb-loc (layout-thumb) set-rect-loc ;
+    dup thumb-loc (layout-thumb)
+    >r [ floor ] map r> set-rect-loc ;
 
 : layout-thumb-dim ( slider -- )
-    dup dup thumb-dim (layout-thumb)
-    >r >r dup rect-dim r> rot gadget-orientation set-axis r>
-    set-layout-dim ;
+    dup dup thumb-dim (layout-thumb) >r
+    >r dup rect-dim r>
+    rot gadget-orientation set-axis [ ceiling ] map
+    r> set-layout-dim ;
 
 : layout-thumb ( slider -- )
     dup layout-thumb-loc layout-thumb-dim ;