Fix off-by-one slider bug

TODO.FACTOR.txt

@@ -17,8 +17,7 @@
   restores to an unresponsive gadget
 - fix top level window positioning
 - services do not launch if factor not running
-- when scrolling wheel, or moving mouse out of window, rollover is not
-  updated
+- rollover is not updated on focus changes
 - amd64 crash
 - get factor running on mac intel
 - constant branch folding
@@ -62,7 +61,6 @@
 
 - x11 input methods
 - roundoff is still not quite right with tracks
-- clearing pane with ^L leaves scrollbar a pixel off
 - new browser:
   - browse generic words and classes
   - need actions for reloading the source file and opening word in jEdit

library/ui/gadgets/sliders.factor

@@ -25,14 +25,14 @@ TUPLE: slider elevator thumb value saved max page ;
     dup slider-page over slider-max 1 max / 1 min
     swap elevator-length * min-thumb-dim max ;
 
-: slider-max* dup slider-max swap slider-page - 1 max ;
+: slider-max* dup slider-max swap slider-page - 0 max ;
 
 : slider-scale ( slider -- n )
     #! A scaling factor such that if x is a slider co-ordinate,
     #! x*n is the screen position of the thumb, and conversely
     #! for x/n. The '1 max' calls avoid division by zero.
     dup elevator-length over thumb-dim - 1 max
-    swap slider-max* / ;
+    swap slider-max* 1 max / ;
 
 : slider>screen slider-scale * ;