[RFA] libgui panedwindow fix

["Martin M. Hunt" <hunt@redhat.com>]

The current panedwindow code has some bugs with nonresizable panes.  It also
doesn't always handle minimum and maximum settings on resizable panes. This 
has no impact on the current Insight, but breaks some future work.  I've 
tested the following patch and it fixes all the problems I have found, and 
appears to work fine with the current Insight sources.

-- 
Martin Hunt
GDB Engineer
Red Hat, Inc.

2001-09-02  Martin M. Hunt  <hunt@redhat.com>
 
        * library/panedwindow.tcl (fraction): Remove method.
        (_resizeArray): Correct calculations of _max
        and _min for each pane.
        (_moveSash): Take a third parameter, direction.
        (_caclPos): Rename to _calcPos. Take an optional
        third parameter, direction. This is so recursive calls
        to _calcPos continue adjusting panes upward or downward
        and does not loop infinitely.

Index: library/panedwindow.tcl
===================================================================
RCS file: /cvs/src/src/libgui/library/panedwindow.tcl,v
retrieving revision 1.1.1.1
diff -u -p -r1.1.1.1 panedwindow.tcl
--- panedwindow.tcl	2000/02/07 00:19:47	1.1.1.1
+++ panedwindow.tcl	2001/09/04 20:53:31
@@ -31,7 +31,6 @@ class cyg::PanedWindow {
   public {
     method index {index}
     method childsite {args}
-    method fraction {percentage1 percentage2 args}
     method add {tag args}
     method insert {index tag args}
     method delete {index}
@@ -48,11 +47,11 @@ class cyg::PanedWindow {
     method _endDrag {where num}
     method _configDrag {where num}
     method _handleDrag {where num}
-    method _moveSash {where num}
+    method _moveSash {where num {dir ""}}
 
     method _resizeArray {}
     method _setActivePanes {}
-    method _caclPos {where num}
+    method _calcPos {where num {dir ""}}
     method _makeSashes {}
     method _placeSash {i}
     method _placePanes {{start 0} {end end} {forget 0}}
@@ -542,8 +541,11 @@ body cyg::PanedWindow::_resizeArray {} {
   set _ploc(0) 0
   set _max(0) 0
   set _min(0) 0
+
   # calculate the percentage of resizable space
   set resizePerc [expr 1.0 - ($_rPixels.0 / $_dimension)]
+
+  # now set the pane positions
   for {set i 1; set n 0} {$i < $totalpanes} {incr i; incr n} {
     if {$_resizable($n)} {
       set _where($i) [expr $_where($n) + ($_frac($n) * $resizePerc)]
@@ -551,19 +553,36 @@ body cyg::PanedWindow::_resizeArray {} {
       set _where($i) [expr $_where($n) + [expr $_pixels($n).0 / $_dimension]]
     }
     set _ploc($i) [expr $_ploc($n) + $_pixels($n)]
-    if {$_pmax($n)} {
-      set _max($i) [expr $_max($n) + $_pmax($n)]
-    } else {
+    set _max($i) [expr $_max($n) + $_pmax($n)]
+    if {($_max($n) == 0 || $_pmax($n) == 0) && $n != 0} {
       set _max($i) 0
     }
     set _min($i) [expr $_min($n) + $_pmin($n)]
     #puts "where($i)=$_where($i)"
     #puts "ploc($i)=$_ploc($i)"
-    #puts "max($i)=$_max($i)"
     #puts "min($i)=$_min($i)"
+    #puts "pmin($i)=$_pmin($i)"
+    #puts "pmax($i)=$_pmax($i)"
+    #puts "pixels($i)=$_pixels($i)"
   }
   set _ploc($i) $_dimension
   set _where($i) 1.0
+
+  # finally, starting at the bottom,
+  # check the _max and _min arrays
+  set _max($totalpanes) $_dimension
+  set _min($totalpanes) $_dimension
+  #puts "_max($totalpanes) = $_max($totalpanes)"
+  for {set i [expr $totalpanes - 1]} {$i > 0} {incr i -1} {
+    set n [expr $i + 1]
+    set m [expr $_max($n) - $_pmin($i)]
+    if {$_max($i) > $m || !$_max($i)} { set _max($i) $m }
+    if {$_pmax($i)} {
+      set m [expr $_min($n) - $_pmax($i)]
+      if {$_min($i) < $m} {set _min($i) $m }
+    }
+    #puts "$i $_max($i) $_min($i)"
+  }
 }
 
 # ------------------------------------------------------------------
@@ -626,25 +645,25 @@ body cyg::PanedWindow::_handleDrag {wher
 #
 # Move the sash to the absolute pixel location
 # ------------------------------------------------------------------
-body cyg::PanedWindow::_moveSash {where num} {
+body cyg::PanedWindow::_moveSash {where num {dir ""}} {
   #puts "moveSash $where $num"
   set _minsashmoved [expr ($_minsashmoved<$num)?$_minsashmoved:$num]
   set _maxsashmoved [expr ($_maxsashmoved>$num)?$_maxsashmoved:$num]
-  _caclPos $where $num
+  _calcPos $where $num $dir
 }
 
 
 # ------------------------------------------------------------------
-# PRIVATE METHOD: _caclPos where num
+# PRIVATE METHOD: _calcPos where num
 #
-# Determines the new position for the sash.  Make sure theposition does
+# Determines the new position for the sash.  Make sure the position does
 # not go past the minimum for the pane on each side of the sash.
 # ------------------------------------------------------------------
-body cyg::PanedWindow::_caclPos {where num} {
-  #puts "calcPos $num $where"
+body cyg::PanedWindow::_calcPos {where num {direction ""}} {
   set dir [expr $where - $_ploc($num)]
+  #puts "calcPos $where $num $dir $direction"
   if {$dir == 0} { return }
-
+  
   # simplify expressions by computing these now
   set m [expr $num-1]
   set p [expr $num+1]
@@ -662,6 +681,7 @@ body cyg::PanedWindow::_caclPos {where n
     # we have stretched the pane above us to the limit
     set upper1 [expr $_ploc($m) + $_pmax($m)]
   }
+
   # we have squeezed the pane below us to the limit
   set upper2 [expr $_ploc($p) - $_pmin($num)]
 
@@ -670,40 +690,40 @@ body cyg::PanedWindow::_caclPos {where n
   #puts "lower1=$lower1 lower2=$lower2 _min($num)=$_min($num)"
   #puts "upper1=$upper1 upper2=$upper2 _max($num)=$_max($num)"
   if {$dir < 0 && $where > $_min($num)} {
-    if {$where < $lower2} {
+    if {$where < $lower2 && $direction != "down"} {
       set done 1
       if {$p == [llength $_activePanes]} {
 	set _ploc($num) $upper2
       } else {
-	_moveSash [expr $where + $_pmax($num)] $p
+	_moveSash [expr $where + $_pmax($num)] $p up
 	set _ploc($num) [expr $_ploc($p) - $_pmax($num)]
       }
     }
-    if {$where < $lower1} {
+    if {$where < $lower1 && $direction != "up"} {
       set done 1
       if {$num == 1} {
 	set _ploc($num) $lower1
       } else {
-	_moveSash [expr $where - $_pmin($m)] $m
+	_moveSash [expr $where - $_pmin($m)] $m down
 	set _ploc($num) [expr $_ploc($m) + $_pmin($m)]
       }
     }
   } elseif {$dir > 0 && ($_max($num) == 0 || $where < $_max($num))} {
-    if {$where > $upper1} {
+    if {$where > $upper1 && $direction != "up"} {
       set done 1
       if {$num == 1} {
 	set _ploc($num) $upper1
       } else {
-	_moveSash [expr $where - $_pmax($m)] $m
+	_moveSash [expr $where - $_pmax($m)] $m down
 	set _ploc($num) [expr $_ploc($m) + $_pmax($m)]
       }
     }
-    if {$where > $upper2} {
+    if {$where > $upper2 && $direction != "down"} {
       set done 1
       if {$p == [llength $_activePanes]} {
 	set _ploc($num) $upper2
       } else {
-	_moveSash [expr $where + $_pmin($num)] $p
+	_moveSash [expr $where + $_pmin($num)] $p up
 	set _ploc($num) [expr $_ploc($p) - $_pmin($num)]
       }
     }
@@ -711,7 +731,6 @@ body cyg::PanedWindow::_caclPos {where n
 
   if {!$done} {
     if {!($_max($num) > 0 && $where > $_max($num)) && $where >= $_min($num)} 
{
-      #puts "ploc($num)=$where"
       set _ploc($num) $where
     }
   }