From 7bfa509c88f79ec899e7e6ebdb775d3c83e420f9 Mon Sep 17 00:00:00 2001
From: charlie <charlie@xwt.org>
Date: Tue, 30 Mar 2004 13:29:13 +0000
Subject: [PATCH] Full fix for Bug 471

This patch also gives a slight speed increase due to
increased efficiency at handing out slack

darcs-hash:20040330132913-b408a-ee466c2fb945c5b7f159e62d58ad0c2de9e3e482.gz
---
 src/org/ibex/Box.java |   28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/src/org/ibex/Box.java b/src/org/ibex/Box.java
index 180a652..514d301 100644
--- a/src/org/ibex/Box.java
+++ b/src/org/ibex/Box.java
@@ -295,30 +295,32 @@ public final class Box extends JSScope implements Scheduler.Task {
         //#repeat col/row colspan/rowspan contentwidth/contentheight x/y width/height colMaxWidth/rowMaxHeight colWidth/rowHeight \
         //        HSHRINK/VSHRINK maxwidth/maxheight cols/rows minwidth/minheight colWidth/rowHeight x_slack/y_slack
         // PHASE 1: compute column min/max sizes
-        int x_slack = width;
-        for(int i=0; i<cols; i++) x_slack -= colWidth[i];
         for(Box child = firstPackedChild(); child != null; child = child.nextPackedSibling())
             for(int i=child.col; i < child.col + child.colspan; i++) {
-                x_slack += colWidth[i];
                 colWidth[i] = max(colWidth[i], child.contentwidth / child.colspan);
-                x_slack -= colWidth[i];
                 colMaxWidth[i] = max(colMaxWidth[i], (child.test(HSHRINK) ? child.contentwidth : child.maxwidth) / child.colspan);
             }
         
         // PHASE 2: hand out slack
-        for(int startslack = 0; x_slack > 0 && cols > 0 && startslack != x_slack;) {
-            int increment = max(1, x_slack / cols);
-            startslack = x_slack;
-            for(short col=0; col < cols; col++) {
-                // FIXME: double check this
-                int diff = min(min(colMaxWidth[col], colWidth[col] + increment) - colWidth[col], x_slack);
-                x_slack -= diff;
+        int x_slack = width;
+        for(int i=0; i<cols; i++) x_slack -= colWidth[i]; 
+        // loop through until there are no more eligible children or all slack is handed out
+        for(int eligible = cols, slacklevel = 0; x_slack > 0 && eligible > 0;) {
+            int increment = max(1, x_slack / eligible);
+            eligible = 0;
+            for(short col=0, count=0; col < cols; col++) {
+                if (colMaxWidth[col] <= colWidth[col]) continue;
+                if (slacklevel + increment < colWidth[col]) { eligible++; continue; }
+                int diff = min(increment, min(colMaxWidth[col] - colWidth[col], slacklevel + increment - colWidth[col]));
+                eligible++;
                 colWidth[col] += diff;
+                x_slack -= diff;
             }
-        }   
+            slacklevel += increment;
+        }
         //#end
 
-        // Phase 3: assign childrens' actual sizes
+        // PHASE 3: assign childrens' actual sizes
         for(Box child = getChild(0); child != null; child = child.nextSibling()) {
             if (!child.test(VISIBLE)) continue;
             int child_width, child_height, child_x, child_y;
-- 
1.7.10.4