From f2eb219ce27c52c73497841797addbe33863ac63 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C3=93scar=20Gonz=C3=A1lez=20Fern=C3=A1ndez?=
 <ogonzalez@igalia.com>
Date: Fri, 6 May 2011 19:47:28 +0200
Subject: [PATCH] [Bug #1059] Fix bug

Fractions can overflow if the numerator and the denominators they
carry are big. In that case big decimals are used instead.

FEA: ItEr74S04BugFixing
---
 .../org/zkoss/ganttz/DatesMapperOnInterval.java | 17 +++++++++++++++--
 .../java/org/zkoss/ganttz/util/Interval.java    | 14 +++++++-------
 2 files changed, 22 insertions(+), 9 deletions(-)

diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/DatesMapperOnInterval.java b/ganttzk/src/main/java/org/zkoss/ganttz/DatesMapperOnInterval.java
index 9d13b00c5..b58866c6a 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/DatesMapperOnInterval.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/DatesMapperOnInterval.java
@@ -24,6 +24,9 @@
  */
 package org.zkoss.ganttz;
 
+import java.math.BigDecimal;
+import java.math.RoundingMode;
+
 import org.apache.commons.lang.math.Fraction;
 import org.joda.time.DateTime;
 import org.joda.time.Duration;
@@ -67,8 +70,18 @@ public class DatesMapperOnInterval implements IDatesMapper {
     }
 
     private int toPixels(Fraction proportion) {
-        return proportion.multiplyBy(Fraction.getFraction(horizontalSize, 1))
-                .intValue();
+        try {
+            return proportion.multiplyBy(Fraction.getFraction(horizontalSize, 1))
+                    .intValue();
+        } catch (ArithmeticException e) {
+            double d = Math.log10(horizontalSize);
+            int scale = (int) d + 1;
+            BigDecimal quotient = new BigDecimal(proportion.getNumerator())
+                    .divide(new BigDecimal(proportion.getDenominator()), scale,
+                            RoundingMode.HALF_UP);
+            return quotient.multiply(new BigDecimal(horizontalSize))
+                    .intValue();
+        }
     }
 
     @Override
diff --git a/ganttzk/src/main/java/org/zkoss/ganttz/util/Interval.java b/ganttzk/src/main/java/org/zkoss/ganttz/util/Interval.java
index 8702af1f5..68526d270 100644
--- a/ganttzk/src/main/java/org/zkoss/ganttz/util/Interval.java
+++ b/ganttzk/src/main/java/org/zkoss/ganttz/util/Interval.java
@@ -82,9 +82,13 @@ public class Interval {
     public Fraction getProportion(DateTime date) {
         Days fromStartToDate = Days.daysBetween(startInclusive,
                 date.toLocalDate());
-        Fraction fraction = Fraction.getFraction(fromStartToDate.getDays(),
+        Fraction result = Fraction.getFraction(fromStartToDate.getDays(),
                 this.daysBetween.getDays());
-        return fraction.add(inTheDayIncrement(date));
+        try {
+            return result.add(inTheDayIncrement(date));
+        } catch (ArithmeticException e) {
+            return result;
+        }
     }
 
     private Fraction inTheDayIncrement(DateTime date) {
@@ -92,11 +96,7 @@ public class Interval {
         Duration duration = new Duration(atStartOfDay, date);
         double result = ((double) duration.getMillis())
                 / lengthBetween.getMillis();
-        try {
-            return Fraction.getFraction(result);
-        } catch (ArithmeticException e) {
-            return Fraction.ZERO;
-        }
+        return Fraction.getFraction(result);
     }
 
     @SuppressWarnings("unchecked")