From e8a9c7bf0a1ef4429ebe7a3a6dbac41c2bc583da Mon Sep 17 00:00:00 2001
From: Norman Walsh <ndw@nwalsh.com>
Date: Fri, 15 Nov 2002 13:50:53 +0000
Subject: [PATCH] Correct rounding errors in column percentage width
 calculation

---
 .../saxon643/com/nwalsh/saxon/Table.java      | 46 ++++++++++++++++++-
 .../xalan2/com/nwalsh/xalan/Table.java        | 46 ++++++++++++++++++-
 2 files changed, 88 insertions(+), 4 deletions(-)

diff --git a/xsl/extensions/saxon643/com/nwalsh/saxon/Table.java b/xsl/extensions/saxon643/com/nwalsh/saxon/Table.java
index cd9add142..c49632a1e 100644
--- a/xsl/extensions/saxon643/com/nwalsh/saxon/Table.java
+++ b/xsl/extensions/saxon643/com/nwalsh/saxon/Table.java
@@ -378,8 +378,9 @@ public class Table {
 	for (int count = 0; count < numColumns; count++) {
 	  float rel = relParts[count] / relTotal * 100;
 	  Float f = new Float(rel);
-	  widths[count] = Integer.toString(f.intValue()) + "%";
+	  widths[count] = Integer.toString(f.intValue());
 	}
+	widths = correctRoundingError(widths);
       } else {
 	int pixelWidth = nominalWidth;
 
@@ -415,8 +416,9 @@ public class Table {
 	  for (int count = 0; count < numColumns; count++) {
 	    float rel = relParts[count] / absTotal * 100;
 	    Float f = new Float(rel);
-	    widths[count] = Integer.toString(f.intValue()) + "%";
+	    widths[count] = Integer.toString(f.intValue());
 	  }
+	  widths = correctRoundingError(widths);
 	}
       }
 
@@ -432,4 +434,44 @@ public class Table {
       return rtf;
     }
   }
+
+  /**
+   * Correct rounding errors introduced in calculating the width of each
+   * column. Make sure they sum to 100% in the end.
+   */
+  protected static String[] correctRoundingError(String widths[]) {
+    int totalWidth = 0;
+
+    for (int count = 0; count < widths.length; count++) {
+      try {
+	int width = Integer.parseInt(widths[count]);
+	totalWidth += width;
+      } catch (NumberFormatException nfe) {
+	// nop; "can't happen"
+      }
+    }
+
+    float totalError = 100 - totalWidth;
+    float columnError = totalError / widths.length;
+    float error = 0;
+
+    for (int count = 0; count < widths.length; count++) {
+      try {
+	int width = Integer.parseInt(widths[count]);
+	error = error + columnError;
+	if (error >= 1.0) {
+	  int adj = (int) Math.round(Math.floor(error));
+	  error = error - (float) Math.floor(error);
+	  width = width + adj;
+	  widths[count] = Integer.toString(width) + "%";
+	} else {
+	  widths[count] = Integer.toString(width) + "%";
+	}
+      } catch (NumberFormatException nfe) {
+	// nop; "can't happen"
+      }
+    }
+
+    return widths;
+  }
 }
diff --git a/xsl/extensions/xalan2/com/nwalsh/xalan/Table.java b/xsl/extensions/xalan2/com/nwalsh/xalan/Table.java
index bad7039e2..58b4d0b59 100644
--- a/xsl/extensions/xalan2/com/nwalsh/xalan/Table.java
+++ b/xsl/extensions/xalan2/com/nwalsh/xalan/Table.java
@@ -357,8 +357,9 @@ public class Table {
       for (int count = 0; count < numColumns; count++) {
 	float rel = relParts[count] / relTotal * 100;
 	Float f = new Float(rel);
-	widths[count] = Integer.toString(f.intValue()) + "%";
+	widths[count] = Integer.toString(f.intValue());
       }
+      widths = correctRoundingError(widths);
     } else {
       int pixelWidth = nominalWidth;
 
@@ -394,8 +395,9 @@ public class Table {
 	for (int count = 0; count < numColumns; count++) {
 	  float rel = relParts[count] / absTotal * 100;
 	  Float f = new Float(rel);
-	  widths[count] = Integer.toString(f.intValue()) + "%";
+	  widths[count] = Integer.toString(f.intValue());
 	}
+	widths = correctRoundingError(widths);
       }
     }
 
@@ -486,4 +488,44 @@ public class Table {
     }
     return attrs;
   }
+
+  /**
+   * Correct rounding errors introduced in calculating the width of each
+   * column. Make sure they sum to 100% in the end.
+   */
+  protected String[] correctRoundingError(String widths[]) {
+    int totalWidth = 0;
+
+    for (int count = 0; count < widths.length; count++) {
+      try {
+	int width = Integer.parseInt(widths[count]);
+	totalWidth += width;
+      } catch (NumberFormatException nfe) {
+	// nop; "can't happen"
+      }
+    }
+
+    float totalError = 100 - totalWidth;
+    float columnError = totalError / widths.length;
+    float error = 0;
+
+    for (int count = 0; count < widths.length; count++) {
+      try {
+	int width = Integer.parseInt(widths[count]);
+	error = error + columnError;
+	if (error >= 1.0) {
+	  int adj = (int) Math.round(Math.floor(error));
+	  error = error - (float) Math.floor(error);
+	  width = width + adj;
+	  widths[count] = Integer.toString(width) + "%";
+	} else {
+	  widths[count] = Integer.toString(width) + "%";
+	}
+      } catch (NumberFormatException nfe) {
+	// nop; "can't happen"
+      }
+    }
+
+    return widths;
+  }
 }
-- 
2.50.1