From 528191d2feb45cd42c5b4f48420687346705119d Mon Sep 17 00:00:00 2001
From: gmungoc <g.m.carstairs@dundee.ac.uk>
Date: Mon, 30 May 2016 14:46:13 +0100
Subject: [PATCH] JAL-1989 equals method strengthened to fully match
 selection/hidden cols

---
 src/jalview/datamodel/ColumnSelection.java      |   48 +++++++++++++++++++++--
 test/jalview/datamodel/ColumnSelectionTest.java |    6 +++
 2 files changed, 51 insertions(+), 3 deletions(-)

diff --git a/src/jalview/datamodel/ColumnSelection.java b/src/jalview/datamodel/ColumnSelection.java
index 74c58b7..aaf70b8 100644
--- a/src/jalview/datamodel/ColumnSelection.java
+++ b/src/jalview/datamodel/ColumnSelection.java
@@ -1651,14 +1651,56 @@ public class ColumnSelection
     return hashCode;
   }
 
+  /**
+   * Answers true if comparing to a ColumnSelection with the same selected
+   * columns and hidden columns, else false
+   */
   @Override
   public boolean equals(Object obj)
   {
-    if (obj instanceof ColumnSelection)
+    if (!(obj instanceof ColumnSelection))
     {
-      return hashCode() == obj.hashCode();
+      return false;
     }
-    return false;
+    ColumnSelection that = (ColumnSelection) obj;
+
+    /*
+     * check columns selected are either both null, or match
+     */
+    if (this.selection == null)
+    {
+      if (that.selection != null)
+      {
+        return false;
+      }
+    }
+    if (!this.selection.equals(that.selection))
+    {
+      return false;
+    }
+
+    /*
+     * check hidden columns are either both null, or match
+     */
+    if (this.hiddenColumns == null)
+    {
+      return (that.hiddenColumns == null);
+    }
+    if (that.hiddenColumns == null
+            || that.hiddenColumns.size() != this.hiddenColumns.size())
+    {
+      return false;
+    }
+    int i = 0;
+    for (int[] thisRange : hiddenColumns)
+    {
+      int[] thatRange = that.hiddenColumns.get(i++);
+      if (thisRange[0] != thatRange[0] || thisRange[1] != thatRange[1])
+      {
+        return false;
+      }
+    }
+    return true;
   }
 
 }
diff --git a/test/jalview/datamodel/ColumnSelectionTest.java b/test/jalview/datamodel/ColumnSelectionTest.java
index e1d04eb..1a7ae32 100644
--- a/test/jalview/datamodel/ColumnSelectionTest.java
+++ b/test/jalview/datamodel/ColumnSelectionTest.java
@@ -495,6 +495,12 @@ public class ColumnSelectionTest
     cs2.addElement(1);
     cs2.addElement(513);
     cs2.addElement(0);
+
+    // with no hidden columns
+    assertFalse(cs.equals(cs2));
+    assertFalse(cs2.equals(cs));
+
+    // with hidden columns added in a different order
     cs2.hideColumns(6, 9);
     cs2.hideColumns(5, 8);
     cs2.hideColumns(3);
-- 
1.7.10.2