JAL-2388 Unit tests and tidies

[jalview.git] / src / jalview / datamodel / HiddenSequences.java

diff --git a/src/jalview/datamodel/HiddenSequences.java b/src/jalview/datamodel/HiddenSequences.java
index aca0be6..d3aa01a 100755 (executable)
--- a/src/jalview/datamodel/HiddenSequences.java
+++ b/src/jalview/datamodel/HiddenSequences.java
@@ -260,8 +260,14 @@ public class HiddenSequences
     }
     int index = 0;
     int hiddenSeqs = 0;
+    int diff = 0;
     if (hiddenSequences.length <= alignmentIndex)
     {
+      // if the alignmentIndex runs past the end of hidden sequences
+      // and therefore actually past the end of the alignment
+      // store the difference to add back on at the end, so that behaviour
+      // is consistent with hidden columns behaviour (used by overview panel)
+      diff = alignmentIndex - hiddenSequences.length + 1;
       alignmentIndex = hiddenSequences.length - 1;
     }
 
@@ -274,7 +280,42 @@ public class HiddenSequences
       index++;
     }
 
-    return (alignmentIndex - hiddenSeqs);
+    return (alignmentIndex - hiddenSeqs + diff);
+  }
+
+  /**
+   * Find the visible row which is a given visible number of rows above another
+   * visible row. i.e. for a startRow x, the row which is distance 1 away will
+   * be row x-1.
+   * 
+   * @param visibleDistance
+   *          the number of visible rows to offset by
+   * @param startRow
+   *          the row to start from
+   * @return the position of the row in the visible alignment
+   */
+  public int findIndexNAboveRow(int visibleDistance, int startRow)
+  {
+    // walk upwards through the alignment
+    // count all the non-null sequences until we have visibleDistance counted
+    // then return the next visible sequence
+    if (hiddenSequences == null)
+    {
+      return startRow - visibleDistance;
+    }
+
+    int index = startRow;
+    int count = 0;
+    while ((index > -1) && (count < visibleDistance))
+    {
+      if (hiddenSequences[index] == null)
+      {
+        // count visible sequences
+        count++;
+      }
+      index--;
+    }
+    return index;
   }
 
   /**