/*
 * Jalview - A Sequence Alignment Editor and Viewer ($$Version-Rel$$)
 * Copyright (C) $$Year-Rel$$ The Jalview Authors
 * 
 * This file is part of Jalview.
 * 
 * Jalview is free software: you can redistribute it and/or
 * modify it under the terms of the GNU General Public License 
 * as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *  
 * Jalview is distributed in the hope that it will be useful, but 
 * WITHOUT ANY WARRANTY; without even the implied warranty 
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
 * PURPOSE.  See the GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with Jalview.  If not, see <http://www.gnu.org/licenses/>.
 * The Jalview Authors are detailed in the 'AUTHORS' file.
 */
package jalview.datamodel;

import static org.testng.AssertJUnit.assertEquals;
import static org.testng.AssertJUnit.assertFalse;
import static org.testng.AssertJUnit.assertSame;
import static org.testng.AssertJUnit.assertTrue;
import static org.testng.AssertJUnit.fail;

import java.util.Arrays;
import java.util.BitSet;
import java.util.Collections;
import java.util.ConcurrentModificationException;
import java.util.List;

import org.testng.annotations.Test;

public class ColumnSelectionTest
{

  @Test(groups = { "Functional" })
  public void testAddElement()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(2);
    cs.addElement(5);
    cs.addElement(3);
    cs.addElement(5); // ignored
    List<Integer> sel = cs.getSelected();
    assertEquals("[2, 5, 3]", sel.toString());
  }

  /**
   * Test the remove method - in particular to verify that remove(int i) removes
   * the element whose value is i, _NOT_ the i'th element.
   */
  @Test(groups = { "Functional" })
  public void testRemoveElement()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(2);
    cs.addElement(5);

    // removing elements not in the list has no effect
    cs.removeElement(0);
    cs.removeElement(1);
    List<Integer> sel = cs.getSelected();
    assertEquals(2, sel.size());
    assertEquals(new Integer(2), sel.get(0));
    assertEquals(new Integer(5), sel.get(1));

    // removing an element in the list removes it
    cs.removeElement(2);
    // ...and also from the read-only view
    assertEquals(1, sel.size());
    sel = cs.getSelected();
    assertEquals(1, sel.size());
    assertEquals(new Integer(5), sel.get(0));
  }

  /**
   * Test the method that finds the visible column position of an alignment
   * column, allowing for hidden columns.
   */
  @Test(groups = { "Functional" })
  public void testFindColumnPosition()
  {
    ColumnSelection cs = new ColumnSelection();
    assertEquals(5, cs.findColumnPosition(5));

    // hiding column 6 makes no difference
    cs.hideColumns(6, 6);
    assertEquals(5, cs.findColumnPosition(5));

    // hiding column 4 moves column 5 to column 4
    cs.hideColumns(4, 4);
    assertEquals(4, cs.findColumnPosition(5));

    // hiding columns 1 and 2 moves column 5 to column 2
    cs.hideColumns(1, 2);
    assertEquals(2, cs.findColumnPosition(5));
  }

  /**
   * Test the code used to locate the reference sequence ruler origin
   */
  @Test(groups = { "Functional" })
  public void testLocateVisibleBoundsofSequence()
  {
    ColumnSelection cs = new ColumnSelection();
    SequenceI seq = new Sequence("RefSeq", "-A-SD-ASD--E---");
    assertEquals(2, seq.findIndex(seq.getStart()));

    // no hidden columns
    assertEquals(
            Arrays.toString(new int[] { seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1, seq.getStart(),
                seq.getEnd(), seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1 }),
            Arrays.toString(cs.locateVisibleBoundsOfSequence(seq)));

    // hidden column on gap after end of sequence - should not affect bounds
    cs.hideColumns(13);
    assertEquals(
            Arrays.toString(new int[] { seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1, seq.getStart(),
                seq.getEnd(), seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1 }),
            Arrays.toString(cs.locateVisibleBoundsOfSequence(seq)));

    cs.revealAllHiddenColumns();
    // hidden column on gap before beginning of sequence - should vis bounds by
    // one
    cs.hideColumns(0);
    assertEquals(
            Arrays.toString(new int[] { seq.findIndex(seq.getStart()) - 2,
                seq.findIndex(seq.getEnd()) - 2, seq.getStart(),
                seq.getEnd(), seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1 }),
            Arrays.toString(cs.locateVisibleBoundsOfSequence(seq)));

    cs.revealAllHiddenColumns();
    // hide columns around most of sequence - leave one residue remaining
    cs.hideColumns(1, 3);
    cs.hideColumns(6, 11);
    assertEquals("-D",
            cs.getVisibleSequenceStrings(0, 5, new SequenceI[] { seq })[0]);
    assertEquals(
            Arrays.toString(new int[] { 1, 1, 3, 3,
                seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1 }),
            Arrays.toString(cs.locateVisibleBoundsOfSequence(seq)));
    cs.revealAllHiddenColumns();

    // hide whole sequence - should just get location of hidden region
    // containing sequence
    cs.hideColumns(1, 11);
    assertEquals(
            Arrays.toString(new int[] { 0, 1, 0, 0,
                seq.findIndex(seq.getStart()) - 1,
                seq.findIndex(seq.getEnd()) - 1 }),
            Arrays.toString(cs.locateVisibleBoundsOfSequence(seq)));

  }

  @Test(groups={"Functional"})
  public void testLocateVisibleBoundsPathologicals()
  {
    // test some pathological cases we missed
    AlignmentI al = new Alignment(new SequenceI[] { new Sequence("refseqGaptest","KTDVTI----------NFI-----G----L")});
    ColumnSelection cs = new ColumnSelection();
    cs.hideInsertionsFor(al.getSequenceAt(0));
    assertEquals(
            "G",
            ""
                    + al.getSequenceAt(0).getCharAt(
                            cs.adjustForHiddenColumns(9)));


  }
  @Test(groups = { "Functional" })
  public void testHideColumns()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.hideColumns(5);
    List<int[]> hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[5, 5]", Arrays.toString(hidden.get(0)));

    cs.hideColumns(3);
    assertEquals(2, hidden.size());
    // two hidden ranges, in order:
    assertSame(hidden, cs.getHiddenColumns());
    assertEquals("[3, 3]", Arrays.toString(hidden.get(0)));
    assertEquals("[5, 5]", Arrays.toString(hidden.get(1)));

    // hiding column 4 expands [3, 3] to [3, 4]
    // not fancy enough to coalesce this into [3, 5] though
    cs.hideColumns(4);
    hidden = cs.getHiddenColumns();
    assertEquals(2, hidden.size());
    assertEquals("[3, 4]", Arrays.toString(hidden.get(0)));
    assertEquals("[5, 5]", Arrays.toString(hidden.get(1)));

    // clear hidden columns (note they are added to selected)
    cs.revealAllHiddenColumns();
    // it is now actually null but getter returns an empty list
    assertTrue(cs.getHiddenColumns().isEmpty());

    cs.hideColumns(3, 6);
    hidden = cs.getHiddenColumns();
    int[] firstHiddenRange = hidden.get(0);
    assertEquals("[3, 6]", Arrays.toString(firstHiddenRange));

    // adding a subrange of already hidden should do nothing
    cs.hideColumns(4, 5);
    assertEquals(1, hidden.size());
    assertSame(firstHiddenRange, cs.getHiddenColumns().get(0));
    cs.hideColumns(3, 5);
    assertEquals(1, hidden.size());
    assertSame(firstHiddenRange, cs.getHiddenColumns().get(0));
    cs.hideColumns(4, 6);
    assertEquals(1, hidden.size());
    assertSame(firstHiddenRange, cs.getHiddenColumns().get(0));
    cs.hideColumns(3, 6);
    assertEquals(1, hidden.size());
    assertSame(firstHiddenRange, cs.getHiddenColumns().get(0));

    cs.revealAllHiddenColumns();
    cs.hideColumns(2, 4);
    hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[2, 4]", Arrays.toString(hidden.get(0)));

    // extend contiguous with 2 positions overlap
    cs.hideColumns(3, 5);
    assertEquals(1, hidden.size());
    assertEquals("[2, 5]", Arrays.toString(hidden.get(0)));

    // extend contiguous with 1 position overlap
    cs.hideColumns(5, 6);
    assertEquals(1, hidden.size());
    assertEquals("[2, 6]", Arrays.toString(hidden.get(0)));

    // extend contiguous with overlap both ends:
    cs.hideColumns(1, 7);
    assertEquals(1, hidden.size());
    assertEquals("[1, 7]", Arrays.toString(hidden.get(0)));
  }

  /**
   * Test the method that hides a specified column including any adjacent
   * selected columns. This is a convenience method for the case where multiple
   * column regions are selected and then hidden using menu option View | Hide |
   * Selected Columns.
   */
  @Test(groups = { "Functional" })
  public void testHideColumns_withSelection()
  {
    ColumnSelection cs = new ColumnSelection();
    // select columns 4-6
    cs.addElement(4);
    cs.addElement(5);
    cs.addElement(6);
    // hide column 5 (and adjacent):
    cs.hideColumns(5);
    // 4,5,6 now hidden:
    List<int[]> hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[4, 6]", Arrays.toString(hidden.get(0)));
    // none now selected:
    assertTrue(cs.getSelected().isEmpty());

    // repeat, hiding column 4 (5 and 6)
    cs = new ColumnSelection();
    cs.addElement(4);
    cs.addElement(5);
    cs.addElement(6);
    cs.hideColumns(4);
    hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[4, 6]", Arrays.toString(hidden.get(0)));
    assertTrue(cs.getSelected().isEmpty());

    // repeat, hiding column (4, 5 and) 6
    cs = new ColumnSelection();
    cs.addElement(4);
    cs.addElement(5);
    cs.addElement(6);
    cs.hideColumns(6);
    hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[4, 6]", Arrays.toString(hidden.get(0)));
    assertTrue(cs.getSelected().isEmpty());

    // repeat, with _only_ adjacent columns selected
    cs = new ColumnSelection();
    cs.addElement(4);
    cs.addElement(6);
    cs.hideColumns(5);
    hidden = cs.getHiddenColumns();
    assertEquals(1, hidden.size());
    assertEquals("[4, 6]", Arrays.toString(hidden.get(0)));
    assertTrue(cs.getSelected().isEmpty());
  }

  /**
   * Test the method that hides all (possibly disjoint) selected column ranges
   */
  @Test(groups = { "Functional" })
  public void testHideSelectedColumns()
  {
    ColumnSelection cs = new ColumnSelection();
    int[] sel = { 2, 3, 4, 7, 8, 9, 20, 21, 22 };
    for (int col : sel)
    {
      cs.addElement(col);
    }
    cs.hideColumns(15, 18);

    cs.hideSelectedColumns();
    assertTrue(cs.getSelected().isEmpty());
    List<int[]> hidden = cs.getHiddenColumns();
    assertEquals(4, hidden.size());
    assertEquals("[2, 4]", Arrays.toString(hidden.get(0)));
    assertEquals("[7, 9]", Arrays.toString(hidden.get(1)));
    assertEquals("[15, 18]", Arrays.toString(hidden.get(2)));
    assertEquals("[20, 22]", Arrays.toString(hidden.get(3)));
  }

  /**
   * Test the method that gets runs of selected columns ordered by column. If
   * this fails, HideSelectedColumns may also fail
   */
  @Test(groups = { "Functional" })
  public void testGetSelectedRanges()
  {
    /*
     * getSelectedRanges returns ordered columns regardless
     * of the order in which they are added
     */
    ColumnSelection cs = new ColumnSelection();
    int[] sel = { 4, 3, 7, 21, 9, 20, 8, 22, 2 };
    for (int col : sel)
    {
      cs.addElement(col);
    }
    List<int[]> range;
    range = cs.getSelectedRanges();
    assertEquals(3, range.size());
    assertEquals("[2, 4]", Arrays.toString(range.get(0)));
    assertEquals("[7, 9]", Arrays.toString(range.get(1)));
    assertEquals("[20, 22]", Arrays.toString(range.get(2)));
    cs.addElement(0);
    cs.addElement(1);
    range = cs.getSelectedRanges();
    assertEquals(3, range.size());
    assertEquals("[0, 4]", Arrays.toString(range.get(0)));
  }

  /**
   * Test the method that reveals a range of hidden columns given the start
   * column of the range
   */
  @Test(groups = { "Functional" })
  public void testRevealHiddenColumns()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.hideColumns(5, 8);
    cs.addElement(10);
    cs.revealHiddenColumns(5);
    // hidden columns list now null but getter returns empty list:
    assertTrue(cs.getHiddenColumns().isEmpty());
    // revealed columns are marked as selected (added to selection):
    assertEquals("[10, 5, 6, 7, 8]", cs.getSelected().toString());

    // calling with a column other than the range start does nothing:
    cs = new ColumnSelection();
    cs.hideColumns(5, 8);
    List<int[]> hidden = cs.getHiddenColumns();
    cs.revealHiddenColumns(6);
    assertSame(hidden, cs.getHiddenColumns());
    assertTrue(cs.getSelected().isEmpty());
  }

  @Test(groups = { "Functional" })
  public void testRevealAllHiddenColumns()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.hideColumns(5, 8);
    cs.hideColumns(2, 3);
    cs.addElement(11);
    cs.addElement(1);
    cs.revealAllHiddenColumns();

    /*
     * revealing hidden columns adds them (in order) to the (unordered)
     * selection list
     */
    assertTrue(cs.getHiddenColumns().isEmpty());
    assertEquals("[11, 1, 2, 3, 5, 6, 7, 8]", cs.getSelected().toString());
  }

  @Test(groups = { "Functional" })
  public void testIsVisible()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.hideColumns(2, 4);
    cs.hideColumns(6, 7);
    assertTrue(cs.isVisible(0));
    assertTrue(cs.isVisible(-99));
    assertTrue(cs.isVisible(1));
    assertFalse(cs.isVisible(2));
    assertFalse(cs.isVisible(3));
    assertFalse(cs.isVisible(4));
    assertTrue(cs.isVisible(5));
    assertFalse(cs.isVisible(6));
    assertFalse(cs.isVisible(7));
  }

  @Test(groups = { "Functional" })
  public void testGetVisibleContigs()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.hideColumns(3, 6);
    cs.hideColumns(8, 9);
    cs.hideColumns(12, 12);

    // start position is inclusive, end position exclusive:
    int[] visible = cs.getVisibleContigs(1, 13);
    assertEquals("[1, 2, 7, 7, 10, 11]", Arrays.toString(visible));

    visible = cs.getVisibleContigs(4, 14);
    assertEquals("[7, 7, 10, 11, 13, 13]", Arrays.toString(visible));

    visible = cs.getVisibleContigs(3, 10);
    assertEquals("[7, 7]", Arrays.toString(visible));

    visible = cs.getVisibleContigs(4, 6);
    assertEquals("[]", Arrays.toString(visible));
  }

  @Test(groups = { "Functional" })
  public void testInvertColumnSelection()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(4);
    cs.addElement(6);
    cs.addElement(8);
    cs.hideColumns(3, 3);
    cs.hideColumns(6, 6);

    // invert selection from start (inclusive) to end (exclusive)
    // hidden columns are _not_ changed
    cs.invertColumnSelection(2, 9);
    assertEquals("[2, 5, 7]", cs.getSelected().toString());

    cs.invertColumnSelection(1, 9);
    assertEquals("[1, 4, 8]", cs.getSelected().toString());
  }

  @Test(groups = { "Functional" })
  public void testMaxColumnSelection()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(0);
    cs.addElement(513);
    cs.addElement(1);
    assertEquals(513, cs.getMax());
    cs.removeElement(513);
    assertEquals(1, cs.getMax());
    cs.removeElement(1);
    assertEquals(0, cs.getMax());
    cs.addElement(512);
    cs.addElement(513);
    assertEquals(513, cs.getMax());

  }

  @Test(groups = { "Functional" })
  public void testMinColumnSelection()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(0);
    cs.addElement(513);
    cs.addElement(1);
    assertEquals(0, cs.getMin());
    cs.removeElement(0);
    assertEquals(1, cs.getMin());
    cs.addElement(0);
    assertEquals(0, cs.getMin());
  }

  @Test(groups = { "Functional" })
  public void testEquals()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(0);
    cs.addElement(513);
    cs.addElement(1);
    cs.hideColumns(3);
    cs.hideColumns(7);
    cs.hideColumns(5,9);

    // same selections added in a different order
    ColumnSelection cs2 = new ColumnSelection();
    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);
    
    assertTrue(cs.equals(cs2));
    assertTrue(cs.equals(cs));
    assertTrue(cs2.equals(cs));
    assertTrue(cs2.equals(cs2));

    cs2.addElement(12);
    assertFalse(cs.equals(cs2));
    assertFalse(cs2.equals(cs));

    cs2.removeElement(12);
    assertTrue(cs.equals(cs2));

    cs2.hideColumns(88);
    assertFalse(cs.equals(cs2));
    /*
     * unhiding a column adds it to selection!
     */
    cs2.revealHiddenColumns(88);
    assertFalse(cs.equals(cs2));
    cs.addElement(88);
    assertTrue(cs.equals(cs2));
  }

  /**
   * Test the method that returns selected columns, in the order in which they
   * were added
   */
  @Test(groups = { "Functional" })
  public void testGetSelected()
  {
    ColumnSelection cs = new ColumnSelection();
    int[] sel = { 4, 3, 7, 21 };
    for (int col : sel)
    {
      cs.addElement(col);
    }

    List<Integer> selected = cs.getSelected();
    assertEquals(4, selected.size());
    assertEquals("[4, 3, 7, 21]", selected.toString());

    /*
     * getSelected returns a read-only view of the list
     * verify the view follows any changes in it
     */
    cs.removeElement(7);
    cs.addElement(1);
    cs.removeElement(4);
    assertEquals("[3, 21, 1]", selected.toString());
  }

  /**
   * Test to verify that the list returned by getSelection cannot be modified
   */
  @Test(groups = { "Functional" })
  public void testGetSelected_isReadOnly()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(3);

    List<Integer> selected = cs.getSelected();
    try
    {
      selected.clear();
      fail("expected exception");
    } catch (UnsupportedOperationException e)
    {
      // expected
    }
    try
    {
      selected.add(1);
      fail("expected exception");
    } catch (UnsupportedOperationException e)
    {
      // expected
    }
    try
    {
      selected.remove(3);
      fail("expected exception");
    } catch (UnsupportedOperationException e)
    {
      // expected
    }
    try
    {
      Collections.sort(selected);
      fail("expected exception");
    } catch (UnsupportedOperationException e)
    {
      // expected
    }
  }

  /**
   * Test that demonstrates a ConcurrentModificationException is thrown if you
   * change the selection while iterating over it
   */
  @Test(
    groups = "Functional",
    expectedExceptions = { ConcurrentModificationException.class })
  public void testGetSelected_concurrentModification()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(0);
    cs.addElement(1);
    cs.addElement(2);

    /*
     * simulate changing the list under us (e.g. in a separate
     * thread) while iterating over it -> ConcurrentModificationException
     */
    List<Integer> selected = cs.getSelected();
    for (Integer col : selected)
    {
      if (col.intValue() == 0)
      {
        cs.removeElement(1);
      }
    }
  }

  @Test(groups = "Functional")
  public void testMarkColumns()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(5); // this will be cleared
    BitSet toMark = new BitSet();
    toMark.set(1);
    toMark.set(3);
    toMark.set(6);
    toMark.set(9);

    assertTrue(cs.markColumns(toMark, 3, 8, false, false, false));
    List<Integer> selected = cs.getSelected();
    assertEquals(2, selected.size());
    assertTrue(selected.contains(3));
    assertTrue(selected.contains(6));
  }

  @Test(groups = "Functional")
  public void testMarkColumns_extend()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(1);
    cs.addElement(5);
    BitSet toMark = new BitSet();
    toMark.set(1);
    toMark.set(3);
    toMark.set(6);
    toMark.set(9);

    /*
     * extending selection of {3, 6} should leave {1, 3, 5, 6} selected
     */
    assertTrue(cs.markColumns(toMark, 3, 8, false, true, false));
    List<Integer> selected = cs.getSelected();
    assertEquals(4, selected.size());
    assertTrue(selected.contains(1));
    assertTrue(selected.contains(3));
    assertTrue(selected.contains(5));
    assertTrue(selected.contains(6));
  }

  @Test(groups = "Functional")
  public void testMarkColumns_invert()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(5); // this will be cleared
    BitSet toMark = new BitSet();
    toMark.set(1);
    toMark.set(3);
    toMark.set(6);
    toMark.set(9);

    /*
     * inverted selection of {3, 6} should select {4, 5, 7, 8}
     */
    assertTrue(cs.markColumns(toMark, 3, 8, true, false, false));
    List<Integer> selected = cs.getSelected();
    assertEquals(4, selected.size());
    assertTrue(selected.contains(4));
    assertTrue(selected.contains(5));
    assertTrue(selected.contains(7));
    assertTrue(selected.contains(8));
  }

  @Test(groups = "Functional")
  public void testMarkColumns_toggle()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(1); // outside change range
    cs.addElement(3);
    cs.addElement(4);
    cs.addElement(10); // outside change range
    BitSet toMark = new BitSet();
    toMark.set(1);
    toMark.set(3);
    toMark.set(6);
    toMark.set(9);

    /*
     * toggling state of {3, 6} should leave {1, 4, 6, 10} selected
     */
    assertTrue(cs.markColumns(toMark, 3, 8, false, false, true));
    List<Integer> selected = cs.getSelected();
    assertEquals(4, selected.size());
    assertTrue(selected.contains(1));
    assertTrue(selected.contains(4));
    assertTrue(selected.contains(6));
    assertTrue(selected.contains(10));
  }

  @Test(groups = "Functional")
  public void testCopyConstructor()
  {
    ColumnSelection cs = new ColumnSelection();
    cs.addElement(3);
    cs.addElement(1);
    cs.hideColumns(10, 11);
    cs.hideColumns(5, 7);
    assertEquals("[5, 7]", Arrays.toString(cs.getHiddenColumns().get(0)));

    ColumnSelection cs2 = new ColumnSelection(cs);
    assertTrue(cs2.hasSelectedColumns());
    assertTrue(cs2.hasHiddenColumns());
    // order of column selection is preserved
    assertEquals("[3, 1]", cs2.getSelected().toString());
    assertEquals(2, cs2.getHiddenColumns().size());
    // hidden columns are held in column order
    assertEquals("[5, 7]", Arrays.toString(cs2.getHiddenColumns().get(0)));
    assertEquals("[10, 11]", Arrays.toString(cs2.getHiddenColumns().get(1)));
  }
}