content: //  Copyright 2006, Clark N. Hobbie
  //
  //  This file is part of the util library.
  //
  //  The util library is free software; you can redistribute it and/or modify it
  //  under the terms of the Lesser GNU General Public License as published by
  //  the Free Software Foundation; either version 2.1 of the License, or (at
  //  your option) any later version.
  //
  //  The util library 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 Lesser GNU General Public
  //  License for more details.
  //
  //  You should have received a copy of the Lesser GNU General Public License
  //  along with the util library; if not, write to the Free Software Foundation,
  //  Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  //
  package com.lts.swing.table;
  
  
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.Graphics;
  import java.awt.event.MouseAdapter;
  import java.awt.event.MouseEvent;
  import java.awt.event.MouseListener;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  import javax.swing.Icon;
  import javax.swing.JLabel;
  import javax.swing.JTable;
  import javax.swing.event.TableModelEvent;
  import javax.swing.event.TableModelListener;
  import javax.swing.table.AbstractTableModel;
  import javax.swing.table.JTableHeader;
  import javax.swing.table.TableCellRenderer;
  import javax.swing.table.TableColumnModel;
  import javax.swing.table.TableModel;
  
  /**
   * TableSorter is a decorator for TableModels; adding sorting
   * functionality to a supplied TableModel. TableSorter does
   * not store or copy the data in its TableModel; instead it maintains
   * a map from the row indexes of the view to the row indexes of the
   * model. As requests are made of the sorter (like getValueAt(row, col))
   * they are passed to the underlying model after the row numbers
   * have been translated via the internal mapping array. This way,
   * the TableSorter appears to hold another copy of the table
   * with the rows in a different order.
   * <p/>
   * TableSorter registers itself as a listener to the underlying model,
   * just as the JTable itself would. Events recieved from the model
   * are examined, sometimes manipulated (typically widened), and then
   * passed on to the TableSorter's listeners (typically the JTable).
   * If a change to the model has invalidated the order of TableSorter's
   * rows, a note of this is made and the sorter will resort the
   * rows the next time a value is requested.
   * <p/>
   * When the tableHeader property is set, either by using the
   * setTableHeader() method or the two argument constructor, the
   * table header may be used as a complete UI for TableSorter.
   * The default renderer of the tableHeader is decorated with a renderer
   * that indicates the sorting status of each column. In addition,
   * a mouse listener is installed with the following behavior:
   * <ul>
   * <li>
   * Mouse-click: Clears the sorting status of all other columns
   * and advances the sorting status of that column through three
   * values: {NOT_SORTED, ASCENDING, DESCENDING} (then back to
   * NOT_SORTED again).
   * <li>
   * SHIFT-mouse-click: Clears the sorting status of all other columns
   * and cycles the sorting status of the column through the same
   * three values, in the opposite order: {NOT_SORTED, DESCENDING, ASCENDING}.
   * <li>
   * CONTROL-mouse-click and CONTROL-SHIFT-mouse-click: as above except
   * that the changes to the column do not cancel the statuses of columns
   * that are already sorting - giving a way to initiate a compound
   * sort.
   * </ul>
   * <p/>
   * This is a long overdue rewrite of a class of the same name that
   * first appeared in the swing table demos in 1997.
   * 
   * @author Philip Milne
   * @author Brendon McLean 
   * @author Dan van Enckevort
   * @author Parwinder Sekhon
   * @version 2.0 02/27/04
   */
  
  public class TableSorter extends AbstractTableModel {
      /**
  	 * 
  	 */
  	private static final long serialVersionUID = 1L;
  
  	protected TableModel tableModel;
  
      public static final int DESCENDING = -1;
      public static final int NOT_SORTED = 0;
      public static final int ASCENDING = 1;
  
      private static Directive EMPTY_DIRECTIVE = new Directive(-1, NOT_SORTED);
  
      public static final Comparator COMPARABLE_COMAPRATOR = new Comparator() {
          public int compare(Object o1, Object o2) {
              return ((Comparable) o1).compareTo(o2);
          }
      };
      public static final Comparator LEXICAL_COMPARATOR = new Comparator() {
          public int compare(Object o1, Object o2) {
              return o1.toString().compareTo(o2.toString());
          }
      };
  
      private Row[] viewToModel;
      private int[] modelToView;
  
      private JTableHeader tableHeader;
      private MouseListener mouseListener;
      private TableModelListener tableModelListener;
      private Map columnComparators = new HashMap();
      private List sortingColumns = new ArrayList();
  
      public TableSorter() {
          this.mouseListener = new MouseHandler();
          this.tableModelListener = new TableModelHandler();
      }
  
      public TableSorter(TableModel tableModel) {
          this();
          setTableModel(tableModel);
      }
  
      public TableSorter(TableModel tableModel, JTableHeader tableHeader) {
          this();
          setTableHeader(tableHeader);
          setTableModel(tableModel);
      }
  
      private void clearSortingState() {
          viewToModel = null;
          modelToView = null;
      }
  
      public TableModel getTableModel() {
          return tableModel;
      }
  
      public void setTableModel(TableModel tableModel) {
          if (this.tableModel != null) {
              this.tableModel.removeTableModelListener(tableModelListener);
          }
  
          this.tableModel = tableModel;
          if (this.tableModel != null) {
              this.tableModel.addTableModelListener(tableModelListener);
          }
  
          clearSortingState();
          fireTableStructureChanged();
      }
  
      public JTableHeader getTableHeader() {
          return tableHeader;
      }
  
      public void setTableHeader(JTableHeader tableHeader) {
          if (this.tableHeader != null) {
              this.tableHeader.removeMouseListener(mouseListener);
              TableCellRenderer defaultRenderer = this.tableHeader.getDefaultRenderer();
              if (defaultRenderer instanceof SortableHeaderRenderer) {
                  this.tableHeader.setDefaultRenderer(((SortableHeaderRenderer) defaultRenderer).tableCellRenderer);
              }
          }
          this.tableHeader = tableHeader;
          if (this.tableHeader != null) {
              this.tableHeader.addMouseListener(mouseListener);
              this.tableHeader.setDefaultRenderer(
                      new SortableHeaderRenderer(this.tableHeader.getDefaultRenderer()));
          }
      }
  
      public boolean isSorting() {
          return sortingColumns.size() != 0;
      }
  
      private Directive getDirective(int column) {
          for (int i = 0; i < sortingColumns.size(); i++) {
              Directive directive = (Directive)sortingColumns.get(i);
              if (directive.column == column) {
                  return directive;
              }
          }
          return EMPTY_DIRECTIVE;
      }
  
      public int getSortingStatus(int column) {
          return getDirective(column).direction;
      }
  
      private void sortingStatusChanged() {
          clearSortingState();
          fireTableDataChanged();
          if (tableHeader != null) {
              tableHeader.repaint();
          }
      }
  
      public void setSortingStatus(int column, int status) {
          Directive directive = getDirective(column);
          if (directive != EMPTY_DIRECTIVE) {
              sortingColumns.remove(directive);
          }
          if (status != NOT_SORTED) {
              sortingColumns.add(new Directive(column, status));
          }
          sortingStatusChanged();
      }
  
      protected Icon getHeaderRendererIcon(int column, int size) {
          Directive directive = getDirective(column);
          if (directive == EMPTY_DIRECTIVE) {
              return null;
          }
          return new Arrow(directive.direction == DESCENDING, size, sortingColumns.indexOf(directive));
      }
  
      private void cancelSorting() {
          sortingColumns.clear();
          sortingStatusChanged();
      }
  
      public void setColumnComparator(Class type, Comparator comparator) {
          if (comparator == null) {
              columnComparators.remove(type);
          } else {
              columnComparators.put(type, comparator);
          }
      }
  
      protected Comparator getComparator(int column) {
          Class columnType = tableModel.getColumnClass(column);
          Comparator comparator = (Comparator) columnComparators.get(columnType);
          if (comparator != null) {
              return comparator;
          }
          if (Comparable.class.isAssignableFrom(columnType)) {
              return COMPARABLE_COMAPRATOR;
          }
          return LEXICAL_COMPARATOR;
      }
  
      private Row[] getViewToModel() {
          if (viewToModel == null) {
              int tableModelRowCount = tableModel.getRowCount();
              viewToModel = new Row[tableModelRowCount];
              for (int row = 0; row < tableModelRowCount; row++) {
                  viewToModel[row] = new Row(row);
              }
  
              if (isSorting()) {
                  Arrays.sort(viewToModel);
              }
          }
          return viewToModel;
      }
  
      public int modelIndex(int viewIndex) {
          return getViewToModel()[viewIndex].modelIndex;
      }
  
      private int[] getModelToView() {
          if (modelToView == null) {
              int n = getViewToModel().length;
              modelToView = new int[n];
              for (int i = 0; i < n; i++) {
                  modelToView[modelIndex(i)] = i;
              }
          }
          return modelToView;
      }
  
      // TableModel interface methods 
  
      public int getRowCount() {
          return (tableModel == null) ? 0 : tableModel.getRowCount();
      }
  
      public int getColumnCount() {
          return (tableModel == null) ? 0 : tableModel.getColumnCount();
      }
  
      public String getColumnName(int column) {
          return tableModel.getColumnName(column);
      }
  
      public Class getColumnClass(int column) {
          return tableModel.getColumnClass(column);
      }
  
      public boolean isCellEditable(int row, int column) {
          return tableModel.isCellEditable(modelIndex(row), column);
      }
  
      public Object getValueAt(int row, int column) {
          return tableModel.getValueAt(modelIndex(row), column);
      }
  
      public void setValueAt(Object aValue, int row, int column) {
          tableModel.setValueAt(aValue, modelIndex(row), column);
      }
  
      // Helper classes
      
      private class Row implements Comparable {
          private int modelIndex;
  
          public Row(int index) {
              this.modelIndex = index;
          }
  
          public int compareTo(Object o) {
              int row1 = modelIndex;
              int row2 = ((Row) o).modelIndex;
  
              for (Iterator it = sortingColumns.iterator(); it.hasNext();) {
                  Directive directive = (Directive) it.next();
                  int column = directive.column;
                  Object o1 = tableModel.getValueAt(row1, column);
                  Object o2 = tableModel.getValueAt(row2, column);
  
                  int comparison = 0;
                  // Define null less than everything, except null.
                  if (o1 == null && o2 == null) {
                      comparison = 0;
                  } else if (o1 == null) {
                      comparison = -1;
                  } else if (o2 == null) {
                      comparison = 1;
                  } else {
                      comparison = getComparator(column).compare(o1, o2);
                  }
                  if (comparison != 0) {
                      return directive.direction == DESCENDING ? -comparison : comparison;
                  }
              }
              return 0;
          }
      }
  
      private class TableModelHandler implements TableModelListener {
          public void tableChanged(TableModelEvent e) {
              // If we're not sorting by anything, just pass the event along.             
              if (!isSorting()) {
                  clearSortingState();
                  fireTableChanged(e);
                  return;
              }
                  
              // If the table structure has changed, cancel the sorting; the             
              // sorting columns may have been either moved or deleted from             
              // the model. 
              if (e.getFirstRow() == TableModelEvent.HEADER_ROW) {
                  cancelSorting();
                  fireTableChanged(e);
                  return;
              }
  
              // We can map a cell event through to the view without widening             
              // when the following conditions apply: 
              // 
              // a) all the changes are on one row (e.getFirstRow() == e.getLastRow()) and, 
              // b) all the changes are in one column (column != TableModelEvent.ALL_COLUMNS) and,
              // c) we are not sorting on that column (getSortingStatus(column) == NOT_SORTED) and, 
              // d) a reverse lookup will not trigger a sort (modelToView != null)
              //
              // Note: INSERT and DELETE events fail this test as they have column == ALL_COLUMNS.
              // 
              // The last check, for (modelToView != null) is to see if modelToView 
              // is already allocated. If we don't do this check; sorting can become 
              // a performance bottleneck for applications where cells  
              // change rapidly in different parts of the table. If cells 
              // change alternately in the sorting column and then outside of             
              // it this class can end up re-sorting on alternate cell updates - 
              // which can be a performance problem for large tables. The last 
              // clause avoids this problem. 
              int column = e.getColumn();
              if (e.getFirstRow() == e.getLastRow()
                      && column != TableModelEvent.ALL_COLUMNS
                      && getSortingStatus(column) == NOT_SORTED
                      && modelToView != null) {
                  int viewIndex = getModelToView()[e.getFirstRow()];
                  fireTableChanged(new TableModelEvent(TableSorter.this, 
                                                       viewIndex, viewIndex, 
                                                       column, e.getType()));
                  return;
              }
  
              // Something has happened to the data that may have invalidated the row order. 
              clearSortingState();
              fireTableDataChanged();
              return;
          }
      }
  
      private class MouseHandler extends MouseAdapter {
          public void mouseClicked(MouseEvent e) {
              JTableHeader h = (JTableHeader) e.getSource();
              TableColumnModel columnModel = h.getColumnModel();
              int viewColumn = columnModel.getColumnIndexAtX(e.getX());
              int column = columnModel.getColumn(viewColumn).getModelIndex();
              if (column != -1) {
                  int status = getSortingStatus(column);
                  if (!e.isControlDown()) {
                      cancelSorting();
                  }
                  // Cycle the sorting states through {NOT_SORTED, ASCENDING, DESCENDING} or 
                  // {NOT_SORTED, DESCENDING, ASCENDING} depending on whether shift is pressed. 
                  status = status + (e.isShiftDown() ? -1 : 1);
                  status = (status + 4) % 3 - 1; // signed mod, returning {-1, 0, 1}
                  setSortingStatus(column, status);
              }
          }
      }
  
      private static class Arrow implements Icon {
          private boolean descending;
          private int size;
          private int priority;
  
          public Arrow(boolean descending, int size, int priority) {
              this.descending = descending;
              this.size = size;
              this.priority = priority;
          }
  
          public void paintIcon(Component c, Graphics g, int x, int y) {
              Color color = c == null ? Color.GRAY : c.getBackground();             
              // In a compound sort, make each succesive triangle 20% 
              // smaller than the previous one. 
              int dx = (int)(size/2*Math.pow(0.8, priority));
              int dy = descending ? dx : -dx;
              // Align icon (roughly) with font baseline. 
              y = y + 5*size/6 + (descending ? -dy : 0);
              int shift = descending ? 1 : -1;
              g.translate(x, y);
  
              // Right diagonal. 
              g.setColor(color.darker());
              g.drawLine(dx / 2, dy, 0, 0);
              g.drawLine(dx / 2, dy + shift, 0, shift);
              
              // Left diagonal. 
              g.setColor(color.brighter());
              g.drawLine(dx / 2, dy, dx, 0);
              g.drawLine(dx / 2, dy + shift, dx, shift);
              
              // Horizontal line. 
              if (descending) {
                  g.setColor(color.darker().darker());
              } else {
                  g.setColor(color.brighter().brighter());
              }
              g.drawLine(dx, 0, 0, 0);
  
              g.setColor(color);
              g.translate(-x, -y);
          }
  
          public int getIconWidth() {
              return size;
          }
  
          public int getIconHeight() {
              return size;
          }
      }
  
      private class SortableHeaderRenderer implements TableCellRenderer {
          private TableCellRenderer tableCellRenderer;
  
          public SortableHeaderRenderer(TableCellRenderer tableCellRenderer) {
              this.tableCellRenderer = tableCellRenderer;
          }
  
          public Component getTableCellRendererComponent(JTable table, 
                                                         Object value,
                                                         boolean isSelected, 
                                                         boolean hasFocus,
                                                         int row, 
                                                         int column) {
              Component c = tableCellRenderer.getTableCellRendererComponent(table, 
                      value, isSelected, hasFocus, row, column);
              if (c instanceof JLabel) {
                  JLabel l = (JLabel) c;
                  l.setHorizontalTextPosition(JLabel.LEFT);
                  int modelColumn = table.convertColumnIndexToModel(column);
                  l.setIcon(getHeaderRendererIcon(modelColumn, l.getFont().getSize()));
              }
              return c;
          }
      }
  
      private static class Directive {
          private int column;
          private int direction;
  
          public Directive(int column, int direction) {
              this.column = column;
              this.direction = direction;
          }
      }
  }
  