/********************************************************************************
    * InternetCafe is a software solution that helps the management of Cybercafes 
    * according with the ITALIAN DECREE LAW ON ANTI-TERROR MEASURES, 27 JULY 2005.
    * Copyright (C) 2006  Guido Angelo Ingenito
   
    * This program 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 2
    * of the License, or (at your option) any later version.
  
   * This program 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 this program; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   *******************************************************************************/
  package ui.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
   */
  
  @SuppressWarnings("serial") //$NON-NLS-1$
  public class TableSorter extends AbstractTableModel {
  	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);
  
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	public static final Comparator<Object> COMPARABLE_COMAPRATOR = new Comparator() {
 		public int compare(Object o1, Object o2) {
 			return ((Comparable<Object>) o1).compareTo(o2);
 		}
 	};
 
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	public static final Comparator<Object> 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<Class, Comparator> columnComparators = new HashMap<Class, Comparator>();
 
 	private List<Directive> sortingColumns = new ArrayList<Directive>();
 
 	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 = 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();
 		}
 	}
 
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	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();
 	}
 
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	public void setColumnComparator(Class type, Comparator comparator) {
 		if (comparator == null) {
 			columnComparators.remove(type);
 		} else {
 			columnComparators.put(type, comparator);
 		}
 	}
 
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	protected Comparator<Object> getComparator(int column) {
 		Class columnType = tableModel.getColumnClass(column);
 		Comparator<Object> 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);
 	}
 
 	@SuppressWarnings("unchecked") //$NON-NLS-1$
 	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;
 		}
 
 		@SuppressWarnings("unchecked") //$NON-NLS-1$
 		public int compareTo(Object o) {
 			int row1 = modelIndex;
 			int row2 = ((Row) o).modelIndex;
 
 			for (Iterator<Directive> it = sortingColumns.iterator(); it
 					.hasNext();) {
 				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;
 		}
 	}
 }