/**
    * Copyright 2008 WebPhotos
    *
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package net.sf.webphotos.gui.util;
  
  import java.awt.*;
  import java.awt.event.*;
  import java.util.*;
  import java.util.List;
  import javax.swing.*;
  import javax.swing.event.TableModelEvent;
  import javax.swing.event.TableModelListener;
  import javax.swing.table.*;
  
  /**
   * 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 final class TableSorter extends AbstractTableModel {
  
      private static final long serialVersionUID = -5572044930561418466L;
      /**
       *
       */
      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<Object>> COMPARABLE_COMPARATOR = new Comparator<Comparable<Object>>() {
 
         @Override
         public int compare(Comparable<Object> o1, Comparable<Object> o2) {
             return o1.compareTo(o2);
         }
     };
     /**
      *
      */
     public static final Comparator<Comparable<Object>> LEXICAL_COMPARATOR = new Comparator<Comparable<Object>>() {
 
         @Override
         public int compare(Comparable<Object> o1, Comparable<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();
     }
 
     /**
      *
      * @param tableModel
      */
     public TableSorter(TableModel tableModel) {
         this();
         setTableModel(tableModel);
     }
 
     /**
      *
      * @param tableModel
      * @param tableHeader
      */
     public TableSorter(TableModel tableModel, JTableHeader tableHeader) {
         this();
         setTableHeader(tableHeader);
         setTableModel(tableModel);
     }
 
     private void clearSortingState() {
         viewToModel = null;
         modelToView = null;
     }
 
     /**
      *
      * @return
      */
     public TableModel getTableModel() {
         return tableModel;
     }
 
     /**
      *
      * @param 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();
     }
 
     /**
      *
      * @return
      */
     public JTableHeader getTableHeader() {
         return tableHeader;
     }
 
     /**
      *
      * @param 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()));
         }
     }
 
     /**
      *
      * @return
      */
     public boolean isSorting() {
         return !sortingColumns.isEmpty();
     }
 
     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;
     }
 
     /**
      *
      * @param column
      * @return
      */
     public int getSortingStatus(int column) {
         return getDirective(column).direction;
     }
 
     private void sortingStatusChanged() {
         clearSortingState();
         fireTableDataChanged();
         if (tableHeader != null) {
             tableHeader.repaint();
         }
     }
 
     /**
      *
      * @param column
      * @param status
      */
     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();
     }
 
     /**
      *
      * @param column
      * @param size
      * @return
      */
     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();
     }
 
     /**
      *
      * @param type
      * @param comparator
      */
     public void setColumnComparator(Class<?> type, Comparator<?> comparator) {
         if (comparator == null) {
             columnComparators.remove(type);
         } else {
             columnComparators.put(type, comparator);
         }
     }
 
     /**
      *
      * @param column
      * @return
      */
     @SuppressWarnings("unchecked")
     protected Comparator<Comparable<Object>> getComparator(int column) {
         Class<?> columnType = tableModel.getColumnClass(column);
         Comparator<Comparable<Object>> comparator = (Comparator<Comparable<Object>>) columnComparators.get(columnType);
         if (comparator != null) {
             return comparator;
         }
         if (Comparable.class.isAssignableFrom(columnType)) {
             return COMPARABLE_COMPARATOR;
         }
         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;
     }
 
     /**
      *
      * @param viewIndex
      * @return
      */
     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 
     @Override
     public int getRowCount() {
         return (tableModel == null) ? 0 : tableModel.getRowCount();
     }
 
     @Override
     public int getColumnCount() {
         return (tableModel == null) ? 0 : tableModel.getColumnCount();
     }
 
     @Override
     public String getColumnName(int column) {
         return tableModel.getColumnName(column);
     }
 
     @Override
     public Class<?> getColumnClass(int column) {
         return tableModel.getColumnClass(column);
     }
 
     @Override
     public boolean isCellEditable(int row, int column) {
         return tableModel.isCellEditable(modelIndex(row), column);
     }
 
     @Override
     public Object getValueAt(int row, int column) {
         return tableModel.getValueAt(modelIndex(row), column);
     }
 
     @Override
     public void setValueAt(Object aValue, int row, int column) {
         tableModel.setValueAt(aValue, modelIndex(row), column);
     }
 
     // Helper classes
     private class Row implements Comparable<Row> {
 
         private int modelIndex;
 
         public Row(int index) {
             this.modelIndex = index;
         }
 
         @SuppressWarnings("unchecked")
         @Override
         public int compareTo(Row o) {
             int row1 = modelIndex;
             int row2 = o.modelIndex;
 
             for (Iterator<Directive> 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((Comparable<Object>) o1, (Comparable<Object>) o2);
                 }
                 if (comparison != 0) {
                     return directive.direction == DESCENDING ? -comparison : comparison;
                 }
             }
             return 0;
         }
     }
 
     private class TableModelHandler implements TableModelListener {
 
         @Override
         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();
         }
     }
 
     private class MouseHandler extends MouseAdapter {
 
         @Override
         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;
         }
 
         @Override
         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);
         }
 
         @Override
         public int getIconWidth() {
             return size;
         }
 
         @Override
         public int getIconHeight() {
             return size;
         }
     }
 
     private class SortableHeaderRenderer implements TableCellRenderer {
 
         private TableCellRenderer tableCellRenderer;
 
         public SortableHeaderRenderer(TableCellRenderer tableCellRenderer) {
             this.tableCellRenderer = tableCellRenderer;
         }
 
         @Override
         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;
         }
     }
 }