Visual Cafe 3/Visual Cafe 3.ISO/Vcafe/Sample.bin/SimpleSortTableModel.java

Java Source | 1998-09-28 | 10.8 KB | 387 lines

import com.sun.java.swing.*;
import com.sun.java.swing.table.*;
import com.sun.java.swing.event.*;

import java.awt.event.*;
import java.io.*;
import java.beans.*;
import java.util.*;

public class SimpleSortTableModel extends com.sun.java.swing.table.AbstractTableModel implements java.io.Serializable, TableModelListener
{
    TableModel model=null;

    int[] indexes = {};
    Vector sortingColumns = new Vector();
    boolean ascending=true;
    int compares;

    public SimpleSortTableModel()
    {
    }

    // There is no-where else to put this.
    // Add a mouse listener to the Table to trigger a table sort
    // when a column heading is clicked in the JTable.
    public void addMouseListenerToHeaderInTable(JTable table)
    {
        final SimpleSortTableModel sorter = this;
        final JTable tableView = table;
        tableView.setColumnSelectionAllowed(false);
        MouseAdapter listMouseListener = new MouseAdapter()
        {
            public void mouseClicked(MouseEvent e)
            {
                TableColumnModel columnModel = tableView.getColumnModel();
                int viewColumn = columnModel.getColumnIndexAtX(e.getX());
                int column = tableView.convertColumnIndexToModel(viewColumn);
                if(e.getClickCount() == 1 && column != -1)
                {
                    System.out.println("Sorting ...");
                    int shiftPressed = e.getModifiers()&InputEvent.SHIFT_MASK;
                    boolean ascending = (shiftPressed == 0);
                    sorter.sortByColumn(column, ascending);
                }
             }
         };
        JTableHeader th = tableView.getTableHeader();
        th.addMouseListener(listMouseListener);
    }

    public void reallocateIndexes()
    {
        int rowCount = model.getRowCount();

        // Set up a new array of indexes with the right number of elements
        // for the new data model.
        indexes = new int[rowCount];

        // Initialise with the identity mapping.
        for(int row = 0; row < rowCount; row++)
        {
            indexes[row] = row;
        }
    }

    public int compareRowsByColumn(int row1, int row2, int column)
    {
        Class type = model.getColumnClass(column);
        TableModel data = model;

        // Check for nulls

        Object o1 = data.getValueAt(row1, column);
        Object o2 = data.getValueAt(row2, column);

        // If both values are null return 0
        if (o1 == null && o2 == null)
        {
            return 0;
        }
        else if (o1 == null)
        { // Define null less than everything.
            return -1;
        }
        else if (o2 == null)
        {
            return 1;
        }

/* We copy all returned values from the getValue call in case
an optimised model is reusing one object to return many values.
The Number subclasses in the JDK are immutable and so will not be used in
this way but other subclasses of Number might want to do this to save
space and avoid unnecessary heap allocation.
*/
        if (type.getSuperclass() == java.lang.Number.class)
        {
            Number n1 = (Number)data.getValueAt(row1, column);
            double d1 = n1.doubleValue();
            Number n2 = (Number)data.getValueAt(row2, column);
            double d2 = n2.doubleValue();

            if (d1 < d2)
            {
                return -1;
            }
            else if (d1 > d2)
            {
                return 1;
            }
            else
            {
                return 0;
            }
        }
        else if (type == java.util.Date.class)
        {
            Date d1 = (Date)data.getValueAt(row1, column);
            long n1 = d1.getTime();
            Date d2 = (Date)data.getValueAt(row2, column);
            long n2 = d2.getTime();

            if (n1 < n2)
            {
                return -1;
            }
            else if (n1 > n2)
            {
                return 1;
            }
            else
            {
                return 0;
            }
        }
        else if (type == String.class)
        {
            String s1 = (String)data.getValueAt(row1, column);
            String s2    = (String)data.getValueAt(row2, column);
            int result = s1.compareTo(s2);

            if (result < 0)
            {
                return -1;
            }
            else if (result > 0)
            {
                return 1;
            }
            else
            {
                return 0;
            }
        }
        else if (type == Boolean.class)
        {
            Boolean bool1 = (Boolean)data.getValueAt(row1, column);
            boolean b1 = bool1.booleanValue();
            Boolean bool2 = (Boolean)data.getValueAt(row2, column);
            boolean b2 = bool2.booleanValue();

            if (b1 == b2)
            {
                return 0;
            }
            else if (b1) // Define false < true
            {
                return 1;
            }
            else
            {
                return -1;
            }
        }
        else
        {
            Object v1 = data.getValueAt(row1, column);
            String s1 = v1.toString();
            Object v2 = data.getValueAt(row2, column);
            String s2 = v2.toString();
            int result = s1.compareTo(s2);

            if (result < 0)
            {
                return -1;
            }
            else if (result > 0)
            {
                return 1;
            }
            else
            {
                return 0;
            }
        }
    }

    public int compare(int row1, int row2)
    {
        compares++;
        for(int level = 0; level < sortingColumns.size(); level++)
        {
            Integer column = (Integer)sortingColumns.elementAt(level);
            int result = compareRowsByColumn(row1, row2, column.intValue());
            if (result != 0)
            {
                return ascending ? result : -result;
            }
        }
        return 0;
    }

    public void checkModel()
    {
        if (indexes.length != model.getRowCount())
        {
            System.err.println("Sorter not informed of a change in model.");
        }
    }

    public void  sort(Object sender)
    {
        checkModel();

        compares = 0;
        // n2sort();
        // qsort(0, indexes.length-1);
        shuttlesort((int[])indexes.clone(), indexes, 0, indexes.length);
        System.out.println("Compares: "+compares);
    }
    public void n2sort()
    {
        for(int i = 0; i < getRowCount(); i++)
        {
            for(int j = i+1; j < getRowCount(); j++)
            {
                if (compare(indexes[i], indexes[j]) == -1)
                {
                    swap(i, j);
                }
            }
        }
    }

    // This is a home-grown implementation which we have not had time
    // to research - it may perform poorly in some circumstances. It
    // requires twice the space of an in-place algorithm and makes
    // NlogN assigments shuttling the values between the two
    // arrays. The number of compares appears to vary between N-1 and
    // NlogN depending on the initial order but the main reason for
    // using it here is that, unlike qsort, it is stable.
    public void shuttlesort(int from[], int to[], int low, int high)
    {
        if (high - low < 2)
        {
            return;
        }
        int middle = (low + high)/2;
        shuttlesort(to, from, low, middle);
        shuttlesort(to, from, middle, high);

        int p = low;
        int q = middle;

        /* This is an optional short-cut; at each recursive call,
        check to see if the elements in this subset are already
        ordered.  If so, no further comparisons are needed; the
        sub-array can just be copied.  The array must be copied rather
        than assigned otherwise sister calls in the recursion might
        get out of sinc.  When the number of elements is three they
        are partitioned so that the first set, [low, mid), has one
        element and and the second, [mid, high), has two. We skip the
        optimisation when the number of elements is three or less as
        the first compare in the normal merge will produce the same
        sequence of steps. This optimization seems to be worthwhile
        for partially ordered lists but some analysis is needed to
        find out how the performance drops to Nlog(N) as the initial
        order diminishes - it may drop very quickly.  */

        if (high - low >= 4 && compare(from[middle-1], from[middle]) <= 0)
        {
            for (int i = low; i < high; i++)
            {
                to[i] = from[i];
            }
            return;
        }

        // A normal merge.

        for(int i = low; i < high; i++)
        {
            if (q >= high || (p < middle && compare(from[p], from[q]) <= 0))
            {
                to[i] = from[p++];
            }
            else
            {
                to[i] = from[q++];
            }
        }
    }

    public void swap(int i, int j)
    {
        int tmp = indexes[i];
        indexes[i] = indexes[j];
        indexes[j] = tmp;
    }

    public void sortByColumn(int column)
    {
        sortByColumn(column, true);
    }

    public void sortByColumn(int column, boolean ascending)
    {
        this.ascending = ascending;
        sortingColumns.removeAllElements();
        sortingColumns.addElement(new Integer(column));
        sort(this);
        fireTableChanged(new TableModelEvent(this));
    }

//Properties:
    public void setModel(TableModel tm)
    {
        if (model!=null)
        {
            model.removeTableModelListener(this);
        }
        model = tm;
        model.addTableModelListener(this);

        reallocateIndexes();
    }
    public TableModel getModel()
    {
        return model;
    }

//TableModel methods:
    public Object getValueAt(int row, int col)
    {
        checkModel();
        return model.getValueAt(indexes[row], col);
    }
    public void setValueAt(Object value, int row, int col)
    {
        checkModel();
        model.setValueAt(value,indexes[row],col);
    }

    public int getRowCount()
    {
        return model==null ? 0 : model.getRowCount();
    }

    public int getColumnCount()
    {
        return model==null ? 0 : model.getColumnCount();
    }

    public String getColumnName(int col)
    {
        return model.getColumnName(col);
    }

    public Class getColumnClass(int col)
    {
        return model.getColumnClass(col);
    }

    public boolean isCellEditable(int row, int col)
    {
        return model.isCellEditable(indexes[row], col);
    }

// Implementation of the TableModelListener interface,

    public void tableChanged(TableModelEvent e)
    {
        System.out.println("SimpleSortTableModel:table changed");
        reallocateIndexes();
        fireTableChanged(e);
    }
}