/*

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * particular file as subject to the "Classpath" exception as provided

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 */

package javax.swing.table;

import javax.swing.*;

import javax.swing.event.*;

import java.io.Serializable;

import java.util.EventListener;

/**

 *  This abstract class provides default implementations for most of

 *  the methods in the <code>TableModel</code> interface. It takes care of

 *  the management of listeners and provides some conveniences for generating

 *  <code>TableModelEvents</code> and dispatching them to the listeners.

 *  To create a concrete <code>TableModel</code> as a subclass of

 *  <code>AbstractTableModel</code> you need only provide implementations

 *  for the following three methods:

 *

 *  <pre>

 *  public int getRowCount();

 *  public int getColumnCount();

 *  public Object getValueAt(int row, int column);

 *  </pre>

 * <p>

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @author Alan Chung

 * @author Philip Milne

 */

public abstract class AbstractTableModel implements TableModel, Serializable

{

//

// Instance Variables

//

    /** List of listeners */

    protected EventListenerList listenerList = new EventListenerList();

//

// Default Implementation of the Interface

//

    /**

     *  Returns a default name for the column using spreadsheet conventions:

     *  A, B, C, ... Z, AA, AB, etc.  If <code>column</code> cannot be found,

     *  returns an empty string.

     *

     * @param column  the column being queried

     * @return a string containing the default name of <code>column</code>

     */

    public String getColumnName(int column) {

        String result = "";

        for (; column >= 0; column = column / 26 - 1) {

            result = (char)((char)(column%26)+'A') + result;

        }

        return result;

    }

    /**

     * Returns a column given its name.

     * Implementation is naive so this should be overridden if

     * this method is to be called often. This method is not

     * in the <code>TableModel</code> interface and is not used by the

     * <code>JTable</code>.

     *

     * @param columnName string containing name of column to be located

     * @return the column with <code>columnName</code>, or -1 if not found

     */

    public int findColumn(String columnName) {

        for (int i = 0; i < getColumnCount(); i++) {

            if (columnName.equals(getColumnName(i))) {

                return i;

            }

        }

        return -1;

    }

    /**

     *  Returns <code>Object.class</code> regardless of <code>columnIndex</code>.

     *

     *  @param columnIndex  the column being queried

     *  @return the Object.class

     */

    public Class<?> getColumnClass(int columnIndex) {

        return Object.class;

    }

    /**

     *  Returns false.  This is the default implementation for all cells.

     *

     *  @param  rowIndex  the row being queried

     *  @param  columnIndex the column being queried

     *  @return false

     */

    public boolean isCellEditable(int rowIndex, int columnIndex) {

        return false;

    }

    /**

     *  This empty implementation is provided so users don't have to implement

     *  this method if their data model is not editable.

     *

     *  @param  aValue   value to assign to cell

     *  @param  rowIndex   row of cell

     *  @param  columnIndex  column of cell

     */

    public void setValueAt(Object aValue, int rowIndex, int columnIndex) {

    }

//

//  Managing Listeners

//

    /**

     * Adds a listener to the list that's notified each time a change

     * to the data model occurs.

     *

     * @param   l               the TableModelListener

     */

    public void addTableModelListener(TableModelListener l) {

        listenerList.add(TableModelListener.class, l);

    }

    /**

     * Removes a listener from the list that's notified each time a

     * change to the data model occurs.

     *

     * @param   l               the TableModelListener

     */

    public void removeTableModelListener(TableModelListener l) {

        listenerList.remove(TableModelListener.class, l);

    }

    /**

     * Returns an array of all the table model listeners

     * registered on this model.

     *

     * @return all of this model's <code>TableModelListener</code>s

     *         or an empty

     *         array if no table model listeners are currently registered

     *

     * @see #addTableModelListener

     * @see #removeTableModelListener

     *

     * @since 1.4

     */

    public TableModelListener[] getTableModelListeners() {

        return listenerList.getListeners(TableModelListener.class);

    }

//

//  Fire methods

//

    /**

     * Notifies all listeners that all cell values in the table's

     * rows may have changed. The number of rows may also have changed

     * and the <code>JTable</code> should redraw the

     * table from scratch. The structure of the table (as in the order of the

     * columns) is assumed to be the same.

     *

     * @see TableModelEvent

     * @see EventListenerList

     * @see javax.swing.JTable#tableChanged(TableModelEvent)

     */

    public void fireTableDataChanged() {

        fireTableChanged(new TableModelEvent(this));

    }

    /**

     * Notifies all listeners that the table's structure has changed.

     * The number of columns in the table, and the names and types of

     * the new columns may be different from the previous state.

     * If the <code>JTable</code> receives this event and its

     * <code>autoCreateColumnsFromModel</code>

     * flag is set it discards any table columns that it had and reallocates

     * default columns in the order they appear in the model. This is the

     * same as calling <code>setModel(TableModel)</code> on the

     * <code>JTable</code>.

     *

     * @see TableModelEvent

     * @see EventListenerList

     */

    public void fireTableStructureChanged() {

        fireTableChanged(new TableModelEvent(this, TableModelEvent.HEADER_ROW));

    }

    /**

     * Notifies all listeners that rows in the range

     * <code>[firstRow, lastRow]</code>, inclusive, have been inserted.

     *

     * @param  firstRow  the first row

     * @param  lastRow   the last row

     *

     * @see TableModelEvent

     * @see EventListenerList

     *

     */

    public void fireTableRowsInserted(int firstRow, int lastRow) {

        fireTableChanged(new TableModelEvent(this, firstRow, lastRow,

                             TableModelEvent.ALL_COLUMNS, TableModelEvent.INSERT));

    }

    /**

     * Notifies all listeners that rows in the range

     * <code>[firstRow, lastRow]</code>, inclusive, have been updated.

     *

     * @param firstRow  the first row

     * @param lastRow   the last row

     *

     * @see TableModelEvent

     * @see EventListenerList

     */

    public void fireTableRowsUpdated(int firstRow, int lastRow) {

        fireTableChanged(new TableModelEvent(this, firstRow, lastRow,

                             TableModelEvent.ALL_COLUMNS, TableModelEvent.UPDATE));

    }

    /**

     * Notifies all listeners that rows in the range

     * <code>[firstRow, lastRow]</code>, inclusive, have been deleted.

     *

     * @param firstRow  the first row

     * @param lastRow   the last row

     *

     * @see TableModelEvent

     * @see EventListenerList

     */

    public void fireTableRowsDeleted(int firstRow, int lastRow) {

        fireTableChanged(new TableModelEvent(this, firstRow, lastRow,

                             TableModelEvent.ALL_COLUMNS, TableModelEvent.DELETE));

    }

    /**

     * Notifies all listeners that the value of the cell at

     * <code>[row, column]</code> has been updated.

     *

     * @param row  row of cell which has been updated

     * @param column  column of cell which has been updated

     * @see TableModelEvent

     * @see EventListenerList

     */

    public void fireTableCellUpdated(int row, int column) {

        fireTableChanged(new TableModelEvent(this, row, row, column));

    }

    /**

     * Forwards the given notification event to all

     * <code>TableModelListeners</code> that registered

     * themselves as listeners for this table model.

     *

     * @param e  the event to be forwarded

     *

     * @see #addTableModelListener

     * @see TableModelEvent

     * @see EventListenerList

     */

    public void fireTableChanged(TableModelEvent e) {

        // Guaranteed to return a non-null array

        Object[] listeners = listenerList.getListenerList();

        // Process the listeners last to first, notifying

        // those that are interested in this event

        for (int i = listeners.length-2; i>=0; i-=2) {

            if (listeners[i]==TableModelListener.class) {

                ((TableModelListener)listeners[i+1]).tableChanged(e);

            }

        }

    }

    /**

     * Returns an array of all the objects currently registered

     * as <code><em>Foo</em>Listener</code>s

     * upon this <code>AbstractTableModel</code>.

     * <code><em>Foo</em>Listener</code>s are registered using the

     * <code>add<em>Foo</em>Listener</code> method.

     *

     * <p>

     *

     * You can specify the <code>listenerType</code> argument

     * with a class literal,

     * such as

     * <code><em>Foo</em>Listener.class</code>.

     * For example, you can query a

     * model <code>m</code>

     * for its table model listeners with the following code:

     *

     * <pre>TableModelListener[] tmls = (TableModelListener[])(m.getListeners(TableModelListener.class));</pre>

     *

     * If no such listeners exist, this method returns an empty array.

     *

     * @param listenerType the type of listeners requested; this parameter

     *          should specify an interface that descends from

     *          <code>java.util.EventListener</code>

     * @return an array of all objects registered as

     *          <code><em>Foo</em>Listener</code>s on this component,

     *          or an empty array if no such

     *          listeners have been added

     * @exception ClassCastException if <code>listenerType</code>

     *          doesn't specify a class or interface that implements

     *          <code>java.util.EventListener</code>

     *

     * @see #getTableModelListeners

     *

     * @since 1.3

     */

    public <T extends EventListener> T[] getListeners(Class<T> listenerType) {

        return listenerList.getListeners(listenerType);

    }

} // End of class AbstractTableModel