petstoreui.java

rule engine drools-2.0-beta-18

package org.drools.examples.petstore;

/*
 * $Id: PetStoreUI.java,v 1.3 2004/11/23 05:31:47 dbarnett Exp $
 * 
 * Copyright 2001-2003 (C) The Werken Company. All Rights Reserved.
 * 
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "drools" must not be used to endorse or promote products derived
 * from this Software without prior written permission of The Werken Company.
 * For written permission, please contact [e-mail].
 * 
 * 4. Products derived from this Software may not be called "drools" nor may
 * "drools" appear in their names without prior written permission of The Werken
 * Company. "drools" is a trademark of The Werken Company.
 * 
 * 5. Due credit should be given to The Werken Company. (http://werken.com/)
 * 
 * THIS SOFTWARE IS PROVIDED BY THE WERKEN COMPANY AND CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE WERKEN COMPANY OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *  
 */

import java.awt.BorderLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.ArrayList;
import java.util.List;
import java.util.Vector;

import javax.swing.AbstractButton;
import javax.swing.BorderFactory;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTable;
import javax.swing.JTextArea;
import javax.swing.ListSelectionModel;
import javax.swing.ScrollPaneConstants;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableCellRenderer;
import javax.swing.table.TableColumnModel;

/**
 * @author mproctor
 * 
 * This swing UI is used to create a simple shopping cart to allow a user to add
 * and remove items from a shopping cart before doign a checkout upon doing a
 * checkout a callback is used to allow drools interaction with the shopping
 * cart ui.
 */
public class PetStoreUI extends JPanel
{
    private JTextArea        output;

    private TableModel       tableModel;

    private CheckoutCallback callback;

    /**
     * Build UI using specified items and using the given callback to pass the
     * items and jframe reference to the drools application
     * 
     * @param listData
     * @param callback
     */
    public PetStoreUI(Vector items, CheckoutCallback callback)
    {
        super( new BorderLayout( ) );
        this.callback = callback;

        //Create main vertical split panel
        JSplitPane splitPane = new JSplitPane( JSplitPane.VERTICAL_SPLIT );
        add( splitPane, BorderLayout.CENTER );

        //create top half of split panel and add to parent
        JPanel topHalf = new JPanel( );
        topHalf.setLayout( new BoxLayout( topHalf, BoxLayout.X_AXIS ) );
        topHalf.setBorder( BorderFactory.createEmptyBorder( 5, 5, 0, 5 ) );
        topHalf.setMinimumSize( new Dimension( 400, 50 ) );
        topHalf.setPreferredSize( new Dimension( 450, 250 ) );
        splitPane.add( topHalf );

        //create bottom top half of split panel and add to parent
        JPanel bottomHalf = new JPanel( new BorderLayout( ) );
        bottomHalf.setMinimumSize( new Dimension( 400, 50 ) );
        bottomHalf.setPreferredSize( new Dimension( 450, 300 ) );
        splitPane.add( bottomHalf );

        //Container that list container that shows available store items
        JPanel listContainer = new JPanel( new GridLayout( 1, 1 ) );
        listContainer.setBorder( BorderFactory.createTitledBorder( "List" ) );
        topHalf.add( listContainer );

        //Create JList for items, add to scroll pane and then add to parent
        // container
        JList list = new JList( items );
        ListSelectionModel listSelectionModel = list.getSelectionModel( );
        listSelectionModel
                          .setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
        //handler adds item to shopping cart
        list.addMouseListener( new ListSelectionHandler( ) );
        JScrollPane listPane = new JScrollPane( list );
        listContainer.add( listPane );

        JPanel tableContainer = new JPanel( new GridLayout( 1, 1 ) );
        tableContainer.setBorder( BorderFactory.createTitledBorder( "Table" ) );
        topHalf.add( tableContainer );

        //Container that displays table showing items in cart
        tableModel = new TableModel( );
        JTable table = new JTable( tableModel );
        //handler removes item to shopping cart
        table.addMouseListener( new TableSelectionHandler( ) );
        ListSelectionModel tableSelectionModel = table.getSelectionModel( );
        tableSelectionModel
                           .setSelectionMode( ListSelectionModel.SINGLE_SELECTION );
        TableColumnModel tableColumnModel = table.getColumnModel( );
        //notice we have a custom renderer for each column as both columns
        // point to the same underlying object
        tableColumnModel.getColumn( 0 ).setCellRenderer( new NameRenderer( ) );
        tableColumnModel.getColumn( 1 ).setCellRenderer( new PriceRenderer( ) );
        tableColumnModel.getColumn( 1 ).setMaxWidth( 50 );

        JScrollPane tablePane = new JScrollPane( table );
        tablePane.setPreferredSize( new Dimension( 150, 100 ) );
        tableContainer.add( tablePane );

        //Create panel for checkout button and add to bottomHalf parent
        JPanel checkoutPane = new JPanel( );
        JButton button = new JButton( "Checkout" );
        button.setVerticalTextPosition( AbstractButton.CENTER );
        button.setHorizontalTextPosition( AbstractButton.LEADING );
        //attach handler to assert items into working memory
        button.addMouseListener( new CheckoutButtonHandler( ) );
        button.setActionCommand( "checkout" );
        checkoutPane.add( button );
        bottomHalf.add( checkoutPane, BorderLayout.NORTH );

        button = new JButton( "Reset" );
        button.setVerticalTextPosition( AbstractButton.CENTER );
        button.setHorizontalTextPosition( AbstractButton.TRAILING );
        //attach handler to assert items into working memory
        button.addMouseListener( new ResetButtonHandler( ) );
        button.setActionCommand( "reset" );
        checkoutPane.add( button );
        bottomHalf.add( checkoutPane, BorderLayout.NORTH );

        //Create output area, imbed in scroll area an add to bottomHalf parent
        //Scope is at instance level so it can be easily referenced from other
        // methods
        output = new JTextArea( 1, 10 );
        output.setEditable( false );
        JScrollPane outputPane = new JScrollPane(
                                                  output,
                                                  ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS,
                                                  ScrollPaneConstants.HORIZONTAL_SCROLLBAR_AS_NEEDED );
        bottomHalf.add( outputPane, BorderLayout.CENTER );
    }

    /**
     * Create and show the GUI
     *  
     */
    public void createAndShowGUI()
    {
        //Create and set up the window.
        JFrame frame = new JFrame( "Pet Store Demo" );
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        
        setOpaque( true );
        frame.setContentPane( this );

        //Display the window.
        frame.pack( );
        frame.setVisible( true );
    }

    /**
     * Adds the selected item to the table
     */
    private class ListSelectionHandler extends MouseAdapter
    {
        public void mouseReleased(MouseEvent e)
        {
            JList jlist = ( JList ) e.getSource( );
            tableModel.addItem( ( CartItem ) jlist.getSelectedValue( ) );
        }
    }

    /**
     * Removes the selected item from the table
     */
    private class TableSelectionHandler extends MouseAdapter
    {
        public void mouseReleased(MouseEvent e)
        {
            JTable jtable = ( JTable ) e.getSource( );
            TableModel tableModel = ( TableModel ) jtable.getModel( );
            tableModel.removeItem( jtable.getSelectedRow( ) );
        }
    }

    /**
     * Calls the referenced callback, passing a the jrame and selected items.
     *  
     */
    private class CheckoutButtonHandler extends MouseAdapter
    {
        public void mouseReleased(MouseEvent e)
        {
            JButton button = ( JButton ) e.getComponent( );
            try
            {
                output
                      .append( callback
                                       .checkout(
                                                  ( JFrame ) button
                                                                   .getTopLevelAncestor( ),
                                                  tableModel.getItems( ) ) );
            }
            catch ( org.drools.FactException fe )
            {
                fe.printStackTrace( );
            }
        }
    }

    /**
     * Resets the shopping cart, allowing the user to begin again.
     *  
     */
    private class ResetButtonHandler extends MouseAdapter
    {
        public void mouseReleased(MouseEvent e)
        {
            JButton button = ( JButton ) e.getComponent( );
            output.setText( null );
            tableModel.clear( );
            System.out.println( "------ Reset ------" );
        }
    }

    /**
     * Used to render the name column in the table
     */
    private class NameRenderer extends DefaultTableCellRenderer
    {
        public NameRenderer()
        {
            super( );
        }

        public void setValue(Object object)
        {
            CartItem item = ( CartItem ) object;
            setText( item.getName( ) );
        }
    }

    /**
     * Used to render the price column in the table
     */
    private class PriceRenderer extends DefaultTableCellRenderer
    {
        public PriceRenderer()
        {
            super( );
        }

        public void setValue(Object object)
        {
            CartItem item = ( CartItem ) object;
            setText( Double.toString( item.getCost( ) ) );
        }
    }

    /**
     * This is the table model used to represent the users shopping cart While
     * we have two colums, both columns point to the same object. We user a
     * different renderer to display the different information abou the object -
     * name and price.
     */
    private class TableModel extends AbstractTableModel
    {
        private String[]  columnNames = {"Name", "Price"};

        private ArrayList items;

        public TableModel()
        {
            super( );
            items = new ArrayList( );
        }

        public int getColumnCount()
        {
            return columnNames.length;
        }

        public int getRowCount()
        {
            return items.size( );
        }

        public String getColumnName(int col)
        {
            return columnNames[col];
        }

        public Object getValueAt(int row, int col)
        {
            return items.get( row );
        }

        public Class getColumnClass(int c)
        {
            return CartItem.class;
        }

        public void addItem(CartItem item)
        {
            items.add( item );
            fireTableRowsInserted( items.size( ), items.size( ) );
        }

        public void removeItem(int row)
        {
            items.remove( row );
            fireTableRowsDeleted( row, row );
        }

        public List getItems()
        {
            return items;
        }

        public void clear()
        {
            int lastRow = items.size( );
            items.clear( );
            fireTableRowsDeleted( 0, lastRow );
        }
    }

}