Java Swing - Search on combobox

Question

I want to search on combobox, please help me

Codes were here and here

Answer 1

Not exactly what you want (because you can't display headings in the drop down)but the following code shows examples of custom renderers that can display multiple columns in the combo box dropdown:

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.text.*;

public class ComboBoxMultiColumn extends JFrame
{
    public ComboBoxMultiColumn()
    {
        getContentPane().setLayout( new GridLayout(0, 2) );

        Vector items = new Vector();
        items.addElement( new Item("123456789", "Car" ) );
        items.addElement( new Item("23", "Plane" ) );
        items.addElement( new Item("345", "Train" ) );
        items.addElement( new Item("4567", "Nuclear Submarine" ) );

        //  Use a JTextArea as a renderer

        JComboBox comboBox1 = new JComboBox( items );
        comboBox1.setRenderer( new TextAreaRenderer(5) );

        getContentPane().add( new JLabel("TextArea Renderer") );
        getContentPane().add( comboBox1 );

        //  Use a JTextPane as a renderer

        JComboBox comboBox2 = new JComboBox( items );
        comboBox2.setRenderer( new TextPaneRenderer(10) );

        getContentPane().add( new JLabel("TextPane Renderer") );
        getContentPane().add( comboBox2 );

        //  Use a JPanel as a renderer

        JComboBox comboBox3 = new JComboBox( items );
        comboBox3.setRenderer( new PanelRenderer(50) );

        getContentPane().add( new JLabel("Panel Renderer") );
        getContentPane().add( comboBox3 );

        //  Using HTML

        JComboBox comboBox4 = new JComboBox( items );
        comboBox4.setRenderer( new HTMLRenderer() );

        getContentPane().add( new JLabel("HTML Renderer") );
        getContentPane().add( comboBox4 );
    }

    class Item
    {
        private String id;
        private String description;

        public Item(String id, String description)
        {
            this.id = id;
            this.description = description;
        }

        public String getId()
        {
            return id;
        }

        public String getDescription()
        {
            return description;
        }

        public String toString()
        {
            return description;
        }
    }

    public static void main(String[] args)
    {
        JFrame frame = new ComboBoxMultiColumn();
        frame.setDefaultCloseOperation( EXIT_ON_CLOSE );
        frame.pack();
        frame.setVisible( true );
    }

    /*
    **  Tabs are easier to use in a JTextArea, but not very flexible
    */
    class TextAreaRenderer extends JTextArea implements ListCellRenderer
    {
        public TextAreaRenderer(int tabSize)
        {
            setTabSize(tabSize);
        }

        public Component getListCellRendererComponent(JList list, Object value,
            int index, boolean isSelected, boolean cellHasFocus)
        {
            Item item = (Item)value;
            setText(item.getId() + "\t" + item.getDescription());
            setBackground(isSelected ? list.getSelectionBackground() : null);
            setForeground(isSelected ? list.getSelectionForeground() : null);
            return this;
        }
    }

    /*
    **  Tabs are harder to use in a JTextPane, but much more flexible
    */
    class TextPaneRenderer extends JTextPane implements ListCellRenderer
    {
        public TextPaneRenderer(int tabColumn)
        {
            setMargin( new Insets(0, 0, 0, 0) );

            FontMetrics fm = getFontMetrics( getFont() );
            int width = fm.charWidth( 'w' ) * tabColumn;

            TabStop[] tabs = new TabStop[1];
            tabs[0] = new TabStop( width, TabStop.ALIGN_LEFT, TabStop.LEAD_NONE );
            TabSet tabSet = new TabSet(tabs);

            SimpleAttributeSet attributes = new SimpleAttributeSet();
            StyleConstants.setTabSet(attributes, tabSet);
            getStyledDocument().setParagraphAttributes(0, 0, attributes, false);
        }

        public Component getListCellRendererComponent(JList list, Object value,
            int index, boolean isSelected, boolean cellHasFocus)
        {
            Item item = (Item)value;

            if (index == -1)
                setText( item.getDescription() );
            else
                setText(item.getId() + "\t" + item.getDescription());

            setBackground(isSelected ? list.getSelectionBackground() : null);
            setForeground(isSelected ? list.getSelectionForeground() : null);
            return this;
        }
    }

    /*
    **  Use a panel to hold multiple components
    */
    class PanelRenderer implements ListCellRenderer
    {
        private JPanel renderer;
        private JLabel first;
        private JLabel second;

        public PanelRenderer(int firstColumnWidth)
        {
            renderer = new JPanel();
            renderer.setLayout(new BoxLayout(renderer, BoxLayout.X_AXIS) );

            first = new JLabel(" ");
            Dimension d = first.getPreferredSize();
            d.width = firstColumnWidth;
            first.setMaximumSize(d);
            second = new JLabel();
            renderer.add(first );
            renderer.add(second );
        }

        public Component getListCellRendererComponent(JList list, Object value,
            int index, boolean isSelected, boolean cellHasFocus)
        {
            Item item = (Item)value;

            first.setText( item.getId() );
            second.setText( item.getDescription() );

            renderer.setBackground(isSelected ? list.getSelectionBackground() : null);
            renderer.setForeground(isSelected ? list.getSelectionForeground() : null);

            return renderer;
        }
    }

    /*
    **  Use HTML to format the text
    */
    class HTMLRenderer extends DefaultListCellRenderer
    {
        private static final String START = "<html><table><tr><td width=40>";
        private static final String MIDDLE = "</td><td width=120>";
        private static final String END = "</td></tr></table></html>";

        public Component getListCellRendererComponent(JList list, Object value,
            int index, boolean isSelected, boolean cellHasFocus)
        {
            super.getListCellRendererComponent(
                list, value, index, isSelected, cellHasFocus);

            Item item = (Item)value;
            setText(START
                + item.getId()
                + MIDDLE
                + item.getDescription()
                + END);

            return this;
        }
    }

}

As you will see, if you run the code, the alignment of the text in each column will be a problem because a combo box is not designed to display multiples of data as each cell is rendered independently of the others so a cell does not know the width of every column of data. You would need to hard code the widths somehow.

So as you can see a combo box is probably not a very good solution.