Character based Search

[sharjeel afzal]

Hello

I am developing a java desktop application
I want when some one starting to enter a character in textfield all the names starting from that character should shown in a list below
When he enter the second character search is based on 2 characters all names starting from that two charcters should be displayed in list user can select one
from list

How i achieve this thing in java (How to open drop down help)

[Mohamed Sanaulla]

You can listen for the KeyTyped event of the JTextField. And then use getText() to get the String typed. You can add a JComboBox and populate the entries to this drop down depending on your search criteria.

By the way- There's s Swing/AWT Forum where you can post queries related to Swing/AWT/JFace.

[Rob Camick]

Use a DocumentListener so you are notified when any change is made to the Document (either insertions or deletions).

[Mark O'Neal]

This might be what you are looking for.

import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.JComboBox;
import javax.swing.JTextField;
import javax.swing.event.AncestorEvent;
import javax.swing.event.AncestorListener;
import javax.swing.plaf.basic.BasicComboBoxEditor;
import javax.swing.text.JTextComponent;

public class SearchableComboBox extends JComboBox
{

    /**
     * @author Mark.O'Neal
     * Date July 27 2009
     * 
     * Purpose: Allow the search of the combobox contents as the user types
     * in the searched for pattern.
     * As the user types, it will highlight the first match it finds in the
     * drop down.
     * 
     * Note(1): character matches are compared in lowercase and the text is
     * displayed in uppercase.
     */
    
    private JComboBox currentBox;   // adds to readability
    private JTextField boxField;    // field is updated as the user types
    
    private int lastSelectedIndex = -1; //used in the event of a mouse out to set the combobox back
                                        //to the last found item during the search.
    
    public SearchableComboBox()
    {
        currentBox  = this;
        boxField    = (JTextField) ((BasicComboBoxEditor)currentBox.getEditor()).getEditorComponent();
        
        currentBox.setEditable(true);
        currentBox.setEnabled(true);
        
        addTextFieldFocusListener(); 
        addSearchableKeyListener();
        addSearchableAncestorListener();
        
    }
    
    public void addItemToSearchable(Object[] items)
    {
        currentBox.addItem(items);
    }
    
    public void addItemToSearchable(Object item)
    {
        currentBox.addItem(item);
    }
    
    public void removeItemFromSearchable(Object item)
    {
        currentBox.removeItem(item);
    }
    
    public void setPopupVisible(boolean v)
    {
        if(currentBox.getItemCount() > 0)
        {
            if(v == false) //they want to disable the drop down
            {
                int index = currentBox.getSelectedIndex();
                if(index <= -1)
                {
                    index = 0; //reset it to the first item.
                }
                // if lastSelectedIndex is -1.... we left the keylistener on a return
                // or a tab
                if(lastSelectedIndex != -1)
                {
                    //lastSelectedIndex isn't -1, so something else got focus.
                    //set index to the last found item.
                    index = lastSelectedIndex;
                }
                currentBox.setSelectedIndex(index);
                currentBox.setSelectedItem(currentBox.getItemAt(index));
                updateTextField(currentBox.getItemAt(index).toString());
            }
        }
        super.setPopupVisible(v);
    }
    
    protected void updateTextField(String value)
    {
        boxField.setText(value);
    }
    
    protected void addTextFieldFocusListener()
    {
        boxField.addFocusListener(new FocusListener()
        {

            
            public void focusGained(FocusEvent arg0)
            {
            }
            
            public void focusLost(FocusEvent arg0)
            {
                setPopupVisible(false);
            }
            
        });
    }
    
    /**
     * traps the key strokes of the user and attempts to match the
     * letters being typed to the character values in the combobox.
     */
    protected void addSearchableKeyListener()
    {
        ((JTextComponent)currentBox.getEditor().getEditorComponent()).addKeyListener(
                new KeyAdapter()
                {
                    public void keyReleased(KeyEvent e)
                    {
                        if(currentBox.isEditable() == true)
                        {
                            String keyString = (String) boxField.getText().toLowerCase();
                            currentBox.setPopupVisible(true);
                            for(int i = 0; i < currentBox.getItemCount(); i++)
                            {
                                if(currentBox.getItemAt(i).toString().toLowerCase().contains(keyString) == true)
                                {
                                    currentBox.setSelectedIndex(i);
                                    lastSelectedIndex = i;
                                    if(e.getKeyCode() != e.VK_ENTER && e.getKeyCode() != e.VK_TAB)
                                    {
                                        //reverts textfield back to the characters input
                                        updateTextField(keyString.toUpperCase());
                                    }
                                    else
                                    {
                                        lastSelectedIndex = -1;
                                        currentBox.setPopupVisible(false);
                                    }
                                    break;
                                }
                            }
                        }
                    }
                    public void keyPressed(KeyEvent e)
                    {
                        
                    }
                    public void keyTyped(KeyEvent e)
                    {
                        
                    }
                });
    }
    
    protected void addSearchableAncestorListener()
    {
        currentBox.addAncestorListener(new AncestorListener()
        {
            
            public void ancestorAdded(AncestorEvent e)
            {
                currentBox.setPopupVisible(false);                
            }

            
            public void ancestorMoved(AncestorEvent e)
            {
            }
            
            public void ancestorRemoved(AncestorEvent e)
            {
                if(e.getSource() != currentBox)
                {
                    currentBox.setPopupVisible(false);
                }                
            }            
        }
        );
    }
}

Mark.....

[sharjeel afzal]

Thank you very much Mark O'Neal

[sharjeel afzal]

I try this code

import java.awt.BorderLayout;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;

import javax.swing.DefaultListModel;
import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JTextField;
import javax.swing.Popup;
import javax.swing.PopupFactory;
import javax.swing.border.Border;
import javax.swing.event.ListSelectionEvent;
import javax.swing.event.ListSelectionListener;


public class Test extends JFrame{

	final JTextField txtField=new JTextField(10);
	final JList l=new JList();
	final DefaultListModel model=new DefaultListModel();
	final PopupFactory factory=PopupFactory.getSharedInstance(); 

	Popup pop=null;
    
    
	/**
	 * @param args
	 */
	public static void main(String[] args) {
	
		Test t=new Test();

	}
	
	
	public void csearch(String text,String [] result) {
		
		
		
		boolean option=false;
		
		
		for (int i = 0; i < result.length; i++) {
			if(result[i].startsWith(text))
			{
				model.addElement(result[i]);
				option=true;
			}else
			{
				
			}
		}
		l.setModel(model);
		l.setOpaque(true);
		l.addListSelectionListener(new ListSelectionListener()
		{
			public void valueChanged(ListSelectionEvent e)
			{
				if(l.getSelectedIndex()!=-1)
				{
					txtField.setText(l.getSelectedValue().toString());
					pop.hide();
					
				}
			}
			
		});
		
		int x=txtField.getX();
		int y=txtField.getY()+txtField.getHeight();
		
		pop=factory.getPopup(txtField, l, x+5, y+30);
		
		if(option==true)
		{
			pop.show();
		}
		else
			pop.hide();
		
		
	}	
	
	Test()
	{
		hide();
		setVisible(true);
		this.setBounds(0, 0, 100, 100);
		this.setVisible(true);
		this.add(BorderLayout.NORTH,txtField);
//		DefaultListModel d2=new DefaultListModel();
//		d2.addElement("a");
//		d2.addElement("b");
//		
//		l.setModel(d2);
		
	
		
		final String result[]={"apple","aaa","aab","banana","bat","canda","ca"};
		
		txtField.addKeyListener(new KeyAdapter()
		{
			public void keyReleased(KeyEvent ke)
			{
				
				model.removeAllElements();
//				l.setModel(model);
//				l.repaint();
				hide();
				setVisible(true);
				
				csearch(txtField.getText(),result);
			}

		});
		
		
		
		
		
		
		
		
	}
	

}

but it required to show and hide frame else popUp cannot hide

any help