KeyListener not working for JLabel.

[Sharad Kharya]

Hi,
I am working on Swing application and not able to add keyListener on my JLabel component.
But mouseListener is working properly.

I need to add 3 keyboard events
1) Enter - To get inside label folder
2) Ctrl – need to perform ctrl+click operation.
3) Tab – to navigate from one Label to another.(and after browsing to the selected label user can press enter key)

Below is the code snippet

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Frame;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.util.Hashtable;
import javax.swing.BorderFactory;
import javax.swing.Box;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JDialog;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JPopupMenu;
import javax.swing.JScrollPane;
import javax.swing.JToolBar;
import javax.swing.border.BevelBorder;
import javax.swing.border.EmptyBorder;

public class ChkOutUI
{
	//public JDialog checkoutDialog         	 				= null;
	private JPanel checkoutPanel            				= null;
	private JComboBox directoryComboBox     				= null;
	private JButton detailsButton           				= null;
	private JPopupMenu viewPopup                			= null;
	private JMenuItem detailsView							= null;
	private JMenuItem thumbnailView							= null;
	private JScrollPane scrollPane							= null;
	private GridBagConstraints layoutContraints 			= null;
	private JButton openBtn                     			= null;
	public int  selectedRow                  				= 0;
	private JPanel centerPanel 								= null;
	private JLabel thumbnailsLabel[]						= null;
	private Hashtable posMap					= null;
	private JPanel thumbnailPanel 							= null;
	private int pos							= 0;

	public static void main(String[] args) {
		ChkOutUI ui = new ChkOutUI();
		ui.initDialog();
	}
	
	public void initDialog() 
	{	
		try{
			checkoutPanel=new JPanel();		
			checkoutPanel.setBorder(new EmptyBorder(4, 10, 10, 10));
			checkoutPanel.setLayout(new BorderLayout(8, 8));
			checkoutPanel.add(topFrame(), BorderLayout.NORTH);
			checkoutPanel.add(centralFrame(), BorderLayout.CENTER);	
			checkoutPanel.add(bottomFrame(), BorderLayout.SOUTH);		
			JFrame f = new JFrame("Open");
			f.getContentPane().add(checkoutPanel);
			f.pack();
			f.setVisible(true);
			f.setLocation(300,200);
		}catch(Exception e){
			e.printStackTrace();
		}
	}

	public JToolBar topFrame()
	{
		JToolBar topPanel = new JToolBar();
		topPanel.setFloatable(false);
		
		JLabel lookInLabel = new JLabel("LookIn");
		topPanel.add(Box.createRigidArea(new Dimension(4,0)));
		topPanel.add(lookInLabel);
		topPanel.add(Box.createRigidArea(new Dimension(4,0)));

		directoryComboBox = new JComboBox();
		directoryComboBox.addItem("Folder Path");
		directoryComboBox.setPreferredSize(new Dimension(250,20));		
		directoryComboBox.addActionListener( new ActionListener(){
			public void actionPerformed(ActionEvent e){	
				System.out.println("combox box listener");
			}
		});
		topPanel.add(directoryComboBox);
		
		detailsButton = new JButton("view");   
		topPanel.add(detailsButton);
		detailsButton.addMouseListener(new MouseAdapter(){
			public void mouseClicked(MouseEvent e){
				viewPopup = new JPopupMenu();
				detailsView = new JMenuItem("Details");
				thumbnailView = new JMenuItem("Thumbnails");
				viewPopup.add(detailsView);
				viewPopup.add(thumbnailView);
				viewPopup.show(detailsButton, e.getX(), e.getY());
			} 
		});
		return topPanel;		
	}
	
	public Component centralFrame()
	{	
		BorderLayout centerPanelLayout = new BorderLayout();
		centerPanel = new JPanel(centerPanelLayout);
		centerPanel.setBorder(new BevelBorder(BevelBorder.LOWERED));
		thumbnailPanel = new JPanel(new GridBagLayout());
		thumbnailPanel.setBackground(Color.WHITE);
		
		thumbnailsLabel = new JLabel[2];
		
		layoutContraints = new GridBagConstraints();
		layoutContraints.insets = new Insets(10,25,10,10);
		layoutContraints.weightx = 1.0;
		layoutContraints.weighty = 1.0;
		layoutContraints.fill = GridBagConstraints.NONE;
		layoutContraints.anchor = GridBagConstraints.NORTHWEST;
		posMap = new Hashtable();
		for(pos=0; pos<2; pos++)
		{
			layoutContraints.gridx = pos;
			layoutContraints.gridy = GridBagConstraints.RELATIVE;
			String label = "Label "+new Integer(pos).toString();
			thumbnailsLabel[pos] = new JLabel(label, JLabel.CENTER);
			thumbnailsLabel[pos].setPreferredSize(new Dimension(150,150));
			thumbnailsLabel[pos].setBorder(BorderFactory.createEtchedBorder());

			posMap.put(thumbnailsLabel[pos], new Integer(pos));
			
			thumbnailsLabel[pos].addMouseListener(new MouseAdapter(){
				public void mouseClicked(MouseEvent evt){
					JLabel tempLabel = 	(JLabel)evt.getSource();
					String text = tempLabel.getText();
					selectedRow = ((Integer) posMap.get(tempLabel)).intValue();
					tempLabel.setBackground(Color.BLUE);
					for(int i=0;i<thumbnailsLabel.length;i++){
						if(i != selectedRow){
							thumbnailsLabel[i].setBackground(Color.WHITE);
						}
					}
					if(evt.getButton() == MouseEvent.BUTTON1 && evt.getClickCount() == 2){
						System.out.println("inside double click");														
					}
					else if(evt.getButton() == MouseEvent.BUTTON3 && evt.getClickCount() == 1){
						System.out.println("Inside right click");
					}
				}					
			});
				
			thumbnailsLabel[pos].addKeyListener( new KeyAdapter(){
				public void keyPressed(KeyEvent k){
					if(k.getKeyCode() == KeyEvent.VK_ENTER){
						System.out.println("Enter click "+pos);
					}else if(k.getKeyCode() == KeyEvent.VK_CONTROL){
						System.out.println("ctrl key ");
					}else if(k.getKeyCode() == KeyEvent.VK_TAB){
						JLabel tempLabel = 	(JLabel)k.getSource();
						tempLabel.setBackground(Color.blue);
						selectedRow = ((Integer) posMap.get(tempLabel)).intValue();
						for(int i=0;i<thumbnailsLabel.length;i++){
							if(i != selectedRow){
								thumbnailsLabel[i].setBackground(Color.WHITE);
							}
						}
					}					
				}					
			});

			thumbnailPanel.add(thumbnailsLabel[pos], layoutContraints, pos);
		}
		scrollPane = new JScrollPane(thumbnailPanel,JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED,JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED);
		scrollPane.setPreferredSize(new Dimension(400, 350));
		return scrollPane;		
	}

	public JPanel bottomFrame()
	{
		JPanel bottomPanel = new JPanel(new FlowLayout());
		openBtn = new JButton("Open");		
		bottomPanel.add( openBtn);
		openBtn.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent evt){
				System.out.println("open clicked");
			}
		});	
		return bottomPanel;
	}
}

Please let me know who to resolve keyboard event handling issue properly here.

Thanks
Sharad>

[K. Tsang]

have you try comment out the mouse listener part and see if key stuff works? If it doesn't probably something wrong inside those overridden methods. If not try put key listener in front of mouse listener. Oh shouldn't the label be focused before key actions are detected? Just a thought.

[Michael Dunn]

> Below is the code snippet

just interested to know how menu, toolbar, border, combobox, button, awt.frame, diaolg, popup and scrollpane,
has anything to do with the subject line?

[Paul Clapham]

Sharad Golu wrote:Hi,
I am working on Swing application and not able to add keyListener on my JLabel component.
But mouseListener is working properly.

I need to add 3 keyboard events
1) Enter - To get inside label folder
2) Ctrl – need to perform ctrl+click operation.
3) Tab – to navigate from one Label to another.(and after browsing to the selected label user can press enter key)

I don't understand where the KeyListener comes into your design. You certainly don't need to listen for Tab keys, that's the job of the FocusListener for whatever component contains your JLabel. Likewise if the JLabel has focus, then pressing Enter will automatically do the same as if you clicked on the JLabel.

And I believe you would look for Ctrl-click in a MouseListener rather than a KeyListener.

I didn't look at any of your code because I don't think any of it was relevant (because of what I just posted above). But even if some of it was relevant, there was way too much of it. A small program with one or two labels would have sufficed. Anything else would just distract from the actual question.