Display arrow button over label icon on focus

[Deepu James]

Hello,
I have JLabel displayed on one of my JTable cells. One of the label has Icon image displayed over it. I would like to display arrow button on mouse over Jlabel and displat next ImageIcon on the label when I click on the arrow.
How can I diplay small arrows over a Jlabel Image component when mouse is moved over it? Any help or sample code for this would be very helpfull

Thanks
DJ

[Brian Cole]

Allow me to quote parts of your post out of order.

Originally posted by Deepu James:
How can I diplay small arrows over a Jlabel Image component when mouse is moved over it? Any help or sample code for this would be very helpfull

You can add a MouseListener to your JLabel instance and play tricks
with its icon and/or paint() method. However, it may be easier to
just use a JButton. JButton has some built-in rollover support, and
it's not hard to make a JButton look like a label.

I have JLabel displayed on one of my JTable cells. One of the label has Icon image displayed over it. I would like to display arrow button on mouse over Jlabel and displat next ImageIcon on the label when I click on the arrow.

But in the context of JTable cells, things are different. That's because
the contents of JTable cells (possibly excluding the cell being edited)
are not Components. What you see in a cell is the image of its renderer
Component, but there's no point adding listeners to the renderer Component
(or trying to use rollover) because it's not there anymore by the time
you move your mouse over it.
For that I guess you would need to add a MouseMotionListener for the
entire JTable, then either cause specific cells to be repainted or
draw on top of the cells.

[Craig Wood]

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.*;
import java.util.EventObject;
import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import javax.swing.table.*;
 
public class Rollover {
    RolloverEditor rolloverEditor;
 
    private JScrollPane getTableComponent(BufferedImage[] images) {
        String[] colIds = { "column 1", "column 2", "column 3", "column 4" };
        final Object[][] data = new Object[][] {
            { new RolloverStore(images[0], images[1], "one"),
              new RolloverStore(images[2], images[3], "two"),
              "three", "four" }
        };
        DefaultTableModel model = new DefaultTableModel(data, colIds) {
            public Class getColumnClass(int column) {
                return data[0][column].getClass();
            }
        };
        JTable table = new JTable(model);
        table.setRowHeight(75);
        Dimension d = table.getPreferredSize();
        d.width = 600;
        table.setPreferredScrollableViewportSize(d);
        table.setCellSelectionEnabled(true);
        table.addMouseListener(iconRoller);
        table.addMouseMotionListener(iconRoller);
        table.setDefaultRenderer(RolloverStore.class, new RolloverRenderer());
        rolloverEditor = new RolloverEditor();
        table.setDefaultEditor(RolloverStore.class, rolloverEditor);
        return new JScrollPane(table);
    }
 
    public static void main(String[] args) throws IOException {
        String[] ids = { "-c---", "--g--", "---h-", "----t" };
        BufferedImage[] images = new BufferedImage[ids.length];
        for(int i = 0; i < images.length; i++) {       // 83, 67
            String path = "images/geek/geek" + ids[i] + ".gif";
            images[i] = javax.imageio.ImageIO.read(new File(path));
        }
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(new Rollover().getTableComponent(images));
        f.pack();
        f.setLocation(100,100);
        f.setVisible(true);
    }
 
    private MouseInputAdapter iconRoller = new MouseInputAdapter() {
        boolean hovering = false;
        int selectedColumn = -1;
 
        public void mouseMoved(MouseEvent e) {
            Point p = e.getPoint();
            JTable table = (JTable)e.getComponent();
            int col = table.columnAtPoint(p);
            boolean overStore =
                table.getValueAt(0, col) instanceof RolloverStore;
            if(overStore && (!hovering || col != selectedColumn)) {
                if(col != selectedColumn) {
                    rolloverEditor.cancelCellEditing();
                    selectedColumn = col;
                    table.editCellAt(0, col);
                }
                hovering = true;
            }
            if(hovering && !overStore) {
                cancel();
            }
        }
 
        private void cancel() {
            hovering = false;
            selectedColumn = -1;
            rolloverEditor.cancelCellEditing();
        }
 
        public void mouseExited(MouseEvent e) {
            cancel();
        }
 
        public void mousePressed(MouseEvent e) {
            Point p = e.getPoint();
            JTable table = (JTable)e.getComponent();
            int col = table.columnAtPoint(p);
            if(table.isCellSelected(0, col) && table.isEditing()) {
                Point xp = SwingUtilities.convertPoint(table, p,
                                              rolloverEditor.editPanel);
                rolloverEditor.checkForHit(xp);
            }
        }
    };
}
 
class RolloverEditor extends AbstractCellEditor implements TableCellEditor {
    EditPanel editPanel = new EditPanel();
    JLabel label = new JLabel();
    RolloverStore store;
    Shape arrow;
 
    public RolloverEditor() {
        label.setBorder(BorderFactory.createEmptyBorder(1,1,1,1));
        editPanel.add(label);
    }
 
    public Component getTableCellEditorComponent(JTable table,
                                                 Object value,
                                                 boolean isSelected,
                                                 int row, int column) {
        store = (RolloverStore)value;
        label.setIcon(store.getIcon());
        label.setText(store.text);
        return editPanel;
    }
 
    public Object getCellEditorValue() {        
        return store;
    }
 
    public void checkForHit(Point p) {
        if(arrow.contains(p)) {
            store.toggleIndex();
            label.setIcon(store.getIcon());
            label.repaint();
        }
    }
 
    private class EditPanel extends JPanel {
        Polygon polygon = new Polygon();
 
        public EditPanel() {
            super(new BorderLayout());
            polygon.addPoint(0,0);
            polygon.addPoint(30,30);
            polygon.addPoint(0,60);
            setBackground(UIManager.getColor("Table.background"));
        }
 
        public void paint(Graphics g) {
            super.paint(g);
            Graphics2D g2 = (Graphics2D)g;
            g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                                RenderingHints.VALUE_ANTIALIAS_ON);
            int w = getWidth();
            int h = getHeight();
            Rectangle r = polygon.getBounds();
            double x = (w - r.width)/2;
            double y = (h - r.height)/2;
            AffineTransform at = AffineTransform.getTranslateInstance(x,y);
            arrow = at.createTransformedShape(polygon);
            g2.setPaint(Color.red);
            g2.fill(arrow);
        }
    }
}
 
class RolloverRenderer extends DefaultTableCellRenderer {
    public Component getTableCellRendererComponent(JTable table,
                                                   Object value,
                                                   boolean isSelected,
                                                   boolean hasFocus,
                                                   int row, int column) {
        super.getTableCellRendererComponent(table, value, isSelected,
                                            hasFocus, row, column);
        RolloverStore store = (RolloverStore)value;
        setIcon(store.getIcon());
        setText(store.text);
        return this;
    }
}
 
class RolloverStore {
    ImageIcon[] icons;
    String text;
    int showingIndex;
 
    public RolloverStore(BufferedImage image1,
                         BufferedImage image2, String s) {
        icons = new ImageIcon[2];
        icons[0] = new ImageIcon(image1);
        icons[1] = new ImageIcon(image2);
        showingIndex = 0;
        text = s;
    }
 
    public ImageIcon getIcon() {
        return icons[showingIndex];
    }
 
    public void toggleIndex() {
        showingIndex = (showingIndex == 0) ? 1 : 0;
    }
}