make node blink in jtree

[pavan in]

Is it possible to make a node blinking in jtree?If yes, how?
When the usr clicks on a button, I want the node selected to start blinking and when the user clicks on another button, it should stop blinking.
Thanks.

[Nathan Pruett]

Here's a short example...

import java.awt.Color;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
    
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellRenderer;
    
public class BlinkenTree extends JTree implements Runnable {
    
    private Thread blinkThread;
    private boolean blinking = false;
    
    public BlinkenTree() {
        super();
        setCellRenderer( new BlinkenRenderer() );
        blinkThread = new Thread( this );
        blinkThread.start();
    }
    
    public void blink( boolean b ) {
        blinking = b;
        BlinkenRenderer.blinking = b;
        repaint();
    }
    
    public void run() {
        while ( true ) {
            if ( blinking ) {
                BlinkenRenderer.blinking = !BlinkenRenderer.blinking;
                repaint();
            }
            try {
                Thread.sleep( 200 );
            }
            catch ( InterruptedException x ) {
                
            }
        } 
    }
    
    public static void main(String[] args) {
        JFrame f = new JFrame( "BlinkenTree" );
        f.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        final BlinkenTree tree = new BlinkenTree();
        JScrollPane scroll = new JScrollPane( tree );
        JPanel p = new JPanel();
        JButton start = new JButton( "Start der blinken" );
        start.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent e ) {
                tree.blink( true );
            }
        } );
        JButton stop = new JButton( "Stop der blinken" );
        stop.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent e ) {
                tree.blink( false );
            }
        } );
        p.add( start );
        p.add( stop );
        JSplitPane split = new JSplitPane( JSplitPane.VERTICAL_SPLIT, scroll, p );
        f.getContentPane().add( split );
        f.pack();
        f.setVisible( true );
    }
    
    private static class BlinkenRenderer extends DefaultTreeCellRenderer {
        
        static boolean blinking = false;
        
        public BlinkenRenderer() {
            super();
            setOpaque( true );
        }
        
        public Component getTreeCellRendererComponent( JTree tree, Object value,
                boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus ) {
            Component c = super.getTreeCellRendererComponent( tree, value, selected,
                    expanded, leaf, row, hasFocus );
            if ( selected ) {
                if ( blinking ) {
                    c.setBackground( Color.red );
                }
                else {
                    c.setBackground( Color.pink );
                }
            }
            else {
                c.setBackground( getBackgroundNonSelectionColor() );
            }
            return c;
        }
    }
}

[pavan in]

Cool. Thanks a looot.

[pavan in]

Nathan,
One more requirement.
when the user clicks on node 1 and clicks start.Node 1 should start blinking (works fine with the code you have given)). Now, the user clicks on another node (node 2). node 1 should be blinking while node 2 should be shown as normal selection. is it possible to do this task?
Thanks.

[Nathan Pruett]

Here's how I changed the code to save what nodes were blinking... Though at this point the nodes themselves are having to remember a lot about their state, so I would start putting this behavior in the objects in the model rather than just the renderer...

import java.awt.Color;
import java.awt.Component;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;
 
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JSplitPane;
import javax.swing.JTree;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreePath;
 
public class BlinkenTree extends JTree implements Runnable {
    
    private Thread blinkThread;
    private volatile boolean blinking = false;
    
    public BlinkenTree() {
        super();
        setCellRenderer( new BlinkenRenderer() );
        blinkThread = new Thread( this );
        blinkThread.start();
    }
    
    public void blink( boolean b ) {
        BlinkenRenderer.blinkingValues.clear();
        TreePath[] path = this.getSelectionPaths();
        for ( int i = 0; i < path.length; i++ ) {
            BlinkenRenderer.blinkingValues.add( path[i].getLastPathComponent() );
        }
        blinking = b;
        BlinkenRenderer.blinking = b;
        repaint();
    }
    
    public void run() {
        while ( true ) {
            if ( blinking ) {
                BlinkenRenderer.blinking = !BlinkenRenderer.blinking;
                repaint();
            }
            try {
                Thread.sleep( 200 );
            }
            catch ( InterruptedException x ) {
                
            }
        } 
    }
 
    public static void main(String[] args) {
        JFrame f = new JFrame( "BlinkenTree" );
        f.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
        final BlinkenTree tree = new BlinkenTree();
        JScrollPane scroll = new JScrollPane( tree );
        JPanel p = new JPanel();
        JButton start = new JButton( "Start der blinken" );
        start.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent e ) {
                tree.blink( true );
            }
        } );
        JButton stop = new JButton( "Stop der blinken" );
        stop.addActionListener( new ActionListener() {
            public void actionPerformed( ActionEvent e ) {
                tree.blink( false );
            }
        } );
        p.add( start );
        p.add( stop );
        JSplitPane split = new JSplitPane( JSplitPane.VERTICAL_SPLIT, scroll, p );
        f.getContentPane().add( split );
        f.pack();
        f.setVisible( true );
    }
    
    private static class BlinkenRenderer extends DefaultTreeCellRenderer {
        
        static volatile boolean blinking = false;
        static volatile Vector blinkingValues = new Vector();
        
        BlinkenRenderer() {
            super();
            setOpaque( true );
        }
        
        public Component getTreeCellRendererComponent( JTree tree, Object value,
                boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus ) {
            Component c = super.getTreeCellRendererComponent( tree, value, selected,
                    expanded, leaf, row, hasFocus );
            if (blinking && blinkingValues.contains( value ) ) {
                c.setBackground( Color.red );
            }
            else if ( selected ) {
                c.setBackground( Color.pink );
            }
            else {
                c.setBackground( getBackgroundNonSelectionColor() );
            }
            return c;
        }
    }
}

[pavan in]

Thanks Nathan.
I should make the tree -> jtree.getSelectionModel().setSelectionMode(TreeSelectionModel.DISCONTIGUOUS_TREE_SELECTION);
is it right?
But, I want only one node to be selected at any point.so, i have set the selection model as SINGLE_TREE_SELECTION.
is it possible to make the node 1 blinking and still be able to select only 1 node?

[pavan in]

Nathan,
In the above example, when i select node 2, the node 1 stops blinking. because, 'value' is changed when the user selects another node.isnt it?

[Nathan Pruett]

The selection changes only if you call the blink() method of the tree again...

And it shouldn't matter if you use single selection. The new code saves whatever nodes are selected (whether it is one or many) when the blink() method of the tree is called. Then those nodes blink until either blinking is turned off, or a new node selection is made by calling the blink() method again.

[pavan in]

Nathan,
Once I select node 2 in the tree, the node 1 which was blinking gets deselected and node 2 is highlighted. but, i want node 1 to blink while node 2 is highlighted.

[Nathan Pruett]

Have you run the second code posting?

It does exactly that!

Click a node (node 1).

Click "start".

node 1 blinks.

Now you can select any other nodes, and node 1 is still blinking.
[ March 13, 2003: Message edited by: Nathan Pruett ]

[Stan James]

Just a thought - A Sun (I think Sun) tutorial on Timer suggested it as an alternative to managing your own threads for blinking and other animation effects. The main advantage is that it can manage many timers on only one thread for a little less overhead.