jtable change cell value effect

[Pham Duy Hung]

I have a problem with jtable, i wanna build a jtable, when i change cell value (using setValueAt() or any way), background color of this cell will be changed to a specified color (ex: Color.RED), after 500ms, it will be changed to default background color (ex: Color.BLACK), i'm using thread, but it can not resolve my problem, here's my sample code:

Thank in advance..

   

public class ColoredTableCellRenderer extends DefaultTableCellRenderer {

	private static final long serialVersionUID = -7272725735288258640L;
	
	private JTable table;
	
	public ColoredTableCellRenderer(JTable table){
		this.table = table;
	}

  
        @Override
	public void setValue(Object value) {
                if(value!=null){

                 //change value in current cell
                        setText(value.toString());
                //change background color
		        setBackground(Color.RED);
                //create a thread to change to default color after 500ms
		        new thrdChangeToDefaultColor(this).start();
                }
	}

	public class thrdChangeToDefaultColor extends Thread {

		private ColoredTableCellRenderer component;

		public thrdChangeToDefaultColor(ColoredTableCellRenderer component) {
			this.component = component;
		}

		@Override
		public synchronized void run() {
			try {
				sleep(500);
				this.component.setBackground(Color.BLACK);
				table.repaint();
				join();
			} catch (InterruptedException e) {
				e.printStackTrace();
			}

		}
	}

}

 

[Rob Camick]

A renderer is shared by all cells in column so its values are always reset to the defaults before the cell is painted. So every time the cell is repainted the background will be reset to red. So what you really need is a method in your renderer that indicates if the cell should be painted in its default color or the blinking color. You would turn this on when you need it to blink and then each blink should turn it off.

Also, table.repaint() is not the way to do this. This will cause all the cells to be repainted. You should use the AbstractTableModel.fireTableCellUpdate(...) to invoke repainting of a specific cell.

[Pham Duy Hung]

Rob Camick wrote:A renderer is shared by all cells in column so its values are always reset to the defaults before the cell is painted. So every time the cell is repainted the background will be reset to red. So what you really need is a method in your renderer that indicates if the cell should be painted in its default color or the blinking color. You would turn this on when you need it to blink and then each blink should turn it off.

Also, table.repaint() is not the way to do this. This will cause all the cells to be repainted. You should use the AbstractTableModel.fireTableCellUpdate(...) to invoke repainting of a specific cell.

Thank for your help, i'll try, but in this case, i change bgcolor in setValue() method, so i can not pass 2 agr row and column to AbstractTableModel.fireTableCellUpdate(...) (where can i take it), can you show me an example, thank very much.

[Rob Camick]

Here is a complicated example. Maybe you can figure out how to customize it for your specific purpose:

import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.Timer;
import javax.swing.*;
import javax.swing.table.*;

public class TableColor extends JFrame
{
	ColorRenderer colorRenderer;

	public TableColor()
	{
		String[] columnNames = {"Date", "String", "Integer", "Boolean"};
		Object[][] data =
		{
			{new Date(), "A", new Integer(1), new Boolean(true)},
			{new Date(), "B", new Integer(2), new Boolean(false)},
			{new Date(), "C", new Integer(3), new Boolean(true)},
			{new Date(), "D", new Integer(4), new Boolean(false)}
		};

		final DefaultTableModel model = new DefaultTableModel(data, columnNames);
		final JTable table = new JTable( model )
		{
			public Class getColumnClass(int column)
			{
				return getValueAt(0, column).getClass();
			}

			//  Apply background to existing renderer

			public Component prepareRenderer(
				TableCellRenderer renderer, int row, int column)
			{
				Component c = super.prepareRenderer(renderer, row, column);
				colorRenderer.setBackground(c, row, column);
				return c;
			}
		};
		table.setPreferredScrollableViewportSize(table.getPreferredSize());
		JScrollPane scrollPane = new JScrollPane( table );
		getContentPane().add( scrollPane );

		JButton button = new JButton( "Add Row" );
		button.addActionListener( new ActionListener()
		{
			public void actionPerformed(ActionEvent e)
			{
//				model.addRow( createRow() );
				model.setRowCount( model.getRowCount() + 1 );
				int row = table.getRowCount() - 1;
//				table.changeSelection(row, 0, false, false);
				table.requestFocusInWindow();
				colorRenderer.setRowColor(row, Color.YELLOW);
			}
		});
		getContentPane().add(button, BorderLayout.SOUTH);

		//  Create blinking color renderer

		colorRenderer = new ColorRenderer( table );
		colorRenderer.setCellColor(1, 1, Color.RED);
		colorRenderer.setRowColor(1, Color.GREEN);
		colorRenderer.setColumnColor(1, Color.BLUE);
		colorRenderer.startBlinking(1000);
	}

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

	/*
	**  Color cell background
	*/
	class ColorRenderer implements ActionListener
	{
		private JTable table;
		private AbstractTableModel model;
		private Map colors;
		private boolean isBlinking = true;
		private Timer timer;
		private Point location;

		public ColorRenderer(JTable table)
		{
			this.table = table;
			model = (AbstractTableModel)table.getModel();
			colors = new HashMap();
			location = new Point();
		}

		public void setBackground(Component c, int row, int column)
		{
			//  Don't override the background color of a selected cell

			if ( table.isCellSelected(row, column) ) return;

			//  The default render does not reset the background color
			//  that was set for the previous cell, so reset it here

			if (c instanceof DefaultTableCellRenderer)
			{
				c.setBackground( table.getBackground() );
			}

			//  Don't highlight this time

			if ( !isBlinking ) return;

			//  In case columns have been reordered, convert the column number

			column = table.convertColumnIndexToModel(column);

			//  Get cell color

			Object key = getKey(row, column);
			Object o = colors.get( key );

			if (o != null)
			{
				c.setBackground( (Color)o );
				return;
			}

			//  Get row color

			key = getKey(row, -1);
			o = colors.get( key );

			if (o != null)
			{
				c.setBackground( (Color)o );
				return;
			}

			//  Get column color

			key = getKey(-1, column);
			o = colors.get( key );

			if (o != null)
			{
				c.setBackground( (Color)o );
				return;
			}

		}

		public void setCellColor(int row, int column, Color color)
		{
			Point key = new Point(row, column);
			colors.put(key, color);
		}

		public void setColumnColor(int column, Color color)
		{
			setCellColor(-1, column, color);
		}

		public void setRowColor(int row, Color color)
		{
			setCellColor(row, -1, color);
		}

		private Object getKey(int row, int column)
		{
			location.x = row;
			location.y = column;
			return location;
		}

		public void startBlinking(int interval)
		{
			timer = new Timer(interval, this);
			timer.start();
		}

		public void stopBlinking()
		{
			timer.stop();
		}

		public void actionPerformed(ActionEvent e)
		{
			isBlinking = !isBlinking;

			Iterator it = colors.keySet().iterator();

			while ( it.hasNext() )
			{
				Point key = (Point)it.next();
				int row = key.x;
				int column = key.y;

				if (column == -1)
				{
					model.fireTableRowsUpdated(row, row);
				}
				else if (row == -1)
				{
					int rows = table.getRowCount();

					for (int i = 0; i < rows; i++)
					{
						model.fireTableCellUpdated(i, column);
					}
				}
				else
				{
					model.fireTableCellUpdated(row, column);
				}
			}
		}
	}
}