Scroll JTable in Scrollpane with mouse drag

Question

Hello developers !
I'm trying to make a scrollable Jtable. The table have to be scrollable with the mouse drag event. But I have a "flashing" Problem. I can catch the Mouse events from the table (I'm listener the mouse motion and mouse events).
When I receive a new mouse drag event, I set the new position from the viewport. The problem is, that the Table flash:
For example:
I drag the mouse to the bottom of the table. The mouse "y" position have to increase, but it doesn't:
first motion event position (10, 10)
second motion event position (10, 15)
third motion event position (10, 12)
etc..
The position of the mouse event are in relation of the component position. I think, the problem is that I change the position of the view port and than the new mouse event is "on a wrong reference".
Could someone help me? How could I make a work around for this Problem?

Answer 1

I have the solution... it is easy.
I post the solution because i spent two days making working around (changing viewport position other scrollbar values, etc).
You dont need to implement the Autoscroll interface. The Autoscroll interface is for Drag and Drop classes.
The key was the function JTable#scrollRectToVisible....
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class ScrollableTableFrame extends JFrame{
  protected ScrollableTable table;
  public ScrollableTableFrame() {
    super("Scrollable Table");
    setSize(600, 300);
    String data[][] = new String[40][40];
    String header[] = new String[40];
    for(int i = 0; i < 40; i++){
      header[i] = "Header " + i;
      for(int j = 0; j < 40; j++){
        data[i][j] = "(" + i + ", " + j +")";
    ScrollableTable table = new ScrollableTable(data, header);
    table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    JScrollPane sp = new JScrollPane();
    sp.getViewport().setBackground(table.getBackground());
    sp.getViewport().add(table);
    getContentPane().add(sp, BorderLayout.CENTER);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(400, 400);
    setVisible(true);
  public static void main(String args[]){
    new ScrollableTableFrame();
class ScrollableTable extends JTable{
  private Point firstPressedPoint;
  public ScrollableTable(Object rowData[][], Object columnNames[]){
    super(rowData, columnNames);
  protected void processMouseEvent(MouseEvent e){
    int id = e.getID();
    switch(id) {
      case MouseEvent.MOUSE_PRESSED:
        firstPressedPoint = e.getPoint();
        break;
      case MouseEvent.MOUSE_RELEASED:
        firstPressedPoint = null;
        break;
      case MouseEvent.MOUSE_CLICKED:
      case MouseEvent.MOUSE_EXITED:
      case MouseEvent.MOUSE_ENTERED:
    super.processMouseEvent(e);
  protected void processMouseMotionEvent(MouseEvent e){
    if(e.getID() == MouseEvent.MOUSE_DRAGGED){
      Rectangle r = getVisibleRect();
      Point p = e.getPoint();
      int dx = (firstPressedPoint.x-p.x);
      int dy = (firstPressedPoint.y-p.y);
      Rectangle aRect = new Rectangle(r.x + dx, r.y + dy , r.width + dx, r.height + dy);
      scrollRectToVisible(aRect);
}P.S.: jarshe, thank you for your help !!