Interactive Panel

[homistar]

Dear Members,

I am sorry to used that Thread , and i attached my code as a zip file with the reply , anyway I am so sorry for all that , well here is my code I am facing problem in mouse events.

class GraphicComponent extends JPanel  {
    // make points of view data       
    JLabel xViewLabel;
    JLabel yViewLabel;
    JLabel xModelLabel;
    JLabel yModelLabel;
    double [] data = {1.0 , 5.8, 7.4 , 3.2};
    AffineTransform xform;
    AffineTransform inverted;
    final int PAD = 20;
public GraphicComponent ()
{
         }

    public void setPoint(Point p, int x, int y) {
        p.setLocation(x,y);
        repaint();
    }

   protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        if(xform == null) setTransform();
        double w = getWidth();
        double h = getHeight();
        // draw axes
        g2.draw(new Line2D.Double(PAD, PAD, PAD, h-PAD));  // top - to bottom        
        g2.draw(new Line2D.Double(PAD, h-PAD, w-PAD, h-PAD)); // left to write
        // draw data
        g2.setPaint(Color.red);
        for(int i = 0; i < data.length ; i++) {
            Point2D.Double p = modelToView(i, data[i]);
            g2.fill(new Ellipse2D.Double(p.x-1.5, p.y-1.5, 4, 4));
        }
    }


    private Point2D.Double modelToView(double x, double y) {
        Point2D.Double dst = new Point2D.Double();
        xform.transform(new Point2D.Double(x, y), dst);
        return dst;
    }
    private Point2D.Double viewToModel(Point p) {
        Point2D.Double dst = new Point2D.Double();
        inverted.transform(p, dst);
        return dst;
    }
      private void setTransform() {
        xform = new AffineTransform();
        double w = getWidth();
        double h = getHeight();
        double dataMax = getDataMax();
        double max = Math.ceil(dataMax/10)*10;
        System.out.printf("dataMax = %f  max = %f%n", dataMax, max);
        double yScale = (h - 2*PAD)/max;
        double xScale = (w - 2*PAD)/(data.length-1);
        xform.translate(PAD, h-PAD);  // PAD = x-axis , h-PAD = y-axis
        xform.scale(xScale, -yScale); // xScale = x-axis , -yscale = y-axis

        setInverted();
    }
      private void setInverted() {
        inverted = (AffineTransform)xform.clone();
        if(inverted.getDeterminant() != 0) {
            try {
                inverted.invert();
            } catch(NoninvertibleTransformException e) {
                System.out.println("invert error: " + e.getMessage());
            }
        } else {
            inverted.setToIdentity();

        }
    }

    private double getDataMax() {     
        double [] copy = Arrays.copyOf(data, data.length);
        Arrays.sort(copy);
        return copy[data.length-1];
    }

    private JPanel getOutputPanels() {
        Dimension d = new Dimension(65, 25);
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.weightx = 1.0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        panel.add(getViewPanel(d), gbc);
        panel.add(getModelPanel(d), gbc);
        return panel;
    }

    private JPanel getViewPanel(Dimension d) {
        xViewLabel = getLabel(d);
        yViewLabel = getLabel(d);
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,2,2,2);
        JLabel label = getLabel(d);
        label.setText("View");
        panel.add(label, gbc);
        gbc.weightx = 1.0;
        addComponents("x", xViewLabel, panel, gbc, true);
        addComponents("y", yViewLabel, panel, gbc, false);
        return panel;
    }

    private JPanel getModelPanel(Dimension d) {
        xModelLabel = getLabel(d);
        yModelLabel = getLabel(d);
        JPanel panel = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(2,2,2,2);
        JLabel label = getLabel(d);
        label.setText("Model");
        panel.add(label, gbc);
        gbc.weightx = 1.0;
        addComponents("x", xModelLabel, panel, gbc, true);
        addComponents("y", yModelLabel, panel, gbc, false);
        return panel;
    }

    private JLabel getLabel(Dimension d) {
        JLabel label = new JLabel();
        label.setPreferredSize(d);
        label.setBorder(BorderFactory.createEtchedBorder());
        return label;
    }

    private void addComponents(String s, JLabel label, Container c,
                               GridBagConstraints gbc, boolean b) {
        gbc.weightx = b ? 1.0 : 0;
        gbc.anchor = GridBagConstraints.EAST;
        c.add(new JLabel(s), gbc);
        gbc.weightx = b ? 0 : 1.0;
        gbc.anchor = GridBagConstraints.WEST;
        c.add(label, gbc);
    }

    public static void main(String[] args)
    {
        GraphicComponent gc = new GraphicComponent();
        JFrame f = new JFrame();
         f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.add(gc);
         f.add(gc.getOutputPanels(), "Last");
         f.setSize(400,400);
        f.setLocation(100,100);
        f.setVisible(true);
        //make and show gui
        DragClass dc = new DragClass(gc);
        gc.addMouseListener(dc);
        gc.addMouseMotionListener(dc);
    }

      }

class DragClass extends MouseAdapter {
    GraphicComponent component;
    Point selPoint;
     double [] data ;
    boolean okayToDrag = false;
    Point offset = new Point();
    int closeEnough;
     private int dragIndex = NOT_DRAGGING;
     private final static int NOT_DRAGGING = -1;
    private int x;
    private int y;
     private   int NEIGHBORHOOD = 4;
    public DragClass(GraphicComponent gc) {
        component = gc;
        this.data = component.data;
    }

    @Override
    public void mousePressed(MouseEvent e) {
      dragIndex = NOT_DRAGGING;
        int minDistance = Integer.MAX_VALUE;
         Point p = e.getPoint();
              closeEnough = -1;
for ( int i = 0; i < data.length ; i++)
{
    selPoint.x = i;
    selPoint.y = (int) data[i];
    offset.x = p.x - selPoint.x;
    offset.y = p.y - selPoint.y;
     int distance = (int) (Math.sqrt( offset.x* offset.x + offset.y + offset.y));
    if (distance < minDistance) {
        minDistance = distance;
       closeEnough = i;
      
      }
        break;    
} // end of for loop
              if (minDistance > NEIGHBORHOOD)
      return;

    dragIndex = closeEnough;
   } // end of pressed event

    @Override
    public void mouseReleased(MouseEvent e) {
        if (dragIndex == NOT_DRAGGING)
      return;
        dragIndex = NOT_DRAGGING;
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        if (dragIndex == NOT_DRAGGING)
      return;
     
            x = e.getX() - offset.x;
            y = e.getY() - offset.y;
            component.setPoint(selPoint, x, y);


    }
}

Thanks you

[DarrylBurke]

> I am facing problem in mouse events.
Patient: Doctor, I am facing problem in my, er, um, mouse events
Doctor: here you go. 2 tablets 3 times a day and you'll be right as rain.

Not a likely scenario, huh? The doctor would need more information, or the patient could get the wrong medicine and end up with no mouse events at all, or too many.

How To Ask Questions The Smart Way

db

[Fubarable]

Dear Members,
I am sorry to used that Thread ,

I think that you refer to this: http://www.java-forums.org/showthread.php?t=19927
No biggie.

and i attached my code as a zip file with the reply ,

???

anyway I am so sorry for all that , well here is my code I am facing problem in mouse events.

You may wish to give us more information here as "problem in mouse events" tells very little.

Much luck.

[homistar]

Hi Again,

<CODE>
public void mousePressed(MouseEvent e) {
dragIndex = NOT_DRAGGING;
int minDistance = Integer.MAX_VALUE;
Point p = e.getPoint();
closeEnough = -1;
for ( int i = 0; i < data.length ; i++)
{
selPoint.x = i;
selPoint.y = (int) data[i];

offset.x = p.x - selPoint.x;
offset.y = p.y - selPoint.y;
int distance = (int) (Math.sqrt( offset.x* offset.x + offset.y + offset.y));
if (distance < minDistance) {
minDistance = distance;
closeEnough = i;

}
</CODE>

I am getting NullPointer exception in upper mentioned code in Dark Red color
Data is double array holding actual data model values.

Appreciated if you answer me..
Thanks

[r035198x]

That means that selPoint is null at that point so you can't do selPoint.x.