How to call?

I want to draw an ellipse/line/rectangle when I click the JButtons. So far this is what I did. No compile error. But I don't figure out how to call functions on JButtons.

Please help me.

Code:

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import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.*;
import java.util.ArrayList;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.ButtonGroup;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.FlowLayout;


public class DrawingBoardWithMatrix extends JFrame{

  public static void main(String[] args) {
      new DrawingBoardWithMatrix();
  }

  public DrawingBoardWithMatrix() {
    super("Mini Paint Applet");
    ButtonGroup cbg = new ButtonGroup();
    JButton lineButton = new JButton("Line");
    JButton ovalButton = new JButton("Oval");
    JButton rectangleButton = new JButton("Rectangle");
    cbg.add(lineButton);
    cbg.add(ovalButton);
    cbg.add(rectangleButton);
    JPanel shapePanel = new JPanel(new FlowLayout());
    shapePanel.add(lineButton);
    shapePanel.add(ovalButton);
    shapePanel.add(rectangleButton);
    this.setLayout(new BorderLayout());
    this.add(shapePanel, BorderLayout.NORTH);
    this.setSize(800, 800);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.add(new PaintSurface(), BorderLayout.CENTER);
    this.setVisible(true);
  }

  private class PaintSurface extends JComponent {
    ArrayList<Shape> shapes = new ArrayList<Shape>();
    String shapeType = "Rectangle";

    Point startDrag, endDrag;

    public PaintSurface() {
      this.addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
          startDrag = new Point(e.getX(), e.getY());
          endDrag = startDrag;
          repaint();
        }

        public void mouseReleased(MouseEvent e) {
//          Shape r = makeRectangle(startDrag.x, startDrag.y, e.getX(), e.getY());
          Shape l = makeLine(startDrag.x, startDrag.y, e.getX(), e.getY());
//          Shape el = makeEllipse(startDrag.x, startDrag.y, e.getX(), e.getY());
//          shapes.add(r);
            shapes.add(l);
//          shapes.add(el);
          startDrag = null;
          endDrag = null;
          repaint();
        }
      });

      this.addMouseMotionListener(new MouseMotionAdapter() {
        public void mouseDragged(MouseEvent e) {
          endDrag = new Point(e.getX(), e.getY());
          repaint();
        }
      });
    }
    private void paintBackground(Graphics2D g2){
      g2.setPaint(Color.LIGHT_GRAY);
      for (int i = 0; i < getSize().width; i += 10) {
        Shape line = new Line2D.Float(i, 0, i, getSize().height);
        g2.draw(line);
      }

      for (int i = 0; i < getSize().height; i += 10) {
        Shape line = new Line2D.Float(0, i, getSize().width, i);
        g2.draw(line);
      }


    }
    public void paint(Graphics g) {
      Graphics2D g2 = (Graphics2D) g;
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      paintBackground(g2);
      Color[] colors = { Color.YELLOW, Color.MAGENTA, Color.CYAN , Color.RED, Color.BLUE, Color.PINK};
      int colorIndex = 0;

      g2.setStroke(new BasicStroke(2));
      g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.50f));

      for (Shape s : shapes) {
        g2.setPaint(Color.BLACK);
        g2.draw(s);
        g2.setPaint(colors[(colorIndex++) % 6]);
        g2.fill(s);
      }

      if (startDrag != null && endDrag != null) {
        g2.setPaint(Color.LIGHT_GRAY);
//        Shape r = makeRectangle(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
//        g2.draw(r);

        Shape l = makeLine(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
        g2.draw(l);
//        Shape el = makeLine(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
//        g2.draw(el);
      }
    }

    private Line2D.Float makeLine(int x1, int y1, int x2, int y2) {
        return new Line2D.Float(x1, y1, x2, y2);
 }


//    private Rectangle2D.Float makeRectangle(int x1, int y1, int x2, int y2) {
//      return new Rectangle2D.Float(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));
//    }

/*    private Ellipse2D.Float makeEllipse(int x1, int y1, int x2, int y2) {
      return new Ellipse2D.Float(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));
    }
*/ 
}
}

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Quote:

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Originally Posted by scopolamine

I want to draw an ellipse/line/rectangle when I click the JButtons. So far this is what I did. No compile error. But I don't figure out how to call functions on JButtons.

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Please have a look at the tutorials on this which you can find here:
How to Use Buttons, Check Boxes, and Radio Buttons
How to Write an Action Listener

Much luck!

Quote:

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Originally Posted by Fubarable

Please have a look at the tutorials on this which you can find here:
How to Use Buttons, Check Boxes, and Radio Buttons
How to Write an Action Listener

Much luck!

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When I add the ActionListener, it gives me a compile error.

Leaking in this constructor.

Quote:

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Originally Posted by scopolamine

When I add the ActionListener, it gives me a compile error.

Leaking in this constructor.

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Have you showed us the code where you try to do this, because I can't find it, so I don't know what you're doing wrong.

Here it is(edited version):

Code:

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import java.awt.AlphaComposite;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Point;
import java.awt.RenderingHints;
import java.awt.Shape;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.*;
import java.util.ArrayList;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.ButtonGroup;
import javax.swing.JPanel;
import javax.swing.JButton;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;


public class DrawingBoardWithMatrix extends JFrame{

  public static void main(String[] args) {
      new DrawingBoardWithMatrix();
  }

  public DrawingBoardWithMatrix() {
    super("Mini Paint Applet");
    ButtonGroup cbg = new ButtonGroup();
    JButton lineButton = new JButton("Line");
    JButton ovalButton = new JButton("Oval");
    JButton rectangleButton = new JButton("Rectangle");
    lineButton.addActionListener( this );
    cbg.add(lineButton);
    cbg.add(ovalButton);
    cbg.add(rectangleButton);
    JPanel shapePanel = new JPanel(new FlowLayout());
    shapePanel.add(lineButton);
    shapePanel.add(ovalButton);
    shapePanel.add(rectangleButton);
    this.setLayout(new BorderLayout());
    this.add(shapePanel, BorderLayout.NORTH);
    this.setSize(800, 800);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    this.add(new PaintSurface(), BorderLayout.CENTER);
    this.setVisible(true);
  }

 
  private class PaintSurface extends JComponent {
    ArrayList<Shape> shapes = new ArrayList<Shape>();
    String shapeType = "Rectangle";

    Point startDrag, endDrag;

    public PaintSurface() {
      this.addMouseListener(new MouseAdapter() {
        public void mousePressed(MouseEvent e) {
          startDrag = new Point(e.getX(), e.getY());
          endDrag = startDrag;
          repaint();
        }

  public void ActionPerformed( ActionEvent e ) {
  Object source = e.getSource();
  if ( source == lineButton )
  System.out.println( "Button clicked" );
 }
       
        public void mouseReleased(MouseEvent e) {
//          Shape r = makeRectangle(startDrag.x, startDrag.y, e.getX(), e.getY());
          Shape l = makeLine(startDrag.x, startDrag.y, e.getX(), e.getY());
//          Shape el = makeEllipse(startDrag.x, startDrag.y, e.getX(), e.getY());
//          shapes.add(r);
            shapes.add(l);
//          shapes.add(el);
          startDrag = null;
          endDrag = null;
          repaint();
        }
      });

      this.addMouseMotionListener(new MouseMotionAdapter() {
        public void mouseDragged(MouseEvent e) {
          endDrag = new Point(e.getX(), e.getY());
          repaint();
        }
      });
    }
    private void paintBackground(Graphics2D g2){
      g2.setPaint(Color.LIGHT_GRAY);
      for (int i = 0; i < getSize().width; i += 10) {
        Shape line = new Line2D.Float(i, 0, i, getSize().height);
        g2.draw(line);
      }

      for (int i = 0; i < getSize().height; i += 10) {
        Shape line = new Line2D.Float(0, i, getSize().width, i);
        g2.draw(line);
      }


    }
    public void paint(Graphics g) {
      Graphics2D g2 = (Graphics2D) g;
      g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
      paintBackground(g2);
      Color[] colors = { Color.YELLOW, Color.MAGENTA, Color.CYAN , Color.RED, Color.BLUE, Color.PINK};
      int colorIndex = 0;

      g2.setStroke(new BasicStroke(2));
      g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.50f));

      for (Shape s : shapes) {
        g2.setPaint(Color.BLACK);
        g2.draw(s);
        g2.setPaint(colors[(colorIndex++) % 6]);
        g2.fill(s);
      }

      if (startDrag != null && endDrag != null) {
        g2.setPaint(Color.LIGHT_GRAY);
//        Shape r = makeRectangle(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
//        g2.draw(r);

        Shape l = makeLine(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
        g2.draw(l);
//        Shape el = makeLine(startDrag.x, startDrag.y, endDrag.x, endDrag.y);
//        g2.draw(el);
      }
    }

    private Line2D.Float makeLine(int x1, int y1, int x2, int y2) {
        return new Line2D.Float(x1, y1, x2, y2);
 }


//    private Rectangle2D.Float makeRectangle(int x1, int y1, int x2, int y2) {
//      return new Rectangle2D.Float(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));
//    }

/*    private Ellipse2D.Float makeEllipse(int x1, int y1, int x2, int y2) {
      return new Ellipse2D.Float(Math.min(x1, x2), Math.min(y1, y2), Math.abs(x1 - x2), Math.abs(y1 - y2));
    }
*/ 
}
}

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When posting code that causes an error, please post the error message and indicate which line causes the error. In your code, this line is giving you an error:

Code:

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lineButton.addActionListener(this);

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"The method addActionListener(ActionListener) in the type AbstractButton is not applicable for the arguments (DrawingBoardWithMatrix)"

Because this, the current DrawingBoardWithMatrix object is not an ActionListener, so the error makes sense. You can only pass an ActionListener into that method. I suggest that you create an anonymous inner ActionListener object for this method. You can read up on these here: Getting in Touch with your Inner Class