Mouse events

[Chris Roberts]

I was trying to store circles in a vector when the mouse is clicked. However, I did not understand how to use the MouseEvent method to detect that this was happening. Can anyone help me?

  
public class CircleDrawer3 extends JFrame {
 
Vector<Shape>Storage = new Vector<Shape>();  //declares a vector of shapes
    
    public CircleDrawer3 () {
Container content = getContentPane();

// Set size, location, color and close behavior
setSize(450,350);
setLocation(300,300);
content.setBackground(Color.WHITE);
    content.setLayout(new BorderLayout());   // specifying layout
    content.add(new drawingPanel(),BorderLayout.CENTER);
    
    
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

    }
    
    public class drawingPanel extends JPanel
    {   public final static int CIRCLE = 1, SQUARE = 2;
    private int shape;
    Dimension mySize = new Dimension(300, 300);
    
    protected void paintComponent(Graphics g)
    {
    super.paintComponent(g);
    
        // register new instance of CircleListener for mouse events
        addMouseListener(new CircleListener());
    
    
    Circle temp;
    Circle c = new Circle();   // creates an instance of Circle
        Storage.add(c);            // adds a Circle to the vector   
 
        System.out.println(Storage);  // testing to see what's in the vector
    
    for(int i = 0; i<Storage.size(); i++)
    {
    System.out.println("Storing a circle");
    temp = (Circle)Storage.elementAt(i);
    g.setColor(Color.blue);
    g.fillOval(temp.getX(), temp.getY(),(int)( 2*temp.getRadius()),
    (int)(2*temp.getRadius()));
    }
    
    }
    
    // override getPreferredSize
    public Dimension getPreferredSize()
    {
    
    return mySize;
    }
    
    // set shape value and repaint drawingPanel
    public void draw(int shapeToDraw)
    {
    shape = shapeToDraw;
    repaint();
    }
    
    }
    
 
    /**
     * Inner class that inherits from MouseAadapter
     * It gets an empty definition of all the MouseListener
     * methods so it only needs to override the one(s) it
     * cares about
     */
    private class CircleListener extends MouseAdapter {
 
/** radius of circle to draw */
private int radius = 25;

public void mousePressed(MouseEvent event) {
    // Get the graphics context to draw on
    Graphics g = getGraphics();
    getPoint(Storage);  // get the x and y position

    // Set the drawing color to blue and draw circle
    // Since the x,y passed to the fillOval is upper-left corner
    // need to offset to make centered at click
    g.setColor(Color.blue);
    g.fillOval(event.getX()-radius,
       event.getY()-radius,
       2*radius,
       2*radius);
}
    }
    public static void main (String[] args) {
CircleDrawer3 cd = new CircleDrawer3();
cd.setVisible(true);
    }
}
 

[Pat Hays]

Move .addMouseListener(new CircleListener()) into the constructor

public CircleDrawer3 ()
{
Container content = getContentPane();
// Set size, location, color and close behavior
setSize(450,350);
setLocation(300,300);

drawingPanel panel1 = new drawingPanel();
panel1.addMouseListener(new CircleListener());

content.setBackground(Color.WHITE);
content.setLayout(new BorderLayout()); // specifying layout
content.add(panel1, BorderLayout.CENTER);

setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
}