Java Swing - how to use drawOval() method correctly

Ok, so I am trying to make a paint project and I am successful so far. I have a "canvas" to draw on and I have a toolbar menu with the color choices. I have made a button and method with drawLine() which takes my current coordinates via the mouse motion listener and my end coordinates, basically drawing the line wherever and however I like on the canvas. Now I want to add a button that when clicked, will draw an oval/circle on my canvas. Here come the problems tho.

First problem - I can get it to draw the oval on my mouse coordinates, but I cannot drag in order to change its size before I release the mouse button and actually paint it (just like you would in Microsoft paint).

Second problem - When I have selected my "Line" button which invokes my draw line method, I can draw lines and its fine, but then when I click the "Oval" button, it draws the Oval but also puts a line when I click the mouse (I am assuming that I need to disable the mouse motion listener on the Line when I select the Oval.) The Opposite is also true, If I have selected the "Oval" button and drawn ovals before, then click the "Line" button, it will draw a line but also put an oval each time I click to start drawing a line.

This is how my simple program looks like: Image

Here is part of the code concerning the drawLine, drawOval and my coordinate gathering methods, since everything else is working as intended:

    // Image in which we're drawing.
    private Image image;
    // Graphics2D object which we used to draw on.
    private Graphics2D g2;
    // Mouse coordinates
    private int currentX, currentY, oldX, oldY;

    public DrawArea(){
        setDoubleBuffered(false);
        addMouseListener(new MouseAdapter(){

            public void mousePressed(MouseEvent e){
                //save coordinates x,y when mouse is pressed.
                oldX=e.getX();
                oldY=e.getY();
            }});

    }

protected void paintComponent(Graphics g){
    if (image==null){
        //image to draw null ==> we create
        image = createImage(getSize().width, getSize().height);
        g2 = (Graphics2D) image.getGraphics();
        //enable antialiasing.
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, 
                RenderingHints.VALUE_ANTIALIAS_ON);
        //clear draw area
        clear();
    }

    g.drawImage(image, 0, 0, null);
}

public void clear(){
    g2.setPaint(Color.white);
    //draw white on entire draw are to clear it.
    g2.fillRect(0, 0, getSize().width, getSize().height);
    g2.setPaint(Color.black);
    repaint();
}

public void Line(){
    addMouseMotionListener(new MouseMotionAdapter(){
        public void mouseDragged(MouseEvent e){
            //coordinates x,y when dragging mouse.
            currentX=e.getX();
            currentY=e.getY();
            if (g2 != null){
                g2.drawLine(oldX, oldY, currentX, currentY);
                repaint();
                oldX = currentX;
                oldY = currentY;
            }   
        }
    }); 
}

public void Oval(){
    addMouseListener(new MouseAdapter(){
        public void mousePressed(MouseEvent e){
            currentX=e.getX();
            currentY=e.getY();
            if (g2 != null){
                g2.drawOval(oldX, oldY, currentX, currentY);
                repaint();
            }   
        }
    }); 
}