>>54351911
FlowLayout doesn't support autofill stuff.

If you want the panel to fill out the entirety of the frame, you can use BorderLayout, and add it to center.

[code]
public class DrawApp extends JPanel{

    private JRadioButton redButton;
    private JRadioButton yellowButton;
    private JRadioButton blueButton;
    private JRadioButton eraserButton;
    private JButton clearButton;
    private JPanel control;
    private ArrayList<Point> pointList;
    private int clickCount;
    private Color penPaint;

    public DrawApp() {
        setLayout(new BorderLayout());
        control = new JPanel();
        control.setBackground(Color.BLACK);
        add(control,BorderLayout.CENTER);

        clickCount = 0;
        pointList = new ArrayList<>();
        redButton = new JRadioButton("Red");
        yellowButton = new JRadioButton("Yellow");
        blueButton = new JRadioButton("Blue");
        eraserButton = new JRadioButton("Eraser");
        clearButton = new JButton("Clear Drawing");
        control.add(redButton);
        control.add(yellowButton);
        control.add(blueButton);
        control.add(eraserButton);
        control.add(clearButton);
    }
[/code]

Also, adding a panel using the BorderLayout.SOUTH parameter doesn't do anything in your example, because you've set the layout to FlowLayout.

pic related is how a basic BorderLayout is set up.