How do I set the position of a GeneralPath in a JPanel?

Question

I have to do an exercise where is required to put a black JPanel on the left where I have to draw a star-shaped GeneralPath and some buttons on the right that will have to move that general path, plus a reset button that will set the position of the general path in the middle of the panel.

This is the code:

import java.awt.*;
import java.awt.geom.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;

public class SunGUI extends JFrame {
    private Space space;
    private Control control;
    private final int DELTA = 50;
    private int posX, posY;

    public SunGUI() {
        Container cnt = getContentPane();

        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setLayout(new BorderLayout());

        space = new Space();
        control = new Control();

        cnt.add(space, BorderLayout.CENTER);
        cnt.add(control, BorderLayout.EAST);

        pack();
        setVisible(true);

    }

    public class Space extends JPanel {
        private GeneralPath sun;

        public Space() {
            setPreferredSize(new Dimension(800, 600));
            sun = createSun();

        }

        public GeneralPath createSun() {
            GeneralPath sun = new GeneralPath();

            sun.moveTo(-30, -30);
            sun.lineTo(50, 50);
            sun.moveTo(50, -30);
            sun.lineTo(-30, 50);
            sun.moveTo(10, -35);
            sun.lineTo(10, 55);
            sun.moveTo(-35, 10);
            sun.lineTo(55, 10);
            sun.moveTo(-5, -25);
            sun.lineTo(25, 45);
            sun.moveTo(25, -25);
            sun.lineTo(-5, 45);
            sun.moveTo(-25, -5);
            sun.lineTo(45, 25);
            sun.moveTo(45, -5);
            sun.lineTo(-25, 25);

            sun.closePath();
            return sun;

        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);
            Graphics2D g2 = (Graphics2D)g;

            setBorder(BorderFactory.createLineBorder(Color.red));
            setBackground(Color.black);

            g2.setPaint(Color.white);
            g2.draw(sun);

        }
    }

    public class Control extends JPanel {
        private JButton up, down, left, right, reset;
        private JPanel arrows, panel, resetPanel, container;

        public Control() {
            setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));

            panel = new JPanel();
            arrows = new JPanel();
            resetPanel = new JPanel();
            container = new JPanel();

            arrows.setLayout(new GridLayout(1, 4));
            resetPanel.setLayout(new GridLayout(1, 1));
            container.setLayout(new GridLayout(2, 1));

            up = new JButton("^");
            down = new JButton("v");
            left = new JButton("<");
            right = new JButton(">");
            reset = new JButton("R");

            arrows.add(up);
            arrows.add(left);
            arrows.add(right);
            arrows.add(down);

            resetPanel.add(reset);

            container.add(arrows);
            container.add(resetPanel);
            arrows.setPreferredSize(new Dimension(160, 20));
            resetPanel.setPreferredSize(new Dimension(160, 20));

            panel.add(container);
            panel.setBorder(new TitledBorder("Comandi"));
            add(panel);

        }
    }

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

    }
}

Right now this code will only show a static GUI with the star-shaped general path in the top-left corner, but what I want to do is to put it in the middle of the black panel.

I've searched around the web but I found nothing, does anybody has an idea?

@Andrew Thompson I used your code, but in this way all the content of the JPanel (included the border) now is translated... How can I move just the GeneralPath? Thank you again. — bury_5, Dec 22 '14 at 14:25
Take a look at the Oracle tutorial docs on transforming (i.e. - translating) a shape. You'll learn a ton and get a much better understanding of the answers below - https://docs.oracle.com/javase/tutorial/2d/advanced/transforming.html — , Oct 16 '20 at 03:22

score 1 · Answer 1 · answered Dec 22 '14 at 14:05

1

super.paintComponent(g);
AffineTransform move = AffineTransform.getTranslateInstance(x,y);
g.setTransform(move);
// draw the shape...

answered Dec 22 '14 at 14:05

Andrew Thompson

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Alternately use [`g2.translate(x,y);`](https://docs.oracle.com/javase/8/docs/api/java/awt/Graphics2D.html#translate-double-double-).. – Andrew Thompson Dec 22 '14 at 14:08

score 1 · Answer 2 · edited May 23 '17 at 12:05

1

You can either translate the whole graphics context with g2.translate, as answered by Andrew Thompson (and then reset the transform), or translate only the shape using the createTransformedShape method of AffineTransform. Here is an example: How to have rotated Ellipse shape in Java?

edited May 23 '17 at 12:05

Community

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1

answered Dec 25 '14 at 06:15

lbalazscs

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How do I set the position of a GeneralPath in a JPanel?

2 Answers2