// -*- mode:java; encoding:utf-8 -*-

// vim:set fileencoding=utf-8:

// @homepage@

package example;

import java.awt.*;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.geom.Path2D;

import java.awt.image.BufferedImage;

import java.io.IOException;

import java.io.InputStream;

import java.util.Optional;

import java.util.logging.Logger;

import javax.imageio.ImageIO;

import javax.swing.*;

public final class MainPanel extends JPanel {

private MainPanel() {

super(new BorderLayout());

String path = "example/test.png";

ClassLoader cl = Thread.currentThread().getContextClassLoader();

Image image = Optional.ofNullable(cl.getResource(path)).map(u -> {

Image img;

try (InputStream s = u.openStream()) {

img = ImageIO.read(s);

} catch (IOException ex) {

img = makeMissingImage();

}

return img;

}).orElseGet(MainPanel::makeMissingImage);

add(new ImagePanel(image));

setPreferredSize(new Dimension(320, 240));

}

private static Image makeMissingImage() {

Icon missingIcon = new MissingIcon();

int w = missingIcon.getIconWidth();

int h = missingIcon.getIconHeight();

BufferedImage bi = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);

Graphics2D g2 = bi.createGraphics();

missingIcon.paintIcon(null, g2, 0, 0);

g2.dispose();

return bi;

}

public static void main(String[] args) {

EventQueue.invokeLater(MainPanel::createAndShowGui);

}

private static void createAndShowGui() {

try {

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

} catch (UnsupportedLookAndFeelException ignored) {

Toolkit.getDefaultToolkit().beep();

} catch (ClassNotFoundException | InstantiationException | IllegalAccessException ex) {

Logger.getGlobal().severe(ex::getMessage);

return;

}

JFrame frame = new JFrame("@title@");

frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

frame.getContentPane().add(new MainPanel());

frame.pack();

frame.setLocationRelativeTo(null);

frame.setVisible(true);

}

}

class ImagePanel extends JPanel {

private transient RubberBandingListener rbl;

private final transient BasicStroke stroke = new BasicStroke(2f);

private final Path2D rubberBand = new Path2D.Double();

private final transient Image image;

protected ImagePanel(Image image) {

super();

this.image = image;

}

@Override public void updateUI() {

removeMouseListener(rbl);

removeMouseMotionListener(rbl);

super.updateUI();

rbl = new RubberBandingListener();

addMouseMotionListener(rbl);

addMouseListener(rbl);

}

@Override protected void paintComponent(Graphics g) {

super.paintComponent(g);

Graphics2D g2 = (Graphics2D) g.create();

int iw = image.getWidth(this);

int ih = image.getHeight(this);

Dimension dim = getSize();

int x = (dim.width - iw) / 2;

int y = (dim.height - ih) / 2;

g.drawImage(image, x, y, iw, ih, this);

g2.setPaint(Color.RED);

g2.fillOval(10, 10, 32, 32);

g2.setPaint(Color.GREEN);

g2.fillOval(50, 10, 32, 32);

g2.setPaint(Color.BLUE);

g2.fillOval(90, 10, 32, 32);

g2.setPaint(Color.PINK);

g2.fillOval(130, 10, 32, 32);

g2.setPaint(Color.CYAN);

g2.fillOval(170, 10, 32, 32);

g2.setPaint(Color.ORANGE);

g2.fillOval(210, 10, 32, 32);

g2.setXORMode(Color.PINK);

g2.fill(rubberBand);

g2.setPaintMode();

g2.setStroke(stroke);

g2.setPaint(Color.WHITE);

g2.draw(rubberBand);

g2.dispose();

}

protected Path2D getRubberBand() {

return rubberBand;

}

private final class RubberBandingListener extends MouseAdapter {

private final Point srcPoint = new Point();

@Override public void mouseDragged(MouseEvent e) {

Point dstPoint = e.getPoint();

Path2D rb = getRubberBand();

rb.reset();

rb.moveTo(srcPoint.x, srcPoint.y);

rb.lineTo(dstPoint.x, srcPoint.y);

rb.lineTo(dstPoint.x, dstPoint.y);

rb.lineTo(srcPoint.x, dstPoint.y);

rb.closePath();

e.getComponent().repaint();

}

@Override public void mouseReleased(MouseEvent e) {

e.getComponent().repaint();

}

@Override public void mousePressed(MouseEvent e) {

getRubberBand().reset();

srcPoint.setLocation(e.getPoint());

e.getComponent().repaint();

}

}

}

class MissingIcon implements Icon {

@Override public void paintIcon(Component c, Graphics g, int x, int y) {

Graphics2D g2 = (Graphics2D) g.create();

int w = getIconWidth();

int h = getIconHeight();

int gap = w / 5;

g2.setColor(Color.WHITE);

g2.translate(x, y);

g2.fillRect(0, 0, w, h);

g2.setColor(Color.RED);

g2.setStroke(new BasicStroke(w / 8f));

g2.drawLine(gap, gap, w - gap, h - gap);

g2.drawLine(gap, h - gap, w - gap, gap);

g2.dispose();

}

@Override public int getIconWidth() {

return 320;

}

@Override public int getIconHeight() {

return 240;

}

}