import java.awt.*; import java.awt.event.*; import java.awt.geom.Rectangle2D; import javax.swing.*; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; import java.net.URL; import javax.imageio.ImageIO; import java.awt.image.BufferedImage; /** * This program demonstrates GradientPaint and TexturePaint. * This class has a main() routine and so can be run as an application. */ public class PaintDemo extends JPanel { /** * The main routine simply opens a window that shows a PaintDemo panel. */ public static void main(String[] args) { JFrame window = new JFrame("PaintDemo - Drag the Vertices"); PaintDemo content = new PaintDemo(); window.setContentPane(content); window.pack(); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); window.setLocation( (screenSize.width - window.getWidth())/2, (screenSize.height - window.getHeight())/2 ); window.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE ); window.setVisible(true); } /** * The display area of the program shows a filled polygon that can be filled * with various kinds of paint. The vertices of the polygon can be dragged * by the user. */ private class Display extends JPanel implements MouseListener, MouseMotionListener { int[] xcoord, ycoord; int draggedPoint = -1; Display() { setBackground(Color.WHITE); setPreferredSize(new Dimension(400,300)); addMouseListener(this); addMouseMotionListener(this); } public void paintComponent(Graphics g) { super.paintComponent(g); Graphics2D g2 = (Graphics2D)g; if (xcoord == null) { xcoord = new int[] { scaleX(0.2), scaleX(0.8), scaleX(0.5), scaleX(0.95), scaleX(0.35), scaleX(0.1) }; ycoord = new int[] { scaleY(0.15), scaleY(0.1), scaleY(0.5), scaleY(0.45), scaleY(0.9), scaleY(0.7) }; } g2.setPaint(paint); g2.fillPolygon(xcoord, ycoord, 6); g2.setColor(Color.BLACK); g2.setStroke(new BasicStroke(2)); g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); g2.drawPolygon(xcoord, ycoord, 6); for (int i = 0; i < 6; i++) g2.fillRect(xcoord[i] - 3, ycoord[i] - 3, 7, 7); } private int scaleX(double x) { return (int)(x * getWidth()); } private int scaleY(double y) { return (int)(y * getHeight()); } public void mousePressed(MouseEvent e) { draggedPoint = -1; for (int i = 0; i < 6; i++) { if (Math.abs(xcoord[i] - e.getX()) < 4 && Math.abs(ycoord[i] - e.getY()) < 4) { draggedPoint = i; break; } } } public void mouseDragged(MouseEvent e) { if (draggedPoint < 0) return; int x = Math.max(0, Math.min(e.getX(),getWidth())); int y = Math.max(0, Math.min(e.getY(),getHeight())); xcoord[draggedPoint] = x; ycoord[draggedPoint] = y; repaint(); } public void mouseReleased(MouseEvent e) { } public void mouseMoved(MouseEvent e) { } public void mouseClicked(MouseEvent e) { } public void mouseEntered(MouseEvent e) { } public void mouseExited(MouseEvent e) { } } /** * Responds when a user clicks on the radio button to set up the labels and sliders * to correspond to the kind of paint that has been selected. Calls setPaint() * to make the display use the new selected paint. */ private ActionListener buttonlistener = new ActionListener() { public void actionPerformed(ActionEvent e) { currentButton = (JRadioButton)e.getSource(); slider1.removeChangeListener(sliderlistener); //(Yuck! Had to do this to avoid notifying slider2.removeChangeListener(sliderlistener); // slider listeners when changes are made.) if (currentButton == gradientButton1 || currentButton == gradientButton2) { label1.setText(" Gradient Angle:"); label2.setText(" Gradient Width:"); slider1.setMinimum(0); slider1.setMaximum(360); slider1.setValue(gradientAngle); slider2.setMinimum(10); slider2.setMaximum(300); slider2.setValue(gradientWidth); } else { label1.setText(" Texture Offset:"); label2.setText(" Texture Scale:"); slider1.setMinimum(0); slider1.setMaximum(100); slider1.setValue(textureOffset); slider2.setMinimum(25); slider2.setMaximum(200); slider2.setValue(textureScale); } slider1.addChangeListener(sliderlistener); slider2.addChangeListener(sliderlistener); setPaint(); } }; /** * When the user changes the value on one of the sliders, this * ChangeListener responds by changing the Paint to reflect the * changed value. */ private ChangeListener sliderlistener = new ChangeListener() { public void stateChanged(ChangeEvent e) { setPaint(); } }; /** * Called when the type of paint or the values on the sliders are changed. * Creates the new Paint and redraws the display to show the change. */ private void setPaint() { if (currentButton == gradientButton1 || currentButton == gradientButton2) { gradientAngle = slider1.getValue(); gradientWidth = slider2.getValue(); int x = getWidth()/2; int y = getHeight()/2; int dx = (int)( gradientWidth * Math.cos(gradientAngle/180.0 * Math.PI) ); int dy = (int)( gradientWidth * Math.sin(gradientAngle/180.0 * Math.PI) ); if (currentButton == gradientButton1) paint = new GradientPaint(x,y,Color.LIGHT_GRAY,x+dx,y+dy,Color.BLACK,true); else paint = new GradientPaint(x,y,Color.RED,x+dx,y+dy,Color.YELLOW,true); } else { textureOffset = slider1.getValue(); textureScale = slider2.getValue(); BufferedImage texture; if (currentButton == textureButton1) texture = smiley; else texture = queen; int width = texture.getWidth() * textureScale / 100; int height = texture.getHeight() * textureScale / 100; int offsetX = width * textureOffset / 100; int offsetY = height * textureOffset / 100; Rectangle2D anchor = new Rectangle2D.Double(offsetX,offsetY,width,height); paint = new TexturePaint(texture,anchor); } display.repaint(); } private Display display = new Display(); // The display area where the polygon is drawn. private Paint paint; // The paint that is used to fill the polygon in the display. private BufferedImage smiley, queen; // Images for texture paint. private JRadioButton gradientButton1, gradientButton2; // Select the type of paint. private JRadioButton textureButton1, textureButton2; private JRadioButton currentButton; // The currently selected radio button. private int gradientAngle = 45, gradientWidth = 50; // Settings that affect the paint. private int textureOffset = 0, textureScale = 100; private JSlider slider1, slider2; // Sliders that control the settings; Which // setting is affected depends on current paint type. private JLabel label1 = new JLabel(" Gradient Angle:"); // Labels change, depending private JLabel label2 = new JLabel(" Gradient Width:"); // on type of paint. /** * Constructor. */ public PaintDemo() { setLayout(new BorderLayout(3,3)); setBorder(BorderFactory.createLineBorder(Color.GRAY,3)); setBackground(Color.GRAY); add(display, BorderLayout.CENTER); JPanel bottom = new JPanel(); bottom.setLayout(new GridLayout(0,2,5,5)); add(bottom, BorderLayout.SOUTH); slider1 = new JSlider(0,360,gradientAngle); slider1.addChangeListener(sliderlistener); slider2 = new JSlider(10,300,gradientWidth); slider2.addChangeListener(sliderlistener); bottom.add(label1); bottom.add(slider1); bottom.add(label2); bottom.add(slider2); ButtonGroup group = new ButtonGroup(); gradientButton1 = new JRadioButton("Black/Gray Gradient"); gradientButton1.addActionListener(buttonlistener); bottom.add(gradientButton1); group.add(gradientButton1); gradientButton1.setSelected(true); currentButton = gradientButton1; gradientButton2 = new JRadioButton("Red/Yellow Gradient"); gradientButton2.addActionListener(buttonlistener); bottom.add(gradientButton2); group.add(gradientButton2); setPaint(); try { ClassLoader cl = PaintDemo.class.getClassLoader(); URL imageURL = cl.getResource("TinySmiley.png"); if (imageURL != null) smiley = ImageIO.read(imageURL); imageURL = cl.getResource("QueenOfHearts.png"); queen = ImageIO.read(imageURL); } catch (Exception e) { return; // Can't load the images, so don't add the texture radio buttons. } textureButton1 = new JRadioButton("Smiley Face"); textureButton1.addActionListener(buttonlistener); bottom.add(textureButton1); group.add(textureButton1); textureButton2 = new JRadioButton("Queen Of Hearts"); textureButton2.addActionListener(buttonlistener); bottom.add(textureButton2); group.add(textureButton2); } }