import java.awt.*; import javax.swing.*; import java.awt.event.*; import java.applet.Applet; import java.awt.geom.*; import java.awt.image.BufferedImage; public class Cubic extends JApplet{ static protected JLabel label; CubicPanel cubicPanel; public void init(){ //Initialize the layout. getContentPane().setLayout(new BorderLayout()); cubicPanel = new CubicPanel(); cubicPanel.setBackground(Color.white); getContentPane().add(cubicPanel); label = new JLabel("Drag the points to adjust the curve."); getContentPane().add("South", label); } public static void main(String s[]) { JFrame f = new JFrame("Cubic"); CubicPanel cubicPanel = new CubicPanel(); f.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) {System.exit(0);} }); JApplet applet = new Cubic(); f.getContentPane().add(applet, BorderLayout.CENTER); applet.init(); f.setSize(new Dimension(350,250)); f.setVisible(true); } } class CubicPanel extends JPanel implements MouseListener, MouseMotionListener{ BufferedImage bi; Graphics2D big; int x, y; Rectangle area, startpt, endpt, ctrl1, ctrl2, rect; CubicCurve2D.Double cubic = new CubicCurve2D.Double(); Point2D.Double start, end, one, two, point; boolean firstTime = true; boolean pressOut = false; public CubicPanel(){ setBackground(Color.white); addMouseMotionListener(this); addMouseListener(this); start = new Point2D.Double(); one = new Point2D.Double(); two = new Point2D.Double(); end = new Point2D.Double(); cubic.setCurve(start, one, two, end); startpt = new Rectangle(0, 0, 8, 8); endpt = new Rectangle(0, 0, 8, 8); ctrl1 = new Rectangle(0, 0, 8, 8); ctrl2 = new Rectangle(0, 0, 8, 8); } public void mousePressed(MouseEvent e){ x = e.getX(); y = e.getY(); if(startpt.contains(x, y)){ rect = startpt; point = start; x = startpt.x - e.getX(); y = startpt.y - e.getY(); updateLocation(e); } else if(endpt.contains(x, y)){ rect = endpt; point = end; x = endpt.x - e.getX(); y = endpt.y - e.getY(); updateLocation(e); } else if(ctrl1.contains(x, y)){ rect = ctrl1; point = one; x = ctrl1.x - e.getX(); y = ctrl1.y - e.getY(); updateLocation(e); } else if(ctrl2.contains(x, y)){ rect = ctrl2; point = two; x = ctrl2.x - e.getX(); y = ctrl2.y - e.getY(); updateLocation(e); } else { pressOut = true; } } public void mouseDragged(MouseEvent e){ if(!pressOut) { updateLocation(e); } } public void mouseReleased(MouseEvent e){ if(startpt.contains(e.getX(), e.getY())){ rect = startpt; point = start; updateLocation(e); } else if(endpt.contains(e.getX(), e.getY())){ rect = endpt; point = end; updateLocation(e); } else if(ctrl1.contains(e.getX(), e.getY())){ rect = ctrl1; point = one; updateLocation(e); } else if(ctrl2.contains(e.getX(), e.getY())){ rect = ctrl2; point = two; updateLocation(e); } else { pressOut = false; } } public void mouseMoved(MouseEvent e){} public void mouseClicked(MouseEvent e){} public void mouseExited(MouseEvent e){} public void mouseEntered(MouseEvent e){} public void updateLocation(MouseEvent e){ rect.setLocation((x + e.getX())-4, (y + e.getY())-4); point.setLocation(x + e.getX(), y + e.getY()); checkPoint(); cubic.setCurve(start, one, two, end); repaint(); } public void paintComponent(Graphics g){ super.paintComponent(g); update(g); } public void update(Graphics g){ Graphics2D g2 = (Graphics2D)g; Dimension dim = getSize(); int w = dim.width; int h = dim.height; if(firstTime){ bi = (BufferedImage)createImage(w, h); big = bi.createGraphics(); start.setLocation(w/2-50, h/2); end.setLocation(w/2+50, h/2); one.setLocation((int)(start.x)+25, (int)(start.y)-25); two.setLocation((int)(end.x)-25, (int)(end.y)+25); startpt.setLocation((int)((start.x)-4), (int)((start.y)-4)); endpt.setLocation((int)((end.x)-4), (int)((end.y)-4)); ctrl1.setLocation((int)((one.x)-4), (int)((one.y)-4)); ctrl2.setLocation((int)((two.x)-4), (int)((two.y)-4)); cubic.setCurve(start, one, two, end); big.setColor(Color.black); big.setStroke(new BasicStroke(5.0f)); big.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); area = new Rectangle(dim); firstTime = false; } // Clears the rectangle that was previously drawn. big.setColor(Color.white); big.clearRect(0, 0, area.width, area.height); // Draws and fills the newly positioned rectangle to the buffer. big.setPaint(Color.black); big.draw(cubic); big.setPaint(Color.red); big.fill(startpt); big.setPaint(Color.magenta); big.fill(endpt); big.setPaint(Color.blue); big.fill(ctrl1); big.setPaint(new Color(0, 200, 0)); big.fill(ctrl2); // Draws the buffered image to the screen. g2.drawImage(bi, 0, 0, this); } /* * Checks if the rectangle is contained within the applet window. If the rectangle * is not contained withing the applet window, it is redrawn so that it is adjacent * to the edge of the window and just inside the window. */ void checkPoint(){ if (area == null) { return; } if((area.contains(rect)) && (area.contains(point))){ return; } int new_x = rect.x; int new_y = rect.y; double new_px = point.x; double new_py = point.y; if((rect.x+rect.width)>area.getWidth()){ new_x = (int)area.getWidth()-(rect.width-1); } if(point.x > area.getWidth()){ new_px = (int)area.getWidth()-1; } if(rect.x < 0){ new_x = -1; } if(point.x < 0){ new_px = -1; } if((rect.y+rect.width)>area.getHeight()){ new_y = (int)area.getHeight()-(rect.height-1); } if(point.y > area.getHeight()){ new_py = (int)area.getHeight()-1; } if(rect.y < 0){ new_y = -1; } if(point.y < 0){ new_py = -1; } rect.setLocation(new_x, new_y); point.setLocation(new_px, new_py); } }