import java.awt.*; import javax.swing.*; import java.awt.geom.AffineTransform; import java.util.ArrayList; public class TransformedShapes extends JPanel { // For managing a stack of transformation, making it possible to // save and restore the current transformation state. private ArrayList transformStack = new ArrayList<>(); //------- For drawing ONLY while paintComponent is being executed! -------- private Graphics2D g; // A copy of the graphics context from paintComponent. /** * Saves a copy of the current transformation on the stack. */ private void pushTransform() { transformStack.add(g.getTransform()); } /** * Pops a transformation from the stack, and replaces the current transformation * with the popped transformation. */ private void popTransform() { g.setTransform(transformStack.remove(transformStack.size() - 1)); } /** * Draws a filled circle of radius 50 (diameter 100) centered at (0,0), * subject to whatever transform(s) have been applied to g2. */ private void circle() { g.fillOval(-50,-50,100,100); } /** * Draws a filled square with side 100 centered at (0,0), subject * to whatever transform(s) have been applied to g2. */ private void square() { g.fillRect(-50,-50,100,100); } /** * Draws a filled triangle with vertices at (-50,50), (50,50), and * (0,-50), subject to whatever transform(s) have been applied to g2. */ private void triangle() { g.fillPolygon(new int[] {-50,50,0}, new int[] {50,50,-50}, 3); } //----------------------------------------------------------------------------------- /** * This method is called just once, when the program starts, to draw * the content of the window. */ private void draw(Graphics2D g) { // TODO Delete all the code in this method and replace it with code that will // draw the required image, using ONLY the five methods defined above, along // with color changes and transforms. /* ------------------------------ sample drawing ---------------------------- */ pushTransform(); g.translate(150,150); circle(); // draw a circle of radius 50 centered at (0,0) popTransform(); pushTransform(); g.translate(450,150); triangle(); // draw a triangle, centered at (0,0) popTransform(); pushTransform(); g.translate(150,450); square(); // draw a square with side 100, centered at (0,0) popTransform(); // draws a red X, consisting of two transformed squares, centered at (0,0) // and then moved to the lower right quadrant pushTransform(); g.setColor(Color.RED); g.translate(450,450); pushTransform(); g.rotate(Math.PI/4); g.scale(2, 0.5); square(); popTransform(); pushTransform(); g.rotate(-Math.PI/4); g.scale(2,0.5); square(); popTransform(); popTransform(); } // end draw(); //----------------------------------------------------------------------------------- protected void paintComponent(Graphics g1) { super.paintComponent(g1); g = (Graphics2D)g1.create(); g.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); draw(g); } // end paintComponent() //-------------------------------------------------------------------------------------- public TransformedShapes() { setPreferredSize(new Dimension(600,600) ); setBackground(Color.WHITE); setBorder(BorderFactory.createLineBorder(Color.BLACK,4)); } public static void main(String[] args) { JFrame window = new JFrame("Drawing With Transforms"); window.setContentPane(new TransformedShapes()); window.pack(); window.setResizable(false); window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); Dimension screen = Toolkit.getDefaultToolkit().getScreenSize(); window.setLocation( (screen.width - window.getWidth())/2, (screen.height - window.getHeight())/2 ); window.setVisible(true); } }
