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Bouncer.javaAPI DocExample6240Mon Apr 05 12:09:20 BST 1999None

Bouncer

public class Bouncer extends AnimationComponent

Fields Summary
private boolean
mAntialiasing
private boolean
mGradient
private boolean
mOutline
private boolean
mTransform
private boolean
mDotted
private boolean
mAxes
private boolean
mClip
public static final int
ANTIALIASING
public static final int
GRADIENT
public static final int
OUTLINE
public static final int
TRANSFORM
public static final int
DOTTED
public static final int
AXES
public static final int
CLIP
private float[]
mPoints
private float[]
mDeltas
private float
mTheta
private int
mN
private Shape
mClipShape
Constructors Summary
public Bouncer()

  
    
    mN = 38;
    mPoints = new float[mN];
    mDeltas = new float[mN];
    Random random = new Random();
    for (int i = 0; i < mN; i++) {
      mPoints[i] = random.nextFloat() * 500;
      mDeltas[i] = random.nextFloat() * 3;
    }
    // Make sure points are within range.
    addComponentListener(new ComponentAdapter() {
      public void componentResized(ComponentEvent ce) {
        Dimension d = getSize();
        for (int i = 0; i < mN; i++) {
          int limit = ((i % 2) == 0) ? d.width : d.height;
          if (mPoints[i] < 0) mPoints[i] = 0;
          else if (mPoints[i] >= limit) mPoints[i] = limit - 1;
        }
      }
    });
Methods Summary
protected java.awt.CheckboxcreateCheckbox(java.lang.String label, int item)

    Checkbox check = new Checkbox(label);
    check.addItemListener(new ItemListener() {
      public void itemStateChanged(ItemEvent ie) {
        setSwitch(item, (ie.getStateChange() == ie.SELECTED));
      }
    });
    return check;
protected java.awt.ShapecreateShape()

    GeneralPath path = new GeneralPath(GeneralPath.WIND_EVEN_ODD,
        mPoints.length);
    path.moveTo(mPoints[0], mPoints[1]);
    for (int i = 2; i < mN; i += 6)
      path.curveTo(mPoints[i], mPoints[i + 1],
          mPoints[i + 2], mPoints[i + 3],
          mPoints[i + 4], mPoints[i + 5]);
    path.closePath();
    return path;
protected voiddrawAxes(java.awt.Graphics2D g2)

    if (mAxes == false) return;
    g2.setPaint(getForeground());
    g2.setStroke(new BasicStroke());
    Dimension d = getSize();
    int side = 20;
    int arrow = 4;
    int w = d.width / 2, h = d.height / 2;
    g2.drawLine(w - side, h, w + side, h);
    g2.drawLine(w + side - arrow, h - arrow, w + side, h);
    g2.drawLine(w, h - side, w, h + side);
    g2.drawLine(w + arrow, h + side - arrow, w, h + side);
public static voidmain(java.lang.String[] args)

    final Bouncer bouncer = new Bouncer();
    Frame f = new AnimationFrame(bouncer);
    f.setFont(new Font("Serif", Font.PLAIN, 12));
    
    Panel controls = new Panel();
    controls.add(bouncer.createCheckbox("Anti.", Bouncer.ANTIALIASING));
    controls.add(bouncer.createCheckbox("Trans.", Bouncer.TRANSFORM));
    controls.add(bouncer.createCheckbox("Gradient", Bouncer.GRADIENT));
    controls.add(bouncer.createCheckbox("Outline", Bouncer.OUTLINE));
    controls.add(bouncer.createCheckbox("Dotted", Bouncer.DOTTED));
    controls.add(bouncer.createCheckbox("Axes", Bouncer.AXES));
    controls.add(bouncer.createCheckbox("Clip", Bouncer.CLIP));
    f.add(controls, BorderLayout.NORTH);
    
    f.setVisible(true);
public voidpaint(java.awt.Graphics g)

    Graphics2D g2 = (Graphics2D)g;
    setAntialiasing(g2);
    setClip(g2);
    setTransform(g2);
    Shape shape = createShape();
    setPaint(g2);
    // Fill the shape.
    g2.fill(shape);
    // Maybe draw the outline.
    if (mOutline) {
      setStroke(g2);
      g2.setPaint(Color.blue);
      g2.draw(shape);
    }
    drawAxes(g2);
protected voidsetAntialiasing(java.awt.Graphics2D g2)

    if (mAntialiasing == false) return;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
        RenderingHints.VALUE_ANTIALIAS_ON);
protected voidsetClip(java.awt.Graphics2D g2)

    if (mClip == false) return;
    if (mClipShape == null) {
      Dimension d = getSize();
      FontRenderContext frc = g2.getFontRenderContext();
      Font font = new Font("Serif", Font.PLAIN, 144);
      String s = "Spoon!";
      GlyphVector gv = font.createGlyphVector(frc, s);
      Rectangle2D bounds = font.getStringBounds(s, frc);
      mClipShape = gv.getOutline((d.width - (float)bounds.getWidth()) / 2,
          (d.height + (float)bounds.getHeight()) / 2);
    }
    g2.clip(mClipShape);
protected voidsetPaint(java.awt.Graphics2D g2)

    if (mGradient) {
      GradientPaint gp = new GradientPaint(0, 0, Color.yellow,
          50, 25, Color.red, true);
      g2.setPaint(gp);
    }
    else g2.setPaint(Color.orange);
protected voidsetStroke(java.awt.Graphics2D g2)

    if (mDotted == false) return;
    // Create a dotted stroke.
    Stroke stroke = new BasicStroke(1, BasicStroke.CAP_BUTT,
        BasicStroke.JOIN_ROUND, 10,
        new float[] { 4, 4 }, 0);
    g2.setStroke(stroke);
public voidsetSwitch(int item, boolean value)

    switch(item) {
      case ANTIALIASING: mAntialiasing = value; break;
      case GRADIENT: mGradient = value; break;
      case OUTLINE: mOutline = value; break;
      case TRANSFORM: mTransform = value; break;
      case DOTTED: mDotted = value; break;
      case AXES: mAxes = value; break;
      case CLIP: mClip = value; break;
      default: break;
    }
protected voidsetTransform(java.awt.Graphics2D g2)

    if (mTransform == false) return;
    Dimension d = getSize();
    g2.rotate(mTheta, d.width / 2, d.height / 2);
public voidtimeStep()

    Dimension d = getSize();
    for (int i = 0; i < mN; i++) {
      float value = mPoints[i] + mDeltas[i];
      int limit = ((i % 2) == 0) ? d.width : d.height;
      if (value < 0 || value > limit) {
        mDeltas[i] = -mDeltas[i];
        mPoints[i] += mDeltas[i];
      }
      else mPoints[i] = value;
    }
    mTheta += Math.PI / 192;
    if (mTheta > (2 * Math.PI)) mTheta -= (2 * Math.PI);