Draw the example
// Paint the entire background using a GradientPaint.
// The background color varies diagonally from deep red to pale blue
g.setPaint(new GradientPaint(0, 0, new Color(150, 0, 0),
WIDTH, HEIGHT, new Color(200, 200, 255)));
g.fillRect(0, 0, WIDTH, HEIGHT); // fill the background
// Use a different GradientPaint to draw a box.
// This one alternates between deep opaque green and transparent green.
// Note: the 4th arg to Color() constructor specifies color opacity
g.setPaint(new GradientPaint(0, 0, new Color(0, 150, 0),
20, 20, new Color(0, 150, 0, 0), true));
g.setStroke(new BasicStroke(15)); // use wide lines
g.drawRect(25, 25, WIDTH-50, HEIGHT-50); // draw the box
// The glyphs of fonts can be used as Shape objects, which enables
// us to use Java2D techniques with letters Just as we would with
// any other shape. Here we get some letter shapes to draw.
Font font = new Font("Serif", Font.BOLD, 10); // a basic font
Font bigfont = // a scaled up version
font.deriveFont(AffineTransform.getScaleInstance(30.0, 30.0));
GlyphVector gv = bigfont.createGlyphVector(g.getFontRenderContext(),
"JAV");
Shape jshape = gv.getGlyphOutline(0); // Shape of letter J
Shape ashape = gv.getGlyphOutline(1); // Shape of letter A
Shape vshape = gv.getGlyphOutline(2); // Shape of letter V
// We're going to outline the letters with a 5-pixel wide line
g.setStroke(new BasicStroke(5.0f));
// We're going to fake shadows for the letters using the
// following Paint and AffineTransform objects
Paint shadowPaint = new Color(0, 0, 0, 100); // Translucent black
AffineTransform shadowTransform =
AffineTransform.getShearInstance(-1.0, 0.0); // Shear to the right
shadowTransform.scale(1.0, 0.5); // Scale height by 1/2
// Move to the baseline of our first letter
g.translate(65, 270);
// Draw the shadow of the J shape
g.setPaint(shadowPaint);
g.translate(15,20); // Compensate for the descender of the J
// transform the J into the shape of its shadow, and fill it
g.fill(shadowTransform.createTransformedShape(jshape));
g.translate(-15,-20); // Undo the translation above
// Now fill the J shape with a solid (and opaque) color
g.setPaint(Color.blue); // Fill with solid, opaque blue
g.fill(jshape); // Fill the shape
g.setPaint(Color.black); // Switch to solid black
g.draw(jshape); // And draw the outline of the J
// Now draw the A shadow
g.translate(75, 0); // Move to the right
g.setPaint(shadowPaint); // Set shadow color
g.fill(shadowTransform.createTransformedShape(ashape)); // draw shadow
// Draw the A shape using a solid transparent color
g.setPaint(new Color(0, 255, 0, 125)); // Transparent green as paint
g.fill(ashape); // Fill the shape
g.setPaint(Color.black); // Switch to solid back
g.draw(ashape); // Draw the outline
// Move to the right and draw the shadow of the letter V
g.translate(175, 0);
g.setPaint(shadowPaint);
g.fill(shadowTransform.createTransformedShape(vshape));
// We're going to fill the next letter using a TexturePaint, which
// repeatedly tiles an image. The first step is to obtain the image.
// We could load it from an image file, but here we create it
// ourselves by drawing a into an off-screen image. Note that we use
// a GradientPaint to fill the off-screen image, so the fill pattern
// combines features of both Paint classes.
BufferedImage tile = // Create an image
new BufferedImage(50, 50, BufferedImage.TYPE_INT_RGB);
Graphics2D tg = tile.createGraphics(); // Get its Graphics for drawing
tg.setColor(Color.pink);
tg.fillRect(0, 0, 50, 50); // Fill tile background with pink
tg.setPaint(new GradientPaint(40, 0, Color.green, // diagonal gradient
0, 40, Color.gray)); // green to gray
tg.fillOval(5, 5, 40, 40); // Draw a circle with this gradient
// Use this new tile to create a TexturePaint and fill the letter V
g.setPaint(new TexturePaint(tile, new Rectangle(0, 0, 50, 50)));
g.fill(vshape); // Fill letter shape
g.setPaint(Color.black); // Switch to solid black
g.draw(vshape); // Draw outline of letter
// Move to the right and draw the shadow of the final A
g.translate(160, 0);
g.setPaint(shadowPaint);
g.fill(shadowTransform.createTransformedShape(ashape));
// For the last letter, use a custom Paint class to fill with a
// complex mathematically defined pattern. The GenericPaint
// class is defined later in the chapter.
g.setPaint(new GenericPaint() {
public int computeRed(double x, double y) { return 128; }
public int computeGreen(double x, double y) {
return (int)((Math.sin(x/7) + Math.cos(y/5) + 2)/4 *255);
}
public int computeBlue(double x, double y) {
return ((int)(x*y))%256;
}
public int computeAlpha(double x, double y) {
return ((int)x%25*8+50) + ((int)y%25*8+50);
}
});
g.fill(ashape); // Fill letter A
g.setPaint(Color.black); // Revert to solid black
g.draw(ashape); // Draw the outline of the A
