Java tutorial
/* * Copyright (c) 2000 David Flanagan. All rights reserved. * This code is from the book Java Examples in a Nutshell, 2nd Edition. * It is provided AS-IS, WITHOUT ANY WARRANTY either expressed or implied. * You may study, use, and modify it for any non-commercial purpose. * You may distribute it non-commercially as long as you retain this notice. * For a commercial use license, or to purchase the book (recommended), * visit http://www.davidflanagan.com/javaexamples2. */ import java.awt.BasicStroke; import java.awt.Color; import java.awt.Font; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Paint; import java.awt.Rectangle; import java.awt.Shape; import java.awt.TexturePaint; import java.awt.font.GlyphVector; import java.awt.geom.AffineTransform; import java.awt.image.BufferedImage; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JPanel; /** A demonstration of Java2D transformations */ public class Paints extends JPanel { static final int WIDTH = 800, HEIGHT = 375; // Size of our example public String getName() { return "Paints"; } public int getWidth() { return WIDTH; } public int getHeight() { return HEIGHT; } /** Draw the example */ public void paint(Graphics g1) { Graphics2D g = (Graphics2D) g1; // 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)); g.fill(ashape); // Fill letter A g.setPaint(Color.black); // Revert to solid black g.draw(ashape); // Draw the outline of the A } public static void main(String[] a) { JFrame f = new JFrame(); f.addWindowListener(new WindowAdapter() { public void windowClosing(WindowEvent e) { System.exit(0); } }); f.setContentPane(new Paints()); f.setSize(800, 375); f.setVisible(true); } }