Java tutorial
/* * $Id: PaintUtils.java,v 1.24 2009/05/25 16:37:52 kschaefe Exp $ * * Copyright 2004 Sun Microsystems, Inc., 4150 Network Circle, * Santa Clara, California 95054, U.S.A. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ import java.awt.Color; import java.awt.FontMetrics; import java.awt.GradientPaint; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Paint; import java.awt.Rectangle; import java.awt.geom.Point2D; import java.awt.geom.Rectangle2D; import java.lang.reflect.Constructor; import java.lang.reflect.InvocationTargetException; import java.lang.reflect.Method; import javax.swing.JComponent; import javax.swing.JLabel; import javax.swing.SwingConstants; /** * A collection of utilties for painting visual effects. * * @author Mark Davidson */ public class PaintUtils { public static final GradientPaint BLUE_EXPERIENCE = new GradientPaint(new Point2D.Double(0, 0), new Color(168, 204, 241), new Point2D.Double(0, 1), new Color(44, 61, 146)); public static final GradientPaint MAC_OSX_SELECTED = new GradientPaint(new Point2D.Double(0, 0), new Color(81, 141, 236), new Point2D.Double(0, 1), new Color(36, 96, 192)); public static final GradientPaint MAC_OSX = new GradientPaint(new Point2D.Double(0, 0), new Color(167, 210, 250), new Point2D.Double(0, 1), new Color(99, 147, 206)); public static final GradientPaint AERITH = new GradientPaint(new Point2D.Double(0, 0), Color.WHITE, new Point2D.Double(0, 1), new Color(64, 110, 161)); public static final GradientPaint GRAY = new GradientPaint(new Point2D.Double(0, 0), new Color(226, 226, 226), new Point2D.Double(0, 1), new Color(250, 248, 248)); public static final GradientPaint RED_XP = new GradientPaint(new Point2D.Double(0, 0), new Color(236, 81, 81), new Point2D.Double(0, 1), new Color(192, 36, 36)); public static final GradientPaint NIGHT_GRAY = new GradientPaint(new Point2D.Double(0, 0), new Color(102, 111, 127), new Point2D.Double(0, 1), new Color(38, 45, 61)); public static final GradientPaint NIGHT_GRAY_LIGHT = new GradientPaint(new Point2D.Double(0, 0), new Color(129, 138, 155), new Point2D.Double(0, 1), new Color(58, 66, 82)); private PaintUtils() { } /** * Returns the bounds that the text of a label will be drawn into. * Takes into account the current font metrics. */ public static Rectangle getTextBounds(Graphics g, JLabel label) { FontMetrics fm = g.getFontMetrics(); Rectangle2D r2d = fm.getStringBounds(label.getText(), g); Rectangle rect = r2d.getBounds(); int xOffset = 0; switch (label.getHorizontalAlignment()) { case SwingConstants.RIGHT: case SwingConstants.TRAILING: xOffset = label.getBounds().width - rect.width; break; case SwingConstants.CENTER: xOffset = (label.getBounds().width - rect.width) / 2; break; default: case SwingConstants.LEFT: case SwingConstants.LEADING: xOffset = 0; break; } int yOffset = 0; switch (label.getVerticalAlignment()) { case SwingConstants.TOP: yOffset = 0; break; case SwingConstants.CENTER: yOffset = (label.getBounds().height - rect.height) / 2; break; case SwingConstants.BOTTOM: yOffset = label.getBounds().height - rect.height; break; } return new Rectangle(xOffset, yOffset, rect.width, rect.height); } /** * Paints a top to bottom gradient fill over the component bounds * from color1 to color2. */ public static void paintGradient(Graphics g, JComponent comp, Color color1, Color color2) { GradientPaint paint = new GradientPaint(0, 0, color1, 0, comp.getHeight(), color2, true); Graphics2D g2 = (Graphics2D) g; Paint oldPaint = g2.getPaint(); g2.setPaint(paint); g2.fillRect(0, 0, comp.getWidth(), comp.getHeight()); g2.setPaint(oldPaint); } /** Resizes a gradient to fill the width and height available. If the * gradient is left to right it will be resized to fill the entire width. * If the gradient is top to bottom it will be resized to fill the entire * height. If the gradient is on an angle it will be resized to go from * one corner to the other of the rectangle formed by (0,0 -> width,height). * * This method can resize java.awt.GradientPaint, java.awt.LinearGradientPaint, * and the LinearGradientPaint implementation from Apache's Batik project. Note, * this method does not require the MultipleGradientPaint.jar from Apache to * compile or to run. MultipleGradientPaint.jar *is* required if you want * to resize the LinearGradientPaint from that jar. * * Any paint passed into this method which is not a kind of gradient paint (like * a Color or TexturePaint) will be returned unmodified. It will not throw * an exception. If the gradient cannot be resized due to other errors the * original paint will be returned unmodified. It will not throw an * exception. * */ public static Paint resizeGradient(Paint p, int width, int height) { if (p == null) return p; if (p instanceof GradientPaint) { GradientPaint gp = (GradientPaint) p; Point2D[] pts = new Point2D[2]; pts[0] = gp.getPoint1(); pts[1] = gp.getPoint2(); pts = adjustPoints(pts, width, height); return new GradientPaint(pts[0], gp.getColor1(), pts[1], gp.getColor2(), gp.isCyclic()); } if ("java.awt.LinearGradientPaint".equals(p.getClass().getName()) || "org.apache.batik.ext.awt.LinearGradientPaint".equals(p.getClass().getName())) { return resizeLinearGradient(p, width, height); } return p; } private static Paint resizeLinearGradient(Paint p, int width, int height) { try { Point2D[] pts = new Point2D[2]; pts[0] = (Point2D) invokeMethod(p, "getStartPoint"); pts[1] = (Point2D) invokeMethod(p, "getEndPoint"); pts = adjustPoints(pts, width, height); float[] fractions = (float[]) invokeMethod(p, "getFractions"); Color[] colors = (Color[]) invokeMethod(p, "getColors"); Constructor<?> con = p.getClass().getDeclaredConstructor(Point2D.class, Point2D.class, new float[0].getClass(), new Color[0].getClass()); return (Paint) con.newInstance(pts[0], pts[1], fractions, colors); } catch (Exception ex) { ex.printStackTrace(); } return p; } private static Object invokeMethod(final Object p, final String methodName) throws NoSuchMethodException, InvocationTargetException, IllegalArgumentException, SecurityException, IllegalAccessException { Method meth = p.getClass().getMethod(methodName); return meth.invoke(p); } private static Point2D[] adjustPoints(Point2D[] pts, int width, int height) { Point2D start = pts[0]; Point2D end = pts[1]; double angle = calcAngle(start, end); double a2 = Math.toDegrees(angle); double e = 1; // if it is near 0 degrees if (Math.abs(angle) < Math.toRadians(e) || Math.abs(angle) > Math.toRadians(360 - e)) { start = new Point2D.Float(0, 0); end = new Point2D.Float(width, 0); } // near 45 if (isNear(a2, 45, e)) { start = new Point2D.Float(0, 0); end = new Point2D.Float(width, height); } // near 90 if (isNear(a2, 90, e)) { start = new Point2D.Float(0, 0); end = new Point2D.Float(0, height); } // near 135 if (isNear(a2, 135, e)) { start = new Point2D.Float(width, 0); end = new Point2D.Float(0, height); } // near 180 if (isNear(a2, 180, e)) { start = new Point2D.Float(width, 0); end = new Point2D.Float(0, 0); } // near 225 if (isNear(a2, 225, e)) { start = new Point2D.Float(width, height); end = new Point2D.Float(0, 0); } // near 270 if (isNear(a2, 270, e)) { start = new Point2D.Float(0, height); end = new Point2D.Float(0, 0); } // near 315 if (isNear(a2, 315, e)) { start = new Point2D.Float(0, height); end = new Point2D.Float(width, 0); } return new Point2D[] { start, end }; } private static boolean isNear(double angle, double target, double error) { return Math.abs(target - Math.abs(angle)) < error; } private static double calcAngle(Point2D p1, Point2D p2) { double x_off = p2.getX() - p1.getX(); double y_off = p2.getY() - p1.getY(); double angle = Math.atan(y_off / x_off); if (x_off < 0) { angle = angle + Math.PI; } if (angle < 0) { angle += 2 * Math.PI; } if (angle > 2 * Math.PI) { angle -= 2 * Math.PI; } return angle; } /* public static void main(String ... args) { LinearGradientPaint in = new LinearGradientPaint( new Point(0,0), new Point(10,0), new float[] {0f, 0.5f, 1f}, new Color[] {Color.RED, Color.GREEN, Color.BLUE}); log.fine("in = " + toString(in)); Paint out = resizeGradient(in,100,100); log.fine(("out = " + toString((MultipleGradientPaint) out)); }*/ /* private static String toString(MultipleGradientPaint paint) { StringBuffer buffer = new StringBuffer(); buffer.append(paint.getClass().getName()); Color[] colors = paint.getColors(); float[] values = paint.getFractions(); buffer.append("["); for(int i=0; i<colors.length; i++) { buffer.append("#").append(Integer.toHexString(colors[i].getRGB())); buffer.append(":"); buffer.append(values[i]); buffer.append(", "); } buffer.append("]"); if(paint instanceof LinearGradientPaint) { LinearGradientPaint lgp = (LinearGradientPaint) paint; buffer.append(", "); buffer.append(""+lgp.getStartPoint().getX() + ", " + lgp.getStartPoint().getY()); buffer.append("->"); buffer.append(""+lgp.getEndPoint().getX() + ", " + lgp.getEndPoint().getY()); } return buffer.toString(); }*/ // private static void p(String string) { // log.fine((string); // } }