Java Tutorial/2D Graphics/Color

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Color class is used to work with colors in Java 2D

   <source lang="java">

import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import javax.swing.JFrame; import javax.swing.JPanel; public class Colors extends JPanel {

 public void paintComponent(Graphics g) {
   super.paintComponent(g);
   Graphics2D g2d = (Graphics2D) g;
   g2d.setColor(new Color(12, 16, 116));
   g2d.fillRect(10, 15, 90, 60);
   g2d.setColor(new Color(42, 19, 31));
   g2d.fillRect(130, 15, 90, 60);
   g2d.setColor(new Color(70, 7, 23));
   g2d.fillRect(250, 15, 90, 60);
   g2d.setColor(new Color(10, 10, 84));
   g2d.fillRect(10, 105, 90, 60);
   g2d.setColor(new Color(22, 21, 61));
   g2d.fillRect(130, 105, 90, 60);
   g2d.setColor(new Color(21, 98, 69));
   g2d.fillRect(250, 105, 90, 60);
   g2d.setColor(new Color(217, 146, 54));
   g2d.fillRect(10, 195, 90, 60);
   g2d.setColor(new Color(63, 121, 186));
   g2d.fillRect(130, 195, 90, 60);
   g2d.setColor(new Color(131, 121, 11));
   g2d.fillRect(250, 195, 90, 60);
 }
 public static void main(String[] args) {
   JFrame frame = new JFrame("Colors");
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   frame.add(new Colors());
   frame.setSize(360, 300);
   frame.setLocationRelativeTo(null);
   frame.setVisible(true);
 }

}</source>





Color Factory

   <source lang="java">

/*

   GNU LESSER GENERAL PUBLIC LICENSE
   Copyright (C) 2006 The Lobo Project
   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
   Contact info: lobochief@users.sourceforge.net
  • /

/*

* Created on Apr 17, 2005
*/

import java.util.*; import java.util.logging.*; import java.awt.*; /**

* @author J. H. S.
*/

public class ColorFactory {

 private static final Logger logger = Logger.getLogger(ColorFactory.class.getName());
 public static final Color TRANSPARENT = new Color(0, 0, 0, 0);
 private static ColorFactory instance;
 private final Map colorMap = new HashMap(256);
 
 private ColorFactory() {
   Map colorMap = this.colorMap;
   synchronized(this) {      
     colorMap.put("transparent", TRANSPARENT);
     //http://www.w3schools.ru/css/css_colornames.asp
     colorMap.put("aliceblue", new Color(0xf0f8ff));
     colorMap.put("antiquewhite", new Color(0xfaebd7));
     colorMap.put("aqua", new Color(0x00ffff));
     colorMap.put("aquamarine", new Color(0x7fffd4));
     colorMap.put("azure", new Color(0xf0ffff));
     colorMap.put("beige", new Color(0xf5f5dc));
     colorMap.put("bisque", new Color(0xffe4c4));
     colorMap.put("black", new Color(0x000000));
     colorMap.put("blanchedalmond", new Color(0xffebcd));
     colorMap.put("blue", new Color(0x0000ff));
     colorMap.put("blueviolet", new Color(0x8a2be2));
     colorMap.put("brown", new Color(0xa52a2a));
     colorMap.put("burlywood", new Color(0xdeb887));
     colorMap.put("cadetblue", new Color(0x5f9ea0));
     colorMap.put("chartreuse", new Color(0x7fff00));
     colorMap.put("chocolate", new Color(0xd2691e));
     colorMap.put("coral", new Color(0xff7f50));
     colorMap.put("cornflowerblue", new Color(0x6495ed));
     colorMap.put("cornsilk", new Color(0xfff8dc));
     colorMap.put("crimson", new Color(0xdc143c));
     colorMap.put("cyan", new Color(0x00ffff));
     colorMap.put("darkblue", new Color(0x00008b));
     colorMap.put("darkcyan", new Color(0x008b8b));
     colorMap.put("darkgoldenrod", new Color(0xb8860b));
     colorMap.put("darkgray", new Color(0xa9a9a9));
     colorMap.put("darkgrey", new Color(0xa9a9a9));
     colorMap.put("darkgreen", new Color(0x006400));
     colorMap.put("darkkhaki", new Color(0xbdb76b));
     colorMap.put("darkmagenta", new Color(0x8b008b));
     colorMap.put("darkolivegreen", new Color(0x556b2f));
     colorMap.put("darkorange", new Color(0xff8c00));
     colorMap.put("darkorchid", new Color(0x9932cc));
     colorMap.put("darkred", new Color(0x8b0000));
     colorMap.put("darksalmon", new Color(0xe9967a));
     colorMap.put("darkseagreen", new Color(0x8fbc8f));
     colorMap.put("darkslateblue", new Color(0x483d8b));
     colorMap.put("darkslategray", new Color(0x2f4f4f));
     colorMap.put("darkslategrey", new Color(0x2f4f4f));
     colorMap.put("darkturquoise", new Color(0x00ced1));
     colorMap.put("darkviolet", new Color(0x9400d3));
     colorMap.put("deeppink", new Color(0xff1493));
     colorMap.put("deepskyblue", new Color(0x00bfff));
     colorMap.put("dimgray", new Color(0x696969));
     colorMap.put("dimgrey", new Color(0x696969));
     colorMap.put("dodgerblue", new Color(0x1e90ff));
     colorMap.put("firebrick", new Color(0xb22222));
     colorMap.put("floralwhite", new Color(0xfffaf0));
     colorMap.put("forestgreen", new Color(0x228b22));
     colorMap.put("fuchsia", new Color(0xff00ff));
     colorMap.put("gainsboro", new Color(0xdcdcdc));
     colorMap.put("ghostwhite", new Color(0xf8f8ff));
     colorMap.put("gold", new Color(0xffd700));
     colorMap.put("goldenrod", new Color(0xdaa520));
     colorMap.put("gray", new Color(0x808080));
     colorMap.put("grey", new Color(0x808080));
     colorMap.put("green", new Color(0x008000));
     colorMap.put("greenyellow", new Color(0xadff2f));
     colorMap.put("honeydew", new Color(0xf0fff0));
     colorMap.put("hotpink", new Color(0xff69b4));
     colorMap.put("indianred", new Color(0xcd5c5c));
     colorMap.put("indigo", new Color(0x4b0082));
     colorMap.put("ivory", new Color(0xfffff0));
     colorMap.put("khaki", new Color(0xf0e68c));
     colorMap.put("lavender", new Color(0xe6e6fa));
     colorMap.put("lavenderblush", new Color(0xfff0f5));
     colorMap.put("lawngreen", new Color(0x7cfc00));
     colorMap.put("lemonchiffon", new Color(0xfffacd));
     colorMap.put("lightblue", new Color(0xadd8e6));
     colorMap.put("lightcoral", new Color(0xf08080));
     colorMap.put("lightcyan", new Color(0xe0ffff));
     colorMap.put("lightgoldenrodyellow", new Color(0xfafad2));
     colorMap.put("lightgray", new Color(0xd3d3d3));
     colorMap.put("lightgrey", new Color(0xd3d3d3));
     colorMap.put("lightgreen", new Color(0x90ee90));
     colorMap.put("lightpink", new Color(0xffb6c1));
     colorMap.put("lightsalmon", new Color(0xffa07a));
     colorMap.put("lightseagreen", new Color(0x20b2aa));
     colorMap.put("lightskyblue", new Color(0x87cefa));
     colorMap.put("lightslategray", new Color(0x778899));
     colorMap.put("lightslategrey", new Color(0x778899));
     colorMap.put("lightsteelblue", new Color(0xb0c4de));
     colorMap.put("lightyellow", new Color(0xffffe0));
     colorMap.put("lime", new Color(0x00ff00));
     colorMap.put("limegreen", new Color(0x32cd32));
     colorMap.put("linen", new Color(0xfaf0e6));
     colorMap.put("magenta", new Color(0xff00ff));
     colorMap.put("maroon", new Color(0x800000));
     colorMap.put("mediumaquamarine", new Color(0x66cdaa));
     colorMap.put("mediumblue", new Color(0x0000cd));
     colorMap.put("mediumorchid", new Color(0xba55d3));
     colorMap.put("mediumpurple", new Color(0x9370d8));
     colorMap.put("mediumseagreen", new Color(0x3cb371));
     colorMap.put("mediumslateblue", new Color(0x7b68ee));
     colorMap.put("mediumspringgreen", new Color(0x00fa9a));
     colorMap.put("mediumturquoise", new Color(0x48d1cc));
     colorMap.put("mediumvioletred", new Color(0xc71585));
     colorMap.put("midnightblue", new Color(0x191970));
     colorMap.put("mintcream", new Color(0xf5fffa));
     colorMap.put("mistyrose", new Color(0xffe4e1));
     colorMap.put("moccasin", new Color(0xffe4b5));
     colorMap.put("navajowhite", new Color(0xffdead));
     colorMap.put("navy", new Color(0x000080));
     colorMap.put("oldlace", new Color(0xfdf5e6));
     colorMap.put("olive", new Color(0x808000));
     colorMap.put("olivedrab", new Color(0x6b8e23));
     colorMap.put("orange", new Color(0xffa500));
     colorMap.put("orangered", new Color(0xff4500));
     colorMap.put("orchid", new Color(0xda70d6));
     colorMap.put("palegoldenrod", new Color(0xeee8aa));
     colorMap.put("palegreen", new Color(0x98fb98));
     colorMap.put("paleturquoise", new Color(0xafeeee));
     colorMap.put("palevioletred", new Color(0xd87093));
     colorMap.put("papayawhip", new Color(0xffefd5));
     colorMap.put("peachpuff", new Color(0xffdab9));
     colorMap.put("peru", new Color(0xcd853f));
     colorMap.put("pink", new Color(0xffc0cb));
     colorMap.put("plum", new Color(0xdda0dd));
     colorMap.put("powderblue", new Color(0xb0e0e6));
     colorMap.put("purple", new Color(0x800080));
     colorMap.put("red", new Color(0xff0000));
     colorMap.put("rosybrown", new Color(0xbc8f8f));
     colorMap.put("royalblue", new Color(0x4169e1));
     colorMap.put("saddlebrown", new Color(0x8b4513));
     colorMap.put("salmon", new Color(0xfa8072));
     colorMap.put("sandybrown", new Color(0xf4a460));
     colorMap.put("seagreen", new Color(0x2e8b57));
     colorMap.put("seashell", new Color(0xfff5ee));
     colorMap.put("sienna", new Color(0xa0522d));
     colorMap.put("silver", new Color(0xc0c0c0));
     colorMap.put("skyblue", new Color(0x87ceeb));
     colorMap.put("slateblue", new Color(0x6a5acd));
     colorMap.put("slategray", new Color(0x708090));
     colorMap.put("slategrey", new Color(0x708090));
     colorMap.put("snow", new Color(0xfffafa));
     colorMap.put("springgreen", new Color(0x00ff7f));
     colorMap.put("steelblue", new Color(0x4682b4));
     colorMap.put("tan", new Color(0xd2b48c));
     colorMap.put("teal", new Color(0x008080));
     colorMap.put("thistle", new Color(0xd8bfd8));
     colorMap.put("tomato", new Color(0xff6347));
     colorMap.put("turquoise", new Color(0x40e0d0));
     colorMap.put("violet", new Color(0xee82ee));
     colorMap.put("wheat", new Color(0xf5deb3));
     colorMap.put("white", new Color(0xffffff));
     colorMap.put("whitesmoke", new Color(0xf5f5f5));
     colorMap.put("yellow", new Color(0xffff00));
     colorMap.put("yellowgreen", new Color(0x9acd32));
   }
 } 
 public static final ColorFactory getInstance() {
   if(instance == null) {
     synchronized(ColorFactory.class) {
       if(instance == null) {
         instance = new ColorFactory();
       }
     }
   }
   return instance;
 }
 
 private static final String RGB_START = "rgb(";
 
 public boolean isColor(String colorSpec) {
   if(colorSpec.startsWith("#")) {
     return true;
   }
   String normalSpec = colorSpec.toLowerCase();
   if(normalSpec.startsWith(RGB_START)) {
     return true;
   }
   synchronized(this) {
     return colorMap.containsKey(normalSpec);
   }
 }
 
 public Color getColor(String colorSpec) {
   String normalSpec = colorSpec.toLowerCase();
   synchronized(this) {
     Color color = (Color) colorMap.get(normalSpec);
     if(color == null) {
       if(normalSpec.startsWith(RGB_START)) {
         // CssParser produces this format.          
         int endIdx = normalSpec.lastIndexOf(")");
         String commaValues = endIdx == -1 ? normalSpec.substring(RGB_START.length()) : normalSpec.substring(RGB_START.length(), endIdx);
         StringTokenizer tok = new StringTokenizer(commaValues, ",");
         int r = 0, g = 0, b = 0;
         if(tok.hasMoreTokens()) {
           String rstr = tok.nextToken().trim();
           try {
             r = Integer.parseInt(rstr);
           } catch(NumberFormatException nfe) {
             // ignore
           }
           if(tok.hasMoreTokens()) {
             String gstr = tok.nextToken().trim();
             try {
               g = Integer.parseInt(gstr);
             } catch(NumberFormatException nfe) {
               // ignore
             }
             if(tok.hasMoreTokens()) {
               String bstr = tok.nextToken().trim();
               try {
                 b = Integer.parseInt(bstr);
               } catch(NumberFormatException nfe) {
                 // ignore
               }
             }
           }
         }
         color = new Color(r, g, b);
       }
       else if(normalSpec.startsWith("#")) {
         //TODO: OPTIMIZE: It would be more efficient to
         //create new Color(hex), but CssParser doesn"t
         //give us values formatted with "#" either way.
         int len = normalSpec.length();
         int[] rgba = new int[4];
         rgba[3] = 255;
         for(int i = 0; i < rgba.length; i++) 
         {
           int idx = 2 * i + 1;
           if(idx < len) 
           {
             String hexText = normalSpec.substring(idx, idx + Math.min(2, len - idx));
             try {
               rgba[i] = Integer.parseInt(hexText, 16);
             } catch(NumberFormatException nfe) {
               // Ignore
             }
           }
         }       
         color = new Color(rgba[0], rgba[1], rgba[2], rgba[3]);
       }
       else {
         if(logger.isLoggable(Level.INFO)) {
           logger.warning("getColor(): Color spec [" + normalSpec + "] unknown.");
         }
         return Color.RED;
       }
       colorMap.put(normalSpec, color);
     }
     return color;
   }
 }
 
 

}</source>





Construct Color object

   <source lang="java">

import java.awt.BorderLayout; import java.awt.Color; import javax.swing.JButton; import javax.swing.JFrame; public class ColorSample {

 public static void main(String args[]) {
   JFrame f = new JFrame("JColorChooser Sample");
   f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   final JButton button = new JButton("Pick to Change Background");
   Color myBlack = new Color(0,0,0);           // Color black

// Color myWhite = new Color(255,255,255); // Color white

 //  Color myGreen = new Color(0,200,0);         // A shade of green
   
   button.setBackground(myBlack);
   f.add(button, BorderLayout.CENTER);
   f.setSize(300, 200);
   f.setVisible(true);
 }

}</source>





Constructs several colors and draws various objects using these colors:

   <source lang="java">

import java.awt.Color; import java.awt.Graphics; import javax.swing.JFrame; public class ColorVariousObjects extends JFrame {

 public static void main(String[] a){
   ColorVariousObjects f = new ColorVariousObjects();
   f.setSize(300,300);
   f.setVisible(true);
 }
 
 
 public void paint(Graphics g) {
   Color c1 = new Color(255, 100, 100);
   Color c2 = new Color(100, 255, 100);
   Color c3 = new Color(100, 100, 255);
   g.setColor(c1);
   g.drawLine(0, 0, 100, 100);
   g.drawLine(0, 100, 100, 0);
   g.setColor(c2);
   g.drawLine(40, 25, 250, 180);
   g.drawLine(75, 90, 400, 400);
   g.setColor(c3);
   g.drawLine(20, 150, 400, 40);
   g.drawLine(5, 290, 80, 19);
   g.setColor(Color.red);
   g.drawOval(10, 10, 50, 50);
   g.fillOval(70, 90, 140, 100);
   g.setColor(Color.blue);
   g.drawOval(190, 10, 90, 30);
   g.drawRect(10, 10, 60, 50);
   g.setColor(Color.cyan);
   g.fillRect(100, 10, 60, 50);
   g.drawRoundRect(190, 10, 60, 50, 15, 15);
 }

}</source>





Convert an integer to an HTML RGB value

   <source lang="java">

/*******************************************************************************

* Copyright (c) 2004 Actuate Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
*  Actuate Corporation  - initial API and implementation
*******************************************************************************/

/**

* Collection of string utilities.
* 
*/

public class StringUtil {

 /**
  * Convert an integer to an HTML RGB value. The result is of the form
  * #hhhhhh. The input rgb integer value will be clipped into the range 0 ~
  * 0xFFFFFF
  * 
  * @param rgb
  *            the integer RGB value
  * @return the value as an HTML RGB string
  */
 public static String toRgbText( int rgb )
 {
   // clip input value.
   if ( rgb > 0xFFFFFF )
     rgb = 0xFFFFFF;
   if ( rgb < 0 )
     rgb = 0;
   String str = "000000" + Integer.toHexString( rgb ); //$NON-NLS-1$ 
   return "#" + str.substring( str.length( ) - 6 ); //$NON-NLS-1$ 
 }

}</source>





Convert HSB to RGB value

   <source lang="java">

import java.awt.Color; public class Main {

 public static void main() {
   float hue = 12; 
   float saturation = 13;
   float brightness = 14;
   
   int rgb = Color.HSBtoRGB(hue, saturation, brightness);
   int red = (rgb >> 16) & 0xFF;
   int green = (rgb >> 8) & 0xFF;
   int blue = rgb & 0xFF;
 }

}</source>





Convert RGB to HSB

   <source lang="java">

import java.awt.Color; public class Main {

 public static void main() {
   int red = 23;
   int green = 66;
   int blue = 99;
   float[] hsb = Color.RGBtoHSB(red, green, blue, null);
   float hue = hsb[0]; 
   float saturation = hsb[1];
   float brightness = hsb[2];
 }

}</source>





Converts a given string into a color.

   <source lang="java">

import java.awt.Color; import java.lang.reflect.Field; /*

* JCommon : a free general purpose class library for the Java(tm) platform
* 
*
* (C) Copyright 2000-2005, by Object Refinery Limited and Contributors.
* 
* Project Info:  http://www.jfree.org/jcommon/index.html
*
* 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 Street, Fifth Floor, Boston, MA  02110-1301, 
* USA.  
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
* in the United States and other countries.]
* 
* -------------------
* PaintUtilities.java
* -------------------
* (C) Copyright 2003-2005, by Object Refinery Limited.
*
* Original Author:  David Gilbert (for Object Refinery Limited);
* Contributor(s):   -;
*
* $Id: PaintUtilities.java,v 1.10 2007/11/02 17:50:37 taqua Exp $
*
* Changes
* -------
* 13-Nov-2003 : Version 1 (DG);
* 04-Oct-2004 : Renamed PaintUtils --> PaintUtilities (DG);
* 23-Feb-2005 : Rewrote equal() method with less indenting required (DG);
*
*/

public class Main {

 /**
  * Converts a given string into a color.
  * 
  * @param value
  *          the string, either a name or a hex-string.
  * @return the color.
  */
 public static Color stringToColor(final String value) {
   if (value == null) {
     return Color.black;
   }
   try {
     // get color by hex or octal value
     return Color.decode(value);
   } catch (NumberFormatException nfe) {
     // if we can"t decode lets try to get it by name
     try {
       // try to get a color by name using reflection
       final Field f = Color.class.getField(value);
       return (Color) f.get(null);
     } catch (Exception ce) {
       // if we can"t get any color return black
       return Color.black;
     }
   }
 }

}</source>





Converts the String representation of a color to an actual Color object.

   <source lang="java">

import java.awt.Color; /*

* Copyright 2007 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

/**

* Some string utilities for joining list of strings.
*
* @author ycoppel@google.ru (Yohann Coppel)
*
*/

public class Utils {

 /**
  * Converts the String representation of a color to an actual
  * Color object.
  *
  * @param value String representation of the color in "r,g,b" format (e.g.
  * "100,255,0")
  * @return Color object that matches the red-green-blue values
  * provided by the parameter. Returns null for empty string.
  */
 public static Color stringToColor(String value) {
   try {
     if (!value.equals("")) {
       String[] s = value.split(",");
       if (s.length == 3) {
         int red = Integer.parseInt(s[0]);
         int green = Integer.parseInt(s[1]);
         int blue = Integer.parseInt(s[2]);
         return new Color(red, green, blue);
       }
     }
   } catch (NumberFormatException ex) {
     // ignore it, don"t change anything.
     return null;
   } catch (IllegalArgumentException ex) {
     // if a user entered 548 as the red value....
     // ignore it, don"t change anything.
     return null;
   }
   return null;
 }

}</source>





Derives a color by adding the specified offsets to the base color"s hue, saturation, and brightness values

   <source lang="java">

/*

* Copyright 2007-2008 Sun Microsystems, Inc.  All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
*   - Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*
*   - Redistributions in binary form must reproduce the above copyright
*     notice, this list of conditions and the following disclaimer in the
*     documentation and/or other materials provided with the distribution.
*
*   - Neither the name of Sun Microsystems nor the names of its
*     contributors may be used to endorse or promote products derived
*     from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

import java.awt.Color; /**

  • @author aim
  • /

public class Utils {

 /**
  * Derives a color by adding the specified offsets to the base color"s 
  * hue, saturation, and brightness values.   The resulting hue, saturation,
  * and brightness values will be contrained to be between 0 and 1.
  * @param base the color to which the HSV offsets will be added
  * @param dH the offset for hue
  * @param dS the offset for saturation
  * @param dB the offset for brightness
  * @return Color with modified HSV values
  */
 public static Color deriveColorHSB(Color base, float dH, float dS, float dB) {
     float hsb[] = Color.RGBtoHSB(
             base.getRed(), base.getGreen(), base.getBlue(), null);
     hsb[0] += dH;
     hsb[1] += dS;
     hsb[2] += dB;
     return Color.getHSBColor(
             hsb[0] < 0? 0 : (hsb[0] > 1? 1 : hsb[0]),
             hsb[1] < 0? 0 : (hsb[1] > 1? 1 : hsb[1]),
             hsb[2] < 0? 0 : (hsb[2] > 1? 1 : hsb[2]));
                                            
 }

}</source>





Drawing with Color

   <source lang="java">

import java.awt.Color; import java.awt.Graphics; import java.awt.Graphics2D; import java.awt.Rectangle; import javax.swing.JComponent; import javax.swing.JFrame; public class BasicDraw {

 public static void main(String[] args) {
   new BasicDraw();
 }
 BasicDraw() {
   JFrame frame = new JFrame();
   frame.add(new MyComponent());
   frame.setSize(300, 300);
   frame.setVisible(true);
 }

} class MyComponent extends JComponent {

 public void paint(Graphics g) {
   Graphics2D g2d = (Graphics2D) g;
   g2d.setColor(Color.red);
   g2d.fill(new Rectangle(20,20,200,200));
   int red = 230;
   int green = 45;
   int blue = 67;
   g2d.setColor(new Color(red, green, blue));
   g2d.fill(new Rectangle(40,40,200,200));
 }

}</source>





Get HTML Color String from Java Color object

   <source lang="java">

import java.awt.Color; public class Utils {

 public static String getHTMLColorString(Color color) {
   String red = Integer.toHexString(color.getRed());
   String green = Integer.toHexString(color.getGreen());
   String blue = Integer.toHexString(color.getBlue());
   return "#" + 
           (red.length() == 1? "0" + red : red) +
           (green.length() == 1? "0" + green : green) +
           (blue.length() == 1? "0" + blue : blue);        

} }</source>





HTML color and Java Color

   <source lang="java">

/**

* Licensed under the Common Development and Distribution License,
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* 
*   http://www.sun.ru/cddl/
*   
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or 
* implied. See the License for the specific language governing
* permissions and limitations under the License.
*/

//Revised from ajax4jsf import java.awt.Color; import java.util.HashMap; import java.util.Map;

/**

* @author shura (latest modification by $Author: slava_kabanovich $)
* @version $Revision: 1.2 $ $Date: 2006/07/12 14:59:33 $
*
*/

public class HtmlColor {

 private static Map colorNames;
 
 static {
   // color names.
   colorNames = new HashMap();
     colorNames.put("black", new Color(0x000000));
   colorNames.put("green", new Color(0x008000));
   colorNames.put("silver", new Color(0xC0C0C0));
   colorNames.put("lime", new Color(0x00FF00));
   colorNames.put("gray", new Color(0x808080));
   colorNames.put("olive", new Color(0x808000));
   colorNames.put("white", new Color(0xFFFFFF));
   colorNames.put("yellow", new Color(0xFFFF00));
   colorNames.put("maroon", new Color(0x800000));
   colorNames.put("navy", new Color(0x000080));
   colorNames.put("red", new Color(0xFF0000));
   colorNames.put("blue", new Color(0x0000FF));
   colorNames.put("purple", new Color(0x800080));
   colorNames.put("teal", new Color(0x008080));
   colorNames.put("fuchsia", new Color(0xFF00FF));
   colorNames.put("aqua", new Color(0x00FFFF));
 }
 /**
  * Decode HTML-attribute style of color to {@link Color}
  * @param color - color name or #RRGGBB string
  * @return - color for this value.
  */
 public static Color decode(String color){
   if(null == color) {
     throw new IllegalArgumentException("NULL_COLOR_PARAMETER_ERROR");
   }
   Color c = (Color) colorNames.get(color.trim().toLowerCase());
   if (null == c) {
     try {
       c = Color.decode(color.trim());
     } catch (NumberFormatException e) {
       throw new IllegalArgumentException("DECODE_COLOR_PARAMETER_ERROR");
     }
   }
   return c;
 }
 
 public static Integer integerValue(String color){
   return new Integer(decode(color).getRGB());
 }
 
 public static String encodeRGB(Color color){
   if(null == color) {
     throw new IllegalArgumentException("NULL_COLOR_PARAMETER_ERROR_2");
   }
   return "#" + Integer.toHexString(color.getRGB()).substring(2).toUpperCase();
 }
 

}</source>





java.awt.Color

A Color object represents a color. Color class provides static fields that return a specific Color object: BLACK, BLUE, GREEN, RED, CYAN, ORANGE, YELLOW.

For example, to obtain a Color object that represents green, use this code:



   <source lang="java">

Color color = Color.GREEN;</source>





Java Predefined Colors

Predefined ColorRGB Valuesblack(0,0,0)blue(0,0,255)cyan(0,255,255)darkGray(64,64,64)gray(128,128,128)green(0,255,0)lightGray(192,192,192)magenta(255,0,255)orange(255,200,0)pink(255,175,175)red(255,0,0)white(255,255,255)yellow(255,255,0)


Map colors into names and vice versa.

   <source lang="java">

/**

* 
* LibSparkline : a free Java sparkline chart library
* 
*
* Project Info:  http://reporting.pentaho.org/libsparkline/
*
* (C) Copyright 2008, by Larry Ogrodnek, Pentaho Corporation and Contributors.
*
* This library is free software; you can redistribute it and/or modify it under the terms
* of the Apache License 2.0.
*
* 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.
*
* You should have received a copy of the Apache License 2.0 along with this library;
* if not, a online version is available at http://www.apache.org/licenses/
*
* [Java is a trademark or registered trademark of Sun Microsystems, Inc.
* in the United States and other countries.]
*
* ------------
* ColorUtilitiy.java
* ------------
*/

import java.awt.Color; import java.lang.reflect.Field; import java.lang.reflect.Modifier; import java.util.HashMap; /**

* A helper class to map colors into names and vice versa.
* 
* @author Thomas Morgner
*/

public final class ColorUtilitiy {

 private static final HashMap knownColorNamesByColor;
 private static final HashMap knownColorsByName;
 static {
   knownColorNamesByColor = new HashMap();
   knownColorsByName = new HashMap();
   try {
     final Field[] fields = Color.class.getFields();
     for (int i = 0; i < fields.length; i++) {
       final Field f = fields[i];
       if (Modifier.isPublic(f.getModifiers()) && Modifier.isFinal(f.getModifiers())
           && Modifier.isStatic(f.getModifiers())) {
         final String name = f.getName();
         final Object oColor = f.get(null);
         if (oColor instanceof Color) {
           knownColorNamesByColor.put(oColor, name.toLowerCase());
           knownColorsByName.put(name.toLowerCase(), oColor);
         }
       }
     }
   } catch (Exception e) {
     // ignore ..
   }
 }
 /**
  * Utility class constructor prevents object creation.
  */
 private ColorUtilitiy() {
 }
 /**
  * Parse a String into a Color. <p/> This method will accept either a color
  * name (a field name from {@link Color}, case insensitive e.g. "red"), or a
  * HTML hex color string (e.g. "#ff0000" for Color.RED).
  * 
  * @param value
  *          String to parse for color name or color number.
  * @return Color for s.
  */
 private static Color parseColor(final String value) {
   if (value == null) {
     return null;
   }
   final Object o = knownColorsByName.get(value.toLowerCase());
   if (o != null) {
     return (Color) o;
   }
   try {
     // get color by hex or octal value
     return Color.decode(value.trim());
   } catch (NumberFormatException nfe) {
     return null;
   }
 }
 /**
  * Parse a String into a Color, and returns the given default value if the
  * color is not parsable. <p/> This method will accept either a color name (a
  * field name from {@link Color}, case insensitive e.g. "red"), or a HTML hex
  * color string (e.g. "#ff0000" for Color.RED).
  * 
  * @param colorText
  *          String to parse for color name or color number.
  * @param defValue
  *          the default value that should be returned if the string is not
  *          parseable or null.
  * @return Color for the text.
  */
 public static Color convertColor(final String colorText, final Color defValue) {
   if (colorText == null || colorText.isEmpty()) {
     return defValue;
   }
   final Color retval = parseColor(colorText);
   if (retval == null) {
     return defValue;
   }
   return retval;
 }

}</source>





Set XOR mode to color blue

   <source lang="java">

// This example is from the book _Java AWT Reference_ by John Zukowski. // Written by John Zukowski. Copyright (c) 1997 O"Reilly & Associates. // You may study, use, modify, and distribute this example for any purpose. // This example is provided WITHOUT WARRANTY either expressed or import java.awt.Color; import java.awt.Graphics; import javax.swing.JFrame; import javax.swing.JPanel; public class xorTest extends JPanel{

   public void init () {
       setBackground (Color.red);
   }
   public void paint (Graphics g) {
       g.setColor (Color.green);
       g.setXORMode (Color.blue);
       g.fillRect (10, 10, 100, 100);
       g.fillRect (10, 60, 100, 100);
   }
   public static void main(String[] a){
     JFrame f = new JFrame();
     f.add(new xorTest());
     f.setSize(300,300);
     f.setVisible(true);
   }

}</source>





To compare two Color objects you can use the equals() method

   <source lang="java">

import java.awt.Color; public class MainClass {

 public static void main(String[] a) {
   Color myBlack = new Color(0, 0, 0); // Color black
   Color myWhite = new Color(255, 255, 255); // Color white
   System.out.println(myBlack.equals(myWhite));
 }

}</source>



false


Using color with and Bit and

   <source lang="java">

import java.awt.Color; import java.awt.Graphics; import javax.swing.JComponent; import javax.swing.JFrame; class MyCanvas extends JComponent {

 Color[] colors = new Color[24];
 public MyCanvas() {
   int  rgb = 0xff;
   for (int i = 0; i < 24; i++) {
     colors[i] = new Color(rgb);
     rgb <<= 1;
     if ((rgb & 0x1000000) != 0) {
       rgb |= 1;
       rgb &= 0xffffff;
     }
   }
 }
 public void paint(Graphics g) {
   int i = 10;
   for (Color c : colors) {
     g.setColor(c);
     i += 10;
     g.drawLine(i, 10, 200, 200);
   }
 }

} public class DrawLine {

 public static void main(String[] a) {
   JFrame window = new JFrame();
   window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   window.setBounds(30, 30, 300, 300);
   window.getContentPane().add(new MyCanvas());
   window.setVisible(true);
 }

}</source>





Using the getRGB() method for comparing colors

   <source lang="java">

import java.awt.Color; public class MainClass {

 public static void main(String[] a) {
   Color myBlack = new Color(0, 0, 0); // Color black
   Color myWhite = new Color(255, 255, 255); // Color white
   System.out.println(myBlack.getRGB() == myWhite.getRGB());
   System.out.println(myBlack.getRGB());
   System.out.println(myWhite.getRGB());
 }

}</source>



false
-16777216
-1