/JGoodies/src/com/jgoodies/common/base/SystemUtils.java

/*

 * Copyright (c) 2009-2013 JGoodies Software GmbH. All Rights Reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 *  o Redistributions of source code must retain the above copyright notice,

 *    this list of conditions and the following disclaimer.

 *

 *  o 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.

 *

 *  o Neither the name of JGoodies Software GmbH 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.

 */



package com.jgoodies.common.base;



import java.awt.HeadlessException;

import java.awt.Toolkit;

import java.util.logging.Logger;



/**

 * Provides convenience behavior to determine the operating system

 * and Java version.

 *

 * @author Karsten Lentzsch

 * @version $Revision: 1.5 $

 */

public class SystemUtils {



    // Internal Constants *****************************************************



    /**

     * The {@code os.name} System Property. Operating system name.<p>

     *

     * Defaults to {@code null}, if the runtime does not have security

     * access to read this property or the property does not exist.

     */

    protected static final String OS_NAME = getSystemProperty("os.name");





    /**

     * The {@code os.version} System Property. Operating system version.<p>

     *

     * Defaults to {@code null}, if the runtime does not have security

     * access to read this property or the property does not exist.

     */

    protected static final String OS_VERSION = getSystemProperty("os.version");





    /**

     * The {@code os.name} System Property. Operating system name.<p>

     *

     * Defaults to {@code null}, if the runtime does not have security

     * access to read this property or the property does not exist.

     */

    protected static final String JAVA_VERSION = getSystemProperty("java.version");





    // Requesting the OS and OS Version ***************************************



    /**

     * Is true if this is Linux.

     */

    public static final boolean IS_OS_LINUX =

        startsWith(OS_NAME, "Linux") || startsWith(OS_NAME, "LINUX");





    /**

     * True if this is the Mac OS.

     */

    public static final boolean IS_OS_MAC =

        startsWith(OS_NAME, "Mac OS");





    /**

     * True if this is Solaris.

     */

    public static final boolean IS_OS_SOLARIS =

        startsWith(OS_NAME, "Solaris");





    /**

     * True if this is Windows.

     */

    public static final boolean IS_OS_WINDOWS =

        startsWith(OS_NAME, "Windows");





    /**

     * True if this is Windows 98.

     */

    public static final boolean IS_OS_WINDOWS_98 =

        startsWith(OS_NAME, "Windows 9") && startsWith(OS_VERSION, "4.1");





    /**

     * True if this is Windows ME.

     */

    public static final boolean IS_OS_WINDOWS_ME =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "4.9");





    /**

     * True if this is Windows 2000.

     */

    public static final boolean IS_OS_WINDOWS_2000 =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "5.0");





    /**

     * True if this is Windows XP.

     */

    public static final boolean IS_OS_WINDOWS_XP =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "5.1");





    /**

     * True if this is Windows Vista or Server 2008.

     */

    public static final boolean IS_OS_WINDOWS_VISTA =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "6.0");





    /**

     * True if this is Windows 7.

     */

    public static final boolean IS_OS_WINDOWS_7 =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "6.1");





    /**

     * True if this is Windows 8.

     */

    public static final boolean IS_OS_WINDOWS_8 =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "6.2");





    /**

     * True if this is Windows Vista/Server 2008/7/2008 R2/8.

     */

    public static final boolean IS_OS_WINDOWS_6_OR_LATER =

        startsWith(OS_NAME, "Windows") && startsWith(OS_VERSION, "6.");





    // Requesting the Java Version ********************************************



    /**

     * True if this is Java 6. We check for a prefix of 1.6.

     */

    public static final boolean IS_JAVA_6 =

        startsWith(JAVA_VERSION, "1.6");





    /**

     * True if this is Java 7. We check for a prefix of 1.7.

     */

    public static final boolean IS_JAVA_7 =

        startsWith(JAVA_VERSION, "1.7");





    /**

     * True if this is Java 7.x or later. We check that it's not 1.6.

     */

    public static final boolean IS_JAVA_7_OR_LATER =

           !IS_JAVA_6;





    /**

     * True if this is Java 7. We check for a prefix of 1.7.

     * 

     * @since 1.6

     */

    public static final boolean IS_JAVA_8 =

        startsWith(JAVA_VERSION, "1.8");





    /**

     * True if this is Java 8.x or later.

     * We check that it's neither 1.6 nor 1.7.

     * 

     * @since 1.6

     */

    public static final boolean IS_JAVA_8_OR_LATER =

           !IS_JAVA_6 && !IS_JAVA_7;





    // Visual Properties ******************************************************



    /**

     * True since Java 6 update 10.

     *

     * @since 1.2

     */

    public static final boolean HAS_MODERN_RASTERIZER = hasModernRasterizer();





    /**

     * True if the Windows XP Look&amp;Feel is enabled.

     *

     * @since 1.2

     */

    public static final boolean IS_LAF_WINDOWS_XP_ENABLED = isWindowsXPLafEnabled();





    /**

     * Is true if this environment's default toolkit reports a screen resolution

     * below 120 dpi.<p>

     *

     * @since 1.2

     */

    public static final boolean IS_LOW_RESOLUTION = isLowResolution();





    // Internal ***************************************************************



    private static final String AWT_UTILITIES_CLASS_NAME =

        "com.sun.awt.AWTUtilities";





    protected SystemUtils() {

        // Override default constructor; prevents instantiation.

    }





    /**

     * Tries to look up the System property for the given key.

     * In untrusted environments this may throw a SecurityException.

     * In this case we catch the exception and answer an empty string.

     *

     * @param key   the name of the system property

     * @return the system property's String value, or {@code null} if there's

     *     no such value, or an empty String when

     *     a SecurityException has been caught

     */

    protected static String getSystemProperty(String key) {

        try {

            return System.getProperty(key);

        } catch (SecurityException e) {

            Logger.getLogger(SystemUtils.class.getName()).warning(

                  "Can't access the System property " + key + ".");

            return "";

        }

    }





    protected static boolean startsWith(String str, String prefix) {

        return str != null && str.startsWith(prefix);

    }





    /**

     * Checks and answers whether this Java runtime has a modern rasterizer

     * or not. More precisely this method aims to understand whether a good

     * or poor rasterizer is used. Sun's Java runtime has improved its

     * rasterizer in the 1.6 N series after build 12.

     *

     * @return {@code true} if the AWTUtilities class is available,

     *     {@code false} if this class is not in the class path.

     */

    private static boolean hasModernRasterizer() {

        try {

            Class.forName(AWT_UTILITIES_CLASS_NAME);

            return true;

        } catch (ClassNotFoundException e) {

            return false;

        }

    }





    /**

     * Checks and answers whether the Windows XP style is enabled.

     * This method is intended to be called only if a Windows look&feel

     * is about to be installed or already active in the UIManager.

     * The XP style of the Windows look&amp;feel is enabled by default on

     * Windows XP platforms since the J2SE 1.4.2; it can be disabled either

     * in the Windows desktop as well as in the Java runtime by setting

     * a System property.<p>

     *

     * First checks the platform, platform version and Java version. Then

     * checks whether the desktop property <tt>win.xpstyle.themeActive</tt>

     * is set or not.

     *

     * @return true if the Windows XP style is enabled

     */

    private static boolean isWindowsXPLafEnabled() {

        return IS_OS_WINDOWS

             && Boolean.TRUE.equals(Toolkit.getDefaultToolkit().

                     getDesktopProperty("win.xpstyle.themeActive"))

             && getSystemProperty("swing.noxp") == null;

    }





    private static boolean isLowResolution() {

        try {

            return Toolkit.getDefaultToolkit().getScreenResolution() < 120;

        } catch (HeadlessException e) {

            return true;

        }

    }





}