1 /* 2 * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package sun.awt; 27 28 import java.awt.GraphicsEnvironment; 29 import java.security.AccessController; 30 import java.security.PrivilegedAction; 31 32 public class PlatformGraphicsInfo { 33 34 public static GraphicsEnvironment createGE() { 35 return new X11GraphicsEnvironment(); 36 } 37 38 /** 39 * Called from java.awt.GraphicsEnvironment when 40 * to check if on this platform, the JDK should default to 41 * headless mode, in the case the application did specify 42 * a value for the java.awt.headless system property. 43 */ 44 public static boolean getDefaultHeadlessProperty() { 45 return 46 AccessController.doPrivileged((PrivilegedAction<Boolean>) () -> { 47 48 final String display = System.getenv("DISPLAY"); 49 return display == null || display.trim().isEmpty(); 50 }); 51 } 52 53 /** 54 * Called from java.awt.GraphicsEnvironment when 55 * getDefaultHeadlessProperty() has returned true, and 56 * the application has called an API that requires headful. 57 */ 58 public static String getDefaultHeadlessMessage() { 59 return 60 "\nNo X11 DISPLAY variable was set,\n" + 61 "but this program performed an operation which requires it."; 62 } 63 }