Here you can find the source of getScreenSize()
public static java.awt.Dimension getScreenSize()
//package com.java2s; /******************************************************************************* * Copyright (C) 2006-2013 AITIA International, Inc. * //from www.ja v a 2 s .c om * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program 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 General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. ******************************************************************************/ public class Main { private static java.awt.Component g_referenceComponent = null; private static java.awt.Dimension g_screenSize = null; /** * Returns the maximum possible size of a fully visible window. * Note that this method is slow and expensive for the first time. */ public static java.awt.Dimension getScreenSize() { if (g_screenSize == null) { java.awt.Component c = getRefComp(); java.awt.Toolkit tk = c.getToolkit(); g_screenSize = tk.getScreenSize(); try { java.awt.Insets in = tk.getScreenInsets(c.getGraphicsConfiguration()); g_screenSize.width -= in.left + in.right; g_screenSize.height -= in.top + in.bottom; } catch (Throwable t) { } //java.awt.Rectangle rect = java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment().getMaximumWindowBounds(); //g_screenSize = rect.getSize(); //System.gc(); } return g_screenSize; } /** * Some functions (such as font/screen size calculation) require a component * e.g. to access the screen. I call it as 'reference component'. * It is recommended to set it to a JLabel/JButton in the main window. */ public static java.awt.Component getRefComp() { if (g_referenceComponent == null) { g_referenceComponent = java.awt.KeyboardFocusManager.getCurrentKeyboardFocusManager().getActiveWindow(); if (g_referenceComponent == null) g_referenceComponent = new javax.swing.JLabel(); } return g_referenceComponent; } }