Java tutorial
/* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. 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 Oracle or 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 layout; /* * BoxLayoutDemo2.java requires one other file: BLDComponent.java */ import java.awt.*; import java.awt.event.*; import javax.swing.*; public class BoxLayoutDemo2 implements ItemListener { protected static int NUM_COMPONENTS = 3; protected static float[] xAlignment = { Component.LEFT_ALIGNMENT, Component.CENTER_ALIGNMENT, Component.RIGHT_ALIGNMENT }; protected static float[] hue = { 0.0f, 0.33f, 0.67f }; protected static boolean restrictSize = true; protected static boolean sizeIsRandom = false; protected static BLDComponent[] bldComponent = new BLDComponent[NUM_COMPONENTS]; public void populateContentPane(Container contentPane) { JPanel panel = new JPanel(); panel.setLayout(new BoxLayout(panel, BoxLayout.PAGE_AXIS)); //Create the rectangles. int shortSideSize = 15; for (int i = 0; i < NUM_COMPONENTS; i++) { if (sizeIsRandom) { shortSideSize = (int) (30.0 * Math.random()) + 30; } else { shortSideSize += 10; } bldComponent[i] = new BLDComponent(xAlignment[i], hue[i], shortSideSize, restrictSize, sizeIsRandom, String.valueOf(i)); panel.add(bldComponent[i]); } //Create the instructions. JLabel label = new JLabel("Click a rectangle to " + "change its X alignment."); JCheckBox cb = new JCheckBox("Restrict maximum rectangle size."); cb.setSelected(restrictSize); cb.addItemListener(this); panel.setBorder(BorderFactory.createLineBorder(Color.red)); Box box = Box.createVerticalBox(); box.add(label); box.add(cb); contentPane.add(panel, BorderLayout.CENTER); contentPane.add(box, BorderLayout.PAGE_END); } public void itemStateChanged(ItemEvent e) { if (e.getStateChange() == ItemEvent.SELECTED) { restrictSize = true; } else { restrictSize = false; } notifyBLDComponents(); } static public void notifyBLDComponents() { for (int i = 0; i < NUM_COMPONENTS; i++) { bldComponent[i].setSizeRestriction(restrictSize); } bldComponent[0].revalidate(); } /** * Create the GUI and show it. For thread safety, * this method should be invoked from the * event-dispatching thread. */ private static void createAndShowGUI() { //Create and set up the window. JFrame frame = new JFrame("BoxLayoutDemo2"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. BoxLayoutDemo2 demo = new BoxLayoutDemo2(); demo.populateContentPane(frame.getContentPane()); //Display the window. frame.pack(); frame.setVisible(true); } public static void main(String[] args) { //Schedule a job for the event-dispatching thread: //creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } }