Java tutorial
/* This program is a part of the companion code for Core Java 8th ed. (http://horstmann.com/corejava) 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/>. */ import java.awt.BorderLayout; import java.awt.GraphicsEnvironment; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.text.DateFormat; import java.text.SimpleDateFormat; import javax.swing.AbstractSpinnerModel; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JSpinner; import javax.swing.SpinnerDateModel; import javax.swing.SpinnerListModel; import javax.swing.SpinnerNumberModel; import javax.swing.event.ChangeEvent; import javax.swing.event.ChangeListener; /** * A program to test spinners. * * @version 1.02 2007-08-01 * @author Cay Horstmann */ public class Main extends JFrame { public static void main(String[] args) { Main frame = new Main(); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.setVisible(true); } public Main() { setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT); JPanel buttonPanel = new JPanel(); okButton = new JButton("Ok"); buttonPanel.add(okButton); add(buttonPanel, BorderLayout.SOUTH); mainPanel = new JPanel(); mainPanel.setLayout(new GridLayout(0, 3)); add(mainPanel, BorderLayout.CENTER); JSpinner defaultSpinner = new JSpinner(); addRow("Default", defaultSpinner); JSpinner boundedSpinner = new JSpinner(new SpinnerNumberModel(5, 0, 10, 0.5)); addRow("Bounded", boundedSpinner); String[] fonts = GraphicsEnvironment.getLocalGraphicsEnvironment().getAvailableFontFamilyNames(); JSpinner listSpinner = new JSpinner(new SpinnerListModel(fonts)); addRow("List", listSpinner); JSpinner reverseListSpinner = new JSpinner(new SpinnerListModel(fonts) { public Object getNextValue() { return super.getPreviousValue(); } public Object getPreviousValue() { return super.getNextValue(); } }); addRow("Reverse List", reverseListSpinner); JSpinner dateSpinner = new JSpinner(new SpinnerDateModel()); addRow("Date", dateSpinner); JSpinner betterDateSpinner = new JSpinner(new SpinnerDateModel()); String pattern = ((SimpleDateFormat) DateFormat.getDateInstance()).toPattern(); betterDateSpinner.setEditor(new JSpinner.DateEditor(betterDateSpinner, pattern)); addRow("Better Date", betterDateSpinner); JSpinner timeSpinner = new JSpinner(new SpinnerDateModel()); pattern = ((SimpleDateFormat) DateFormat.getTimeInstance(DateFormat.SHORT)).toPattern(); timeSpinner.setEditor(new JSpinner.DateEditor(timeSpinner, pattern)); addRow("Time", timeSpinner); JSpinner permSpinner = new JSpinner(new PermutationSpinnerModel("meat")); addRow("Word permutations", permSpinner); } /** * Adds a row to the main panel. * * @param labelText * the label of the spinner * @param spinner * the sample spinner */ public void addRow(String labelText, final JSpinner spinner) { mainPanel.add(new JLabel(labelText)); mainPanel.add(spinner); final JLabel valueLabel = new JLabel(); mainPanel.add(valueLabel); okButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent event) { Object value = spinner.getValue(); valueLabel.setText(value.toString()); } }); } public static final int DEFAULT_WIDTH = 400; public static final int DEFAULT_HEIGHT = 250; private JPanel mainPanel; private JButton okButton; } /** * A model that dynamically generates word permutations */ class PermutationSpinnerModel extends AbstractSpinnerModel { /** * Constructs the model. * * @param w * the word to permute */ public PermutationSpinnerModel(String w) { word = w; ChangeListener lis = new ChangeListener() { @Override public void stateChanged(ChangeEvent e) { System.out.println(e); } }; addChangeListener(lis); ChangeListener[] listeners = getListeners(ChangeListener.class); removeChangeListener(lis); } public Object getValue() { return word; } public void setValue(Object value) { if (!(value instanceof String)) throw new IllegalArgumentException(); word = (String) value; fireStateChanged(); } public Object getNextValue() { int[] codePoints = toCodePointArray(word); for (int i = codePoints.length - 1; i > 0; i--) { if (codePoints[i - 1] < codePoints[i]) { int j = codePoints.length - 1; while (codePoints[i - 1] > codePoints[j]) j--; swap(codePoints, i - 1, j); reverse(codePoints, i, codePoints.length - 1); return new String(codePoints, 0, codePoints.length); } } reverse(codePoints, 0, codePoints.length - 1); return new String(codePoints, 0, codePoints.length); } public Object getPreviousValue() { int[] codePoints = toCodePointArray(word); for (int i = codePoints.length - 1; i > 0; i--) { if (codePoints[i - 1] > codePoints[i]) { int j = codePoints.length - 1; while (codePoints[i - 1] < codePoints[j]) j--; swap(codePoints, i - 1, j); reverse(codePoints, i, codePoints.length - 1); return new String(codePoints, 0, codePoints.length); } } reverse(codePoints, 0, codePoints.length - 1); return new String(codePoints, 0, codePoints.length); } private static int[] toCodePointArray(String str) { int[] codePoints = new int[str.codePointCount(0, str.length())]; for (int i = 0, j = 0; i < str.length(); i++, j++) { int cp = str.codePointAt(i); if (Character.isSupplementaryCodePoint(cp)) i++; codePoints[j] = cp; } return codePoints; } private static void swap(int[] a, int i, int j) { int temp = a[i]; a[i] = a[j]; a[j] = temp; } private static void reverse(int[] a, int i, int j) { while (i < j) { swap(a, i, j); i++; j--; } } private String word; }