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 components; /* * A 1.4 class used by the Converter example. */ import javax.swing.*; import javax.swing.event.*; import java.awt.*; import java.awt.event.*; import java.util.*; import java.text.NumberFormat; import javax.swing.text.NumberFormatter; import java.beans.*; //property change stuff public class ConversionPanel extends JPanel implements ActionListener, ChangeListener, PropertyChangeListener { JFormattedTextField textField; JComboBox unitChooser; JSlider slider; ConverterRangeModel sliderModel; Converter controller; Unit[] units; String title; NumberFormat numberFormat; final static boolean MULTICOLORED = false; final static int MAX = 10000; ConversionPanel(Converter myController, String myTitle, Unit[] myUnits, ConverterRangeModel myModel) { if (MULTICOLORED) { setOpaque(true); setBackground(new Color(0, 255, 255)); } setBorder(BorderFactory.createCompoundBorder(BorderFactory.createTitledBorder(myTitle), BorderFactory.createEmptyBorder(5, 5, 5, 5))); //Save arguments in instance variables. controller = myController; units = myUnits; title = myTitle; sliderModel = myModel; //Create the text field format, and then the text field. numberFormat = NumberFormat.getNumberInstance(); numberFormat.setMaximumFractionDigits(2); NumberFormatter formatter = new NumberFormatter(numberFormat); formatter.setAllowsInvalid(false); formatter.setCommitsOnValidEdit(true);//seems to be a no-op -- //aha -- it changes the value property but doesn't cause the result to //be parsed (that happens on focus loss/return, I think). // textField = new JFormattedTextField(formatter); textField.setColumns(10); textField.setValue(new Double(sliderModel.getDoubleValue())); textField.addPropertyChangeListener(this); //Add the combo box. unitChooser = new JComboBox(); for (int i = 0; i < units.length; i++) { //Populate it. unitChooser.addItem(units[i].description); } unitChooser.setSelectedIndex(0); sliderModel.setMultiplier(units[0].multiplier); unitChooser.addActionListener(this); //Add the slider. slider = new JSlider(sliderModel); sliderModel.addChangeListener(this); //Make the text field/slider group a fixed size //to make stacked ConversionPanels nicely aligned. JPanel unitGroup = new JPanel() { public Dimension getMinimumSize() { return getPreferredSize(); } public Dimension getPreferredSize() { return new Dimension(150, super.getPreferredSize().height); } public Dimension getMaximumSize() { return getPreferredSize(); } }; unitGroup.setLayout(new BoxLayout(unitGroup, BoxLayout.PAGE_AXIS)); if (MULTICOLORED) { unitGroup.setOpaque(true); unitGroup.setBackground(new Color(0, 0, 255)); } unitGroup.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 5)); unitGroup.add(textField); unitGroup.add(slider); //Create a subpanel so the combo box isn't too tall //and is sufficiently wide. JPanel chooserPanel = new JPanel(); chooserPanel.setLayout(new BoxLayout(chooserPanel, BoxLayout.PAGE_AXIS)); if (MULTICOLORED) { chooserPanel.setOpaque(true); chooserPanel.setBackground(new Color(255, 0, 255)); } chooserPanel.add(unitChooser); chooserPanel.add(Box.createHorizontalStrut(100)); //Put everything together. setLayout(new BoxLayout(this, BoxLayout.LINE_AXIS)); add(unitGroup); add(chooserPanel); unitGroup.setAlignmentY(TOP_ALIGNMENT); chooserPanel.setAlignmentY(TOP_ALIGNMENT); } //Don't allow this panel to get taller than its preferred size. //BoxLayout pays attention to maximum size, though most layout //managers don't. public Dimension getMaximumSize() { return new Dimension(Integer.MAX_VALUE, getPreferredSize().height); } /** * Returns the multiplier (units/meter) for the currently * selected unit of measurement. */ public double getMultiplier() { return sliderModel.getMultiplier(); } public double getValue() { return sliderModel.getDoubleValue(); } /** Updates the text field when the main data model is updated. */ public void stateChanged(ChangeEvent e) { int min = sliderModel.getMinimum(); int max = sliderModel.getMaximum(); double value = sliderModel.getDoubleValue(); NumberFormatter formatter = (NumberFormatter) textField.getFormatter(); formatter.setMinimum(new Double(min)); formatter.setMaximum(new Double(max)); textField.setValue(new Double(value)); } /** * Responds to the user choosing a new unit from the combo box. */ public void actionPerformed(ActionEvent e) { //Combo box event. Set new maximums for the sliders. int i = unitChooser.getSelectedIndex(); sliderModel.setMultiplier(units[i].multiplier); controller.resetMaxValues(false); } /** * Detects when the value of the text field (not necessarily the same * number as you'd get from getText) changes. */ public void propertyChange(PropertyChangeEvent e) { if ("value".equals(e.getPropertyName())) { Number value = (Number) e.getNewValue(); sliderModel.setDoubleValue(value.doubleValue()); } } }