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; import javax.swing.*; import java.awt.*; import java.awt.event.*; /* * ListDialog.java is meant to be used by programs such as * ListDialogRunner. It requires no additional files. */ /** * Use this modal dialog to let the user choose one string from a long * list. See ListDialogRunner.java for an example of using ListDialog. * The basics: * <pre> String[] choices = {"A", "long", "array", "of", "strings"}; String selectedName = ListDialog.showDialog( componentInControllingFrame, locatorComponent, "A description of the list:", "Dialog Title", choices, choices[0]); * </pre> */ public class ListDialog extends JDialog implements ActionListener { private static ListDialog dialog; private static String value = ""; private JList list; /** * Set up and show the dialog. The first Component argument * determines which frame the dialog depends on; it should be * a component in the dialog's controlling frame. The second * Component argument should be null if you want the dialog * to come up with its left corner in the center of the screen; * otherwise, it should be the component on top of which the * dialog should appear. */ public static String showDialog(Component frameComp, Component locationComp, String labelText, String title, String[] possibleValues, String initialValue, String longValue) { Frame frame = JOptionPane.getFrameForComponent(frameComp); dialog = new ListDialog(frame, locationComp, labelText, title, possibleValues, initialValue, longValue); dialog.setVisible(true); return value; } private void setValue(String newValue) { value = newValue; list.setSelectedValue(value, true); } private ListDialog(Frame frame, Component locationComp, String labelText, String title, Object[] data, String initialValue, String longValue) { super(frame, title, true); //Create and initialize the buttons. JButton cancelButton = new JButton("Cancel"); cancelButton.addActionListener(this); // final JButton setButton = new JButton("Set"); setButton.setActionCommand("Set"); setButton.addActionListener(this); getRootPane().setDefaultButton(setButton); //main part of the dialog list = new JList(data) { //Subclass JList to workaround bug 4832765, which can cause the //scroll pane to not let the user easily scroll up to the beginning //of the list. An alternative would be to set the unitIncrement //of the JScrollBar to a fixed value. You wouldn't get the nice //aligned scrolling, but it should work. public int getScrollableUnitIncrement(Rectangle visibleRect, int orientation, int direction) { int row; if (orientation == SwingConstants.VERTICAL && direction < 0 && (row = getFirstVisibleIndex()) != -1) { Rectangle r = getCellBounds(row, row); if ((r.y == visibleRect.y) && (row != 0)) { Point loc = r.getLocation(); loc.y--; int prevIndex = locationToIndex(loc); Rectangle prevR = getCellBounds(prevIndex, prevIndex); if (prevR == null || prevR.y >= r.y) { return 0; } return prevR.height; } } return super.getScrollableUnitIncrement(visibleRect, orientation, direction); } }; list.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION); if (longValue != null) { list.setPrototypeCellValue(longValue); //get extra space } list.setLayoutOrientation(JList.HORIZONTAL_WRAP); list.setVisibleRowCount(-1); list.addMouseListener(new MouseAdapter() { public void mouseClicked(MouseEvent e) { if (e.getClickCount() == 2) { setButton.doClick(); //emulate button click } } }); JScrollPane listScroller = new JScrollPane(list); listScroller.setPreferredSize(new Dimension(250, 80)); listScroller.setAlignmentX(LEFT_ALIGNMENT); //Create a container so that we can add a title around //the scroll pane. Can't add a title directly to the //scroll pane because its background would be white. //Lay out the label and scroll pane from top to bottom. JPanel listPane = new JPanel(); listPane.setLayout(new BoxLayout(listPane, BoxLayout.PAGE_AXIS)); JLabel label = new JLabel(labelText); label.setLabelFor(list); listPane.add(label); listPane.add(Box.createRigidArea(new Dimension(0, 5))); listPane.add(listScroller); listPane.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10)); //Lay out the buttons from left to right. JPanel buttonPane = new JPanel(); buttonPane.setLayout(new BoxLayout(buttonPane, BoxLayout.LINE_AXIS)); buttonPane.setBorder(BorderFactory.createEmptyBorder(0, 10, 10, 10)); buttonPane.add(Box.createHorizontalGlue()); buttonPane.add(cancelButton); buttonPane.add(Box.createRigidArea(new Dimension(10, 0))); buttonPane.add(setButton); //Put everything together, using the content pane's BorderLayout. Container contentPane = getContentPane(); contentPane.add(listPane, BorderLayout.CENTER); contentPane.add(buttonPane, BorderLayout.PAGE_END); //Initialize values. setValue(initialValue); pack(); setLocationRelativeTo(locationComp); } //Handle clicks on the Set and Cancel buttons. public void actionPerformed(ActionEvent e) { if ("Set".equals(e.getActionCommand())) { ListDialog.value = (String) (list.getSelectedValue()); } ListDialog.dialog.setVisible(false); } }