import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
/**
* Use this modal dialog to let the user choose one string from a long
* list. See the main method for an example of using ListDialog. The
* basics:
* <pre>
String[] choices = {"A", "long", "array", "of", "strings"};
ListDialog.initialize(componentInControllingFrame, choices,
"Dialog Title",
"A description of the list:");
String selectedName = ListDialog.showDialog(locatorComponent,
initialSelection);
* </pre>
*/
public class ListDialog extends JDialog {
private static ListDialog dialog;
private static String value = "";
private JList list;
/**
* Set up the dialog. The first argument can be null,
* but it really should be a component in the dialog's
* controlling frame.
*/
public static void initialize(Component comp,
String[] possibleValues,
String title,
String labelText) {
Frame frame = JOptionPane.getFrameForComponent(comp);
dialog = new ListDialog(frame, possibleValues,
title, labelText);
}
/**
* Show the initialized dialog. The first argument should
* be null if you want the dialog to come up in the center
* of the screen. Otherwise, the argument should be the
* component on top of which the dialog should appear.
*/
public static String showDialog(Component comp, String initialValue) {
if (dialog != null) {
dialog.setValue(initialValue);
dialog.setLocationRelativeTo(comp);
dialog.setVisible(true);
} else {
System.err.println("ListDialog requires you to call initialize "
+ "before calling showDialog.");
}
return value;
}
private void setValue(String newValue) {
value = newValue;
list.setSelectedValue(value, true);
}
private ListDialog(Frame frame, Object[] data, String title,
String labelText) {
super(frame, title, true);
//buttons
JButton cancelButton = new JButton("Cancel");
final JButton setButton = new JButton("Set");
cancelButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ListDialog.dialog.setVisible(false);
}
});
setButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
ListDialog.value = (String)(list.getSelectedValue());
ListDialog.dialog.setVisible(false);
}
});
getRootPane().setDefaultButton(setButton);
//main part of the dialog
list = new JList(data);
list.setSelectionMode(ListSelectionModel.SINGLE_INTERVAL_SELECTION);
list.addMouseListener(new MouseAdapter() {
public void mouseClicked(MouseEvent e) {
if (e.getClickCount() == 2) {
setButton.doClick();
}
}
});
JScrollPane listScroller = new JScrollPane(list);
listScroller.setPreferredSize(new Dimension(250, 80));
//XXX: Must do the following, too, or else the scroller thinks
//XXX: it's taller than it is:
listScroller.setMinimumSize(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 button.
JPanel listPane = new JPanel();
listPane.setLayout(new BoxLayout(listPane, BoxLayout.Y_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.X_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.SOUTH);
pack();
}
/**
* This is here so that you can view ListDialog even if you
* haven't written the code to include it in a program.
*/
public static void main(String[] args) {
String[] names = {"Arlo", "Cosmo", "Elmo", "Hugo",
"Jethro", "Laszlo", "Milo", "Nemo",
"Otto", "Ringo", "Rocco", "Rollo"};
JFrame f = new JFrame("Name That Baby");
f.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
JLabel intro = new JLabel("The chosen name:");
final JLabel name = new JLabel("Cosmo");
intro.setLabelFor(name);
name.setForeground(Color.black);
JButton button = new JButton("Pick a new name...");
ListDialog.initialize(f, names, "Name Chooser",
"Baby names ending in O:");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String selectedName = ListDialog.showDialog(null,
name.getText());
name.setText(selectedName);
}
});
JPanel contentPane = new JPanel();
f.setContentPane(contentPane);
contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.Y_AXIS));
contentPane.setBorder(BorderFactory.createEmptyBorder(20,20,20,20));
contentPane.add(intro);
contentPane.add(name);
contentPane.add(Box.createRigidArea(new Dimension(0,10)));
contentPane.add(button);
intro.setAlignmentX(JComponent.CENTER_ALIGNMENT);
name.setAlignmentX(JComponent.CENTER_ALIGNMENT);
button.setAlignmentX(JComponent.CENTER_ALIGNMENT);
f.pack();
f.setVisible(true);
}
}
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