javax.swing.JPasswordField#setForeground ( )源码实例Demo

/**
 * Create a single-line password box with the specified name, label, and
 * default value. To control the width of the box, call setTextWidth()
 * first. To get the value, call getCharArrayValue(). Calling
 * getStringValue() on a password entry will result in an error because it
 * is less secure to pass around passwords as Strings than as arrays of
 * characters.
 * <p>
 * The underlying class that is used to implement the password facility is
 * javax.swing.JPasswordField. For details about how to use JPasswordField,
 * see the <a href=
 * "http://java.sun.com/docs/books/tutorial/uiswing/components/passwordfield.html"
 * target="_top">Java Tutorial</a>
 * 
 * @param name
 *            The name used to identify the entry (when accessing the
 *            entry).
 * @param label
 *            The label to attach to the entry.
 * @param defaultValue
 *            Default value to appear in the entry box.
 * @param background
 *            The background color.
 * @param foreground
 *            The foreground color.
 * @since Ptolemy II 3.1
 */
public void addPassword(String name, String label, String defaultValue, Color background, Color foreground) {
	JLabel lbl = new JLabel(label + ": ");
	lbl.setBackground(_background);

	JPasswordField entryBox = new JPasswordField(defaultValue, _width);
	entryBox.setBackground(background);
	entryBox.setForeground(foreground);
	_addPair(name, lbl, entryBox, entryBox);

	// Add the listener last so that there is no notification
	// of the first value.
	entryBox.addActionListener(new QueryActionListener(name));

	// Add a listener for loss of focus. When the entry gains
	// and then loses focus, listeners are notified of an update,
	// but only if the value has changed since the last notification.
	// FIXME: Unfortunately, Java calls this listener some random
	// time after the window has been closed. It is not even a
	// a queued event when the window is closed. Thus, we have
	// a subtle bug where if you enter a value in a line, do not
	// hit return, and then click on the X to close the window,
	// the value is restored to the original, and then sometime
	// later, the focus is lost and the entered value becomes
	// the value of the parameter. I don't know of any workaround.
	entryBox.addFocusListener(new QueryFocusListener(name));
}