Java tutorial
/* * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.swing; import java.awt.*; import java.awt.event.*; import java.awt.image.*; import java.io.Serializable; import java.util.EventListener; import javax.swing.event.*; /** * The default implementation of a <code>Button</code> component's data model. * <p> * <strong>Warning:</strong> * Serialized objects of this class will not be compatible with * future Swing releases. The current serialization support is * appropriate for short term storage or RMI between applications running * the same version of Swing. As of 1.4, support for long term storage * of all JavaBeans™ * has been added to the <code>java.beans</code> package. * Please see {@link java.beans.XMLEncoder}. * * @author Jeff Dinkins * @since 1.2 */ @SuppressWarnings("serial") // Same-version serialization only public class DefaultButtonModel implements ButtonModel, Serializable { /** The bitmask used to store the state of the button. */ protected int stateMask = 0; /** The action command string fired by the button. */ protected String actionCommand = null; /** The button group that the button belongs to. */ protected ButtonGroup group = null; /** The button's mnemonic. */ protected int mnemonic = 0; /** * Only one <code>ChangeEvent</code> is needed per button model * instance since the event's only state is the source property. * The source of events generated is always "this". */ protected transient ChangeEvent changeEvent = null; /** Stores the listeners on this model. */ protected EventListenerList listenerList = new EventListenerList(); // controls the usage of the MenuItem.disabledAreNavigable UIDefaults // property in the setArmed() method private boolean menuItem = false; /** * Constructs a <code>DefaultButtonModel</code>. * */ public DefaultButtonModel() { stateMask = 0; setEnabled(true); } /** * Identifies the "armed" bit in the bitmask, which * indicates partial commitment towards choosing/triggering * the button. */ public static final int ARMED = 1 << 0; /** * Identifies the "selected" bit in the bitmask, which * indicates that the button has been selected. Only needed for * certain types of buttons - such as radio button or check box. */ public static final int SELECTED = 1 << 1; /** * Identifies the "pressed" bit in the bitmask, which * indicates that the button is pressed. */ public static final int PRESSED = 1 << 2; /** * Identifies the "enabled" bit in the bitmask, which * indicates that the button can be selected by * an input device (such as a mouse pointer). */ public static final int ENABLED = 1 << 3; /** * Identifies the "rollover" bit in the bitmask, which * indicates that the mouse is over the button. */ public static final int ROLLOVER = 1 << 4; /** * {@inheritDoc} */ public void setActionCommand(String actionCommand) { this.actionCommand = actionCommand; } /** * {@inheritDoc} */ public String getActionCommand() { return actionCommand; } /** * {@inheritDoc} */ public boolean isArmed() { return (stateMask & ARMED) != 0; } /** * {@inheritDoc} */ public boolean isSelected() { return (stateMask & SELECTED) != 0; } /** * {@inheritDoc} */ public boolean isEnabled() { return (stateMask & ENABLED) != 0; } /** * {@inheritDoc} */ public boolean isPressed() { return (stateMask & PRESSED) != 0; } /** * {@inheritDoc} */ public boolean isRollover() { return (stateMask & ROLLOVER) != 0; } /** * {@inheritDoc} */ public void setArmed(boolean b) { if (isMenuItem() && UIManager.getBoolean("MenuItem.disabledAreNavigable")) { if ((isArmed() == b)) { return; } } else { if ((isArmed() == b) || !isEnabled()) { return; } } if (b) { stateMask |= ARMED; } else { stateMask &= ~ARMED; } fireStateChanged(); } /** * {@inheritDoc} */ public void setEnabled(boolean b) { if (isEnabled() == b) { return; } if (b) { stateMask |= ENABLED; } else { stateMask &= ~ENABLED; // unarm and unpress, just in case stateMask &= ~ARMED; stateMask &= ~PRESSED; } fireStateChanged(); } /** * {@inheritDoc} */ public void setSelected(boolean b) { if (this.isSelected() == b) { return; } if (b) { stateMask |= SELECTED; } else { stateMask &= ~SELECTED; } fireItemStateChanged(new ItemEvent(this, ItemEvent.ITEM_STATE_CHANGED, this, b ? ItemEvent.SELECTED : ItemEvent.DESELECTED)); fireStateChanged(); } /** * {@inheritDoc} */ @SuppressWarnings("deprecation") public void setPressed(boolean b) { if ((isPressed() == b) || !isEnabled()) { return; } if (b) { stateMask |= PRESSED; } else { stateMask &= ~PRESSED; } if (!isPressed() && isArmed()) { int modifiers = 0; AWTEvent currentEvent = EventQueue.getCurrentEvent(); if (currentEvent instanceof InputEvent) { modifiers = ((InputEvent) currentEvent).getModifiers(); } else if (currentEvent instanceof ActionEvent) { modifiers = ((ActionEvent) currentEvent).getModifiers(); } fireActionPerformed(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, getActionCommand(), EventQueue.getMostRecentEventTime(), modifiers)); } fireStateChanged(); } /** * {@inheritDoc} */ public void setRollover(boolean b) { if ((isRollover() == b) || !isEnabled()) { return; } if (b) { stateMask |= ROLLOVER; } else { stateMask &= ~ROLLOVER; } fireStateChanged(); } /** * {@inheritDoc} */ public void setMnemonic(int key) { mnemonic = key; fireStateChanged(); } /** * {@inheritDoc} */ public int getMnemonic() { return mnemonic; } /** * {@inheritDoc} */ public void addChangeListener(ChangeListener l) { listenerList.add(ChangeListener.class, l); } /** * {@inheritDoc} */ public void removeChangeListener(ChangeListener l) { listenerList.remove(ChangeListener.class, l); } /** * Returns an array of all the change listeners * registered on this <code>DefaultButtonModel</code>. * * @return all of this model's <code>ChangeListener</code>s * or an empty * array if no change listeners are currently registered * * @see #addChangeListener * @see #removeChangeListener * * @since 1.4 */ public ChangeListener[] getChangeListeners() { return listenerList.getListeners(ChangeListener.class); } /** * Notifies all listeners that have registered interest for * notification on this event type. The event instance * is created lazily. * * @see EventListenerList */ protected void fireStateChanged() { // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ChangeListener.class) { // Lazily create the event: if (changeEvent == null) changeEvent = new ChangeEvent(this); ((ChangeListener) listeners[i + 1]).stateChanged(changeEvent); } } } /** * {@inheritDoc} */ public void addActionListener(ActionListener l) { listenerList.add(ActionListener.class, l); } /** * {@inheritDoc} */ public void removeActionListener(ActionListener l) { listenerList.remove(ActionListener.class, l); } /** * Returns an array of all the action listeners * registered on this <code>DefaultButtonModel</code>. * * @return all of this model's <code>ActionListener</code>s * or an empty * array if no action listeners are currently registered * * @see #addActionListener * @see #removeActionListener * * @since 1.4 */ public ActionListener[] getActionListeners() { return listenerList.getListeners(ActionListener.class); } /** * Notifies all listeners that have registered interest for * notification on this event type. * * @param e the <code>ActionEvent</code> to deliver to listeners * @see EventListenerList */ protected void fireActionPerformed(ActionEvent e) { // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ActionListener.class) { // Lazily create the event: // if (changeEvent == null) // changeEvent = new ChangeEvent(this); ((ActionListener) listeners[i + 1]).actionPerformed(e); } } } /** * {@inheritDoc} */ public void addItemListener(ItemListener l) { listenerList.add(ItemListener.class, l); } /** * {@inheritDoc} */ public void removeItemListener(ItemListener l) { listenerList.remove(ItemListener.class, l); } /** * Returns an array of all the item listeners * registered on this <code>DefaultButtonModel</code>. * * @return all of this model's <code>ItemListener</code>s * or an empty * array if no item listeners are currently registered * * @see #addItemListener * @see #removeItemListener * * @since 1.4 */ public ItemListener[] getItemListeners() { return listenerList.getListeners(ItemListener.class); } /** * Notifies all listeners that have registered interest for * notification on this event type. * * @param e the <code>ItemEvent</code> to deliver to listeners * @see EventListenerList */ protected void fireItemStateChanged(ItemEvent e) { // Guaranteed to return a non-null array Object[] listeners = listenerList.getListenerList(); // Process the listeners last to first, notifying // those that are interested in this event for (int i = listeners.length - 2; i >= 0; i -= 2) { if (listeners[i] == ItemListener.class) { // Lazily create the event: // if (changeEvent == null) // changeEvent = new ChangeEvent(this); ((ItemListener) listeners[i + 1]).itemStateChanged(e); } } } /** * Returns an array of all the objects currently registered as * <code><em>Foo</em>Listener</code>s * upon this model. * <code><em>Foo</em>Listener</code>s * are registered using the <code>add<em>Foo</em>Listener</code> method. * <p> * You can specify the <code>listenerType</code> argument * with a class literal, such as <code><em>Foo</em>Listener.class</code>. * For example, you can query a <code>DefaultButtonModel</code> * instance <code>m</code> * for its action listeners * with the following code: * * <pre>ActionListener[] als = (ActionListener[])(m.getListeners(ActionListener.class));</pre> * * If no such listeners exist, * this method returns an empty array. * * @param <T> the type of requested listeners * @param listenerType the type of listeners requested; * this parameter should specify an interface * that descends from <code>java.util.EventListener</code> * @return an array of all objects registered as * <code><em>Foo</em>Listener</code>s * on this model, * or an empty array if no such * listeners have been added * @exception ClassCastException if <code>listenerType</code> doesn't * specify a class or interface that implements * <code>java.util.EventListener</code> * * @see #getActionListeners * @see #getChangeListeners * @see #getItemListeners * * @since 1.3 */ public <T extends EventListener> T[] getListeners(Class<T> listenerType) { return listenerList.getListeners(listenerType); } /** Overridden to return <code>null</code>. */ public Object[] getSelectedObjects() { return null; } /** * {@inheritDoc} */ public void setGroup(ButtonGroup group) { this.group = group; } /** * Returns the group that the button belongs to. * Normally used with radio buttons, which are mutually * exclusive within their group. * * @return the <code>ButtonGroup</code> that the button belongs to * * @since 1.3 */ public ButtonGroup getGroup() { return group; } boolean isMenuItem() { return menuItem; } void setMenuItem(boolean menuItem) { this.menuItem = menuItem; } }