/*

 * 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.util.HashSet;

import java.util.Hashtable;

import java.util.Dictionary;

import java.util.Enumeration;

import java.util.Locale;

import java.util.Vector;

import java.util.EventListener;

import java.util.Set;

import java.util.Map;

import java.util.HashMap;

import java.awt.*;

import java.awt.event.*;

import java.awt.image.VolatileImage;

import java.awt.Graphics2D;

import java.awt.peer.LightweightPeer;

import java.awt.dnd.DropTarget;

import java.awt.font.FontRenderContext;

import java.beans.PropertyChangeListener;

import java.beans.VetoableChangeListener;

import java.beans.VetoableChangeSupport;

import java.beans.Transient;

import java.applet.Applet;

import java.io.Serializable;

import java.io.ObjectOutputStream;

import java.io.ObjectInputStream;

import java.io.IOException;

import java.io.ObjectInputValidation;

import java.io.InvalidObjectException;

import javax.swing.border.*;

import javax.swing.event.*;

import javax.swing.plaf.*;

import static javax.swing.ClientPropertyKey.*;

import javax.accessibility.*;

import sun.awt.SunToolkit;

import sun.swing.SwingUtilities2;

import sun.swing.UIClientPropertyKey;

/**

 * The base class for all Swing components except top-level containers.

 * To use a component that inherits from <code>JComponent</code>,

 * you must place the component in a containment hierarchy

 * whose root is a top-level Swing container.

 * Top-level Swing containers --

 * such as <code>JFrame</code>, <code>JDialog</code>,

 * and <code>JApplet</code> --

 * are specialized components

 * that provide a place for other Swing components to paint themselves.

 * For an explanation of containment hierarchies, see

 * <a

 href="http://docs.oracle.com/javase/tutorial/uiswing/components/toplevel.html">Swing Components and the Containment Hierarchy</a>,

 * a section in <em>The Java Tutorial</em>.

 *

 * <p>

 * The <code>JComponent</code> class provides:

 * <ul>

 * <li>The base class for both standard and custom components

 *     that use the Swing architecture.

 * <li>A "pluggable look and feel" (L&amp;F) that can be specified by the

 *     programmer or (optionally) selected by the user at runtime.

 *     The look and feel for each component is provided by a

 *     <em>UI delegate</em> -- an object that descends from

 *     {@link javax.swing.plaf.ComponentUI}.

 *     See <a

 * href="http://docs.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html">How

 *     to Set the Look and Feel</a>

 *     in <em>The Java Tutorial</em>

 *     for more information.

 * <li>Comprehensive keystroke handling.

 *     See the document <a

 * href="http://docs.oracle.com/javase/tutorial/uiswing/misc/keybinding.html">How to Use Key Bindings</a>,

 *     an article in <em>The Java Tutorial</em>,

 *     for more information.

 * <li>Support for tool tips --

 *     short descriptions that pop up when the cursor lingers

 *     over a component.

 *     See <a

 * href="http://docs.oracle.com/javase/tutorial/uiswing/components/tooltip.html">How

 *     to Use Tool Tips</a>

 *     in <em>The Java Tutorial</em>

 *     for more information.

 * <li>Support for accessibility.

 *     <code>JComponent</code> contains all of the methods in the

 *     <code>Accessible</code> interface,

 *     but it doesn't actually implement the interface.  That is the

 *     responsibility of the individual classes

 *     that extend <code>JComponent</code>.

 * <li>Support for component-specific properties.

 *     With the {@link #putClientProperty}

 *     and {@link #getClientProperty} methods,

 *     you can associate name-object pairs

 *     with any object that descends from <code>JComponent</code>.

 * <li>An infrastructure for painting

 *     that includes double buffering and support for borders.

 *     For more information see <a

 * href="http://www.oracle.com/technetwork/java/painting-140037.html#swing">Painting</a> and

 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/components/border.htmll">How

 *     to Use Borders</a>,

 *     both of which are sections in <em>The Java Tutorial</em>.

 * </ul>

 * For more information on these subjects, see the

 * <a href="package-summary.html#package_description">Swing package description</a>

 * and <em>The Java Tutorial</em> section

 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/components/jcomponent.html">The JComponent Class</a>.

 * <p>

 * <code>JComponent</code> and its subclasses document default values

 * for certain properties.  For example, <code>JTable</code> documents the

 * default row height as 16.  Each <code>JComponent</code> subclass

 * that has a <code>ComponentUI</code> will create the

 * <code>ComponentUI</code> as part of its constructor.  In order

 * to provide a particular look and feel each

 * <code>ComponentUI</code> may set properties back on the

 * <code>JComponent</code> that created it.  For example, a custom

 * look and feel may require <code>JTable</code>s to have a row

 * height of 24. The documented defaults are the value of a property

 * BEFORE the <code>ComponentUI</code> has been installed.  If you

 * need a specific value for a particular property you should

 * explicitly set it.

 * <p>

 * In release 1.4, the focus subsystem was rearchitected.

 * For more information, see

 * <a href="http://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">

 * How to Use the Focus Subsystem</a>,

 * a section in <em>The Java Tutorial</em>.

 * <p>

 * <strong>Warning:</strong> Swing is not thread safe. For more

 * information see <a

 * href="package-summary.html#threading">Swing's Threading

 * Policy</a>.

 * <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}.

 *

 * @see KeyStroke

 * @see Action

 * @see #setBorder

 * @see #registerKeyboardAction

 * @see JOptionPane

 * @see #setDebugGraphicsOptions

 * @see #setToolTipText

 * @see #setAutoscrolls

 *

 * @author Hans Muller

 * @author Arnaud Weber

 * @since 1.2

 */

@SuppressWarnings("serial") // Same-version serialization only

public abstract class JComponent extends Container implements Serializable,

                                              TransferHandler.HasGetTransferHandler

{

    /**

     * @see #getUIClassID

     * @see #writeObject

     */

    private static final String uiClassID = "ComponentUI";

    /**

     * @see #readObject

     */

    private static final Hashtable<ObjectInputStream, ReadObjectCallback> readObjectCallbacks =

            new Hashtable<ObjectInputStream, ReadObjectCallback>(1);

    /**

     * Keys to use for forward focus traversal when the JComponent is

     * managing focus.

     */

    private static Set<KeyStroke> managingFocusForwardTraversalKeys;

    /**

     * Keys to use for backward focus traversal when the JComponent is

     * managing focus.

     */

    private static Set<KeyStroke> managingFocusBackwardTraversalKeys;

    // Following are the possible return values from getObscuredState.

    private static final int NOT_OBSCURED = 0;

    private static final int PARTIALLY_OBSCURED = 1;

    private static final int COMPLETELY_OBSCURED = 2;

    /**

     * Set to true when DebugGraphics has been loaded.

     */

    static boolean DEBUG_GRAPHICS_LOADED;

    /**

     * Key used to look up a value from the AppContext to determine the

     * JComponent the InputVerifier is running for. That is, if

     * AppContext.get(INPUT_VERIFIER_SOURCE_KEY) returns non-null, it

     * indicates the EDT is calling into the InputVerifier from the

     * returned component.

     */

    private static final Object INPUT_VERIFIER_SOURCE_KEY =

            new StringBuilder("InputVerifierSourceKey");

    /* The following fields support set methods for the corresponding

     * java.awt.Component properties.

     */

    private boolean isAlignmentXSet;

    private float alignmentX;

    private boolean isAlignmentYSet;

    private float alignmentY;

    /**

     * Backing store for JComponent properties and listeners

     */

    /** The look and feel delegate for this component. */

    protected transient ComponentUI ui;

    /** A list of event listeners for this component. */

    protected EventListenerList listenerList = new EventListenerList();

    private transient ArrayTable clientProperties;

    private VetoableChangeSupport vetoableChangeSupport;

    /**

     * Whether or not autoscroll has been enabled.

     */

    private boolean autoscrolls;

    private Border border;

    private int flags;

    /* Input verifier for this component */

    private InputVerifier inputVerifier = null;

    private boolean verifyInputWhenFocusTarget = true;

    /**

     * Set in <code>_paintImmediately</code>.

     * Will indicate the child that initiated the painting operation.

     * If <code>paintingChild</code> is opaque, no need to paint

     * any child components after <code>paintingChild</code>.

     * Test used in <code>paintChildren</code>.

     */

    transient Component         paintingChild;

    /**

     * Constant used for <code>registerKeyboardAction</code> that

     * means that the command should be invoked when

     * the component has the focus.

     */

    public static final int WHEN_FOCUSED = 0;

    /**

     * Constant used for <code>registerKeyboardAction</code> that

     * means that the command should be invoked when the receiving

     * component is an ancestor of the focused component or is

     * itself the focused component.

     */

    public static final int WHEN_ANCESTOR_OF_FOCUSED_COMPONENT = 1;

    /**

     * Constant used for <code>registerKeyboardAction</code> that

     * means that the command should be invoked when

     * the receiving component is in the window that has the focus

     * or is itself the focused component.

     */

    public static final int WHEN_IN_FOCUSED_WINDOW = 2;

    /**

     * Constant used by some of the APIs to mean that no condition is defined.

     */

    public static final int UNDEFINED_CONDITION = -1;

    /**

     * The key used by <code>JComponent</code> to access keyboard bindings.

     */

    private static final String KEYBOARD_BINDINGS_KEY = "_KeyboardBindings";

    /**

     * An array of <code>KeyStroke</code>s used for

     * <code>WHEN_IN_FOCUSED_WINDOW</code> are stashed

     * in the client properties under this string.

     */

    private static final String WHEN_IN_FOCUSED_WINDOW_BINDINGS = "_WhenInFocusedWindow";

    /**

     * The comment to display when the cursor is over the component,

     * also known as a "value tip", "flyover help", or "flyover label".

     */

    public static final String TOOL_TIP_TEXT_KEY = "ToolTipText";

    private static final String NEXT_FOCUS = "nextFocus";

    /**

     * <code>JPopupMenu</code> assigned to this component

     * and all of its children

     */

    private JPopupMenu popupMenu;

    /** Private flags **/

    private static final int IS_DOUBLE_BUFFERED                       =  0;

    private static final int ANCESTOR_USING_BUFFER                    =  1;

    private static final int IS_PAINTING_TILE                         =  2;

    private static final int IS_OPAQUE                                =  3;

    private static final int KEY_EVENTS_ENABLED                       =  4;

    private static final int FOCUS_INPUTMAP_CREATED                   =  5;

    private static final int ANCESTOR_INPUTMAP_CREATED                =  6;

    private static final int WIF_INPUTMAP_CREATED                     =  7;

    private static final int ACTIONMAP_CREATED                        =  8;

    private static final int CREATED_DOUBLE_BUFFER                    =  9;

    // bit 10 is free

    private static final int IS_PRINTING                              = 11;

    private static final int IS_PRINTING_ALL                          = 12;

    private static final int IS_REPAINTING                            = 13;

    /** Bits 14-21 are used to handle nested writeObject calls. **/

    private static final int WRITE_OBJ_COUNTER_FIRST                  = 14;

    private static final int RESERVED_1                               = 15;

    private static final int RESERVED_2                               = 16;

    private static final int RESERVED_3                               = 17;

    private static final int RESERVED_4                               = 18;

    private static final int RESERVED_5                               = 19;

    private static final int RESERVED_6                               = 20;

    private static final int WRITE_OBJ_COUNTER_LAST                   = 21;

    private static final int REQUEST_FOCUS_DISABLED                   = 22;

    private static final int INHERITS_POPUP_MENU                      = 23;

    private static final int OPAQUE_SET                               = 24;

    private static final int AUTOSCROLLS_SET                          = 25;

    private static final int FOCUS_TRAVERSAL_KEYS_FORWARD_SET         = 26;

    private static final int FOCUS_TRAVERSAL_KEYS_BACKWARD_SET        = 27;

    private static final int REVALIDATE_RUNNABLE_SCHEDULED            = 28;

    /**

     * Temporary rectangles.

     */

    private static java.util.List<Rectangle> tempRectangles = new java.util.ArrayList<Rectangle>(11);

    /** Used for <code>WHEN_FOCUSED</code> bindings. */

    private InputMap focusInputMap;

    /** Used for <code>WHEN_ANCESTOR_OF_FOCUSED_COMPONENT</code> bindings. */

    private InputMap ancestorInputMap;

    /** Used for <code>WHEN_IN_FOCUSED_KEY</code> bindings. */

    private ComponentInputMap windowInputMap;

    /** ActionMap. */

    private ActionMap actionMap;

    /** Key used to store the default locale in an AppContext **/

    private static final String defaultLocale = "JComponent.defaultLocale";

    private static Component componentObtainingGraphicsFrom;

    private static Object componentObtainingGraphicsFromLock = new

            StringBuilder("componentObtainingGraphicsFrom");

    /**

     * AA text hints.

     */

    transient private Object aaTextInfo;

    static Graphics safelyGetGraphics(Component c) {

        return safelyGetGraphics(c, SwingUtilities.getRoot(c));

    }

    static Graphics safelyGetGraphics(Component c, Component root) {

        synchronized(componentObtainingGraphicsFromLock) {

            componentObtainingGraphicsFrom = root;

            Graphics g = c.getGraphics();

            componentObtainingGraphicsFrom = null;

            return g;

        }

    }

    static void getGraphicsInvoked(Component root) {

        if (!JComponent.isComponentObtainingGraphicsFrom(root)) {

            JRootPane rootPane = ((RootPaneContainer)root).getRootPane();

            if (rootPane != null) {

                rootPane.disableTrueDoubleBuffering();

            }

        }

    }

    /**

     * Returns true if {@code c} is the component the graphics is being

     * requested of. This is intended for use when getGraphics is invoked.

     */

    private static boolean isComponentObtainingGraphicsFrom(Component c) {

        synchronized(componentObtainingGraphicsFromLock) {

            return (componentObtainingGraphicsFrom == c);

        }

    }

    /**

     * Returns the Set of <code>KeyStroke</code>s to use if the component

     * is managing focus for forward focus traversal.

     */

    static Set<KeyStroke> getManagingFocusForwardTraversalKeys() {

        synchronized(JComponent.class) {

            if (managingFocusForwardTraversalKeys == null) {

                managingFocusForwardTraversalKeys = new HashSet<KeyStroke>(1);

                managingFocusForwardTraversalKeys.add(

                    KeyStroke.getKeyStroke(KeyEvent.VK_TAB,

                                           InputEvent.CTRL_MASK));

            }

        }

        return managingFocusForwardTraversalKeys;

    }

    /**

     * Returns the Set of <code>KeyStroke</code>s to use if the component

     * is managing focus for backward focus traversal.

     */

    static Set<KeyStroke> getManagingFocusBackwardTraversalKeys() {

        synchronized(JComponent.class) {

            if (managingFocusBackwardTraversalKeys == null) {

                managingFocusBackwardTraversalKeys = new HashSet<KeyStroke>(1);

                managingFocusBackwardTraversalKeys.add(

                    KeyStroke.getKeyStroke(KeyEvent.VK_TAB,

                                           InputEvent.SHIFT_MASK |

                                           InputEvent.CTRL_MASK));

            }

        }

        return managingFocusBackwardTraversalKeys;

    }

    private static Rectangle fetchRectangle() {

        synchronized(tempRectangles) {

            Rectangle rect;

            int size = tempRectangles.size();

            if (size > 0) {

                rect = tempRectangles.remove(size - 1);

            }

            else {

                rect = new Rectangle(0, 0, 0, 0);

            }

            return rect;

        }

    }

    private static void recycleRectangle(Rectangle rect) {

        synchronized(tempRectangles) {

            tempRectangles.add(rect);

        }

    }

    /**

     * Sets whether or not <code>getComponentPopupMenu</code> should delegate

     * to the parent if this component does not have a <code>JPopupMenu</code>

     * assigned to it.

     * <p>

     * The default value for this is false, but some <code>JComponent</code>

     * subclasses that are implemented as a number of <code>JComponent</code>s

     * may set this to true.

     * <p>

     * This is a bound property.

     *

     * @param value whether or not the JPopupMenu is inherited

     * @see #setComponentPopupMenu

     * @beaninfo

     *        bound: true

     *  description: Whether or not the JPopupMenu is inherited

     * @since 1.5

     */

    public void setInheritsPopupMenu(boolean value) {

        boolean oldValue = getFlag(INHERITS_POPUP_MENU);

        setFlag(INHERITS_POPUP_MENU, value);

        firePropertyChange("inheritsPopupMenu", oldValue, value);

    }

    /**

     * Returns true if the JPopupMenu should be inherited from the parent.

     *

     * @return true if the JPopupMenu should be inherited from the parent

     * @see #setComponentPopupMenu

     * @since 1.5

     */

    public boolean getInheritsPopupMenu() {

        return getFlag(INHERITS_POPUP_MENU);

    }

    /**

     * Sets the <code>JPopupMenu</code> for this <code>JComponent</code>.

     * The UI is responsible for registering bindings and adding the necessary

     * listeners such that the <code>JPopupMenu</code> will be shown at

     * the appropriate time. When the <code>JPopupMenu</code> is shown

     * depends upon the look and feel: some may show it on a mouse event,

     * some may enable a key binding.

     * <p>

     * If <code>popup</code> is null, and <code>getInheritsPopupMenu</code>

     * returns true, then <code>getComponentPopupMenu</code> will be delegated

     * to the parent. This provides for a way to make all child components

     * inherit the popupmenu of the parent.

     * <p>

     * This is a bound property.

     *

     * @param popup - the popup that will be assigned to this component

     *                may be null