/*

 * Copyright 1997-2006 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.swing.text;

import java.lang.reflect.Method;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.Collections;

import java.util.HashMap;

import java.util.Hashtable;

import java.util.Enumeration;

import java.util.Vector;

import java.util.Iterator;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

import java.util.concurrent.*;

import java.io.*;

import java.awt.*;

import java.awt.event.*;

import java.awt.print.*;

import java.awt.datatransfer.*;

import java.awt.im.InputContext;

import java.awt.im.InputMethodRequests;

import java.awt.font.TextHitInfo;

import java.awt.font.TextAttribute;

import java.awt.print.Printable;

import java.awt.print.PrinterException;

import javax.print.PrintService;

import javax.print.attribute.PrintRequestAttributeSet;

import java.text.*;

import java.text.AttributedCharacterIterator.Attribute;

import javax.swing.*;

import javax.swing.event.*;

import javax.swing.plaf.*;

import javax.accessibility.*;

import javax.print.attribute.*;

import sun.awt.AppContext;

import sun.swing.PrintingStatus;

import sun.swing.SwingUtilities2;

import sun.swing.text.TextComponentPrintable;

/**

 * <code>JTextComponent</code> is the base class for swing text

 * components.  It tries to be compatible with the

 * <code>java.awt.TextComponent</code> class

 * where it can reasonably do so.  Also provided are other services

 * for additional flexibility (beyond the pluggable UI and bean

 * support).

 * You can find information on how to use the functionality

 * this class provides in

 * <a href="http://java.sun.com/docs/books/tutorial/uiswing/components/generaltext.html">General Rules for Using Text Components</a>,

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

 *

 * <p>

 * <dl>

 * <dt><b><font size=+1>Caret Changes</font></b>

 * <dd>

 * The caret is a pluggable object in swing text components.

 * Notification of changes to the caret position and the selection

 * are sent to implementations of the <code>CaretListener</code>

 * interface that have been registered with the text component.

 * The UI will install a default caret unless a customized caret

 * has been set. <br>

 * By default the caret tracks all the document changes

 * performed on the Event Dispatching Thread and updates it's position

 * accordingly if an insertion occurs before or at the caret position

 * or a removal occurs before the caret position. <code>DefaultCaret</code>

 * tries to make itself visible which may lead to scrolling

 * of a text component within <code>JScrollPane</code>. The default caret

 * behavior can be changed by the {@link DefaultCaret#setUpdatePolicy} method.

 * <br>

 * <b>Note</b>: Non-editable text components also have a caret though

 * it may not be painted.

 *

 * <p>

 * <dt><b><font size=+1>Commands</font></b>

 * <dd>

 * Text components provide a number of commands that can be used

 * to manipulate the component.  This is essentially the way that

 * the component expresses its capabilities.  These are expressed

 * in terms of the swing <code>Action</code> interface,

 * using the <code>TextAction</code> implementation.

 * The set of commands supported by the text component can be

 * found with the {@link #getActions} method.  These actions

 * can be bound to key events, fired from buttons, etc.

 *

 * <p>

 * <dt><b><font size=+1>Text Input</font></b>

 * <dd>

 * The text components support flexible and internationalized text input, using

 * keymaps and the input method framework, while maintaining compatibility with

 * the AWT listener model.

 * <p>

 * A {@link javax.swing.text.Keymap} lets an application bind key

 * strokes to actions.

 * In order to allow keymaps to be shared across multiple text components, they

 * can use actions that extend <code>TextAction</code>.

 * <code>TextAction</code> can determine which <code>JTextComponent</code>

 * most recently has or had focus and therefore is the subject of

 * the action (In the case that the <code>ActionEvent</code>

 * sent to the action doesn't contain the target text component as its source).

 * <p>

 * The <a href="../../../../technotes/guides/imf/spec.html">input method framework</a>

 * lets text components interact with input methods, separate software

 * components that preprocess events to let users enter thousands of

 * different characters using keyboards with far fewer keys.

 * <code>JTextComponent</code> is an <em>active client</em> of

 * the framework, so it implements the preferred user interface for interacting

 * with input methods. As a consequence, some key events do not reach the text

 * component because they are handled by an input method, and some text input

 * reaches the text component as committed text within an {@link

 * java.awt.event.InputMethodEvent} instead of as a key event.

 * The complete text input is the combination of the characters in

 * <code>keyTyped</code> key events and committed text in input method events.

 * <p>

 * The AWT listener model lets applications attach event listeners to

 * components in order to bind events to actions. Swing encourages the

 * use of keymaps instead of listeners, but maintains compatibility

 * with listeners by giving the listeners a chance to steal an event

 * by consuming it.

 * <p>

 * Keyboard event and input method events are handled in the following stages,

 * with each stage capable of consuming the event:

 *

 * <table border=1 summary="Stages of keyboard and input method event handling">

 * <tr>

 * <th id="stage"><p align="left">Stage</p></th>

 * <th id="ke"><p align="left">KeyEvent</p></th>

 * <th id="ime"><p align="left">InputMethodEvent</p></th></tr>

 * <tr><td headers="stage">1.   </td>

 *     <td headers="ke">input methods </td>

 *     <td headers="ime">(generated here)</td></tr>

 * <tr><td headers="stage">2.   </td>

 *     <td headers="ke">focus manager </td>

 *     <td headers="ime"></td>

 * </tr>

 * <tr>

 *     <td headers="stage">3.   </td>

 *     <td headers="ke">registered key listeners</td>

 *     <td headers="ime">registered input method listeners</tr>

 * <tr>

 *     <td headers="stage">4.   </td>

 *     <td headers="ke"></td>

 *     <td headers="ime">input method handling in JTextComponent</tr>

 * <tr>

 *     <td headers="stage">5.   </td><td headers="ke ime" colspan=2>keymap handling using the current keymap</td></tr>

 * <tr><td headers="stage">6.   </td><td headers="ke">keyboard handling in JComponent (e.g. accelerators, component navigation, etc.)</td>

 *     <td headers="ime"></td></tr>

 * </table>

 *

 * <p>

 * To maintain compatibility with applications that listen to key

 * events but are not aware of input method events, the input

 * method handling in stage 4 provides a compatibility mode for

 * components that do not process input method events. For these

 * components, the committed text is converted to keyTyped key events

 * and processed in the key event pipeline starting at stage 3

 * instead of in the input method event pipeline.

 * <p>

 * By default the component will create a keymap (named <b>DEFAULT_KEYMAP</b>)

 * that is shared by all JTextComponent instances as the default keymap.

 * Typically a look-and-feel implementation will install a different keymap

 * that resolves to the default keymap for those bindings not found in the

 * different keymap. The minimal bindings include:

 * <ul>

 * <li>inserting content into the editor for the

 *  printable keys.

 * <li>removing content with the backspace and del

 *  keys.

 * <li>caret movement forward and backward

 * </ul>

 *

 * <p>

 * <dt><b><font size=+1>Model/View Split</font></b>

 * <dd>

 * The text components have a model-view split.  A text component pulls

 * together the objects used to represent the model, view, and controller.

 * The text document model may be shared by other views which act as observers

 * of the model (e.g. a document may be shared by multiple components).

 *

 * <p align=center><img src="doc-files/editor.gif" alt="Diagram showing interaction between Controller, Document, events, and ViewFactory"

 *                  HEIGHT=358 WIDTH=587></p>

 *

 * <p>

 * The model is defined by the {@link Document} interface.

 * This is intended to provide a flexible text storage mechanism

 * that tracks change during edits and can be extended to more sophisticated

 * models.  The model interfaces are meant to capture the capabilities of

 * expression given by SGML, a system used to express a wide variety of

 * content.

 * Each modification to the document causes notification of the

 * details of the change to be sent to all observers in the form of a

 * {@link DocumentEvent} which allows the views to stay up to date with the model.

 * This event is sent to observers that have implemented the

 * {@link DocumentListener}

 * interface and registered interest with the model being observed.

 *

 * <p>

 * <dt><b><font size=+1>Location Information</font></b>

 * <dd>

 * The capability of determining the location of text in

 * the view is provided.  There are two methods, {@link #modelToView}

 * and {@link #viewToModel} for determining this information.

 *

 * <p>

 * <dt><b><font size=+1>Undo/Redo support</font></b>

 * <dd>

 * Support for an edit history mechanism is provided to allow

 * undo/redo operations.  The text component does not itself

 * provide the history buffer by default, but does provide

 * the <code>UndoableEdit</code> records that can be used in conjunction

 * with a history buffer to provide the undo/redo support.

 * The support is provided by the Document model, which allows

 * one to attach UndoableEditListener implementations.

 *

 * <p>

 * <dt><b><font size=+1>Thread Safety</font></b>

 * <dd>

 * The swing text components provide some support of thread

 * safe operations.  Because of the high level of configurability

 * of the text components, it is possible to circumvent the

 * protection provided.  The protection primarily comes from

 * the model, so the documentation of <code>AbstractDocument</code>

 * describes the assumptions of the protection provided.

 * The methods that are safe to call asynchronously are marked

 * with comments.

 *

 * <p>

 * <dt><b><font size=+1>Newlines</font></b>

 * <dd>

 * For a discussion on how newlines are handled, see

 * <a href="DefaultEditorKit.html">DefaultEditorKit</a>.

 *

 * <p>

 * <dt><b><font size=+1>Printing support</font></b>

 * <dd>

 * Several {@link #print print} methods are provided for basic

 * document printing.  If more advanced printing is needed, use the

 * {@link #getPrintable} method.

 * </dl>

 *

 * <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<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @beaninfo

 *     attribute: isContainer false

 *

 * @author  Timothy Prinzing

 * @author Igor Kushnirskiy (printing support)

 * @see Document

 * @see DocumentEvent

 * @see DocumentListener

 * @see Caret

 * @see CaretEvent

 * @see CaretListener

 * @see TextUI

 * @see View

 * @see ViewFactory

 */

public abstract class JTextComponent extends JComponent implements Scrollable, Accessible

{

    /**

     * Creates a new <code>JTextComponent</code>.

     * Listeners for caret events are established, and the pluggable

     * UI installed.  The component is marked as editable.  No layout manager

     * is used, because layout is managed by the view subsystem of text.

     * The document model is set to <code>null</code>.

     */

    public JTextComponent() {

        super();

        // enable InputMethodEvent for on-the-spot pre-editing

        enableEvents(AWTEvent.KEY_EVENT_MASK | AWTEvent.INPUT_METHOD_EVENT_MASK);

        caretEvent = new MutableCaretEvent(this);

        addMouseListener(caretEvent);

        addFocusListener(caretEvent);

        setEditable(true);

        setDragEnabled(false);

        setLayout(null); // layout is managed by View hierarchy

        updateUI();

    }

    /**

     * Fetches the user-interface factory for this text-oriented editor.

     *

     * @return the factory

     */

    public TextUI getUI() { return (TextUI)ui; }

    /**

     * Sets the user-interface factory for this text-oriented editor.

     *

     * @param ui the factory

     */

    public void setUI(TextUI ui) {

        super.setUI(ui);

    }

    /**

     * Reloads the pluggable UI.  The key used to fetch the

     * new interface is <code>getUIClassID()</code>.  The type of

     * the UI is <code>TextUI</code>.  <code>invalidate</code>

     * is called after setting the UI.

     */

    public void updateUI() {

        setUI((TextUI)UIManager.getUI(this));

        invalidate();

    }

    /**

     * Adds a caret listener for notification of any changes

     * to the caret.

     *

     * @param listener the listener to be added

     * @see javax.swing.event.CaretEvent

     */

    public void addCaretListener(CaretListener listener) {

        listenerList.add(CaretListener.class, listener);

    }

    /**

     * Removes a caret listener.

     *

     * @param listener the listener to be removed

     * @see javax.swing.event.CaretEvent

     */

    public void removeCaretListener(CaretListener listener) {

        listenerList.remove(CaretListener.class, listener);

    }

    /**

     * Returns an array of all the caret listeners

     * registered on this text component.

     *

     * @return all of this component's <code>CaretListener</code>s

     *         or an empty

     *         array if no caret listeners are currently registered

     *

     * @see #addCaretListener

     * @see #removeCaretListener

     *

     * @since 1.4

     */

    public CaretListener[] getCaretListeners() {

        return (CaretListener[])listenerList.getListeners(CaretListener.class);

    }

    /**

     * Notifies all listeners that have registered interest for

     * notification on this event type.  The event instance

     * is lazily created using the parameters passed into

     * the fire method.  The listener list is processed in a

     * last-to-first manner.

     *

     * @param e the event

     * @see EventListenerList

     */

    protected void fireCaretUpdate(CaretEvent 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]==CaretListener.class) {

                ((CaretListener)listeners[i+1]).caretUpdate(e);

            }

        }

    }

    /**

     * Associates the editor with a text document.

     * The currently registered factory is used to build a view for

     * the document, which gets displayed by the editor after revalidation.

     * A PropertyChange event ("document") is propagated to each listener.

     *

     * @param doc  the document to display/edit

     * @see #getDocument

     * @beaninfo

     *  description: the text document model

     *        bound: true

     *       expert: true

     */

    public void setDocument(Document doc) {

        Document old = model;

        /*

         * aquire a read lock on the old model to prevent notification of

         * mutations while we disconnecting the old model.

         */

        try {

            if (old instanceof AbstractDocument) {

                ((AbstractDocument)old).readLock();

            }

            if (accessibleContext != null) {

                model.removeDocumentListener(

                    ((AccessibleJTextComponent)accessibleContext));

            }

            if (inputMethodRequestsHandler != null) {

                model.removeDocumentListener((DocumentListener)inputMethodRequestsHandler);

            }

            model = doc;

            // Set the document's run direction property to match the

            // component's ComponentOrientation property.

            Boolean runDir = getComponentOrientation().isLeftToRight()

                             ? TextAttribute.RUN_DIRECTION_LTR

                             : TextAttribute.RUN_DIRECTION_RTL;

            if (runDir != doc.getProperty(TextAttribute.RUN_DIRECTION)) {

                doc.putProperty(TextAttribute.RUN_DIRECTION, runDir );

            }

            firePropertyChange("document", old, doc);

        } finally {

            if (old instanceof AbstractDocument) {

                ((AbstractDocument)old).readUnlock();

            }

        }

        revalidate();

        repaint();

        if (accessibleContext != null) {

            model.addDocumentListener(

                ((AccessibleJTextComponent)accessibleContext));

        }

        if (inputMethodRequestsHandler != null) {

            model.addDocumentListener((DocumentListener)inputMethodRequestsHandler);

        }

    }

    /**

     * Fetches the model associated with the editor.  This is

     * primarily for the UI to get at the minimal amount of

     * state required to be a text editor.  Subclasses will

     * return the actual type of the model which will typically

     * be something that extends Document.

     *

     * @return the model

     */

    public Document getDocument() {

        return model;

    }

    // Override of Component.setComponentOrientation

    public void setComponentOrientation( ComponentOrientation o ) {

        // Set the document's run direction property to match the

        // ComponentOrientation property.

        Document doc = getDocument();

        if( doc !=  null ) {

            Boolean runDir = o.isLeftToRight()

                             ? TextAttribute.RUN_DIRECTION_LTR

                             : TextAttribute.RUN_DIRECTION_RTL;

            doc.putProperty( TextAttribute.RUN_DIRECTION, runDir );

        }

        super.setComponentOrientation( o );

    }

    /**

     * Fetches the command list for the editor.  This is

     * the list of commands supported by the plugged-in UI

     * augmented by the collection of commands that the

     * editor itself supports.  These are useful for binding

     * to events, such as in a keymap.

     *

     * @return the command list

     */

    public Action[] getActions() {

        return getUI().getEditorKit(this).getActions();

    }

    /**

     * Sets margin space between the text component's border

     * and its text.  The text component's default <code>Border</code>

     * object will use this value to create the proper margin.

     * However, if a non-default border is set on the text component,

     * it is that <code>Border</code> object's responsibility to create the

     * appropriate margin space (else this property will effectively

     * be ignored).  This causes a redraw of the component.

     * A PropertyChange event ("margin") is sent to all listeners.

     *

     * @param m the space between the border and the text

     * @beaninfo

     *  description: desired space between the border and text area

     *        bound: true

     */

    public void setMargin(Insets m) {

        Insets old = margin;