/*

 * Copyright (c) 1997, 2017, 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

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 * questions.

 */

package javax.swing.text;

import sun.awt.SunToolkit;

import java.io.*;

import java.awt.*;

import java.awt.event.ActionEvent;

import java.text.*;

import javax.swing.Action;

import javax.swing.KeyStroke;

import javax.swing.SwingConstants;

import javax.swing.UIManager;

/**

 * This is the set of things needed by a text component

 * to be a reasonably functioning editor for some <em>type</em>

 * of text document.  This implementation provides a default

 * implementation which treats text as plain text and

 * provides a minimal set of actions for a simple editor.

 *

 * <dl>

 * <dt><b>Newlines</b>

 * <dd>

 * There are two properties which deal with newlines.  The

 * system property, <code>line.separator</code>, is defined to be

 * platform-dependent, either "\n", "\r", or "\r\n".  There is also

 * a property defined in <code>DefaultEditorKit</code>, called

 * <a href=#EndOfLineStringProperty><code>EndOfLineStringProperty</code></a>,

 * which is defined automatically when a document is loaded, to be

 * the first occurrence of any of the newline characters.

 * When a document is loaded, <code>EndOfLineStringProperty</code>

 * is set appropriately, and when the document is written back out, the

 * <code>EndOfLineStringProperty</code> is used.  But while the document

 * is in memory, the "\n" character is used to define a

 * newline, regardless of how the newline is defined when

 * the document is on disk.  Therefore, for searching purposes,

 * "\n" should always be used.  When a new document is created,

 * and the <code>EndOfLineStringProperty</code> has not been defined,

 * it will use the System property when writing out the

 * document.

 * <p>Note that <code>EndOfLineStringProperty</code> is set

 * on the <code>Document</code> using the <code>get/putProperty</code>

 * methods.  Subclasses may override this behavior.

 *

 * </dl>

 *

 * @author  Timothy Prinzing

 */

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

public class DefaultEditorKit extends EditorKit {

    /**

     * default constructor for DefaultEditorKit

     */

    public DefaultEditorKit() {

    }

    /**

     * Gets the MIME type of the data that this

     * kit represents support for.  The default

     * is <code>text/plain</code>.

     *

     * @return the type

     */

    public String getContentType() {

        return "text/plain";

    }

    /**

     * Fetches a factory that is suitable for producing

     * views of any models that are produced by this

     * kit.  The default is to have the UI produce the

     * factory, so this method has no implementation.

     *

     * @return the view factory

     */

    public ViewFactory getViewFactory() {

        return null;

    }

    /**

     * Fetches the set of commands that can be used

     * on a text component that is using a model and

     * view produced by this kit.

     *

     * @return the command list

     */

    public Action[] getActions() {

        return defaultActions;

    }

    /**

     * Fetches a caret that can navigate through views

     * produced by the associated ViewFactory.

     *

     * @return the caret

     */

    public Caret createCaret() {

        return null;

    }

    /**

     * Creates an uninitialized text storage model (PlainDocument)

     * that is appropriate for this type of editor.

     *

     * @return the model

     */

    public Document createDefaultDocument() {

        return new PlainDocument();

    }

    /**

     * Inserts content from the given stream which is expected

     * to be in a format appropriate for this kind of content

     * handler.

     *

     * @param in  The stream to read from

     * @param doc The destination for the insertion.

     * @param pos The location in the document to place the

     *   content >=0.

     * @exception IOException on any I/O error

     * @exception BadLocationException if pos represents an invalid

     *   location within the document.

     */

    public void read(InputStream in, Document doc, int pos)

        throws IOException, BadLocationException {

        read(new InputStreamReader(in), doc, pos);

    }

    /**

     * Writes content from a document to the given stream

     * in a format appropriate for this kind of content handler.

     *

     * @param out The stream to write to

     * @param doc The source for the write.

     * @param pos The location in the document to fetch the

     *   content >=0.

     * @param len The amount to write out >=0.

     * @exception IOException on any I/O error

     * @exception BadLocationException if pos represents an invalid

     *   location within the document.

     */

    public void write(OutputStream out, Document doc, int pos, int len)

        throws IOException, BadLocationException {

        OutputStreamWriter osw = new OutputStreamWriter(out);

        write(osw, doc, pos, len);

        osw.flush();

    }

    /**

     * Gets the input attributes for the pane. This method exists for

     * the benefit of StyledEditorKit so that the read method will

     * pick up the correct attributes to apply to inserted text.

     * This class's implementation simply returns null.

     *

     * @return null

     */

    MutableAttributeSet getInputAttributes() {

        return null;

    }

    /**

     * Inserts content from the given stream, which will be

     * treated as plain text.

     *

     * @param in  The stream to read from

     * @param doc The destination for the insertion.

     * @param pos The location in the document to place the

     *   content >=0.

     * @exception IOException on any I/O error

     * @exception BadLocationException if pos represents an invalid

     *   location within the document.

     */

    public void read(Reader in, Document doc, int pos)

        throws IOException, BadLocationException {

        char[] buff = new char[4096];

        int nch;

        boolean lastWasCR = false;

        boolean isCRLF = false;

        boolean isCR = false;

        int last;

        boolean wasEmpty = (doc.getLength() == 0);

        AttributeSet attr = getInputAttributes();

        // Read in a block at a time, mapping \r\n to \n, as well as single

        // \r's to \n's. If a \r\n is encountered, \r\n will be set as the

        // newline string for the document, if \r is encountered it will

        // be set as the newline character, otherwise the newline property

        // for the document will be removed.

        while ((nch = in.read(buff, 0, buff.length)) != -1) {

            last = 0;

            for(int counter = 0; counter < nch; counter++) {

                switch(buff[counter]) {

                case '\r':

                    if (lastWasCR) {

                        isCR = true;

                        if (counter == 0) {

                            doc.insertString(pos, "\n", attr);

                            pos++;

                        }

                        else {

                            buff[counter - 1] = '\n';

                        }

                    }

                    else {

                        lastWasCR = true;

                    }

                    break;

                case '\n':

                    if (lastWasCR) {

                        if (counter > (last + 1)) {

                            doc.insertString(pos, new String(buff, last,

                                            counter - last - 1), attr);

                            pos += (counter - last - 1);

                        }

                        // else nothing to do, can skip \r, next write will

                        // write \n

                        lastWasCR = false;

                        last = counter;

                        isCRLF = true;

                    }

                    break;

                default:

                    if (lastWasCR) {

                        isCR = true;

                        if (counter == 0) {

                            doc.insertString(pos, "\n", attr);

                            pos++;

                        }

                        else {

                            buff[counter - 1] = '\n';

                        }

                        lastWasCR = false;

                    }

                    break;

                }

            }

            if (last < nch) {

                if(lastWasCR) {

                    if (last < (nch - 1)) {

                        doc.insertString(pos, new String(buff, last,

                                         nch - last - 1), attr);

                        pos += (nch - last - 1);

                    }

                }

                else {

                    doc.insertString(pos, new String(buff, last,

                                     nch - last), attr);

                    pos += (nch - last);

                }

            }

        }

        if (lastWasCR) {

            doc.insertString(pos, "\n", attr);

            isCR = true;

        }

        if (wasEmpty) {

            if (isCRLF) {

                doc.putProperty(EndOfLineStringProperty, "\r\n");

            }

            else if (isCR) {

                doc.putProperty(EndOfLineStringProperty, "\r");

            }

            else {

                doc.putProperty(EndOfLineStringProperty, "\n");

            }

        }

    }

    /**

     * Writes content from a document to the given stream

     * as plain text.

     *

     * @param out  The stream to write to

     * @param doc The source for the write.

     * @param pos The location in the document to fetch the

     *   content from >=0.

     * @param len The amount to write out >=0.

     * @exception IOException on any I/O error

     * @exception BadLocationException if pos is not within 0 and

     *   the length of the document.

     */

    public void write(Writer out, Document doc, int pos, int len)

        throws IOException, BadLocationException {

        if ((pos < 0) || ((pos + len) > doc.getLength())) {

            throw new BadLocationException("DefaultEditorKit.write", pos);

        }

        Segment data = new Segment();

        int nleft = len;

        int offs = pos;

        Object endOfLineProperty = doc.getProperty(EndOfLineStringProperty);

        if (endOfLineProperty == null) {

            endOfLineProperty = System.lineSeparator();

        }

        String endOfLine;

        if (endOfLineProperty instanceof String) {

            endOfLine = (String)endOfLineProperty;

        }

        else {

            endOfLine = null;

        }

        if (endOfLineProperty != null && !endOfLine.equals("\n")) {

            // There is an end of line string that isn't \n, have to iterate

            // through and find all \n's and translate to end of line string.

            while (nleft > 0) {

                int n = Math.min(nleft, 4096);

                doc.getText(offs, n, data);

                int last = data.offset;

                char[] array = data.array;

                int maxCounter = last + data.count;

                for (int counter = last; counter < maxCounter; counter++) {

                    if (array[counter] == '\n') {

                        if (counter > last) {

                            out.write(array, last, counter - last);

                        }

                        out.write(endOfLine);

                        last = counter + 1;

                    }

                }

                if (maxCounter > last) {

                    out.write(array, last, maxCounter - last);

                }

                offs += n;

                nleft -= n;

            }

        }

        else {

            // Just write out text, will already have \n, no mapping to

            // do.

            while (nleft > 0) {

                int n = Math.min(nleft, 4096);

                doc.getText(offs, n, data);

                out.write(data.array, data.offset, data.count);

                offs += n;

                nleft -= n;

            }

        }

        out.flush();

    }

    /**

     * When reading a document if a CRLF is encountered a property

     * with this name is added and the value will be "\r\n".

     */

    public static final String EndOfLineStringProperty = "__EndOfLine__";

    // --- names of well-known actions ---------------------------

    /**

     * Name of the action to place content into the associated

     * document.  If there is a selection, it is removed before

     * the new content is added.

     * @see #getActions

     */

    public static final String insertContentAction = "insert-content";

    /**

     * Name of the action to place a line/paragraph break into

     * the document.  If there is a selection, it is removed before

     * the break is added.

     * @see #getActions

     */

    public static final String insertBreakAction = "insert-break";

    /**

     * Name of the action to place a tab character into

     * the document.  If there is a selection, it is removed before

     * the tab is added.

     * @see #getActions

     */

    public static final String insertTabAction = "insert-tab";

    /**

     * Name of the action to delete the character of content that

     * precedes the current caret position.

     * @see #getActions

     */

    public static final String deletePrevCharAction = "delete-previous";

    /**

     * Name of the action to delete the character of content that

     * follows the current caret position.

     * @see #getActions

     */

    public static final String deleteNextCharAction = "delete-next";

    /**

     * Name of the action to delete the word that

     * follows the beginning of the selection.

     * @see #getActions

     * @see JTextComponent#getSelectionStart

     * @since 1.6

     */

    public static final String deleteNextWordAction = "delete-next-word";

    /**

     * Name of the action to delete the word that

     * precedes the beginning of the selection.

     * @see #getActions

     * @see JTextComponent#getSelectionStart

     * @since 1.6

     */

    public static final String deletePrevWordAction = "delete-previous-word";

    /**

     * Name of the action to set the editor into read-only

     * mode.

     * @see #getActions

     */

    public static final String readOnlyAction = "set-read-only";

    /**

     * Name of the action to set the editor into writeable

     * mode.

     * @see #getActions

     */

    public static final String writableAction = "set-writable";

    /**

     * Name of the action to cut the selected region

     * and place the contents into the system clipboard.

     * @see JTextComponent#cut

     * @see #getActions

     */

    public static final String cutAction = "cut-to-clipboard";

    /**

     * Name of the action to copy the selected region

     * and place the contents into the system clipboard.

     * @see JTextComponent#copy

     * @see #getActions

     */

    public static final String copyAction = "copy-to-clipboard";

    /**

     * Name of the action to paste the contents of the

     * system clipboard into the selected region, or before the

     * caret if nothing is selected.

     * @see JTextComponent#paste

     * @see #getActions

     */

    public static final String pasteAction = "paste-from-clipboard";

    /**

     * Name of the action to create a beep.

     * @see #getActions

     */

    public static final String beepAction = "beep";

    /**

     * Name of the action to page up vertically.

     * @see #getActions

     */

    public static final String pageUpAction = "page-up";

    /**

     * Name of the action to page down vertically.

     * @see #getActions

     */

    public static final String pageDownAction = "page-down";

    /**

     * Name of the action to page up vertically, and move the

     * selection.

     * @see #getActions

     */

    /*public*/ static final String selectionPageUpAction = "selection-page-up";

    /**

     * Name of the action to page down vertically, and move the

     * selection.

     * @see #getActions

     */

    /*public*/ static final String selectionPageDownAction = "selection-page-down";

    /**

     * Name of the action to page left horizontally, and move the

     * selection.

     * @see #getActions

     */

    /*public*/ static final String selectionPageLeftAction = "selection-page-left";

    /**

     * Name of the action to page right horizontally, and move the

     * selection.

     * @see #getActions

     */

    /*public*/ static final String selectionPageRightAction = "selection-page-right";

    /**

     * Name of the Action for moving the caret

     * logically forward one position.

     * @see #getActions

     */

    public static final String forwardAction = "caret-forward";

    /**