source: other-projects/rsyntax-textarea/src/java/org/fife/ui/rsyntaxtextarea/TextEditorPane.java@ 25584

/*
 * 11/25/2008
 *
 * TextEditorPane.java - A syntax highlighting text area that has knowledge of
 * the file it is editing on disk.
 * 
 * This library is distributed under a modified BSD license.  See the included
 * RSyntaxTextArea.License.txt file for details.
 */
package org.fife.ui.rsyntaxtextarea;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.nio.charset.Charset;
import java.nio.charset.UnsupportedCharsetException;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.Document;

import org.fife.io.UnicodeReader;
import org.fife.io.UnicodeWriter;
import org.fife.ui.rsyntaxtextarea.RSyntaxTextArea;
import org.fife.ui.rtextarea.RTextAreaEditorKit;


/**
 * An extension of {@link org.fife.ui.rsyntaxtextarea.RSyntaxTextArea}
 * that adds information about the file being edited, such as:
 *
 * <ul>
 *   <li>Its name and location.
 *   <li>Is it dirty?
 *   <li>Is it read-only?
 *   <li>The last time it was loaded or saved to disk (local files only).
 *   <li>The file's encoding on disk.
 *   <li>Easy access to the line separator.
 * </ul>
 *
 * Loading and saving is also built into the editor.<p>
 * Both local and remote files (e.g. ftp) are supported.  See the
 * {@link FileLocation} class for more information.
 *
 * @author Robert Futrell
 * @version 1.0
 * @see FileLocation
 */
public class TextEditorPane extends RSyntaxTextArea implements
                                    DocumentListener {

    private static final long serialVersionUID = 1L;

    public static final String FULL_PATH_PROPERTY   = "TextEditorPane.fileFullPath";
    public static final String DIRTY_PROPERTY   = "TextEditorPane.dirty";
    public static final String READ_ONLY_PROPERTY   = "TextEditorPane.readOnly";

    /**
     * The location of the file being edited.
     */
    private FileLocation loc;

    /**
     * The charset to use when reading or writing this file.
     */
    private String charSet;

    /**
     * Whether the file should be treated as read-only.
     */
    private boolean readOnly;

    /**
     * Whether the file is dirty.
     */
    private boolean dirty;

    /**
     * The last time this file was modified on disk, for local files.
     * For remote files, this value should always be
     * {@link #LAST_MODIFIED_UNKNOWN}.
     */
    private long lastSaveOrLoadTime;

    /**
     * The value returned by {@link #getLastSaveOrLoadTime()} for remote files.
     */
    public static final long LAST_MODIFIED_UNKNOWN      = 0;

    /**
     * The default name given to files if none is specified in a constructor.
     */
    private static final String DEFAULT_FILE_NAME = "Untitled.txt";


    /**
     * Constructor.  The file will be given a default name.
     */
    public TextEditorPane() {
        this(INSERT_MODE);
    }


    /**
     * Constructor.  The file will be given a default name.
     *
     * @param textMode Either <code>INSERT_MODE</code> or
     *        <code>OVERWRITE_MODE</code>.
     */
    public TextEditorPane(int textMode) {
        this(textMode, false);
    }


    /**
     * Creates a new <code>TextEditorPane</code>.  The file will be given
     * a default name.
     *
     * @param textMode Either <code>INSERT_MODE</code> or
     *        <code>OVERWRITE_MODE</code>.
     * @param wordWrapEnabled Whether or not to use word wrap in this pane.
     */
    public TextEditorPane(int textMode, boolean wordWrapEnabled) {
        super(textMode);
        setLineWrap(wordWrapEnabled);
        try {
            init(null, null);
        } catch (IOException ioe) { // Never happens
            ioe.printStackTrace();
        }
    }


    /**
     * Creates a new <code>TextEditorPane</code>.
     *
     * @param textMode Either <code>INSERT_MODE</code> or
     *        <code>OVERWRITE_MODE</code>.
     * @param wordWrapEnabled Whether or not to use word wrap in this pane.
     * @param loc The location of the text file being edited.  If this value
     *        is <code>null</code>, a file named "Untitled.txt" in the current
     *        directory is used.
     * @throws IOException If an IO error occurs reading the file at
     *         <code>loc</code>.  This of course won't happen if
     *         <code>loc</code> is <code>null</code>.
     */
    public TextEditorPane(int textMode, boolean wordWrapEnabled,
                            FileLocation loc) throws IOException {
        this(textMode, wordWrapEnabled, loc, null);
    }


    /**
     * Creates a new <code>TextEditorPane</code>.
     *
     * @param textMode Either <code>INSERT_MODE</code> or
     *        <code>OVERWRITE_MODE</code>.
     * @param wordWrapEnabled Whether or not to use word wrap in this pane.
     * @param loc The location of the text file being edited.  If this value
     *        is <code>null</code>, a file named "Untitled.txt" in the current
     *        directory is used.  This file is displayed as empty even if it
     *        actually exists.
     * @param defaultEnc The default encoding to use when opening the file,
     *        if the file is not Unicode.  If this value is <code>null</code>,
     *        a system default value is used.
     * @throws IOException If an IO error occurs reading the file at
     *         <code>loc</code>.  This of course won't happen if
     *         <code>loc</code> is <code>null</code>.
     */
    public TextEditorPane(int textMode, boolean wordWrapEnabled,
                FileLocation loc, String defaultEnc) throws IOException {
        super(textMode);
        setLineWrap(wordWrapEnabled);
        init(loc, defaultEnc);
    }


    /**
     * Callback for when styles in the current document change.
     * This method is never called.
     *
     * @param e The document event.
     */
    public void changedUpdate(DocumentEvent e) {
    }



    /**
     * Returns the default encoding for this operating system.
     *
     * @return The default encoding.
     */
    private static final String getDefaultEncoding() {
        // TODO: Change to "Charset.defaultCharset().name()" when 1.4 support
        // is no longer needed.
        // NOTE:  The "file.encoding" property is not guaranteed to be set by
        // the spec, so we cannot rely on it.
        String encoding = System.getProperty("file.encoding");
        if (encoding==null) {
            try {
                File f = File.createTempFile("rsta", null);
                FileWriter w = new FileWriter(f);
                encoding = w.getEncoding();
                w.close();
                f.deleteOnExit();//delete();  Keep FindBugs happy
            } catch (IOException ioe) {
                encoding = "US-ASCII";
            }
        }
        return encoding;
    }


    /**
     * Returns the encoding to use when reading or writing this file.
     *
     * @return The encoding.
     * @see #setEncoding(String)
     */
    public String getEncoding() {
        return charSet;
    }


    /**
     * Returns the full path to this document.
     *
     * @return The full path to the document.
     */
    public String getFileFullPath() {
        return loc==null ? null : loc.getFileFullPath();
    }


    /**
     * Returns the file name of this document.
     *
     * @return The file name.
     */
    public String getFileName() {
        return loc.getFileName();
    }


    /**
     * Returns the timestamp for when this file was last loaded or saved
     * <em>by this editor pane</em>.  If the file has been modified on disk by
     * another process after it was loaded into this editor pane, this method
     * will not return the actual file's last modified time.<p>
     *
     * For remote files, this method will always return
     * {@link #LAST_MODIFIED_UNKNOWN}.
     *
     * @return The timestamp when this file was last loaded or saved by this
     *         editor pane, if it is a local file, or
     *         {@link #LAST_MODIFIED_UNKNOWN} if it is a remote file.
     * @see #isModifiedOutsideEditor()
     */
    public long getLastSaveOrLoadTime() {
        return lastSaveOrLoadTime;
    }


    /**
     * Returns the line separator used when writing this file (e.g.
     * "<code>\n</code>", "<code>\r\n</code>", or "<code>\r</code>").<p>
     * 
     * Note that this value is an <code>Object</code> and not a
     * <code>String</code> as that is the way the {@link Document} interface
     * defines its property values.  If you always use
     * {@link #setLineSeparator(String)} to modify this value, then the value
     * returned from this method will always be a <code>String</code>.
     *
     * @return The line separator.  If this value is <code>null</code>, then
     *         the system default line separator is used (usually the value
     *         of <code>System.getProperty("line.separator")</code>).
     * @see #setLineSeparator(String)
     * @see #setLineSeparator(String, boolean)
     */
    public Object getLineSeparator() {
        return getDocument().getProperty(
                            RTextAreaEditorKit.EndOfLineStringProperty);
    }


    /**
     * Initializes this editor with the specified file location.
     *
     * @param loc The file location.  If this is <code>null</code>, a default
     *        location is used and an empty file is displayed.
     * @param defaultEnc The default encoding to use when opening the file,
     *        if the file is not Unicode.  If this value is <code>null</code>,
     *        a system default value is used.
     * @throws IOException If an IO error occurs reading from <code>loc</code>.
     *         If <code>loc</code> is <code>null</code>, this cannot happen.
     */
    private void init(FileLocation loc, String defaultEnc) throws IOException {

        if (loc==null) {
            // Don't call load() just in case Untitled.txt actually exists,
            // just to ensure there is no chance of an IOException being thrown
            // in the default case.
            this.loc = FileLocation.create(DEFAULT_FILE_NAME);
            charSet = defaultEnc==null ? getDefaultEncoding() : defaultEnc;
            // Ensure that line separator always has a value, even if the file
            // does not exist (or is the "default" file).  This makes life
            // easier for host applications that want to display this value.
            setLineSeparator(System.getProperty("line.separator"));
        }
        else {
            load(loc, defaultEnc); // Sets this.loc
        }

        if (this.loc.isLocalAndExists()) {
            File file = new File(this.loc.getFileFullPath());
            lastSaveOrLoadTime = file.lastModified();
            setReadOnly(!file.canWrite());
        }
        else {
            lastSaveOrLoadTime = LAST_MODIFIED_UNKNOWN;
            setReadOnly(false);
        }

        setDirty(false);

    }


    /**
     * Callback for when text is inserted into the document.
     *
     * @param e Information on the insertion.
     */
    public void insertUpdate(DocumentEvent e) {
        if (!dirty) {
            setDirty(true);
        }
    }


    /**
     * Returns whether or not the text in this editor has unsaved changes.
     *
     * @return Whether or not the text has unsaved changes.
     */
    public boolean isDirty() {
        return dirty;
    }


    /**
     * Returns whether this file is a local file.
     *
     * @return Whether this is a local file.
     */
    public boolean isLocal() {
        return loc.isLocal();
    }


    /**
     * Returns whether this is a local file that already exists.
     *
     * @return Whether this is a local file that already exists.
     */
    public boolean isLocalAndExists() {
        return loc.isLocalAndExists();
    }


    /**
     * Returns whether the text file has been modified outside of this editor
     * since the last load or save operation.  Note that if this is a remote
     * file, this method will always return <code>false</code>.<p>
     *
     * This method may be used by applications to implement a reloading
     * feature, where the user is prompted to reload a file if it has been
     * modified since their last open or save.
     *
     * @return Whether the text file has been modified outside of this
     *         editor.
     * @see #getLastSaveOrLoadTime()
     */
    public boolean isModifiedOutsideEditor() {
        return loc.getActualLastModified()>getLastSaveOrLoadTime();
    }


    /**
     * Returns whether or not the text area should be treated as read-only.
     *
     * @return Whether or not the text area should be treated as read-only.
     * @see #setReadOnly(boolean)
     */
    public boolean isReadOnly() {
        return readOnly;
    }


    /**
     * Loads the specified file in this editor.  This method fires a property
     * change event of type {@link #FULL_PATH_PROPERTY}.
     *
     * @param loc The location of the file to load.  This cannot be
     *        <code>null</code>.
     * @param defaultEnc The encoding to use when loading/saving the file.
     *        This encoding will only be used if the file is not Unicode.
     *        If this value is <code>null</code>, the system default encoding
     *        is used.
     * @throws IOException If an IO error occurs.
     * @see #save()
     * @see #saveAs(FileLocation)
     */
    public void load(FileLocation loc, String defaultEnc) throws IOException {

        // For new local files, just go with it.
        if (loc.isLocal() && !loc.isLocalAndExists()) {
            this.charSet = defaultEnc!=null ? defaultEnc : getDefaultEncoding();
            this.loc = loc;
            return;
        }

        // Old local files and remote files, load 'em up.  UnicodeReader will
        // check for BOMs and handle them correctly in all cases, then pass
        // rest of stream down to InputStreamReader.
        UnicodeReader ur = new UnicodeReader(loc.getInputStream(), defaultEnc);

        // Remove listener so dirty flag doesn't get set when loading a file.
        Document doc = getDocument();
        doc.removeDocumentListener(this);
        BufferedReader r = new BufferedReader(ur);
        try {
            read(r, null);
        } finally {
            doc.addDocumentListener(this);
            r.close();
        }

        // No IOException thrown, so we can finally change the location.
        charSet = ur.getEncoding();
        String old = getFileFullPath();
        this.loc = loc;
        firePropertyChange(FULL_PATH_PROPERTY, old, getFileFullPath());

    }


    /**
     * Reloads this file from disk.  The file must exist for this operation
     * to not throw an exception.<p>
     * 
     * The file's "dirty" state will be set to <code>false</code> after this
     * operation.  If this is a local file, its "last modified" time is
     * updated to reflect that of the actual file.<p>
     *
     * Note that if the file has been modified on disk, and is now a Unicode
     * encoding when before it wasn't (or if it is a different Unicode now),
     * this will cause this {@link TextEditorPane}'s encoding to change.
     * Otherwise, the file's encoding will stay the same.
     *
     * @throws IOException If the file does not exist, or if an IO error
     *         occurs reading the file.
     * @see #isLocalAndExists()
     */
    public void reload() throws IOException {
        String oldEncoding = getEncoding();
        UnicodeReader ur = new UnicodeReader(loc.getInputStream(), oldEncoding);
        String encoding = ur.getEncoding();
        BufferedReader r = new BufferedReader(ur);
        try {
            read(r, null); // Dumps old contents.
        } finally {
            r.close();
        }
        setEncoding(encoding);
        setDirty(false);
        syncLastSaveOrLoadTimeToActualFile();
        discardAllEdits(); // Prevent user from being able to undo the reload
    }


    /**
     * Called whenever text is removed from this editor.
     *
     * @param e The document event.
     */
    public void removeUpdate(DocumentEvent e) {
        if (!dirty) {
            setDirty(true);
        }
    }


    /**
     * Saves the file in its current encoding.<p>
     *
     * The text area's "dirty" state is set to <code>false</code>, and if
     * this is a local file, its "last modified" time is updated.
     *
     * @throws IOException If an IO error occurs.
     * @see #saveAs(FileLocation)
     * @see #load(FileLocation, String)
     */
    public void save() throws IOException {
        saveImpl(loc);
        setDirty(false);
        syncLastSaveOrLoadTimeToActualFile();
    }


    /**
     * Saves this file in a new local location.  This method fires a property
     * change event of type {@link #FULL_PATH_PROPERTY}.
     *
     * @param loc The location to save to.
     * @throws IOException If an IO error occurs.
     * @see #save()
     * @see #load(FileLocation, String)
     */
    public void saveAs(FileLocation loc) throws IOException {
        saveImpl(loc);
        // No exception thrown - we can "rename" the file.
        String old = getFileFullPath();
        this.loc = loc;
        setDirty(false);
        lastSaveOrLoadTime = loc.getActualLastModified();
        firePropertyChange(FULL_PATH_PROPERTY, old, getFileFullPath());
    }


    /**
     * Saves the text in this editor to the specified location.
     *
     * @param loc The location to save to.
     * @throws IOException If an IO error occurs.
     */
    private void saveImpl(FileLocation loc) throws IOException {
        OutputStream out = loc.getOutputStream();
        PrintWriter w = new PrintWriter(
            new BufferedWriter(new UnicodeWriter(out, getEncoding())));
        try {
            write(w);
        } finally {
            w.close();
        }
    }


    /**
     * Sets whether or not this text in this editor has unsaved changes.
     * This fires a property change event of type {@link #DIRTY_PROPERTY}.
     *
     * @param dirty Whether or not the text has been modified.
     * @see #isDirty()
     */
    private void setDirty(boolean dirty) {
        if (this.dirty!=dirty) {
            this.dirty = dirty;
            firePropertyChange(DIRTY_PROPERTY, !dirty, dirty);
        }
    }


    /**
     * Sets the document for this editor.
     *
     * @param doc The new document.
     */
    public void setDocument(Document doc) {
        Document old = getDocument();
        if (old!=null) {
            old.removeDocumentListener(this);
        }
        super.setDocument(doc);
        doc.addDocumentListener(this);
    }


    /**
     * Sets the encoding to use when reading or writing this file.  This
     * method sets the editor's dirty flag when the encoding is changed.
     *
     * @param encoding The new encoding.
     * @throws UnsupportedCharsetException If the encoding is not supported.
     * @throws NullPointerException If <code>encoding</code> is
     *         <code>null</code>.
     * @see #getEncoding()
     */
    public void setEncoding(String encoding) {
        if (encoding==null) {
            throw new NullPointerException("encoding cannot be null");
        }
        else if (!Charset.isSupported(encoding)) {
            throw new UnsupportedCharsetException(encoding);
        }
        if (charSet==null || !charSet.equals(encoding)) {
            charSet = encoding;
            setDirty(true);
        }
    }


    /**
     * Sets the line separator sequence to use when this file is saved (e.g.
     * "<code>\n</code>", "<code>\r\n</code>" or "<code>\r</code>").
     *
     * Besides parameter checking, this method is preferred over
     * <code>getDocument().putProperty()</code> because it sets the editor's
     * dirty flag when the line separator is changed.
     *
     * @param separator The new line separator.
     * @throws NullPointerException If <code>separator</code> is
     *         <code>null</code>.
     * @throws IllegalArgumentException If <code>separator</code> is not one
     *         of "<code>\n</code>", "<code>\r\n</code>" or "<code>\r</code>".
     * @see #getLineSeparator()
     */
    public void setLineSeparator(String separator) {
        setLineSeparator(separator, true);
    }


    /**
     * Sets the line separator sequence to use when this file is saved (e.g.
     * "<code>\n</code>", "<code>\r\n</code>" or "<code>\r</code>").
     *
     * Besides parameter checking, this method is preferred over
     * <code>getDocument().putProperty()</code> because can set the editor's
     * dirty flag when the line separator is changed.
     *
     * @param separator The new line separator.
     * @param setDirty Whether the dirty flag should be set if the line
     *        separator is changed.
     * @throws NullPointerException If <code>separator</code> is
     *         <code>null</code>.
     * @throws IllegalArgumentException If <code>separator</code> is not one
     *         of "<code>\n</code>", "<code>\r\n</code>" or "<code>\r</code>".
     * @see #getLineSeparator()
     */
    public void setLineSeparator(String separator, boolean setDirty) {
        if (separator==null) {
            throw new NullPointerException("terminator cannot be null");
        }
        if (!"\r\n".equals(separator) && !"\n".equals(separator) &&
                !"\r".equals(separator)) {
            throw new IllegalArgumentException("Invalid line terminator");
        }
        Document doc = getDocument();
        Object old = doc.getProperty(
                        RTextAreaEditorKit.EndOfLineStringProperty);
        if (!separator.equals(old)) {
            doc.putProperty(RTextAreaEditorKit.EndOfLineStringProperty,
                            separator);
            if (setDirty) {
                setDirty(true);
            }
        }
    }


    /**
     * Sets whether or not this text area should be treated as read-only.
     * This fires a property change event of type {@link #READ_ONLY_PROPERTY}.
     *
     * @param readOnly Whether or not the document is read-only.
     * @see #isReadOnly()
     */
    public void setReadOnly(boolean readOnly) {
        if (this.readOnly!=readOnly) {
            this.readOnly = readOnly;
            firePropertyChange(READ_ONLY_PROPERTY, !readOnly, readOnly);
        }
    }


    /**
     * Syncs this text area's "last saved or loaded" time to that of the file
     * being edited, if that file is local and exists.  If the file is
     * remote or is local but does not yet exist, nothing happens.<p>
     *
     * You normally do not have to call this method, as the "last saved or
     * loaded" time for {@link TextEditorPane}s is kept up-to-date internally
     * during such operations as {@link #save()}, {@link #reload()}, etc.
     *
     * @see #getLastSaveOrLoadTime()
     * @see #isModifiedOutsideEditor()
     */
    public void syncLastSaveOrLoadTimeToActualFile() {
        if (loc.isLocalAndExists()) {
            lastSaveOrLoadTime = loc.getActualLastModified();
        }
    }


}