//
// TextEditor.java
//
/*
VisAD system for interactive analysis and visualization of numerical
data. Copyright (C) 1996 - 2017 Bill Hibbard, Curtis Rueden, Tom
Rink, Dave Glowacki, Steve Emmerson, Tom Whittaker, Don Murray, and
Tommy Jasmin.
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
MA 02111-1307, USA
*/
package visad.util;
import java.awt.Font;
import java.io.*;
import javax.swing.*;
import javax.swing.text.JTextComponent;
import javax.swing.event.*;
import javax.swing.undo.*;
/** A general-purpose editor for reading and writing text files. */
public class TextEditor extends JScrollPane implements UndoableEditListener {
/** monospaced font */
public static final Font MONO = new Font("monospaced", Font.PLAIN, 12);
/** debugging flag */
public static final boolean DEBUG = false;
/** main text area */
protected JTextArea text;
/** file chooser dialog box */
private JFileChooser fileChooser;
/** undo manager */
protected UndoManager undo = new UndoManager();
/** file being edited */
protected File currentFile;
/** whether the text has changed since last save */
protected boolean changed = false;
/** constructs a TextEditor */
public TextEditor() {
this(null);
}
/** constructs a TextEditor containing text from the given filename */
public TextEditor(String filename) {
super();
text = new JTextArea();
// load file, if any
try {
openFile(filename);
}
catch (IOException exc) {
if (DEBUG) exc.printStackTrace();
}
// setup text area
text.setFont(MONO);
setViewportView(text);
// provide support for undo and redo
addUndoableEditListener(this);
// setup file chooser dialog box
}
/** Create and initialize the the file chooser */
protected JFileChooser doMakeFileChooser() {
JFileChooser tmpChooser = new JFileChooser(System.getProperty("user.dir"));
tmpChooser.addChoosableFileFilter(
new ExtensionFileFilter("txt", "Text files"));
return tmpChooser;
}
/** Create if needed and return the file chooser */
protected JFileChooser getFileChooser() {
if(fileChooser == null) {
fileChooser = doMakeFileChooser();
}
return fileChooser;
}
/** starts from scratch with a blank document */
public void newFile() {
currentFile = null;
setText("");
undo.discardAllEdits();
changed = false;
}
/** opens the given file */
public void openFile(String filename) throws IOException {
File file = (filename == null ? null : new File(filename));
openFile(file);
}
/** opens the given file */
public void openFile(File file) throws IOException {
String fileText;
if (file == null) fileText = "";
else {
int len = (int) file.length();
byte[] bytes = new byte[len];
FileInputStream in = new FileInputStream(file);
in.read(bytes);
in.close();
fileText = new String(bytes);
}
currentFile = file;
setText(fileText);
changed = false;
}
/** saves the given file */
public void saveFile(String filename) throws IOException {
File file = (filename == null ? null : new File(filename));
saveFile(file);
}
/** saves the given file */
public void saveFile(File file) throws IOException {
byte[] bytes = getText().getBytes();
FileOutputStream out = new FileOutputStream(file);
out.write(bytes);
out.close();
currentFile = file;
changed = false;
}
/** pops up a dialog box for the user to select a file to open */
public boolean openDialog() {
getFileChooser().setDialogType(JFileChooser.OPEN_DIALOG);
if (getFileChooser().showOpenDialog(this) != JFileChooser.APPROVE_OPTION) {
// user has canceled request
return false;
}
try {
openFile(getFileChooser().getSelectedFile());
}
catch (IOException exc) {
if (DEBUG) exc.printStackTrace();
return false;
}
return true;
}
/** pops up a dialog box for the user to select a file to save */
public boolean saveDialog() {
getFileChooser().setDialogType(JFileChooser.SAVE_DIALOG);
if (getFileChooser().showSaveDialog(this) != JFileChooser.APPROVE_OPTION) {
// user has canceled request
return false;
}
try {
saveFile(getFileChooser().getSelectedFile());
}
catch (IOException exc) {
if (DEBUG) exc.printStackTrace();
return false;
}
return true;
}
/** saves the file under its current name */
public boolean saveFile() {
boolean success = false;
if (currentFile == null) success = saveDialog();
else {
try {
saveFile(currentFile);
success = true;
}
catch (IOException exc) {
// display error box
JOptionPane.showMessageDialog(this, "Could not save the file.",
"VisAD Text Editor", JOptionPane.ERROR_MESSAGE);
}
}
return success;
}
/** undoes the last edit */
public void undo() throws CannotUndoException {
undo.undo();
changed = true;
}
/** redoes the last undone edit */
public void redo() throws CannotRedoException {
undo.redo();
changed = true;
}
/** cuts the selected text to the clipboard */
public void cut() {
text.cut();
}
/** copies the selected text to the clipboard */
public void copy() {
text.copy();
}
/** pastes the clipboard into the text document */
public void paste() {
text.paste();
}
/**
* Provide direct access to the text component
*
* @return the text component
*/
public JTextComponent getTextComponent() {
return text;
}
/** returns a string containing the text of the document */
public String getText() {
return text.getText();
}
/** sets the text of this document to the current string */
public void setText(String text) {
this.text.setText(text);
}
/**
* Insert the given text at the caret
*
* @param textToInsert the text
*/
public void insertText(String textToInsert) {
int pos = this.text.getCaretPosition();
String t = this.text.getText();
t = t.substring(0, pos) + textToInsert + t.substring(pos);
this.text.setText(t);
this.text.setCaretPosition(pos + textToInsert.length());
}
/** returns the filename being edited */
public String getFilename() {
return (currentFile == null ? null : currentFile.getPath());
}
/** returns the file being edited */
public File getFile() {
return currentFile;
}
/** returns whether an undo command is possible */
public boolean canUndo() {
return undo.canUndo();
}
/** returns whether a redo command is possible */
public boolean canRedo() {
return undo.canRedo();
}
/** returns the name of the undo command */
public String getUndoName() {
return undo.getUndoPresentationName();
}
/** returns the name of the redo command */
public String getRedoName() {
return undo.getRedoPresentationName();
}
/** returns whether the document has changed since the last save */
public boolean hasChanged() {
return changed;
}
/** handle undoable edits */
public void undoableEditHappened(UndoableEditEvent e) {
if (!e.getEdit().isSignificant()) return;
undo.addEdit(e.getEdit());
changed = true;
}
/** add an undoable edit listener */
public void addUndoableEditListener(UndoableEditListener l) {
text.getDocument().addUndoableEditListener(l);
}
/** remove an undoable edit listener */
public void removeUndoableEditListener(UndoableEditListener l) {
text.getDocument().removeUndoableEditListener(l);
}
}
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