/*******************************************************************************
* Copyright 2015 Maximilian Stark | Dakror <mail@dakror.de>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package de.dakror.arise.ui;
import java.awt.Color;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import javax.swing.text.SimpleAttributeSet;
import javax.swing.text.StyleConstants;
/*
* Create a simple console to display text messages.
* Messages can be directed here from different sources. Each source can
* have its messages displayed in a different color.
* Messages can either be appended to the console or inserted as the first
* line of the console
* You can limit the number of lines to hold in the Document.
*/
public class MessageConsole {
private JTextComponent textComponent;
private Document document;
private boolean isAppend;
private DocumentListener limitLinesListener;
public MessageConsole(JTextComponent textComponent) {
this(textComponent, true);
}
/*
* Use the text component specified as a simply console to display
* text messages.
* The messages can either be appended to the end of the console or
* inserted as the first line of the console.
*/
public MessageConsole(JTextComponent textComponent, boolean isAppend) {
this.textComponent = textComponent;
document = textComponent.getDocument();
this.isAppend = isAppend;
textComponent.setEditable(false);
}
/*
* Redirect the output from the standard output to the console
* using the default text color and null PrintStream
*/
public void redirectOut() {
redirectOut(null, null);
}
/*
* Redirect the output from the standard output to the console
* using the specified color and PrintStream. When a PrintStream
* is specified the message will be added to the Document before
* it is also written to the PrintStream.
*/
public void redirectOut(Color textColor, PrintStream printStream) {
ConsoleOutputStream cos = new ConsoleOutputStream(textColor, printStream);
System.setOut(new PrintStream(cos, true));
}
/*
* Redirect the output from the standard error to the console
* using the default text color and null PrintStream
*/
public void redirectErr() {
redirectErr(null, null);
}
/*
* Redirect the output from the standard error to the console
* using the specified color and PrintStream. When a PrintStream
* is specified the message will be added to the Document before
* it is also written to the PrintStream.
*/
public void redirectErr(Color textColor, PrintStream printStream) {
ConsoleOutputStream cos = new ConsoleOutputStream(textColor, printStream);
System.setErr(new PrintStream(cos, true));
}
/*
* To prevent memory from being used up you can control the number of
* lines to display in the console
* This number can be dynamically changed, but the console will only
* be updated the next time the Document is updated.
*/
public void setMessageLines(int lines) {
if (limitLinesListener != null) document.removeDocumentListener(limitLinesListener);
limitLinesListener = new LimitLinesDocumentListener(lines, isAppend);
document.addDocumentListener(limitLinesListener);
}
/*
* Class to intercept output from a PrintStream and add it to a Document.
* The output can optionally be redirected to a different PrintStream.
* The text displayed in the Document can be color coded to indicate
* the output source.
*/
class ConsoleOutputStream extends ByteArrayOutputStream {
private final String EOL = System.getProperty("line.separator");
private SimpleAttributeSet attributes;
private PrintStream printStream;
private StringBuffer buffer = new StringBuffer(80);
private boolean isFirstLine;
/*
* Specify the option text color and PrintStream
*/
public ConsoleOutputStream(Color textColor, PrintStream printStream) {
if (textColor != null) {
attributes = new SimpleAttributeSet();
StyleConstants.setForeground(attributes, textColor);
}
this.printStream = printStream;
if (isAppend) isFirstLine = true;
}
/*
* Override this method to intercept the output text. Each line of text
* output will actually involve invoking this method twice:
* a) for the actual text message
* b) for the newLine string
* The message will be treated differently depending on whether the line
* will be appended or inserted into the Document
*/
@Override
public void flush() {
String message = toString();
if (message.length() == 0) return;
if (isAppend) handleAppend(message);
else handleInsert(message);
reset();
}
/*
* We don't want to have blank lines in the Document. The first line
* added will simply be the message. For additional lines it will be:
* newLine + message
*/
private void handleAppend(String message) {
if (EOL.equals(message)) {
buffer.append(message);
} else {
buffer.append(message);
clearBuffer();
}
}
/*
* We don't want to merge the new message with the existing message
* so the line will be inserted as:
* message + newLine
*/
private void handleInsert(String message) {
buffer.append(message);
if (EOL.equals(message)) {
clearBuffer();
}
}
/*
* The message and the newLine have been added to the buffer in the
* appropriate order so we can now update the Document and send the
* text to the optional PrintStream.
*/
private void clearBuffer() {
// In case both the standard out and standard err are being redirected
// we need to insert a newline character for the first line only
if (isFirstLine && document.getLength() != 0) {
buffer.insert(0, "\n");
}
isFirstLine = false;
String line = buffer.toString();
try {
if (isAppend) {
int offset = document.getLength();
document.insertString(offset, line, attributes);
textComponent.setCaretPosition(document.getLength());
} else {
document.insertString(0, line, attributes);
textComponent.setCaretPosition(0);
}
} catch (BadLocationException ble) {}
if (printStream != null) {
printStream.print(line);
}
buffer.setLength(0);
}
}
}