ConsoleDocument.java

/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You 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 org.apache.ivyde.internal.eclipse.ui.console;

public class ConsoleDocument {

    private int[] lineTypes;

    private String[] lines;

    private int writeIndex = 0;

    private int readIndex = 0;

    private static final int BUFFER_SIZE = 200;

    protected static class ConsoleLine {
        private String line;

        private int type;

        ConsoleLine(String line, int type) {
            this.line = line;
            this.type = type;
        }

        public String getLine() {
            return line;
        }

        public int getType() {
            return type;
        }
    }

    /**
     * Creates an empty console document.
     */
    public ConsoleDocument() {
        // nothing to initialize
    }

    /**
     * Clears the console document.
     */
    public void clear() {
        lineTypes = null;
        lines = null;
        writeIndex = 0;
        readIndex = 0;
    }

    /**
     * Appends a line of the specified type to the end of the console.
     */
    public void appendConsoleLine(int type, String line) {
        if (lines == null) {
            lines = new String[BUFFER_SIZE];
            lineTypes = new int[BUFFER_SIZE];
        }
        lines[writeIndex] = line; //$NON-NLS-1$
        lineTypes[writeIndex] = type;

        if (++writeIndex >= BUFFER_SIZE) {
            writeIndex = 0;
        }
        if (writeIndex == readIndex) {
            if (++readIndex >= BUFFER_SIZE) {
                readIndex = 0;
            }
        }
    }

    public ConsoleLine[] getLines() {
        if (isEmpty()) {
            return new ConsoleLine[0];
        }
        ConsoleLine[] docLines = new ConsoleLine[readIndex > writeIndex ? BUFFER_SIZE : writeIndex];
        int index = readIndex;
        for (int i = 0; i < docLines.length; i++) {
            docLines[i] = new ConsoleLine(lines[index], lineTypes[index]);
            if (++index >= BUFFER_SIZE) {
                index = 0;
            }
        }
        return docLines;
    }

    public boolean isEmpty() {
        return writeIndex == readIndex;
    }
}