shell.gui.plugin/src/main/java/org/apache/felix/shell/gui/plugin/ScrollableOutputArea.java

/*
 *   Copyright 2006 The Apache Software Foundation
 *
 *   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 org.apache.felix.shell.gui.plugin;

import java.awt.Font;

import javax.swing.*;

public class ScrollableOutputArea extends JScrollPane
{
    private JTextArea m_textArea = null;

    public ScrollableOutputArea()
    {
        super();
        m_textArea = new JTextArea();
        initialize();
    }

    public ScrollableOutputArea(int rows, int columns)
    {
        super();
        m_textArea = new JTextArea(rows, columns);
        initialize();
    }

    private void initialize()
    {
        setViewportView(m_textArea);
        m_textArea.setLineWrap(true);
        m_textArea.setAutoscrolls(true);
        m_textArea.setEnabled(true);
        m_textArea.setEditable(false);
        m_textArea.setFont(new Font("Monospaced", 0, 12));
        setAutoscrolls(true);
    }

    public void setText(String s)
    {
        m_textArea.setText(s);
    }

    public void addText(String text)
    {
        m_textArea.append(text);
        if (m_textArea.isDisplayable())
        {
            try
            {
                m_textArea.setCaretPosition(Integer.MAX_VALUE); // Scroll to end of window
            }
            catch (Exception e)
            {
                // Just for safety
            }
        }
        validate();
        JScrollBar sb = getVerticalScrollBar();
        if ((sb != null) && (sb.isVisible()))
        {
            sb.setValue(Integer.MAX_VALUE);
        }
    }
}