BaseDemoOutputStream.java

/*
  BaseDemoOutputStream.java

  (c) 2012-2013 Edward Swartz

  All rights reserved. This program and the accompanying materials
  are made available under the terms of the Eclipse Public License v1.0
  which accompanies this distribution, and is available at
  http://www.eclipse.org/legal/epl-v10.html
 */
package v9t9.engine.demos.stream;

import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import v9t9.common.demos.IDemoOutputBuffer;
import v9t9.common.demos.IDemoOutputStream;
import ejs.base.utils.CountingOutputStream;

/**
 * @author ejs
 *
 */
public abstract class BaseDemoOutputStream implements IDemoOutputStream {

	protected final CountingOutputStream os;
	
	protected abstract void writeTimerTick() throws IOException;

	protected List<IDemoOutputBuffer> buffers = new ArrayList<IDemoOutputBuffer>(4);

	/**
	 * @param os 
	 * 
	 */
	public BaseDemoOutputStream(OutputStream os_) {
		this.os = os_ instanceof CountingOutputStream ? (CountingOutputStream) os_ : new CountingOutputStream(os_);
		
	}

	public synchronized void close() throws IOException {
		flushAll();

		preClose();
		
		if (os != null) {
			os.close();
		}
		
		buffers.clear();
	}

	/**
	 * Called immediately before closing.
	 * @throws IOException
	 */
	protected void preClose() throws IOException {
		
	}


	protected boolean anythingToFlush() {
		boolean any = false;
		for (IDemoOutputBuffer buffer : buffers) {
			any |= !buffer.isEmpty();
		}
		return any;
	}
	
	protected void flushAll() throws IOException {
		for (IDemoOutputBuffer buffer : buffers) {
			buffer.flush();
		}
	}

	/* (non-Javadoc)
	 * @see v9t9.common.demo.IDemoOutputStream#getPosition()
	 */
	@Override
	public long getPosition() {
		return os.getPosition();
	}
	
	/* (non-Javadoc)
	 * @see v9t9.common.demo.IDemoOutputStream#getOutputStream()
	 */
	@Override
	public OutputStream getOutputStream() {
		return os;
	}
}