ColorBalance.java

/* 
 * Copyright (c) 2009 Levente Farkas
 * Copyright (c) 2009 Tamas Korodi <kotyo@zamba.fm>
 * 
 * This file is part of gstreamer-java.
 *
 * This code is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License version 3 only, as
 * published by the Free Software Foundation.
 *
 * This code 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 Lesser General Public License
 * version 3 for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * version 3 along with this work.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.gstreamer.interfaces;

import java.util.List;

import org.gstreamer.Element;
import org.gstreamer.lowlevel.GstAPI.GstCallback;

import com.sun.jna.Pointer;

import static org.gstreamer.lowlevel.GstColorBalanceAPI.GSTCOLORBALANCE_API;

public class ColorBalance extends GstInterface {
	/**
	 * Wraps the {@link Element} in a <tt>ColorBalance</tt> interface
	 * 
	 * @param element
	 *            the element to use as a <tt>ColorBalance</tt>
	 * @return a <tt>ColorBalance</tt> for the element
	 */
	public static final ColorBalance wrap(Element element) {
		return new ColorBalance(element);
	}

	/**
	 * Creates a new ColorBalance instance
	 * 
	 * @param element
	 *            the element that implements the ColorBalance interface
	 */
	private ColorBalance(Element element) {
		super(element, GSTCOLORBALANCE_API.gst_color_balance_get_type());
	}

	/**
	 * Retrieves a list of ColorBalanceChannels from the ColorBalance
	 * 
	 * @return a list of color balance channels available on this device
	 */
	public List<ColorBalanceChannel> getChannelList() {
		return objectList(GSTCOLORBALANCE_API.gst_color_balance_list_channels(this),
				new ListElementCreator<ColorBalanceChannel>() {
					public ColorBalanceChannel create(Pointer pointer) {
						return channelFor(pointer, true);
					}
				});
	}

	/**
	 * Retrieves a ColorBalanceChannel for the given Pointer
	 * 
	 * @param pointer
	 * @param needRef
	 * @return a ColorBalanceChannel instance
	 */
	private final ColorBalanceChannel channelFor(Pointer pointer,
			boolean needRef) {
		return new ColorBalanceChannel(this, pointer, needRef, true);
	}

	/**
	 * Signal emitted when color balance value changed
	 * 
	 * @see #connect(VALUE_CHANGED)
	 * @see #disconnect(VALUE_CHANGED)
	 */
	public static interface VALUE_CHANGED {
		/**
		 * Called when the color balance channel value changes
		 */
		public void colorBalanceValueChanged(ColorBalance colorBalance,
				ColorBalanceChannel channel, int value);
	}

	/**
	 * Add a listener for norm-changed messages.
	 * 
	 * @param listener
	 *            the listener to be called when the norm changes
	 */
	public void connect(final VALUE_CHANGED listener) {
		element.connect(VALUE_CHANGED.class, listener, new GstCallback() {
			@SuppressWarnings("unused")
			public boolean callback(Pointer colorBalance, ColorBalanceChannel channel, int value) {
				listener.colorBalanceValueChanged(ColorBalance.this, channel, value);
				return true;
			}
		});
	}

	/**
	 * Disconnect the listener for norm-changed messages.
	 * 
	 * @param listener
	 *            the listener that was registered to receive the message.
	 */
	public void disconnect(VALUE_CHANGED listener) {
		element.disconnect(VALUE_CHANGED.class, listener);
	}

}