/*
 * FSWaitForFrame.java
 * Transform
 * 
 * Copyright (c) 2001-2008 Flagstone Software Ltd. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, 
 * are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice, this
 *    list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 *  * Neither the name of Flagstone Software Ltd. nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package com.flagstone.transform;

/**
 * The FSWaitForFrame action instructs the player to wait until the specified
 * frame number has been loaded.
 * 
 * <p>
 * If the frame has been loaded then the actions in the following <i>n</i>
 * actions are executed. This action is most often used to execute a short
 * animation loop that plays until the main part of a movie has been loaded.
 * </p>
 * 
 * <table class="datasheet">
 * 
 * <tr>
 * <th align="left" colspan="2">Attributes</th>
 * </tr>
 * 
 * <tr>
 * <td>type</td>
 * <td>Identifies the action when it is encoded. Read-only.</td>
 * </tr>
 * 
 * <tr>
 * <td>frameNumber</td>
 * <td>The number of the frame to check to see whether it has been loaded.</td>
 * </tr>
 * 
 * <tr>
 * <td>actionCount</td>
 * <td>The number of actions, following the FSWaitForFrame action that will be
 * executed when the frame has been loaded.</td>
 * </tr>
 * </table>
 * 
 * <h1 class="datasheet">Examples</h1>
 * The following example instructs the Flash Player to wait until the eighth
 * frame of a movie clip has been loaded then to move the time-line to the
 * loaded frame:
 * 
 * <pre>
 * actions.add(new FSWaitForFrame(8, 1));
 * actions.add(new FSGotoFrame(8));
 * </pre>
 * 
 * <p>
 * This method of waiting until a frame has been loaded is considered obsolete.
 * Determining the number of frames loaded using the FramesLoaded property of
 * the Flash player in combination with an FSIf action is now the preferred
 * mechanism:
 * </p>
 * 
 * <pre>
 * FSDoAction actions = new FSDoAction();
 * 
 * actions.add(new FSPush(&quot;_root&quot;));
 * actions.add(new FSAction(FSAction.GetVariable));
 * actions.add(new FSPush(FSPush.FramesLoaded));
 * actions.add(new FSAction(FSAction.GetProperty));
 * actions.add(new FSPush(8));
 * actions.add(new FSAction(FSAction.Less));
 * actions.add(new FSIf(-29));
 * 
 * actions.add(new FSGotoFrame(8));
 * </pre>
 * 
 * <h1 class="datasheet">History</h1>
 * 
 * <p>
 * The FSWaitForFrame class represents the ActionWaitForFrame action of the
 * Macromedia Flash (SWF) File Format Specification. It was introduced in Flash
 * 3.
 * </p>
 */
public class FSWaitForFrame extends FSActionObject
{
	private int frameNumber = 1;
	private int actionCount = 0;

	/**
	 * Construct an FSWaitForFrame object, initialising it with values decoded
	 * from an encoded object.
	 * 
	 * @param coder
	 *            an FSCoder containing the binary data.
	 */
	public FSWaitForFrame(FSCoder coder)
	{
		super(WaitForFrame);
		decode(coder);
	}

	/**
	 * Constructs an FSWaitForFrame object with the specified frame number and
	 * the number of actions that will be executed when the frame is loaded.
	 * 
	 * @param aFrameNumber
	 *            the number of the frame to wait for.
	 * @param anActionCount
	 *            the number of actions to execute.
	 */
	public FSWaitForFrame(int aFrameNumber, int anActionCount)
	{
		super(WaitForFrame);
		setFrameNumber(aFrameNumber);
		setActionCount(anActionCount);
	}

	/**
	 * Constructs an FSWaitForFrame object by copying values from an existing
	 * object.
	 * 
	 * @param obj
	 *            an FSWaitForFrame object.
	 */
	public FSWaitForFrame(FSWaitForFrame obj)
	{
		super(obj);
		frameNumber = obj.frameNumber;
		actionCount = obj.actionCount;
	}

	/**
	 * Gets the frame number.
	 * 
	 * @return the number of the frame to wait for.
	 */
	public int getFrameNumber()
	{
		return frameNumber;
	}

	/**
	 * Gets the number of actions that will be executed when the specified frame
	 * is loaded.
	 * 
	 * @return the number of actions.
	 */
	public int getActionCount()
	{
		return actionCount;
	}

	/**
	 * Sets the frame number.
	 * 
	 * @param aNumber
	 *            the number of the frame to wait for.
	 */
	public void setFrameNumber(int aNumber)
	{
		frameNumber = aNumber;
	}

	/**
	 * Sets the number of actions to execute if the frame has been loaded.
	 * Unlike other actions it is the number of actions that are specified not
	 * the number of bytes in memory they occupy.
	 * 
	 * @param aNumber
	 *            the number of actions to execute.
	 */
	public void setActionCount(int aNumber)
	{
		actionCount = aNumber;
	}

	public boolean equals(Object anObject)
	{
		boolean result = false;

		if (super.equals(anObject))
		{
			FSWaitForFrame typedObject = (FSWaitForFrame) anObject;

			result = frameNumber == typedObject.frameNumber;
			result = result && actionCount == typedObject.actionCount;
		}
		return result;
	}

	public void appendDescription(StringBuffer buffer, int depth)
	{
		buffer.append(name());

		if (depth > 0)
		{
			buffer.append(": { ");
			Transform.append(buffer, "frameNumber", frameNumber);
			Transform.append(buffer, "actionCount", actionCount);
			buffer.append("}");
		}
	}

	public int length(FSCoder coder)
	{
		super.length(coder);

		length += 3;

		return length;
	}

	public void encode(FSCoder coder)
	{
		super.encode(coder);
		coder.writeWord(frameNumber, 2);
		coder.writeWord(actionCount, 1);
		coder.endObject(name());
	}

	public void decode(FSCoder coder)
	{
		super.decode(coder);
		frameNumber = coder.readWord(2, false);
		actionCount = coder.readWord(1, false);
		coder.endObject(name());
	}
}
