ShowFrameTag.cs :  » GUI » SwfDotNet » SwfDotNet » IO » Tags » C# / CSharp Open Source

/*
  SwfDotNet is an open source library for writing and reading 
  Macromedia Flash (SWF) bytecode.
  Copyright (C) 2005 Olivier Carpentier - Adelina foundation
  see Licence.cs for GPL full text!
    
  SwfDotNet.IO uses a part of the open source library SwfOp actionscript 
  byte code management, writted by Florian Krsch, Copyright (C) 2004 .
  
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
  
  This library 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
  General Public License for more details.
  
  You should have received a copy of the GNU General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
using System;
using System.IO;
using System.Xml;
using System.Collections;

using SwfDotNet.IO.Utils;
using SwfDotNet.IO.Tags;

namespace SwfDotNet.IO.Tags{
  
  /// <summary>
  /// ShowFrameTag tag is used to instruct the Flash Player to 
  /// display a single frame in a movie or movie clip.
  /// </summary>
  /// <remarks>
  /// <p>
  /// When a frame is displayed the Flash Player performs the following:
  /// <ul>
  /// <li>The contents of the Flash Player's display list are drawn on the screen.</li>
  /// <li>Any actions defined using a DoActionTag object are executed.</li>
  /// </ul>
  /// </p>
  /// <p>
  /// Objects are placed in the display list using the PlaceObjectTag and 
  /// PlaceObject2Tag classes and removed using the RemoveObjectTag and 
  /// RemoveObject2Tag classes. An object which has been added to the 
  /// display list will be displayed in each frame until it is explicitly 
  /// removed. There is no need to repeatedly add it to the display list.
  /// </p>
  /// <p>
  /// The scope of a frame is delineated by successive ShowFrameTag objects. 
  /// All the commands that affect change the state of the display list or 
  /// define actions to be executed take effect when the Flash Player displays 
  /// the frame. All the objects displayed in a frame must be defined before 
  /// they can be displayed. The movie is displayed as it is downloaded so 
  /// displaying objects that are defined later in a movie is not allowed.
  /// </p>
  /// <p>
  /// This tag was introduced in Flash 1.
  /// </p>
  /// </remarks>
  /// <example>
    /// <p>
    /// <code lang="C#">
    /// Swf swf = new Swf();
    /// // Frame 1 - starts from the beginning of the file....
    /// swf.Add(new ShowFrameTag());
    /// // Frame 2 - starts when the previous frame is displayed.
    /// // All displayable objects are referenced using unique identifier.
    /// int identifer = swf.newIdentifier();
    /// // Define a shape to be displayed.
    /// swf.Add(new DefineShapeTag(identifer, ......));
    /// // Add the shape to the display list - on layer 1 at coordinates (400, 400)
    /// swf.Add(new PlaceObjectTag(identifier, 1, 400, 400));
    /// // Add some actions
    /// DoActionTag frameActions = new DoActionTag(); 
    /// frameActions.add(anAction);
    /// frameActions.add(anotherAction);
    /// swf.Add(frameActions);
    /// // The shape is displayed and the actions executed when the FSShowFrame command is executed.
    /// swf.Add(new ShowFrameTag());
    /// </code>
    /// </p>
  /// </example>
  public class ShowFrameTag : BaseTag 
    {
        #region Ctor

        /// <summary>
        /// Creates a new <see cref="ShowFrameTag"/> instance.
        /// </summary>
    public ShowFrameTag() 
    {
      this._tagCode = (int)TagCodeEnum.ShowFrame;
    }

        #endregion

        #region Methods

        /// <summary>
        /// see <see cref="SwfDotNet.IO.Tags.BaseTag">base class</see>
        /// </summary>
        public override void ReadData(byte version, BufferedBinaryReader binaryReader)
        {
            RecordHeader rh = new RecordHeader();
            rh.ReadData(binaryReader);
        }
    
    /// <summary>
    /// see <see cref="SwfDotNet.IO.Tags.BaseTag">base class</see>
    /// </summary>
    public override void UpdateData(byte version) 
    {      
      MemoryStream m = new MemoryStream();
      BufferedBinaryWriter w = new BufferedBinaryWriter(m);
      
      RecordHeader rh = new RecordHeader(TagCode, 0);
      rh.WriteTo(w);
      
            w.Flush();
      // write to data array
      _data = m.ToArray();  
    }    

    /// <summary>
    /// Serializes the specified writer.
    /// </summary>
    /// <param name="writer">Writer.</param>
    public override void Serialize(XmlWriter writer)
    {
      writer.WriteStartElement("ShowFrameTag");
      writer.WriteEndElement();
    }

    #endregion
  }
}