content: package tim.prune.cmd;
  
  import tim.prune.data.TrackInfo;
  
  /**
   * Superclass of all commands, which can be executed on the TrackInfo object
   */
  public abstract class Command
  {
  	private Command _inverse;
  	private final boolean _isUndo;
  	// description is used for undo and redo
  	private String _descriptionText = null;
  	private String _confirmText = null;
  
  
  	protected Command(Command inParent) {
  		_inverse = inParent;
  		_isUndo = (_inverse != null);
  	}
  
  	public Command getInverse() {
  		return _inverse;
  	}
  
  	protected boolean isUndo() {
  		return _isUndo;
  	}
  
  	public final boolean execute(TrackInfo inInfo)
  	{
  		if (_inverse == null)
  		{
  			_inverse = makeInverse(inInfo);
  			assert _inverse == null || _inverse._inverse != null;
  		}
  		return executeCommand(inInfo);
  	}
  
  	protected void setInverse(Command inCommand) {
  		_inverse = inCommand;
  	}
  
  	protected abstract boolean executeCommand(TrackInfo inInfo);
  
  	protected abstract Command makeInverse(TrackInfo inInfo);
  
  	public String getDescription() {
  		return _descriptionText;
  	}
  
  	public String getConfirmText() {
  		return _confirmText;
  	}
  
  	public void setDescription(String inText) {
  		_descriptionText = inText;
  	}
  
  	public void setConfirmText(String inText) {
  		_confirmText = inText;
  	}
  
  	public abstract int getUpdateFlags();
  }
  