content: package tim.prune.load.babel;
  
  import java.awt.event.KeyAdapter;
  import java.awt.event.KeyEvent;
  import java.awt.event.KeyListener;
  
  import javax.swing.JPanel;
  import javax.swing.SwingUtilities;
  
  /**
   * Superclass of all the filter definition panels, to be added in the cardset
   * of the AddFilterDialog
   */
  public abstract class FilterDefinition extends JPanel
  {
  	/** Parent dialog to inform of parameter changes */
  	private AddFilterDialog _parentDialog = null;
  	/** Listener for key presses on the parameter entry fields */
  	protected KeyListener _paramChangeListener = null;
  
  	/**
  	 * Constructor
  	 */
  	public FilterDefinition(AddFilterDialog inFilterDialog)
  	{
  		_parentDialog = inFilterDialog;
  		_paramChangeListener = new KeyAdapter() {
  			public void keyTyped(KeyEvent arg0) {
  				SwingUtilities.invokeLater(() -> _parentDialog.filterParamsChanged());
  			}
  		};
  	}
  
  	/**
  	 * @return true if the filter definition is valid
  	 */
  	public abstract boolean isFilterValid();
  
  	/**
  	 * @return filter definition to pass to gpsbabel
  	 */
  	public String getString() {
  		return "-x " + getFilterName() + getParameters();
  	}
  
  	/** @return filter name */
  	protected abstract String getFilterName();
  
  	/** Construct the GUI elements and add them to the panel */
  	protected abstract void makePanelContents();
  
  	/** @return filter parameters */
  	protected abstract String getParameters();
  }
  