package org.opentrafficsim.swing.gui;
   
   import java.awt.BorderLayout;
   import java.awt.Container;
   import java.awt.FlowLayout;
   import java.awt.event.ActionEvent;
   import java.awt.event.ActionListener;
   
   import javax.swing.JComboBox;
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.border.Border;
  import javax.swing.border.LineBorder;
  
  import org.opentrafficsim.core.animation.gtu.colorer.GTUColorer;
  import org.opentrafficsim.core.animation.gtu.colorer.SwitchableGTUColorer;
  
  /**
   * Let the user select what the colors in the animation mean.
   * <p>
   * Copyright (c) 2013-2019 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="http://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * <p>
   * $LastChangedDate: 2018-10-11 22:54:04 +0200 (Thu, 11 Oct 2018) $, @version $Revision: 4696 $, by $Author: averbraeck $,
   * initial version 27 mei 2015 <br>
   * @author <a href="http://www.tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class ColorControlPanel extends JPanel implements ActionListener
  {
      /** */
      private static final long serialVersionUID = 20150527L;
  
      /** The combo box that sets the coloring for the GTUs. */
      private JComboBox<GTUColorer> comboBoxGTUColor;
  
      /** The panel that holds the legend for the currently selected GTUColorer. */
      private final JPanel legendPanel;
  
      /** The GTUColorer that is currently active. */
      private GTUColorer gtuColorer;
  
      /** The SwitchableGTUColorer that is controlled by this ColorControlPanel, if available. */
      private final SwitchableGTUColorer switchableGTUColorer;
  
      /**
       * Add a ColorControlPanel to an AnimationPanel. Initially the ColorControlPanel will have no items. Items are added with
       * the <code>addItem</code> method. The first item added automatically becomes the active one.
       * @param gtuColorer GTUColorer; the switchable GTU colorer that will be controlled by this ColorControlPanel
       */
      public ColorControlPanel(final GTUColorer gtuColorer)
      {
          this.setLayout(new FlowLayout(FlowLayout.LEFT));
          this.legendPanel = new JPanel(new FlowLayout());
  
          if (gtuColorer instanceof SwitchableGTUColorer)
          {
              this.switchableGTUColorer = (SwitchableGTUColorer) gtuColorer;
  
              /**
               * ComboBox for AppearanceControl.
               * @param <T> generic type of the ComboBox
               */
              class AppearanceControlComboBox<T> extends JComboBox<T> implements AppearanceControl
              {
                  /** */
                  private static final long serialVersionUID = 1L;
  
                  /** {@inheritDoc} */
                  @Override
                  public boolean isFont()
                  {
                      return true;
                  }
  
                  /** {@inheritDoc} */
                  @Override
                  public String toString()
                  {
                      return "AppearanceControlComboBox []";
                  }
  
              }
              this.comboBoxGTUColor = new AppearanceControlComboBox<>();
              this.add(this.comboBoxGTUColor);
              this.comboBoxGTUColor.addActionListener(this);
  
              for (GTUColorer colorer : ((SwitchableGTUColorer) gtuColorer).getColorers())
              {
                  addItem(colorer);
              }
          }
          else
          {
              this.gtuColorer = gtuColorer;
              this.switchableGTUColorer = null;
              rebuildLegend();
          }
  
          this.add(this.legendPanel);
     }
 
     /**
      * Add one item to this ColorControlPanel. The <cite>getName</cite> method of the
      * @param colorer GTUColorer; the GTUColorer that will be added
      */
     public final void addItem(final GTUColorer colorer)
     {
         this.comboBoxGTUColor.addItem(colorer);
         // The first item added automatically becomes the current one and triggers a call to actionPerformed.
     }
 
     /** {@inheritDoc} */
     @Override
     public final void actionPerformed(final ActionEvent e)
     {
         GTUColorer newColorer = (GTUColorer) this.comboBoxGTUColor.getSelectedItem();
         if (null != newColorer)
         {
             this.gtuColorer = newColorer;
             rebuildLegend();
 
             if (this.switchableGTUColorer != null)
             {
                 this.switchableGTUColorer.setGTUColorer(this.comboBoxGTUColor.getSelectedIndex());
             }
         }
     }
 
     /**
      * Build or rebuild the legend on the screen.
      */
     private void rebuildLegend()
     {
         this.legendPanel.removeAll();
         for (GTUColorer.LegendEntry legendEntry : this.gtuColorer.getLegend())
         {
             JPanel panel = new JPanel(new BorderLayout());
             /**
              * ColorBox for AppearanceControl.
              */
             class ColorBox extends JLabel implements AppearanceControl
             {
                 /** */
                 private static final long serialVersionUID = 20180206L;
 
                 /**
                  * Constructor.
                  */
                 ColorBox()
                 {
                     super("     ");
                 }
 
                 /** {@inheritDoc} */
                 @Override
                 public String toString()
                 {
                     return "ColorBox []";
                 }
 
             }
             ColorBox colorBox = new ColorBox();
             colorBox.setOpaque(true); // By default, the label is transparent
             colorBox.setBackground(legendEntry.getColor());
             Border border = LineBorder.createBlackLineBorder();
             colorBox.setBorder(border);
             panel.add(colorBox, BorderLayout.LINE_START);
             JLabel name = new JLabel(" " + legendEntry.getName().trim());
             panel.add(name, BorderLayout.CENTER);
             name.setOpaque(true);
             name.setForeground(getForeground());
             name.setBackground(getBackground());
             panel.setToolTipText(legendEntry.getDescription());
             this.legendPanel.add(panel);
         }
         this.legendPanel.revalidate();
 
         Container parentPanel = this.getParent();
 
         if (parentPanel != null)
         {
             parentPanel.repaint();
         }
     }
 
     /** {@inheritDoc} */
     @Override
     public final String toString()
     {
         return "ColorControlPanel [gtuColorer=" + this.gtuColorer + "]";
     }
 
 }