/*
    * Copyright (c) 2005, the JUNG Project and the Regents of the University of
    * California All rights reserved.
    *
    * This software is open-source under the BSD license; see either "license.txt"
    * or http://jung.sourceforge.net/license.txt for a description.
    *
    * Created on Apr 14, 2005
    */
  
  package edu.uci.ics.jung.visualization.renderers;
  
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.Font;
  import java.awt.Rectangle;
  import java.io.Serializable;
  
  import javax.swing.JComponent;
  import javax.swing.JLabel;
  import javax.swing.border.Border;
  import javax.swing.border.EmptyBorder;
  
  /**
   * DefaultVertexLabelRenderer is similar to the cell renderers
   * used by the JTable and JTree jfc classes.
   * 
   * @author Tom Nelson
   *
   * 
   */
  @SuppressWarnings("serial")
  public class DefaultVertexLabelRenderer extends JLabel implements
          VertexLabelRenderer, Serializable {
  
       protected static Border noFocusBorder = new EmptyBorder(0,0,0,0); 
      
       protected Color pickedVertexLabelColor = Color.black;
       
      /**
       * Creates a default table cell renderer.
       */
      public DefaultVertexLabelRenderer(Color pickedVertexLabelColor) {
          this.pickedVertexLabelColor = pickedVertexLabelColor;
          setOpaque(true);
          setBorder(noFocusBorder);
      }
  
      /**
       * Overrides <code>JComponent.setForeground</code> to assign
       * the unselected-foreground color to the specified color.
       * 
       * @param c set the foreground color to this value
       */
      @Override
      public void setForeground(Color c) {
          super.setForeground(c); 
      }
      
      /**
       * Overrides <code>JComponent.setBackground</code> to assign
       * the unselected-background color to the specified color.
       *
       * @param c set the background color to this value
       */
      @Override
      public void setBackground(Color c) {
          super.setBackground(c); 
      }
  
      /**
       * Notification from the <code>UIManager</code> that the look and feel
       * [L&F] has changed.
       * Replaces the current UI object with the latest version from the 
       * <code>UIManager</code>.
       *
       * @see JComponent#updateUI
       */
      @Override
      public void updateUI() {
          super.updateUI(); 
          setForeground(null);
          setBackground(null);
      }
      
      /**
       *
       * Returns the default label renderer for a Vertex
       *
       * @param vv  the <code>VisualizationViewer</code> to render on
       * @param value  the value to assign to the label for
       *			<code>Vertex</code>
       * @param vertex  the <code>Vertex</code>
       * @return the default label renderer
       */
      public <V> Component getVertexLabelRendererComponent(JComponent vv, Object value,
              Font font, boolean isSelected, V vertex) {
          
          super.setForeground(vv.getForeground());
         if(isSelected) setForeground(pickedVertexLabelColor);
         super.setBackground(vv.getBackground());
         if(font != null) {
             setFont(font);
         } else {
             setFont(vv.getFont());
         }
         setIcon(null);
         setBorder(noFocusBorder);
         setValue(value); 
         return this;
     }
     
     /*
      * The following methods are overridden as a performance measure to 
      * to prune code-paths are often called in the case of renders
      * but which we know are unnecessary.  Great care should be taken
      * when writing your own renderer to weigh the benefits and 
      * drawbacks of overriding methods like these.
      */
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public boolean isOpaque() { 
         Color back = getBackground();
         Component p = getParent(); 
         if (p != null) { 
             p = p.getParent(); 
         }
         boolean colorMatch = (back != null) && (p != null) && 
         back.equals(p.getBackground()) && 
         p.isOpaque();
         return !colorMatch && super.isOpaque(); 
     }
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public void validate() {}
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public void revalidate() {}
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public void repaint(long tm, int x, int y, int width, int height) {}
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public void repaint(Rectangle r) { }
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     protected void firePropertyChange(String propertyName, Object oldValue, Object newValue) {	
         // Strings get interned...
         if (propertyName=="text") {
             super.firePropertyChange(propertyName, oldValue, newValue);
         }
     }
 
     /**
      * Overridden for performance reasons.
      * See the <a href="#override">Implementation Note</a> 
      * for more information.
      */
     @Override
     public void firePropertyChange(String propertyName, boolean oldValue, boolean newValue) { }
 
     /**
      * Sets the <code>String</code> object for the cell being rendered to
      * <code>value</code>.
      * 
      * @param value  the string value for this cell; if value is
      *		<code>null</code> it sets the text value to an empty string
      * @see JLabel#setText
      * 
      */
     protected void setValue(Object value) {
         setText((value == null) ? "" : value.toString());
     }
 }