/*
   \* Copyright (c) 2003, The JUNG Authors 
   *
   * All rights reserved.
   *
   * This software is open-source under the BSD license; see either
   * "license.txt" or
   * https://github.com/jrtom/jung/blob/master/LICENSE for a description.
   */
  package edu.uci.ics.jung.visualization;
  
  import java.awt.Color;
  import java.awt.Dimension;
  import java.awt.Graphics;
  import java.awt.Graphics2D;
  import java.awt.RenderingHints;
  import java.awt.RenderingHints.Key;
  import java.awt.event.ComponentAdapter;
  import java.awt.event.ComponentEvent;
  import java.awt.event.ItemEvent;
  import java.awt.event.ItemListener;
  import java.awt.geom.AffineTransform;
  import java.awt.geom.Point2D;
  import java.awt.image.BufferedImage;
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import javax.swing.JPanel;
  import javax.swing.event.ChangeEvent;
  import javax.swing.event.ChangeListener;
  
  import edu.uci.ics.jung.algorithms.layout.GraphElementAccessor;
  import edu.uci.ics.jung.algorithms.layout.Layout;
  import edu.uci.ics.jung.visualization.control.ScalingControl;
  import edu.uci.ics.jung.visualization.decorators.PickableEdgePaintTransformer;
  import edu.uci.ics.jung.visualization.decorators.PickableVertexPaintTransformer;
  import edu.uci.ics.jung.visualization.picking.MultiPickedState;
  import edu.uci.ics.jung.visualization.picking.PickedState;
  import edu.uci.ics.jung.visualization.picking.ShapePickSupport;
  import edu.uci.ics.jung.visualization.renderers.BasicRenderer;
  import edu.uci.ics.jung.visualization.renderers.Renderer;
  import edu.uci.ics.jung.visualization.transform.shape.GraphicsDecorator;
  import edu.uci.ics.jung.visualization.util.Caching;
  import edu.uci.ics.jung.visualization.util.ChangeEventSupport;
  import edu.uci.ics.jung.visualization.util.DefaultChangeEventSupport;
  
  /**
   * A class that maintains many of the details necessary for creating 
   * visualizations of graphs.
   * This is the old VisualizationViewer without tooltips and mouse behaviors. Its purpose is
   * to be a base class that can also be used on the server side of a multi-tiered application.
   * 
   * @author Joshua O'Madadhain
   * @author Tom Nelson
   * @author Danyel Fisher
   */
  @SuppressWarnings("serial")
  public class BasicVisualizationServer<V, E> extends JPanel 
                  implements ChangeListener, ChangeEventSupport, VisualizationServer<V, E>{
  
      protected ChangeEventSupport changeSupport =
          new DefaultChangeEventSupport(this);
      
      /**
       * holds the state of this View
       */
      protected VisualizationModel<V,E> model;
  
  	/**
  	 * handles the actual drawing of graph elements
  	 */
  	protected Renderer<V,E> renderer = new BasicRenderer<V,E>();
  	
  	/**
  	 * rendering hints used in drawing. Anti-aliasing is on
  	 * by default
  	 */
  	protected Map<Key, Object> renderingHints = new HashMap<Key, Object>();
  		
  	/**
  	 * holds the state of which vertices of the graph are
  	 * currently 'picked'
  	 */
  	protected PickedState<V> pickedVertexState;
  	
  	/**
  	 * holds the state of which edges of the graph are
  	 * currently 'picked'
  	 */
      protected PickedState<E> pickedEdgeState;
      
      /**
       * a listener used to cause pick events to result in
       * repaints, even if they come from another view
       */
      protected ItemListener pickEventListener;
  	
 	/**
 	 * an offscreen image to render the graph
 	 * Used if doubleBuffered is set to true
 	 */
 	protected BufferedImage offscreen;
 	
 	/**
 	 * graphics context for the offscreen image
 	 * Used if doubleBuffered is set to true
 	 */
 	protected Graphics2D offscreenG2d;
 	
 	/**
 	 * user-settable choice to use the offscreen image
 	 * or not. 'false' by default
 	 */
 	protected boolean doubleBuffered;
 	
 	/**
 	 * a collection of user-implementable functions to render under
 	 * the topology (before the graph is rendered)
 	 */
 	protected List<Paintable> preRenderers = new ArrayList<Paintable>();
 	
 	/**
 	 * a collection of user-implementable functions to render over the
 	 * topology (after the graph is rendered)
 	 */
 	protected List<Paintable> postRenderers = new ArrayList<Paintable>();
 	
     protected RenderContext<V,E> renderContext;
     
     /**
      * Create an instance with the specified Layout.
      * 
      * @param layout		The Layout to apply, with its associated Graph
      */
 	public BasicVisualizationServer(Layout<V,E> layout) {
 	    this(new DefaultVisualizationModel<V,E>(layout));
 	    renderContext = new PluggableRenderContext<V,E>(layout.getGraph());
 	}
 	
     /**
      * Create an instance with the specified Layout and view dimension.
      * 
      * @param layout		The Layout to apply, with its associated Graph
      * @param preferredSize the preferred size of this View
      */
 	public BasicVisualizationServer(Layout<V,E> layout, Dimension preferredSize) {
 	    this(new DefaultVisualizationModel<V,E>(layout, preferredSize), preferredSize);
 	    renderContext = new PluggableRenderContext<V,E>(layout.getGraph());
 	}
 	
 	/**
 	 * Create an instance with the specified model and a default dimension (600x600).
 	 * 
 	 * @param model the model to use
 	 */
 	public BasicVisualizationServer(VisualizationModel<V,E> model) {
 	    this(model, new Dimension(600,600));
 	}
 	
 	/**
 	 * Create an instance with the specified model and view dimension.
 	 * 
 	 * @param model the model to use
 	 * @param preferredSize initial preferred size of the view
 	 */
     public BasicVisualizationServer(VisualizationModel<V,E> model,
 	        Dimension preferredSize) {
 	    this.model = model;
 	    renderContext = new PluggableRenderContext<V,E>(model.getGraphLayout().getGraph());
 	    model.addChangeListener(this);
 	    setDoubleBuffered(false);
 		this.addComponentListener(new VisualizationListener(this));
 
 		setPickSupport(new ShapePickSupport<V,E>(this));
 		setPickedVertexState(new MultiPickedState<V>());
 		setPickedEdgeState(new MultiPickedState<E>());
         
         renderContext.setEdgeDrawPaintTransformer(new PickableEdgePaintTransformer<E>(getPickedEdgeState(), Color.black, Color.cyan));
         renderContext.setVertexFillPaintTransformer(new PickableVertexPaintTransformer<V>(getPickedVertexState(), 
                 Color.red, Color.yellow));
 		
 		setPreferredSize(preferredSize);
 		renderingHints.put(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
 
         renderContext.getMultiLayerTransformer().addChangeListener(this);
 	}
 	
 	@Override
     public void setDoubleBuffered(boolean doubleBuffered) {
 	    this.doubleBuffered = doubleBuffered;
 	}
 	
 	@Override
     public boolean isDoubleBuffered() {
 	    return doubleBuffered;
 	}
 	
 	/**
 	 * Always sanity-check getSize so that we don't use a
 	 * value that is improbable
 	 * @see java.awt.Component#getSize()
 	 */
 	@Override
 	public Dimension getSize() {
 		Dimension d = super.getSize();
 		if(d.width <= 0 || d.height <= 0) {
 			d = getPreferredSize();
 		}
 		return d;
 	}
 
 	/**
 	 * Ensure that, if doubleBuffering is enabled, the offscreen
 	 * image buffer exists and is the correct size.
 	 * @param d the expected Dimension of the offscreen buffer
 	 */
 	protected void checkOffscreenImage(Dimension d) {
 	    if(doubleBuffered) {
 	        if(offscreen == null || offscreen.getWidth() != d.width || offscreen.getHeight() != d.height) {
 	            offscreen = new BufferedImage(d.width, d.height, BufferedImage.TYPE_INT_ARGB);
 	            offscreenG2d = offscreen.createGraphics();
 	        }
 	    }
 	}
 	
     public VisualizationModel<V,E> getModel() {
         return model;
     }
 
     public void setModel(VisualizationModel<V,E> model) {
         this.model = model;
     }
 
 	public void stateChanged(ChangeEvent e) {
 	    repaint();
 	    fireStateChanged();
 	}
 
 	public void setRenderer(Renderer<V,E> r) {
 	    this.renderer = r;
 	    repaint();
 	}
 	
 	public Renderer<V,E> getRenderer() {
 	    return renderer;
 	}
 
     public void setGraphLayout(Layout<V,E> layout) {
     	Dimension viewSize = getPreferredSize();
     	if(this.isShowing()) {
     		viewSize = getSize();
     	}
 	    model.setGraphLayout(layout, viewSize);
     }
     
     public void scaleToLayout(ScalingControl scaler) {
     	Dimension vd = getPreferredSize();
     	if(this.isShowing()) {
     		vd = getSize();
     	}
 		Dimension ld = getGraphLayout().getSize();
 		if(vd.equals(ld) == false) {
 			scaler.scale(this, (float)(vd.getWidth()/ld.getWidth()), new Point2D.Double());
 		}
     }
 	
 	public Layout<V,E> getGraphLayout() {
 	        return model.getGraphLayout();
 	}
 	
 	@Override
     public void setVisible(boolean aFlag) {
 		super.setVisible(aFlag);
 		if(aFlag == true) {
 			Dimension d = this.getSize();
 			if(d.width <= 0 || d.height <= 0) {
 				d = this.getPreferredSize();
 			}
 			model.getGraphLayout().setSize(d);
 		}
 	}
 
     public Map<Key, Object> getRenderingHints() {
         return renderingHints;
     }
     
     public void setRenderingHints(Map<Key, Object> renderingHints) {
         this.renderingHints = renderingHints;
     }
     
 	@Override
     protected void paintComponent(Graphics g) {
         super.paintComponent(g);
 
 		Graphics2D g2d = (Graphics2D)g;
 		if(doubleBuffered) {
 		    checkOffscreenImage(getSize());
 			renderGraph(offscreenG2d);
 		    g2d.drawImage(offscreen, null, 0, 0);
 		} else {
 		    renderGraph(g2d);
 		}
 	}
 	
 	protected void renderGraph(Graphics2D g2d) {
 	    if(renderContext.getGraphicsContext() == null) {
 	        renderContext.setGraphicsContext(new GraphicsDecorator(g2d));
         } else {
         	renderContext.getGraphicsContext().setDelegate(g2d);
         }
         renderContext.setScreenDevice(this);
 	    Layout<V,E> layout = model.getGraphLayout();
 
 		g2d.setRenderingHints(renderingHints);
 		
 		// the size of the VisualizationViewer
 		Dimension d = getSize();
 		
 		// clear the offscreen image
 		g2d.setColor(getBackground());
 		g2d.fillRect(0,0,d.width,d.height);
 
 		AffineTransform oldXform = g2d.getTransform();
         AffineTransform newXform = new AffineTransform(oldXform);
         newXform.concatenate(
         		renderContext.getMultiLayerTransformer().getTransformer(Layer.VIEW).getTransform());
 		
         g2d.setTransform(newXform);
 
 		// if there are  preRenderers set, paint them
 		for(Paintable paintable : preRenderers) {
 
 		    if(paintable.useTransform()) {
 		        paintable.paint(g2d);
 		    } else {
 		        g2d.setTransform(oldXform);
 		        paintable.paint(g2d);
                 g2d.setTransform(newXform);
 		    }
 		}
 		
         if(layout instanceof Caching) {
         	((Caching)layout).clear();
         }
         
         renderer.render(renderContext, layout);
 		
 		// if there are postRenderers set, do it
 		for(Paintable paintable : postRenderers) {
 
 		    if(paintable.useTransform()) {
 		        paintable.paint(g2d);
 		    } else {
 		        g2d.setTransform(oldXform);
 		        paintable.paint(g2d);
                 g2d.setTransform(newXform);
 		    }
 		}
 		g2d.setTransform(oldXform);
 	}
 
 	/**
 	 * VisualizationListener reacts to changes in the size of the
 	 * VisualizationViewer. When the size changes, it ensures
 	 * that the offscreen image is sized properly. 
 	 * If the layout is locked to this view size, then the layout
 	 * is also resized to be the same as the view size.
 	 *
 	 *
 	 */
 	protected class VisualizationListener extends ComponentAdapter {
 		protected BasicVisualizationServer<V,E> vv;
 		public VisualizationListener(BasicVisualizationServer<V,E> vv) {
 			this.vv = vv;
 		}
 
 		/**
 		 * create a new offscreen image for the graph
 		 * whenever the window is resied
 		 */
 		@Override
         public void componentResized(ComponentEvent e) {
 		    Dimension d = vv.getSize();
 		    if(d.width <= 0 || d.height <= 0) return;
 		    checkOffscreenImage(d);
 		    repaint();
 		}
 	}
 
     public void addPreRenderPaintable(Paintable paintable) {
         if(preRenderers == null) {
             preRenderers = new ArrayList<Paintable>();
         }
         preRenderers.add(paintable);
     }
     
     public void prependPreRenderPaintable(Paintable paintable) {
         if(preRenderers == null) {
             preRenderers = new ArrayList<Paintable>();
         }
         preRenderers.add(0,paintable);
     }
     
     public void removePreRenderPaintable(Paintable paintable) {
         if(preRenderers != null) {
             preRenderers.remove(paintable);
         }
     }
     
     public void addPostRenderPaintable(Paintable paintable) {
         if(postRenderers == null) {
             postRenderers = new ArrayList<Paintable>();
         }
         postRenderers.add(paintable);
     }
     
     public void prependPostRenderPaintable(Paintable paintable) {
         if(postRenderers == null) {
             postRenderers = new ArrayList<Paintable>();
         }
         postRenderers.add(0,paintable);
     }
     
     public void removePostRenderPaintable(Paintable paintable) {
         if(postRenderers != null) {
             postRenderers.remove(paintable);
         }
     }
 
     public void addChangeListener(ChangeListener l) {
         changeSupport.addChangeListener(l);
     }
     
     public void removeChangeListener(ChangeListener l) {
         changeSupport.removeChangeListener(l);
     }
     
     public ChangeListener[] getChangeListeners() {
         return changeSupport.getChangeListeners();
     }
 
     public void fireStateChanged() {
         changeSupport.fireStateChanged();
     }   
     
     public PickedState<V> getPickedVertexState() {
         return pickedVertexState;
     }
 
     public PickedState<E> getPickedEdgeState() {
         return pickedEdgeState;
     }
     
     public void setPickedVertexState(PickedState<V> pickedVertexState) {
         if(pickEventListener != null && this.pickedVertexState != null) {
             this.pickedVertexState.removeItemListener(pickEventListener);
         }
         this.pickedVertexState = pickedVertexState;
         this.renderContext.setPickedVertexState(pickedVertexState);
         if(pickEventListener == null) {
             pickEventListener = new ItemListener() {
 
                 public void itemStateChanged(ItemEvent e) {
                     repaint();
                 }
             };
         }
         pickedVertexState.addItemListener(pickEventListener);
     }
     
     public void setPickedEdgeState(PickedState<E> pickedEdgeState) {
         if(pickEventListener != null && this.pickedEdgeState != null) {
             this.pickedEdgeState.removeItemListener(pickEventListener);
         }
         this.pickedEdgeState = pickedEdgeState;
         this.renderContext.setPickedEdgeState(pickedEdgeState);
         if(pickEventListener == null) {
             pickEventListener = new ItemListener() {
 
                 public void itemStateChanged(ItemEvent e) {
                     repaint();
                 }
             };
         }
         pickedEdgeState.addItemListener(pickEventListener);
     }
     
     public GraphElementAccessor<V,E> getPickSupport() {
         return renderContext.getPickSupport();
     }
 
     public void setPickSupport(GraphElementAccessor<V,E> pickSupport) {
         renderContext.setPickSupport(pickSupport);
     }
     
     public Point2D getCenter() {
         Dimension d = getSize();
         return new Point2D.Float(d.width/2, d.height/2);
     }
 
     public RenderContext<V,E> getRenderContext() {
         return renderContext;
     }
 
     public void setRenderContext(RenderContext<V,E> renderContext) {
         this.renderContext = renderContext;
     }
 }