polygonlayer.java

geotools的源码

/*
 * @(#)PolygonLayer.java  0.5 17 April 1997  James Macgill
 *
 */

package uk.ac.leeds.ccg.geotools;

import java.util.*;
import java.awt.*;
import com.sun.java.util.collections.HashSet;

/**
 * A layer for storing geographic features that can be represented by polygons.
 * A polygon layer maintains a list of GeoPolygons.  If each polygon is properly
 * assigned an ID then this will be used for both Highlights and for Shade colour lookups.<p>
 * Used (Like other layers) in themes for display in a Viewer.<p>
 *
 * Improved selection painting speed by implementing method directly insted of using
 * SimpleLayers repeated calles to paintHighlight
 * 
 * Now extends ShapeLayer, which manages much of the common code used by layers containg GeoShape features
 *
 * @version 0.7.0, 9 Dec 99
 * @author James Macgill
 */
public class PolygonLayer extends ShapeLayer implements Layer,ScaleChangedListener{
    
	/**
	 * Holds the scaled version of the map if bufferScale is on
	 */
	protected Polygon polys[][];
	protected int ids[];

	/**
	 * setting this to true will force the buffer to be updated on the next
	 * call to paintScaled. Note this will not disable buffer all together.
	 * after the buffer has been updated, this variable will be set to false.
	 * if you want to disable buffering (why would you do that?), you'd need
	 * to set bufferScale to false.
	 */
	protected boolean forceBufferFlush = true;

    ContiguityMatrix matrix = null;

    /**
    * default constructor for an empty layer
    */
    public PolygonLayer(){
        super();
    }

	/**
     * Constructs a PolygonLayer with bounds but no polygons. <br>
     * Usefull if you know what the exact bounds of the layer will be
     * prior to adding all the GeoPolygons to the layer at a later stage, or
     * if you want the PolygonLayer to 'lie' about its extent.
     *
     * @param bounds A GeoRectangle representing a box that will atleast contain
     * all of the polygons in this layer.
     */
	public PolygonLayer(GeoRectangle bounds){
	    super(bounds);
	}

    
    /**
     * Do we treat anticlockwise polygons as holes?
     * V.Experimental
     */
    protected boolean anticlockHoles = false;







    /**
     * Adds the specified GeoPolygon this PolygonLayer
     * @param polygon The GeoPolygon to be added
     */
	public void addGeoPolygon(GeoPolygon polygon) {
		this.addGeoPolygon(polygon, false);
	}

    /**
     * Adds the specified GeoPolygon this PolygonLayer
     * @param polygon The GeoPolygon to be added
	 * @param keepquiet Tell the method not to call a LayerChangedEvent
	 * after adding the polgyon. Setting this to true more or less implies
	 * that you will do this yourselve.
     */
	public void addGeoPolygon(GeoPolygon polygon, boolean keepQuiet) {
            this.setForceBufferFlush(true);
            super.addGeoShape(polygon, keepQuiet);
	}

	 /**
	  * Use to determine if scale buffering is available for this layer.
	  * Layers that use this feature should overide this mehtod.
	  * @return boolean true if scale buffering can be used.
	  */
	  public boolean isScaleBufferImplemented(){
	    return true;
	  }
	
	
	
	    
    /**
     * Set anticlockwise polygons up as holes.
     * this is v.experimental at the moment.
     * it defaults to off.
     * @param flag boolean that is true if anticlockwise polygons should be holes.
     */
     public void setAnticlockwiseHoles(boolean flag){
        this.anticlockHoles = flag;
     }
     
     /**
      * are anticlockwise polygons treated as holes?
      */
      public boolean isAnticlockwiseHoles(){
        return this.anticlockHoles;
      }
    
    public void drawPolyFeature(Graphics g,Polygon p,int width){
        g.drawPolygon(p.xpoints,p.ypoints,p.npoints);
    }
    public void fillPolyFeature(Graphics g,Polygon p){
        g.fillPolygon(p.xpoints,p.ypoints,p.npoints);
    }  
        
    /**
     * Paints a scaled version of the layer to the given graphics contex.
     * <br>Generaly only called by a theme that contains this layer.
     * @param gg A GeoGraphics containing all of the info needed to paint this layer to screen
     */
    public void paintScaled(GeoGraphics gg){
        Graphics g = gg.getGraphics();
        Scaler scale = gg.getScale();
        Shader shade = gg.getShade();
        GeoData data = gg.getData();
        ShadeStyle style = gg.getStyle();
        Filter filter = gg.getFilter();
		//Tepory polygons used during scaling.
		GeoPolygon scaledPolygon,temp,tempMain;
		int w = style.getLineWidth();

		//Test to see if the scale has not changed since
		//the last redering && see if we keeped a buffer of the
		//map at that scale.
		if(isExtentSame(scale.getMapExtent()) && bufferScale==true && forceBufferFlush==false){
		    for(int i = 0;i < countPolygons();i++) {

		     if(filter==null || filter.isVisible(ids[i])){
		      for(int j=0;j<polys[i].length;j++){
		        if(polys[i][j]==null) continue;
		        g.setColor(shade.getColor(data.getValue(ids[i])));
			    if( style.isFilled() ){
			       fillPolyFeature(g,polys[i][j]);
			       //g.fillPolygon(polys[i][j]);
			    }
			    if( style.isOutlined() )
			    {
			        if(!style.isLineColorFromShader()){
			            g.setColor(style.getLineColor());
			        }
			        drawPolyFeature(g,polys[i][j],w);
			        //g.drawPolygon(polys[i][j]);
			    }
			  }
		     }
		    }
		}
        else{
         //we don't have a pre scaled version to hand
         //so we caclulate it now.
         if(bufferScale){
		    polys = new Polygon[countPolygons()][];
		    ids = new int[countPolygons()];
		 }
		 Polygon awtPoly;

		 for(int i = 0;i < countPolygons();i++) {
		   tempMain = (GeoPolygon)shapeList.elementAt(i);
		    if(bufferScale){
		        polys[i] = new Polygon[tempMain.getNumParts()];
		    }

		    for(int j=0;j<tempMain.getNumParts();j++){

			temp = (GeoPolygon)tempMain.getPart(j);
			GeoRectangle bounds = temp.getBounds();
			//If the polygon is totaly outside of the current view
			//don't bother to scale it.
			if (bounds.createIntersect(scale.getMapExtent())==null){
			    continue;
			}



			scaledPolygon = scale.scalePolygon(new GeoPolygon(temp));
			awtPoly = scaledPolygon.toAWTPolygon();
			//Add thematic colour here
			/*if(data==null){
			    buildData();
			}*/

			//get a value for this polygon from the GeoData data.
			int id = temp.getID();
			double value = data.getValue(id);
			//look up a colour for that value from the shader.

			if(filter==null || filter.isVisible(id)){
			    g.setColor(shade.getColor(value));

			    if(style.isFilled()){
			        if(!anticlockHoles || (anticlockHoles && temp.isClockwise())) fillPolyFeature(g,awtPoly);
			    }
			    if(style.isOutlined()){
			        if(!style.isLineColorFromShader()){
			            g.setColor(style.getLineColor());
			        }
			        drawPolyFeature(g,awtPoly,w);
			        //g.drawPolygon(awtPoly);
			    }
			}
			if(bufferScale){
			    //keep a record of the scaled version
			    polys[i][j] = awtPoly;
			    ids[i] = id;
			}
			}

		 }

		 if(lastScale != null){
		    lastScale.removeScaleChangedListener(this);
		 }
		 lastScale = scale;
		 lastScale.addScaleChangedListener(this);

		 setForceBufferFlush(false);
		}
       	}
       
    /**
	 * Scales and plots a highlighted version of one of the polygons
	 * <br> Generaly only called by the theme that holds this layer.
	 * <br> The highlight style should be definable, but it isn't yet.
	 * @param g The graphics to paint into
	 * @param scale The scaler to use.
	 * @param id The id of the polygon to highlight
	 */
    public void paintHighlight(Graphics g,Scaler scale,int id,ShadeStyle style){
	   GeoPolygon scaledPolygon;
	   int w = style.getLineWidth();
		for(int i = 0;i < countPolygons();i++) {
			GeoPolygon temp = (GeoPolygon)shapeList.elementAt(i);
			if(temp.getID()==id){
			   for(int j=0;j<temp.getNumParts();j++){
			    scaledPolygon = scale.scalePolygon((GeoPolygon)temp.getPart(j));
			    
			    //Add thematic colour here
			    if(style.isPaintModeXOR()){
			        g.setXORMode(Color.black);
			    }
			    if(style.isFilled()){
			        g.setColor(style.getFillColor());
			       
		
			        fillPolyFeature(g,scaledPolygon.toAWTPolygon());
			        //g.fillPolygon(scaledPolygon.toAWTPolygon());
			    }
			    if(style.isOutlined()){
			        g.setColor(style.getLineColor());
	                //g.drawPolygon(scaledPolygon.toAWTPolygon());
	                drawPolyFeature(g,scaledPolygon.toAWTPolygon(),w);
	            }
	            scaledPolygon = null; //Try to help the GC.?
	            g.setPaintMode();
	        }
	        }
	    }
	}
	
	/**
	 * Scales and plots a highlighted version of one of the polygons
	 * <br> Generaly only called by the theme that holds this layer.
	 * <br> The highlight style should be definable, but it isn't yet.
	 * Modified to select all parts of a multi-part polygon.
	 * @param g The graphics to paint into
	 * @param scale The scaler to use.
	 * @param id The id of the polygon to highlight
	 */
	public void paintSelection(Graphics g,Scaler scale,int ids[],ShadeStyle style){
        GeoPolygon scaledPolygon;
        int w = style.getLineWidth();
		for(int i = 0;i < countPolygons();i++) {
			GeoPolygon temp = (GeoPolygon)shapeList.elementAt(i);
			for(int j=0;j<ids.length;j++){
			    if(temp.getID()==ids[j]){
			      for(int k=0;k<temp.getNumParts();k++){
			        scaledPolygon = scale.scalePolygon(new GeoPolygon((GeoPolygon)temp.getPart(k)));
			    
			        //Add thematic colour here
			        if(style.isPaintModeXOR()){
			            g.setXORMode(Color.black);
			        }
			        if(style.isFilled()){
			            g.setColor(style.getFillColor());
			            fillPolyFeature(g,scaledPolygon.toAWTPolygon());
			            //g.fillPolygon(scaledPolygon.toAWTPolygon());
			        }
			        if(style.isOutlined()){
			            g.setColor(style.getLineColor());
	                    //g.drawPolygon(scaledPolygon.toAWTPolygon());
	                    drawPolyFeature(g,scaledPolygon.toAWTPolygon(),w);
	                }
	                scaledPolygon = null; //Try to help the GC.?
	                g.setPaintMode();
	              }
	            }
	        }
	    }
        
    }

   

    /**
     * Returns the total number of polygons held by the PolygonLayer
     * @deprecated use countFeatures from super class ShapeLayer
     * @return int The number of polygons in this layer
     */
	public int countPolygons() {
		return countFeatures();
	}
	
	
	 
	/**
	 * Called when the scale last used to scale this layer has changed.
	 * as a result the buffer is of no use and will have to be rebuilt next
	 * paint scaled
	 * @param sce A ScaleChangedEvent as thrown by a scaler.
	 */
	public void scaleChanged(ScaleChangedEvent sce){
	    lastScale = null;
	}
	
	
	/**
	 * Experimental method to track the contiguity matrix for this layer.
	 * First call constructs the matrix, unless it has been provided during construction
	 * (not yet possible)
	 */
	 public ContiguityMatrix getContiguityMatrix(){
	    if(matrix == null) buildContiguityMatrix();
	    return matrix;
	 }
	 
	 public void buildContiguityMatrix(){
	    //build one from scratch
	    matrix = new ContiguityMatrix();  
	    for(int i = 0;i < countPolygons();i++) {
		   GeoPolygon temp = (GeoPolygon)shapeList.elementAt(i);
		   Vector list = temp.getContiguityList(shapeList);   
		  
		   HashSet set = new HashSet();
		   for(int j=0;j<list.size();j++){
		    set.add(list.elementAt(j));
		   }
		   matrix.addList(temp,set); 
		   
		}
	    
	 }
         
         public void setContiguityMatrix(ContiguityMatrix m){
             matrix = m;
         }

	public void setForceBufferFlush(boolean newValue) {
		forceBufferFlush = newValue;
	}
	public boolean isForceBufferFlush() {
		return forceBufferFlush;
	}
        
        /**
         * A new experimental method which provides access to the scaled versions of the
         * last set of polygons to be ploted to the screen.<br>
         * In order to work properly scale buffering must be enabled, as this is the<br>
         * default behavour for shapelayers this should not be a problem.
         * @return Polygon[][] A two dimensional array of awt polygons,(the second dymension is for 
         * multipart polygons).
         */
        public Polygon[][] getScaledShapes(){
            return (Polygon[][])polys.clone();
        }
        
        /**
         * Used in conjunction with getScaledPolygons this provides the true id for each
         * shape in the set of scaled polygons
         **/
        public int[] getScaledShapesIdList(){
            return (int[])ids.clone();
        }


}