spatialpanel.java

Java source code for the Ant Colony Optimization Problem.

package jwo.jpss.spatial.gui;  // Part of the spatial GUI package.

import jwo.jpss.spatial.*;     // For spatial classes.
import javax.swing.*;          // For Swing components.
import javax.swing.text.*;     // For text output.
import java.awt.*;             // For cursor handling.
import java.awt.event.*;       // For mouse events.
import java.awt.geom.*;        // For affine transformations.
			
//  **************************************************************
/** Panel for displaying spatial objects.
  * @author Jo Wood.
  * @version 1.1, 21st October, 2001.
  */
//  **************************************************************

public class SpatialPanel extends JPanel
{    
    // --------------- Object and Class Variables ----------------
    
    private JTextComponent output;     // Component to report messages.
    private SpatialModel spModel;      // Spatial model to display.
    private AffineTransform trans,     // Georef to pixel transformation.
                            iTrans;    // Pixel to georef transformation.

    private static final int BORDER_SIZE = 5;

    // --------------------- Constructors ------------------------
    
    /** Creates a panel for displaying the given spatial model.
      * @param spModel Spatial model to display.
      */
    public SpatialPanel(SpatialModel spModel)
    {
        this(spModel, new JTextField());
    }

    /** Creates a panel for displaying the given spatial model.
      * Text output can be sent to the given text component.
      * @param spModel Spatial model to display.
      * @param output Component to display text output.
      */
    public SpatialPanel(SpatialModel spModel, JTextComponent output)
    {
    	super();
        this.spModel = spModel;
        this.output = output;

        setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
        addMouseListener(new MouseClickMonitor());
        addMouseMotionListener(new MouseMoveMonitor());
        addComponentListener(new PanelSizeMonitor());

        setPreferredSize(new Dimension(200,200));
        setBorder(BorderFactory.createEtchedBorder());
    }
    
    // ----------------------- Methods ---------------------------
    
    /** Calculates the transformations required to convert between
      * pixel coordinates and georeferenced coordinates.
      */
    public void calcTransformation()
    {
        // Scale spatial bounds to fit inside panel and flip Y axis.
        
        int panelWidth  = getWidth()  - 2*BORDER_SIZE;
        int panelHeight = getHeight() - 2*BORDER_SIZE;
       	    
        trans = new AffineTransform();
        iTrans = new AffineTransform();
 
        Footprint fp = spModel.getBounds();
        double scaling = Math.min(panelWidth/fp.getMERWidth(),
                                  panelHeight/fp.getMERHeight());

        float centreX = (float)(panelWidth - (fp.getMERWidth()*scaling))/2;
        float centreY = (float)(panelHeight - (fp.getMERHeight()*scaling))/-2;

        trans.translate(BORDER_SIZE+centreX,panelHeight+BORDER_SIZE+centreY);
        trans.scale(scaling,-scaling);
        trans.translate(-fp.getXOrigin(), -fp.getYOrigin());

        iTrans.translate(fp.getXOrigin(),fp.getYOrigin());
        iTrans.scale(1/scaling,-1/scaling);
        iTrans.translate(-centreX-BORDER_SIZE,-centreY-panelHeight-BORDER_SIZE);
    }

    /** Sets the text component to display text output 
      * @param output Component to display text output.
      */
    public void setOutput(JTextComponent output)
    {
        this.output = output;
    }

    // ---------------------- Accessor Methods --------------------

    /** Reports the affine transformation required to convert 
      * georeferenced to pixel coordinates.
      * @return Affine transformation to convert georeferenced
                into pixel coordinates.
      */
    public AffineTransform getGeoToPixel()
    {
        return trans;
    }

    /** Transforms the given footprint from georeferenced to pixel coords.
      * @param fp Georeferenced coordinates to transform.
      * @return Pixel coordinates of the given footprint.
      */
    public Footprint getGeoToPixel(Footprint fp)
    {
        Point2D geo,pxl,geoMax,pxlMax;

        geo = new Point2D.Float(fp.getXOrigin(),fp.getYOrigin());
        pxl = new Point2D.Float();
        trans.transform(geo,pxl);

        if ((fp.getMERWidth()==0) && (fp.getMERHeight()==0)) 
            return new Footprint((float)pxl.getX(),(float)pxl.getY());
        else
        {
            geoMax = new Point2D.Float(fp.getXOrigin()+fp.getMERWidth(),
                                       fp.getYOrigin()+fp.getMERHeight());
            pxlMax = new Point2D.Float();
            trans.transform(geoMax,pxlMax);
            return new Footprint((float)pxl.getX(),(float)pxl.getY(),
                                 (float)(pxlMax.getX()-pxl.getX()),
                                 (float)(pxlMax.getY()-pxl.getY()));
        }
    }

    /** Reports the affine transformation required to convert 
      * pixel to georeferenced coordinates.
      * @return Affine transformation to convert pixel into
                georeferenced coordinates.
      */
    public AffineTransform getPixelToGeo()
    {
        return iTrans;
    }

    /** Transforms the given footprint from pixel to georeferenced coords.
      * @param fp Pixel coordinates to transform.
      * @return Georeferened coordinates of the given footprint.
      */
    public Footprint getPixelToGeo(Footprint fp)
    {
        Point2D geo,pxl,geoMax,pxlMax;

        geo = new Point2D.Float(fp.getXOrigin(),fp.getYOrigin());
        pxl = new Point2D.Float();
        iTrans.transform(geo,pxl);

        if ((fp.getMERWidth()==0) && (fp.getMERHeight()==0)) 
            return new Footprint((float)pxl.getX(),(float)pxl.getY());
        else
        {
            geoMax = new Point2D.Float(fp.getXOrigin()+fp.getMERWidth(),
                                       fp.getYOrigin()+fp.getMERHeight());
            pxlMax = new Point2D.Float();
            iTrans.transform(geoMax,pxlMax);
            return new Footprint((float)pxl.getX(),(float)pxl.getY(),
                                 (float)(pxlMax.getX()-pxl.getX()),
                                 (float)(pxlMax.getY()-pxl.getY()));
        }
    }

    // -------------------- Nested Classes -----------------------

    /** Handles mouse clicks on the panel.
      */
    private class MouseClickMonitor extends MouseAdapter
    {
        /** Handles a mouse click in the panel and reports the coordinates
          * of the mouse when clicked.
          * @param e Mouse event associated with the click.
          */
        public void mousePressed(MouseEvent e)
        {
            Footprint fp = getPixelToGeo(new Footprint(e.getX(),e.getY()));
            float attribute = spModel.getAttribute(fp);
            if (attribute == SpatialModel.OUT_OF_BOUNDS)
                output.setText("Out of bounds");
            else
                if (attribute == SpatialModel.NO_VALUE)
                    output.setText("No object here");
                else
                    output.setText("Attribute "+attribute);                
        }
    }

    /** Handles mouse movement over the panel.
      */
    private class MouseMoveMonitor extends MouseMotionAdapter
    {
        /** Handles mouse movement over the panel by reporting the
          * coordinates of the current mouse position.
          * @param e Mouse event associated with movement.
          */
        public void mouseMoved(MouseEvent e)
        {
            Footprint fp = getPixelToGeo(new Footprint(e.getX(),e.getY()));
            output.setText("Location "+fp.getXOrigin()+","+fp.getYOrigin());
        }
    }

    /** Handles changes in the panel's status.
      */
    private class PanelSizeMonitor extends ComponentAdapter
    {
        /** Handles panel resizing events by updating the pixel-georeference
          * transformation to account for new panel dimensions.
          * @param e Panel resizing event.
          */
        public void componentResized(ComponentEvent e)
        {
            calcTransformation();
        }
    } 
}