tim/prune/gui/map/MapCanvas.java

   1 package tim.prune.gui.map;
   2
   3 import java.awt.Color;
   4 import java.awt.Dimension;
   5 import java.awt.Graphics;
   6 import java.awt.MediaTracker;
   7 import java.awt.image.BufferedImage;
   8 import java.net.MalformedURLException;
   9 import java.net.URL;
  10
  11 import javax.swing.ImageIcon;
  12 import javax.swing.JOptionPane;
  13 import javax.swing.JPanel;
  14
  15 import tim.prune.I18nManager;
  16 import tim.prune.data.DoubleRange;
  17 import tim.prune.data.Track;
  18
  19 /**
  20  * Class for the map canvas, to display a background map and draw on it
  21  */
  22 public class MapCanvas extends JPanel
  23 {
  24
  25         private BufferedImage _mapImage = null;
  26         private Track _track = null;
  27         private DoubleRange _latRange = null, _lonRange = null;
  28         private DoubleRange _xRange = null, _yRange = null;
  29         private boolean _gettingTiles = false;
  30         /** Current zoom level */
  31         private int _currZoom = 0;
  32         /** Maximum zoom level (to avoid panning) */
  33         private int _maxZoom = 0;
  34
  35
  36         /**
  37          * Constructor
  38          * @param inTrack track object
  39          */
  40         public MapCanvas(Track inTrack)
  41         {
  42                 _track = inTrack;
  43                 _latRange = inTrack.getLatRange();
  44                 _lonRange = inTrack.getLonRange();
  45                 _xRange = new DoubleRange(transformX(_lonRange.getMinimum()), transformX(_lonRange.getMaximum()));
  46                 _yRange = new DoubleRange(transformY(_latRange.getMinimum()), transformY(_latRange.getMaximum()));
  47         }
  48
  49         /**
  50          * Paint method
  51          * @see java.awt.Canvas#paint(java.awt.Graphics)
  52          */
  53         public void paint(Graphics g)
  54         {
  55                 super.paint(g);
  56                 if (_mapImage == null && !_gettingTiles) {
  57                         _gettingTiles = true;
  58                         new Thread(new Runnable() {
  59                                 public void run()
  60                                 {
  61                                         getMapTiles();
  62                                 }
  63                         }).start();
  64                 }
  65                 if (_mapImage != null) {
  66                         g.drawImage(_mapImage, 0, 0, 512, 512, null);
  67                 }
  68         }
  69
  70         /**
  71          * Get the map tiles for the specified track range
  72          */
  73         private void getMapTiles()
  74         {
  75                 _mapImage = new BufferedImage(512, 512, BufferedImage.TYPE_INT_RGB);
  76                 // zoom out until mins and maxes all on same group of four tiles
  77                 for (int zoom=15; zoom>1; zoom--)
  78                 {
  79                         int tx1 = (int) Math.floor(_xRange.getMinimum() * (1<<zoom));
  80                         int tx2 = (int) Math.floor(_xRange.getMaximum() * (1<<zoom));
  81                         int ty1 = (int) Math.floor(_yRange.getMinimum() * (1<<zoom));
  82                         int ty2 = (int) Math.floor(_yRange.getMaximum() * (1<<zoom));
  83
  84                         // Stop if reached a block of four adjacent tiles
  85                         if (tx2 <= (tx1+1) && ty1 >= (ty2-1))
  86                         {
  87                                 _currZoom = zoom;
  88                                 _maxZoom = zoom;
  89                                 getMapTiles(tx1, ty1);
  90                                 break;
  91                         }
  92                 }
  93                 _gettingTiles = false;
  94                 repaint();
  95         }
  96
  97         /**
  98          * Get the map tiles for the current zoom level and given tile parameters
  99          * @param inTileX x index of leftmost tile
 100          * @param inTileY y index of lower tile
 101          */
 102         private void getMapTiles(int inTileX, int inTileY)
 103         {
 104                 // Check if tile parameters were given
 105                 if (inTileX == -1 || inTileY == -1) {
 106                         double tileX = _xRange.getMinimum() * (1<<_currZoom);
 107                         double tileY = _yRange.getMinimum() * (1<<_currZoom);
 108                         inTileX = (int) Math.floor(tileX);
 109                         inTileY = (int) Math.floor(tileY);
 110                         // see if should be shifted by 1 to make more central
 111                         if (_currZoom != _maxZoom) {
 112                                 if ((tileX - inTileX) < 0.5) inTileX--; // don't squash to left
 113                                 if ((tileY - inTileY) < 0.5) inTileY--; // don't squash too high
 114                         }
 115                 }
 116                 try
 117                 {
 118                         ImageIcon[] icons = new ImageIcon[4];
 119                         boolean loadingFailed = false;
 120                         // Clear map
 121                         Graphics g = _mapImage.getGraphics();
 122                         g.clearRect(0, 0, 512, 512);
 123                         for (int i=0; i<4 && !loadingFailed; i++)
 124                         {
 125                                 String url = "http://tile.openstreetmap.org/" + _currZoom + "/" + (inTileX + i%2) + "/" + (inTileY + i/2) + ".png";
 126                                 icons[i] = new ImageIcon(new URL(url));
 127                                 if (icons[i] == null || icons[i].getImage() == null || icons[i].getImageLoadStatus() == MediaTracker.ERRORED)
 128                                 {
 129                                         loadingFailed = true;
 130                                 }
 131                                 g.drawImage(icons[i].getImage(), 256*(i%2), 256*(i/2), 256, 256, null);
 132                         }
 133                         // show message if loading failed
 134                         if (loadingFailed) {
 135                                 JOptionPane.showMessageDialog(this,
 136                                         I18nManager.getText("error.osmimage.failed"),
 137                                         I18nManager.getText("error.osmimage.dialogtitle"),
 138                                         JOptionPane.ERROR_MESSAGE);
 139                         }
 140                         // red rectangle
 141                         int rectX1 = (int) (256 * ((_xRange.getMinimum() * (1<<_currZoom)) - inTileX));
 142                         int rectX2 = (int) (256 * ((_xRange.getMaximum() * (1<<_currZoom)) - inTileX));
 143                         int rectY1 = (int) (256 * ((_yRange.getMinimum() * (1<<_currZoom)) - inTileY));
 144                         int rectY2 = (int) (256 * ((_yRange.getMaximum() * (1<<_currZoom)) - inTileY));
 145                         g.setColor(Color.RED);
 146                         g.drawRect(rectX1, rectY1, rectX2-rectX1, rectY2-rectY1);
 147                         // draw points
 148                         g.setColor(Color.BLUE);
 149                         for (int i=0; i<_track.getNumPoints(); i++)
 150                         {
 151                                 int px = (int) (256 * ((transformX(_track.getPoint(i).getLongitude().getDouble()) * (1<<_currZoom)) - inTileX));
 152                                 int py = (int) (256 * ((transformY(_track.getPoint(i).getLatitude().getDouble()) * (1<<_currZoom)) - inTileY));
 153                                 g.drawRect(px, py, 2, 2);
 154                         }
 155                 }
 156                 catch (MalformedURLException urle) {
 157                         _mapImage = null;
 158                 }
 159         }
 160
 161         /**
 162          * Zoom out, if not already at minimum zoom
 163          */
 164         public void zoomOut()
 165         {
 166                 if (_currZoom >= 2)
 167                 {
 168                         _currZoom--;
 169                         getMapTiles(-1, -1);
 170                         repaint();
 171                 }
 172         }
 173
 174         /**
 175          * Zoom in, if not already at maximum zoom
 176          */
 177         public void zoomIn()
 178         {
 179                 if (_currZoom < _maxZoom)
 180                 {
 181                         _currZoom++;
 182                         getMapTiles(-1, -1);
 183                         repaint();
 184                 }
 185         }
 186
 187         /**
 188          * Transform a longitude into an x coordinate
 189          * @param inLon longitude in degrees
 190          * @return scaled X value from 0 to 1
 191          */
 192         private static double transformX(double inLon)
 193         {
 194                 return (inLon + 180.0) / 360.0;
 195         }
 196
 197         /**
 198          * Transform a latitude into a y coordinate
 199          * @param inLat latitude in degrees
 200          * @return scaled Y value from 0 to 1
 201          */
 202         private static double transformY(double inLat)
 203         {
 204                 return (1 - Math.log(Math.tan(inLat * Math.PI / 180) + 1 / Math.cos(inLat * Math.PI / 180)) / Math.PI) / 2;
 205         }
 206
 207         /**
 208          * @see javax.swing.JComponent#getMinimumSize()
 209          */
 210         public Dimension getMinimumSize()
 211         {
 212                 final Dimension minSize = new Dimension(512, 512);
 213                 return minSize;
 214         }
 215
 216         /**
 217          * @see javax.swing.JComponent#getPreferredSize()
 218          */
 219         public Dimension getPreferredSize()
 220         {
 221                 return getMinimumSize();
 222         }
 223 }