001// License: GPL. For details, see Readme.txt file. 002package org.openstreetmap.gui.jmapviewer; 003 004import java.awt.Graphics; 005import java.awt.Graphics2D; 006import java.awt.geom.AffineTransform; 007import java.awt.image.BufferedImage; 008import java.io.IOException; 009import java.io.InputStream; 010import java.util.HashMap; 011import java.util.Map; 012import java.util.concurrent.Callable; 013 014import javax.imageio.ImageIO; 015 016import org.openstreetmap.gui.jmapviewer.interfaces.TileCache; 017import org.openstreetmap.gui.jmapviewer.interfaces.TileSource; 018 019/** 020 * Holds one map tile. Additionally the code for loading the tile image and 021 * painting it is also included in this class. 022 * 023 * @author Jan Peter Stotz 024 */ 025public class Tile { 026 027 /** 028 * Hourglass image that is displayed until a map tile has been loaded, except for overlay sources 029 */ 030 public static final BufferedImage LOADING_IMAGE = loadImage("images/hourglass.png"); 031 032 /** 033 * Red cross image that is displayed after a loading error, except for overlay sources 034 */ 035 public static final BufferedImage ERROR_IMAGE = loadImage("images/error.png"); 036 037 protected TileSource source; 038 protected int xtile; 039 protected int ytile; 040 protected int zoom; 041 protected BufferedImage image; 042 protected String key; 043 protected volatile boolean loaded; // field accessed by multiple threads without any monitors, needs to be volatile 044 protected volatile boolean loading; 045 protected volatile boolean error; 046 protected String error_message; 047 048 /** TileLoader-specific tile metadata */ 049 protected Map<String, String> metadata; 050 051 /** 052 * Creates a tile with empty image. 053 * 054 * @param source Tile source 055 * @param xtile X coordinate 056 * @param ytile Y coordinate 057 * @param zoom Zoom level 058 */ 059 public Tile(TileSource source, int xtile, int ytile, int zoom) { 060 this(source, xtile, ytile, zoom, LOADING_IMAGE); 061 } 062 063 /** 064 * Creates a tile with specified image. 065 * 066 * @param source Tile source 067 * @param xtile X coordinate 068 * @param ytile Y coordinate 069 * @param zoom Zoom level 070 * @param image Image content 071 */ 072 public Tile(TileSource source, int xtile, int ytile, int zoom, BufferedImage image) { 073 this.source = source; 074 this.xtile = xtile; 075 this.ytile = ytile; 076 this.zoom = zoom; 077 this.image = image; 078 this.key = getTileKey(source, xtile, ytile, zoom); 079 } 080 081 private static BufferedImage loadImage(String path) { 082 try { 083 return ImageIO.read(JMapViewer.class.getResourceAsStream(path)); 084 } catch (IOException | IllegalArgumentException ex) { 085 ex.printStackTrace(); 086 return null; 087 } 088 } 089 090 private static class CachedCallable<V> implements Callable<V> { 091 private V result; 092 private Callable<V> callable; 093 094 /** 095 * Wraps callable so it is evaluated only once 096 * @param callable to cache 097 */ 098 CachedCallable(Callable<V> callable) { 099 this.callable = callable; 100 } 101 102 @Override 103 public synchronized V call() { 104 try { 105 if (result == null) { 106 result = callable.call(); 107 } 108 return result; 109 } catch (Exception e) { 110 // this should not happen here 111 throw new RuntimeException(e); 112 } 113 } 114 } 115 116 /** 117 * Tries to get tiles of a lower or higher zoom level (one or two level 118 * difference) from cache and use it as a placeholder until the tile has been loaded. 119 * @param cache Tile cache 120 */ 121 public void loadPlaceholderFromCache(TileCache cache) { 122 /* 123 * use LazyTask as creation of BufferedImage is very expensive 124 * this way we can avoid object creation until we're sure it's needed 125 */ 126 final CachedCallable<BufferedImage> tmpImage = new CachedCallable<>(new Callable<BufferedImage>() { 127 @Override 128 public BufferedImage call() throws Exception { 129 return new BufferedImage(source.getTileSize(), source.getTileSize(), BufferedImage.TYPE_INT_RGB); 130 } 131 }); 132 133 for (int zoomDiff = 1; zoomDiff < 5; zoomDiff++) { 134 // first we check if there are already the 2^x tiles 135 // of a higher detail level 136 int zoomHigh = zoom + zoomDiff; 137 if (zoomDiff < 3 && zoomHigh <= JMapViewer.MAX_ZOOM) { 138 int factor = 1 << zoomDiff; 139 int xtileHigh = xtile << zoomDiff; 140 int ytileHigh = ytile << zoomDiff; 141 final double scale = 1.0 / factor; 142 143 /* 144 * use LazyTask for graphics to avoid evaluation of tmpImage, until we have 145 * something to draw 146 */ 147 CachedCallable<Graphics2D> graphics = new CachedCallable<>(new Callable<Graphics2D>() { 148 @Override 149 public Graphics2D call() throws Exception { 150 Graphics2D g = (Graphics2D) tmpImage.call().getGraphics(); 151 g.setTransform(AffineTransform.getScaleInstance(scale, scale)); 152 return g; 153 } 154 }); 155 156 int paintedTileCount = 0; 157 for (int x = 0; x < factor; x++) { 158 for (int y = 0; y < factor; y++) { 159 Tile tile = cache.getTile(source, xtileHigh + x, ytileHigh + y, zoomHigh); 160 if (tile != null && tile.isLoaded()) { 161 paintedTileCount++; 162 tile.paint(graphics.call(), x * source.getTileSize(), y * source.getTileSize()); 163 } 164 } 165 } 166 if (paintedTileCount == factor * factor) { 167 image = tmpImage.call(); 168 return; 169 } 170 } 171 172 int zoomLow = zoom - zoomDiff; 173 if (zoomLow >= JMapViewer.MIN_ZOOM) { 174 int xtileLow = xtile >> zoomDiff; 175 int ytileLow = ytile >> zoomDiff; 176 final int factor = 1 << zoomDiff; 177 final double scale = factor; 178 CachedCallable<Graphics2D> graphics = new CachedCallable<>(new Callable<Graphics2D>() { 179 @Override 180 public Graphics2D call() throws Exception { 181 Graphics2D g = (Graphics2D) tmpImage.call().getGraphics(); 182 AffineTransform at = new AffineTransform(); 183 int translateX = (xtile % factor) * source.getTileSize(); 184 int translateY = (ytile % factor) * source.getTileSize(); 185 at.setTransform(scale, 0, 0, scale, -translateX, -translateY); 186 g.setTransform(at); 187 return g; 188 } 189 190 }); 191 192 Tile tile = cache.getTile(source, xtileLow, ytileLow, zoomLow); 193 if (tile != null && tile.isLoaded()) { 194 tile.paint(graphics.call(), 0, 0); 195 image = tmpImage.call(); 196 return; 197 } 198 } 199 } 200 } 201 202 public TileSource getSource() { 203 return source; 204 } 205 206 /** 207 * Returns the X coordinate. 208 * @return tile number on the x axis of this tile 209 */ 210 public int getXtile() { 211 return xtile; 212 } 213 214 /** 215 * Returns the Y coordinate. 216 * @return tile number on the y axis of this tile 217 */ 218 public int getYtile() { 219 return ytile; 220 } 221 222 /** 223 * Returns the zoom level. 224 * @return zoom level of this tile 225 */ 226 public int getZoom() { 227 return zoom; 228 } 229 230 public BufferedImage getImage() { 231 return image; 232 } 233 234 public void setImage(BufferedImage image) { 235 this.image = image; 236 } 237 238 public void loadImage(InputStream input) throws IOException { 239 image = ImageIO.read(input); 240 } 241 242 /** 243 * @return key that identifies a tile 244 */ 245 public String getKey() { 246 return key; 247 } 248 249 public boolean isLoaded() { 250 return loaded; 251 } 252 253 public boolean isLoading() { 254 return loading; 255 } 256 257 public void setLoaded(boolean loaded) { 258 this.loaded = loaded; 259 } 260 261 public String getUrl() throws IOException { 262 return source.getTileUrl(zoom, xtile, ytile); 263 } 264 265 /** 266 * Paints the tile-image on the {@link Graphics} <code>g</code> at the 267 * position <code>x</code>/<code>y</code>. 268 * 269 * @param g the Graphics object 270 * @param x x-coordinate in <code>g</code> 271 * @param y y-coordinate in <code>g</code> 272 */ 273 public void paint(Graphics g, int x, int y) { 274 if (image == null) 275 return; 276 g.drawImage(image, x, y, null); 277 } 278 279 /** 280 * Paints the tile-image on the {@link Graphics} <code>g</code> at the 281 * position <code>x</code>/<code>y</code>. 282 * 283 * @param g the Graphics object 284 * @param x x-coordinate in <code>g</code> 285 * @param y y-coordinate in <code>g</code> 286 * @param width width that tile should have 287 * @param height height that tile should have 288 */ 289 public void paint(Graphics g, int x, int y, int width, int height) { 290 if (image == null) 291 return; 292 g.drawImage(image, x, y, width, height, null); 293 } 294 295 @Override 296 public String toString() { 297 return "Tile " + key; 298 } 299 300 /** 301 * Note that the hash code does not include the {@link #source}. 302 * Therefore a hash based collection can only contain tiles 303 * of one {@link #source}. 304 */ 305 @Override 306 public int hashCode() { 307 final int prime = 31; 308 int result = 1; 309 result = prime * result + xtile; 310 result = prime * result + ytile; 311 result = prime * result + zoom; 312 return result; 313 } 314 315 /** 316 * Compares this object with <code>obj</code> based on 317 * the fields {@link #xtile}, {@link #ytile} and 318 * {@link #zoom}. 319 * The {@link #source} field is ignored. 320 */ 321 @Override 322 public boolean equals(Object obj) { 323 if (this == obj) 324 return true; 325 if (obj == null) 326 return false; 327 if (getClass() != obj.getClass()) 328 return false; 329 Tile other = (Tile) obj; 330 if (xtile != other.xtile) 331 return false; 332 if (ytile != other.ytile) 333 return false; 334 if (zoom != other.zoom) 335 return false; 336 if (!getTileSource().equals(other.getTileSource())) { 337 return false; 338 } 339 return true; 340 } 341 342 public static String getTileKey(TileSource source, int xtile, int ytile, int zoom) { 343 return zoom + "/" + xtile + "/" + ytile + "@" + source.getName(); 344 } 345 346 public String getStatus() { 347 if (this.error) 348 return "error"; 349 if (this.loaded) 350 return "loaded"; 351 if (this.loading) 352 return "loading"; 353 return "new"; 354 } 355 356 public boolean hasError() { 357 return error; 358 } 359 360 public String getErrorMessage() { 361 return error_message; 362 } 363 364 public void setError(Exception e) { 365 setError(e.toString()); 366 } 367 368 public void setError(String message) { 369 error = true; 370 setImage(ERROR_IMAGE); 371 error_message = message; 372 } 373 374 /** 375 * Puts the given key/value pair to the metadata of the tile. 376 * If value is null, the (possibly existing) key/value pair is removed from 377 * the meta data. 378 * 379 * @param key Key 380 * @param value Value 381 */ 382 public void putValue(String key, String value) { 383 if (value == null || value.isEmpty()) { 384 if (metadata != null) { 385 metadata.remove(key); 386 } 387 return; 388 } 389 if (metadata == null) { 390 metadata = new HashMap<>(); 391 } 392 metadata.put(key, value); 393 } 394 395 /** 396 * returns the metadata of the Tile 397 * 398 * @param key metadata key that should be returned 399 * @return null if no such metadata exists, or the value of the metadata 400 */ 401 public String getValue(String key) { 402 if (metadata == null) return null; 403 return metadata.get(key); 404 } 405 406 /** 407 * 408 * @return metadata of the tile 409 */ 410 public Map<String, String> getMetadata() { 411 if (metadata == null) { 412 metadata = new HashMap<>(); 413 } 414 return metadata; 415 } 416 417 /** 418 * indicate that loading process for this tile has started 419 */ 420 public void initLoading() { 421 error = false; 422 loading = true; 423 } 424 425 /** 426 * indicate that loading process for this tile has ended 427 */ 428 public void finishLoading() { 429 loading = false; 430 loaded = true; 431 } 432 433 /** 434 * 435 * @return TileSource from which this tile comes 436 */ 437 public TileSource getTileSource() { 438 return source; 439 } 440 441 /** 442 * indicate that loading process for this tile has been canceled 443 */ 444 public void loadingCanceled() { 445 loading = false; 446 loaded = false; 447 } 448 449}