+++ /dev/null
-package tim.prune.gui.map;
-
-import java.awt.Image;
-import java.awt.Toolkit;
-import java.awt.image.ImageObserver;
-import java.net.MalformedURLException;
-import java.net.URL;
-
-
-/**
- * Class to handle the caching of map tiles from openstreetmap
- */
-public class MapTileCacher implements ImageObserver
-{
- /** Parent to be informed of updates */
- private MapCanvas _parent = null;
- /** Array of images to hold tiles */
- private Image[] _tiles = new Image[GRID_SIZE * GRID_SIZE];
- /** Current zoom level */
- private int _zoom = -1;
- /** X coordinate of central tile */
- private int _tileX = -1;
- /** Y coordinate of central tile */
- private int _tileY = -1;
- /** X coord of grid centre */
- private int _gridCentreX = 0;
- /** Y coord of grid centre */
- private int _gridCentreY = 0;
- /** Tile configuration */
- private MapTileConfig _tileConfig = null;
-
- /** Grid size */
- private static final int GRID_SIZE = 15;
- /** max zoom level of map tiles */
- private static final int MAX_TILE_ZOOM = 18;
-
-
- /**
- * Constructor
- * @param inParent parent canvas to be informed of updates
- */
- public MapTileCacher(MapCanvas inParent)
- {
- _parent = inParent;
- }
-
- /**
- * Recentre the map and clear the cache
- * @param inZoom zoom level
- * @param inTileX x coord of central tile
- * @param inTileY y coord of central tile
- */
- public void centreMap(int inZoom, int inTileX, int inTileY)
- {
- int shift = Math.max(Math.abs(inTileX-_tileX), Math.abs(inTileY - _tileY));
- if (shift == 0) {return;}
- // Clear cache if either zoom has changed or map has jumped too far
- if (inZoom != _zoom || shift > GRID_SIZE/2)
- {
- _zoom = inZoom;
- clearAll();
- }
- _gridCentreX = getCacheCoordinate(_gridCentreX + inTileX - _tileX);
- _gridCentreY = getCacheCoordinate(_gridCentreY + inTileY - _tileY);
- _tileX = inTileX;
- _tileY = inTileY;
- // Mark boundaries as invalid
- for (int i=0; i<GRID_SIZE; i++)
- {
- _tiles[getArrayIndex(_tileX + GRID_SIZE/2 + 1, _tileY + i - GRID_SIZE/2)] = null;
- _tiles[getArrayIndex(_tileX + i - GRID_SIZE/2, _tileY + GRID_SIZE/2 + 1)] = null;
- }
- }
-
- /**
- * Clear all the cached images
- */
- public void clearAll()
- {
- // Clear all images if zoom changed
- for (int i=0; i<_tiles.length; i++) {
- _tiles[i] = null;
- }
- }
-
- /**
- * @param inX x index of tile
- * @param inY y index of tile
- * @return selected tile if already loaded, or null otherwise
- */
- public Image getTile(int inX, int inY)
- {
- if (_tileConfig == null) {_tileConfig = new MapTileConfig();}
- int arrayIndex = getArrayIndex(inX, inY);
- Image image = _tiles[arrayIndex];
- if (image != null)
- {
- // image already finished loading so return it
- return image;
- }
-
- // Protect against zoom > max
- if (isOverzoomed()) return null;
-
- // Trigger load if not already triggered
- // Work out tile coords for URL
- int urlX = getUrlCoordinate(inX, _zoom);
- int urlY = getUrlCoordinate(inY, _zoom);
- try
- {
- // Use configured tile server
- String url = _tileConfig.getUrl() + _zoom + "/" + urlX + "/" + urlY + ".png";
- // Load image asynchronously, using observer
- image = Toolkit.getDefaultToolkit().createImage(new URL(url));
- _tiles[arrayIndex] = image;
- if (image.getWidth(this) > 0) {return image;}
- }
- catch (MalformedURLException urle) {} // ignore
- return null;
- }
-
- /**
- * @return true if zoom is too high for tiles
- */
- public boolean isOverzoomed()
- {
- return (_zoom > MAX_TILE_ZOOM);
- }
-
- /**
- * Get the array index for the given coordinates
- * @param inX x coord of tile
- * @param inY y coord of tile
- * @return array index
- */
- private int getArrayIndex(int inX, int inY)
- {
- //System.out.println("Getting array index for (" + inX + ", " + inY + ") where the centre is at (" + _tileX + ", " + _tileY
- // + ") and grid coords (" + _gridCentreX + ", " + _gridCentreY + ")");
- int x = getCacheCoordinate(inX - _tileX + _gridCentreX);
- int y = getCacheCoordinate(inY - _tileY + _gridCentreY);
- //System.out.println("Transformed to (" + x + ", " + y + ")");
- return (x + y * GRID_SIZE);
- }
-
- /**
- * Transform a coordinate from map tiles to array coordinates
- * @param inTile coordinate of tile
- * @return coordinate in array (wrapping around cache grid)
- */
- private static int getCacheCoordinate(int inTile)
- {
- int tile = inTile;
- while (tile >= GRID_SIZE) {tile -= GRID_SIZE;}
- while (tile < 0) {tile += GRID_SIZE;}
- return tile;
- }
-
- /**
- * Make sure a url coordinate is within range
- * @param inTile coordinate of tile in map system
- * @param inZoom zoom factor
- * @return coordinate for url (either vertical or horizontal)
- */
- private static int getUrlCoordinate(int inTile, int inZoom)
- {
- int mapSize = 1 << inZoom;
- int coord = inTile;
- while (coord >= mapSize) {coord -= mapSize;}
- while (coord < 0) {coord += mapSize;}
- // coord is now between 0 and mapsize
- return coord;
- }
-
- /**
- * Convert to string for debug
- * @see java.lang.Object#toString()
- */
- public String toString()
- {
- StringBuffer result = new StringBuffer("Grid centre (" + _gridCentreX + "," + _gridCentreY + ") - (" + _tileX + "," + _tileY + ")\n");
- for (int i=0; i<GRID_SIZE; i++)
- {
- for (int j=0; j<GRID_SIZE; j++) {
- if (i == _gridCentreY && j == _gridCentreX) {
- result.append(_tiles[j + i*GRID_SIZE] == null?"c":"C");
- }
- else {
- result.append(_tiles[j + i*GRID_SIZE] == null?".":"*");
- }
- }
- result.append("\n");
- }
- return result.toString();
- }
-
- /**
- * Method called by image loader to inform of updates to the tiles
- * @param img the image
- * @param infoflags flags describing how much of the image is known
- * @param x ignored
- * @param y ignored
- * @param width ignored
- * @param height ignored
- * @return false to carry on loading, true to stop
- */
- public boolean imageUpdate(Image img, int infoflags, int x, int y, int width, int height)
- {
- boolean loaded = (infoflags & ImageObserver.ALLBITS) > 0;
- boolean error = (infoflags & ImageObserver.ERROR) > 0;
- if (loaded || error) {
- _parent.tilesUpdated(loaded);
- }
- return !loaded;
- }
-
- /**
- * Set or reset the tile config
- * @param inConfig object containing tile config
- */
- public void setTileConfig(MapTileConfig inConfig)
- {
- _tileConfig = inConfig;
- clearAll();
- }
-}
projects / GpsPrune.git / blobdiff