BitmapTileSource.java

package org.oscim.tiling.source.bitmap;

import org.oscim.gdx.client.GwtBitmap;
import org.oscim.layers.tile.LoadDelayTask;
import org.oscim.layers.tile.MapTile;
import org.oscim.layers.tile.TileLoader;
import org.oscim.tiling.ITileDataSink;
import org.oscim.tiling.ITileDataSink.QueryResult;
import org.oscim.tiling.ITileDataSource;
import org.oscim.tiling.source.LwHttp;
import org.oscim.tiling.source.UrlTileSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.google.gwt.event.dom.client.ErrorEvent;
import com.google.gwt.event.dom.client.ErrorHandler;
import com.google.gwt.event.dom.client.LoadEvent;
import com.google.gwt.event.dom.client.LoadHandler;
import com.google.gwt.safehtml.shared.SafeUri;
import com.google.gwt.safehtml.shared.UriUtils;
import com.google.gwt.user.client.ui.Image;
import com.google.gwt.user.client.ui.RootPanel;

public class BitmapTileSource extends UrlTileSource {
	static final Logger log = LoggerFactory.getLogger(LwHttp.class);

	public static class Builder<T extends Builder<T>> extends UrlTileSource.Builder<T> {

		public Builder() {
			super(null, "/{Z}/{X}/{Y}.png", 0, 17);
		}

		public BitmapTileSource build() {
			return new BitmapTileSource(this);
		}
	}

	protected BitmapTileSource(Builder<?> builder) {
		super(builder);
	}

	@SuppressWarnings("rawtypes")
	public static Builder<?> builder() {
		return new Builder();
	}

	/**
	 * Create BitmapTileSource for 'url'
	 * 
	 * By default path will be formatted as: url/z/x/y.png
	 * Use e.g. setExtension(".jpg") to overide ending or
	 * implement getUrlString() for custom formatting.
	 */

	public BitmapTileSource(String url, int zoomMin, int zoomMax) {
		super(url, "/{Z}/{X}/{Y}.png", zoomMin, zoomMax);
	}

	public BitmapTileSource(String url, int zoomMin, int zoomMax, String extension) {
		super(url, "/{Z}/{X}/{Y}" + extension, zoomMin, zoomMax);
	}

	public BitmapTileSource(String url, String tilePath, int zoomMin, int zoomMax) {
		super(url, tilePath, zoomMin, zoomMax);
	}

	@Override
	public ITileDataSource getDataSource() {
		return new BitmapTileDataSource(this);
	}

	public class BitmapTileDataSource implements ITileDataSource {

		protected final UrlTileSource mTileSource;

		public BitmapTileDataSource(BitmapTileSource bitmapTileSource) {
			mTileSource = bitmapTileSource;
		}

		@Override
		public void query(final MapTile tile, final ITileDataSink sink) {

			String url = mTileSource.getTileUrl(tile);

			SafeUri uri = UriUtils.fromTrustedString(url);

			final Image img = new Image();
			img.setVisible(false);

			/* As if researching CORS issues doesnt result in
			 * enough headache...
			 * 
			 * Here are some more special Chrome/Webkit quirks:
			 * MUST SET CORS BEFORE URL! */
			img.getElement().setAttribute("crossorigin", "anonymous");
			img.setUrl(uri);

			RootPanel.get().add(img);

			img.addLoadHandler(new LoadHandler() {
				public void onLoad(LoadEvent event) {
					TileLoader.postLoadDelay(new LoadDelayTask<Image>(tile, sink, img) {

						@Override
						public void continueLoading() {
							if (!tile.state(MapTile.State.LOADING)) {
								sink.completed(QueryResult.FAILED);
								RootPanel.get().remove(data);
							} else {
								sink.setTileImage(new GwtBitmap(data));
								sink.completed(QueryResult.SUCCESS);
							}
						}
					});
				}
			});

			img.addErrorHandler(new ErrorHandler() {

				@Override
				public void onError(ErrorEvent event) {
					sink.completed(QueryResult.FAILED);
					RootPanel.get().remove(img);
				}
			});
		}

		@Override
		public void dispose() {
		}

		@Override
		public void cancel() {
		}

	}
}