TileSource.java

/*
 * Copyright 2013 Hannes Janetzek
 *
 * This file is part of the OpenScienceMap project (http://www.opensciencemap.org).
 *
 * This program is free software: you can redistribute it and/or modify it under the
 * terms of the GNU Lesser General Public License as published by the Free Software
 * Foundation, either version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with
 * this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.oscim.tiling;

import java.util.HashMap;

import org.oscim.layers.tile.bitmap.BitmapTileLayer.FadeStep;

public abstract class TileSource {

	public abstract static class Builder<T extends Builder<T>> {
		protected int zoomMin, zoomMax;
		protected FadeStep[] fadeSteps;

		public T zoomMin(int zoom) {
			zoomMin = zoom;
			return self();
		}

		public T zoomMax(int zoom) {
			zoomMax = zoom;
			return self();
		}

		public T fadeSteps(FadeStep[] fadeSteps) {
			this.fadeSteps = fadeSteps;
			return self();
		}

		@SuppressWarnings("unchecked")
		protected T self() {
			return (T) this;
		}

		public abstract TileSource build();
	}

	protected int mZoomMin = 0;
	protected int mZoomMax = 20;

	protected TileSource() {
	}

	protected TileSource(int zoomMin, int zoomMax) {
		mZoomMin = zoomMin;
		mZoomMax = zoomMax;
	}

	public TileSource(Builder<?> builder) {
		mZoomMin = builder.zoomMin;
		mZoomMax = builder.zoomMax;
		mFadeSteps = builder.fadeSteps;
	}

	public abstract ITileDataSource getDataSource();

	public abstract OpenResult open();

	public abstract void close();

	protected final Options options = new Options();

	public ITileCache tileCache;

	private FadeStep[] mFadeSteps;

	/**
	 * Cache MUST be set before TileSource is added to a TileLayer!
	 */
	public void setCache(ITileCache cache) {
		tileCache = cache;
	}

	public int getZoomLevelMax() {
		return mZoomMax;
	}

	public int getZoomLevelMin() {
		return mZoomMin;
	}

	public FadeStep[] getFadeSteps() {
		return mFadeSteps;
	}

	public TileSource setOption(String key, String value) {
		options.put(key, value);
		return this;
	}

	public String getOption(String key) {
		return options.get(key);
	}

	public static class Options extends HashMap<String, String> {

		private static final long serialVersionUID = 1L;

		@Override
		public boolean equals(Object other) {
			if (!(other instanceof Options))
				return false;

			//if (this.db != ((MapOptions) other).db)
			//	return false;

			// FIXME test if this is correct!
			if (!this.entrySet().equals(((Options) other).entrySet()))
				return false;

			return true;
		}
	}

	/**
	 * A FileOpenResult is a simple DTO which is returned by
	 * IMapDatabase#open().
	 */
	public static class OpenResult {
		/**
		 * Singleton for a FileOpenResult instance with {@code success=true}.
		 */
		public static final OpenResult SUCCESS = new OpenResult();

		private final String errorMessage;
		private final boolean success;

		/**
		 * @param errorMessage
		 *            a textual message describing the error, must not be null.
		 */
		public OpenResult(String errorMessage) {
			if (errorMessage == null) {
				throw new IllegalArgumentException("error message must not be null");
			}

			this.success = false;
			this.errorMessage = errorMessage;
		}

		public OpenResult() {
			this.success = true;
			this.errorMessage = null;
		}

		/**
		 * @return a textual error description (might be null).
		 */
		public String getErrorMessage() {
			return this.errorMessage;
		}

		/**
		 * @return true if the file could be opened successfully, false
		 *         otherwise.
		 */
		public boolean isSuccess() {
			return this.success;
		}

		@Override
		public String toString() {
			return new StringBuilder()
			    .append("FileOpenResult [success=")
			    .append(this.success)
			    .append(", errorMessage=")
			    .append(this.errorMessage)
			    .append("]")
			    .toString();
		}
	}
}