TileLoader.java

/*
 * Copyright 2013 Hannes Janetzek
 *
 * 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.layers.tile;

import static org.oscim.tiling.ITileDataSink.QueryResult.FAILED;
import static org.oscim.tiling.ITileDataSink.QueryResult.SUCCESS;

import org.oscim.backend.canvas.Bitmap;
import org.oscim.core.MapElement;
import org.oscim.renderer.MapRenderer;
import org.oscim.tiling.ITileDataSink;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.utils.Timer;

public abstract class TileLoader implements ITileDataSink {
	final static Logger log = LoggerFactory.getLogger(TileLoader.class);

	private final TileManager mTileManager;
	private Timer mTimer;

	public TileLoader(TileManager tileManager) {
		if (mTimer == null)
			mTimer = new Timer();

		mTileManager = tileManager;
	}

	public abstract void dispose();

	protected abstract boolean loadTile(MapTile tile);

	boolean isInterrupted;

	public void finish() {
		isInterrupted = true;
		// cancel loading
	}

	public void cancel() {
		isInterrupted = true;
		// cancel loading... ?
	}

	boolean mPausing;

	public boolean isCanceled() {
		return mPausing;
	}

	public boolean isPausing() {
		return mPausing;
	}

	public void pause() {
		mPausing = true;
	}

	public void proceed() {
		mPausing = false;
		// FIXME
		mWorking = false;
		if (mTileManager.hasTileJobs())
			go();
	}

	public void awaitPausing() {

	}

	public void start() {
		mPausing = false;
	}

	protected boolean mWorking;
	protected MapTile mTile;

	public void go() {
		if (mWorking)
			return;

		mTile = mTileManager.getTileJob();

		if (mTile == null)
			return;

		try {
			loadTile(mTile);
			mWorking = true;
		} catch (Exception e) {
			e.printStackTrace();
			completed(FAILED);
		}
	}

	public static long lastLoadTime;

	/**
	 * Callback to be called by TileDataSource when finished
	 * loading or on failure. MUST BE CALLED IN ANY CASE!
	 */
	@Override
	public void completed(QueryResult result) {
		boolean success = (result == SUCCESS) && !isInterrupted;
		long now = MapRenderer.frametime;

		//log.debug("completed {}  diff time:{}", mTile, (now - lastLoadTime));
		lastLoadTime = now;

		mTileManager.jobCompleted(mTile, success);
		mTile = null;

		mWorking = false;

		if (mPausing || !mTileManager.hasTileJobs())
			return;

		Gdx.app.postRunnable(new Runnable() {
			@Override
			public void run() {
				go();
			}
		});
	}

	/**
	 * Called by TileDataSource
	 */
	@Override
	public void process(MapElement element) {

	}

	/**
	 * Called by TileDataSource
	 */
	@Override
	public void setTileImage(Bitmap bitmap) {

	}

	public static void postLoadDelay(LoadDelayTask<?> task) {
		Gdx.app.postRunnable(task);
	}

}