altoslib: Fix map preloading callbacks, run in separate thread

The map storage and tile callbacks were muddled together. Create
clearly separate states for map data and have status updates be
delivered when registering for new status events so that registration
is sufficient to track the state without an explicit call to get the
current state.

Run the map tile creation in a separate thread so that even checking
status of files on disk runs out of the UI thread.

These fixes serve to make the pacifier update more smoothly, and also
not over/under count tile loading so that the loading actually
completes when all of the tiles are loaded.

Signed-off-by: Keith Packard <keithp@keithp.com>

11 files changed, 146 insertions, 181 deletions

diff --git a/altosdroid/src/org/altusmetrum/AltosDroid/AltosMapOffline.java b/altosdroid/src/org/altusmetrum/AltosDroid/AltosMapOffline.java
index bde80cfc..ab142b17 100644
--- a/altosdroid/src/org/altusmetrum/AltosDroid/AltosMapOffline.java
+++ b/altosdroid/src/org/altusmetrum/AltosDroid/AltosMapOffline.java
@@ -133,7 +133,7 @@ public class AltosMapOffline extends View implements ScaleGestureDetector.OnScal
 			if (canvas.quickReject(pt.x, pt.y, pt.x + px_size, pt.y + px_size, Canvas.EdgeType.AA))
 				return;
 
-			AltosImage		altos_image = cache.get(this, store, px_size, px_size);
+			AltosImage		altos_image = this.get_image();
 
 			MapImage 		map_image = (MapImage) altos_image;
 
@@ -150,8 +150,8 @@ public class AltosMapOffline extends View implements ScaleGestureDetector.OnScal
 				if (t.has_location()) {
 					String	message = null;
 					switch (status) {
-					case AltosMapTile.loading:
-						message = "Loading...";
+					case AltosMapTile.fetching:
+						message = "Fetching...";
 						break;
 					case AltosMapTile.bad_request:
 						message = "Internal error";
@@ -181,14 +181,14 @@ public class AltosMapOffline extends View implements ScaleGestureDetector.OnScal
 			}
 		}
 
-		public MapTile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-			super(listener, upper_left, center, zoom, maptype, px_size, 2);
+		public MapTile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+			super(cache, upper_left, center, zoom, maptype, px_size, 2);
 		}
 
 	}
 
-	public AltosMapTile new_tile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-		return new MapTile(listener, upper_left, center, zoom, maptype, px_size);
+	public AltosMapTile new_tile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+		return new MapTile(cache, upper_left, center, zoom, maptype, px_size);
 	}
 
 	public AltosMapPath new_path() {
diff --git a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
index 87f03a92..13a44e1f 100644
--- a/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
+++ b/altosdroid/src/org/altusmetrum/AltosDroid/PreloadMapActivity.java
@@ -107,7 +107,6 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 	}
 
 	AltosMap	map;
-	AltosMapLoader	loader;
 
 	class PreloadMapImage implements AltosImage {
 		public void flush() {
@@ -137,14 +136,14 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 		public void paint(AltosMapTransform t) {
 		}
 
-		public PreloadMapTile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-			super(listener, upper_left, center, zoom, maptype, px_size, 2);
+		public PreloadMapTile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+			super(cache, upper_left, center, zoom, maptype, px_size, 2);
 		}
 
 	}
 
-	public AltosMapTile new_tile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-		return new PreloadMapTile(listener, upper_left, center, zoom, maptype, px_size);
+	public AltosMapTile new_tile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+		return new PreloadMapTile(cache, upper_left, center, zoom, maptype, px_size);
 	}
 
 	public int width() {
@@ -265,7 +264,7 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 
 			AltosDebug.debug("PreloadMap load %f %f %d %d %f %d\n",
 					 lat, lon, min, max, r, t);
-			loader.load(lat, lon, min, max, r, t);
+			new AltosMapLoader(map, this, lat, lon, min, max, r, t);
 		} catch (ParseException e) {
 			AltosDebug.debug("PreloadMap load raised exception %s", e.toString());
 		}
@@ -398,8 +397,6 @@ public class PreloadMapActivity extends Activity implements AltosLaunchSiteListe
 
 		map = new AltosMap(this);
 
-		loader = new AltosMapLoader(map, this);
-
 		// Listen for GPS and Network position updates
 		LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
 
diff --git a/altoslib/AltosMap.java b/altoslib/AltosMap.java
index 26851e96..1841277f 100644
--- a/altoslib/AltosMap.java
+++ b/altoslib/AltosMap.java
@@ -328,7 +328,8 @@ public class AltosMap implements AltosMapTileListener, AltosMapStoreListener {
 				if (!tiles.containsKey(point)) {
 					AltosLatLon	ul = transform.lat_lon(point);
 					AltosLatLon	center = transform.lat_lon(new AltosPointDouble(x + AltosMap.px_size/2, y + AltosMap.px_size/2));
-					AltosMapTile tile = map_interface.new_tile(this, ul, center, zoom, maptype, px_size);
+					AltosMapTile tile = map_interface.new_tile(cache, ul, center, zoom, maptype, px_size);
+					tile.add_listener(this);
 					tiles.put(point, tile);
 				}
 			}
@@ -345,11 +346,6 @@ public class AltosMap implements AltosMapTileListener, AltosMapStoreListener {
 		centre(lat, lon);
 		tiles.clear();
 		make_tiles();
-		for (AltosMapTile tile : tiles.values()) {
-			tile.add_store_listener(this);
-			if (tile.store_status() != AltosMapTile.loading)
-				listener.notify_tile(tile, tile.store_status());
-		}
 		repaint();
 	}
 
diff --git a/altoslib/AltosMapCache.java b/altoslib/AltosMapCache.java
index 17a36ff3..38e0f769 100644
--- a/altoslib/AltosMapCache.java
+++ b/altoslib/AltosMapCache.java
@@ -23,25 +23,20 @@ import java.net.*;
 public class AltosMapCache implements AltosMapCacheListener {
 
 	/* An entry in the MapCache */
-	class MapCacheElement implements AltosMapStoreListener {
+	class MapCacheElement implements AltosMapTileListener {
 
 		AltosMapTile		tile;		/* Notify when image has been loaded */
 		AltosImage		image;
-		AltosMapStore		store;
 		long			used;
 
 		class loader implements Runnable {
 			public void run() {
-				if (image != null)
-					tile.notify_image(image);
-				try {
-					image = map_interface.load_image(store.file);
-				} catch (Exception ex) {
+				if (image == null) {
+					try {
+						image = map_interface.load_image(tile.store.file);
+					} catch (Exception ex) {
+					}
 				}
-				if (image == null)
-					tile.set_status(AltosMapTile.failed);
-				else
-					tile.set_status(AltosMapTile.success);
 				tile.notify_image(image);
 			}
 		}
@@ -60,41 +55,21 @@ public class AltosMapCache implements AltosMapCacheListener {
 		}
 
 		public boolean has_map() {
-			return store.status() == AltosMapTile.success;
+			return tile.status == AltosMapTile.loaded;
 		}
 
-		public synchronized void notify_store(AltosMapStore store, int status) {
-			switch (status) {
-			case AltosMapTile.loading:
-				break;
-			case AltosMapTile.success:
+		public synchronized void notify_tile(AltosMapTile tile, int status) {
+			if (status == AltosMapTile.fetched) {
+				System.out.printf("tile fetched, loading image\n");
 				load();
-				break;
-			default:
-				tile.set_status(status);
-				tile.notify_image(null);
 			}
 		}
 
-		public MapCacheElement(AltosMapTile tile, AltosMapStore store) throws IOException {
+		public MapCacheElement(AltosMapTile tile) {
 			this.tile = tile;
 			this.image = null;
-			this.store = store;
 			this.used = 0;
-
-			int status = store.status();
-			switch (status) {
-			case AltosMapTile.loading:
-				store.add_listener(this);
-				break;
-			case AltosMapTile.success:
-				load();
-				break;
-			default:
-				tile.set_status(status);
-				tile.notify_image(null);
-				break;
-			}
+			tile.add_listener(this);
 		}
 	}
 
@@ -135,7 +110,7 @@ public class AltosMapCache implements AltosMapCacheListener {
 		}
 	}
 
-	public AltosImage get(AltosMapTile tile, AltosMapStore store, int width, int height) {
+	public AltosImage get(AltosMapTile tile) {
 		int		oldest = -1;
 		long		age = used;
 
@@ -148,7 +123,7 @@ public class AltosMapCache implements AltosMapCacheListener {
 					oldest = i;
 					break;
 				}
-				if (store.equals(element.store)) {
+				if (tile.store.equals(element.tile.store)) {
 					element.used = used++;
 					return element.image;
 				}
@@ -158,24 +133,15 @@ public class AltosMapCache implements AltosMapCacheListener {
 				}
 			}
 
-			try {
-				element = new MapCacheElement(tile, store);
-				element.used = used++;
-				if (elements[oldest] != null)
-					elements[oldest].flush();
+			element = new MapCacheElement(tile);
+			element.used = used++;
+			if (elements[oldest] != null)
+				elements[oldest].flush();
 
-				elements[oldest] = element;
-
-				if (element.image == null)
-					tile.set_status(AltosMapTile.loading);
-				else
-					tile.set_status(AltosMapTile.success);
-
-				return element.image;
-			} catch (IOException e) {
-				tile.set_status(AltosMapTile.failed);
-				return null;
-			}
+			elements[oldest] = element;
+			System.out.printf("AltosMapCache.get image ? %s\n",
+					  element.image == null ? "false" : "true");
+			return element.image;
 		}
 	}
 
diff --git a/altoslib/AltosMapInterface.java b/altoslib/AltosMapInterface.java
index 71936ad2..756a78f2 100644
--- a/altoslib/AltosMapInterface.java
+++ b/altoslib/AltosMapInterface.java
@@ -29,7 +29,7 @@ public interface AltosMapInterface {
 
 	public abstract AltosMapMark new_mark(double lat, double lon, int state);
 
-	public abstract AltosMapTile new_tile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size);
+	public abstract AltosMapTile new_tile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size);
 
 	public abstract int width();
 
diff --git a/altoslib/AltosMapLoader.java b/altoslib/AltosMapLoader.java
index 15fd756e..7112a1c4 100644
--- a/altoslib/AltosMapLoader.java
+++ b/altoslib/AltosMapLoader.java
@@ -24,7 +24,7 @@ import java.lang.Math;
 import java.net.URL;
 import java.net.URLConnection;
 
-public class AltosMapLoader implements AltosMapTileListener, AltosMapStoreListener {
+public class AltosMapLoader extends Thread implements AltosMapTileListener {
 	AltosMapLoaderListener	listener;
 
 	double	latitude, longitude;
@@ -91,10 +91,8 @@ public class AltosMapLoader implements AltosMapTileListener, AltosMapStoreListen
 				AltosPointInt	point = new AltosPointInt(x, y);
 				AltosLatLon	ul = transform.lat_lon(point);
 				AltosLatLon	center = transform.lat_lon(new AltosPointDouble(x + AltosMap.px_size/2, y + AltosMap.px_size/2));
-				AltosMapTile	tile = map.map_interface.new_tile(this, ul, center, zoom, maptype, AltosMap.px_size);
-				tile.add_store_listener(this);
-				if (tile.store_status() != AltosMapTile.loading)
-					notify_tile(tile, tile.store_status());
+				AltosMapTile	tile = map.map_interface.new_tile(null, ul, center, zoom, maptype, AltosMap.px_size);
+				tile.add_listener(this);
 			}
 		}
 	}
@@ -123,7 +121,7 @@ public class AltosMapLoader implements AltosMapTileListener, AltosMapStoreListen
 		do_load();
 	}
 
-	private void start_load() {
+	public void run() {
 
 		cur_z = min_z;
 		int ntype = 0;
@@ -138,66 +136,64 @@ public class AltosMapLoader implements AltosMapTileListener, AltosMapStoreListen
 
 		cur_type = next_type(0);
 
+		tiles_total = 0;
 		for (int z = min_z; z <= max_z; z++)
-			tiles_total += tiles_per_layer(z);
+			tiles_total += tiles_per_layer(z) * ntype;
 
 		layers_total = (max_z - min_z + 1) * ntype;
 		layers_loaded = 0;
 		tiles_loaded_total = 0;
 
-		listener.debug("total tiles %d\n", tiles_total);
+		listener.debug("total tiles %d layers %d\n", tiles_total, layers_total);
 
 		listener.loader_start(tiles_total);
 		do_load();
 	}
 
-	public void load(double latitude, double longitude, int min_z, int max_z, double radius, int all_types) {
-		listener.debug("lat %f lon %f min_z %d max_z %d radius %f all_types %d\n",
-			       latitude, longitude, min_z, max_z, radius, all_types);
-		this.latitude = latitude;
-		this.longitude = longitude;
-		this.min_z = min_z;
-		this.max_z = max_z;
-		this.radius = radius;
-		this.all_types = all_types;
-		start_load();
-	}
-
-	public synchronized void notify_store(AltosMapStore store, int status) {
+	public synchronized void notify_tile(AltosMapTile tile, int status) {
 		boolean	do_next = false;
-		if (status == AltosMapTile.loading)
+		if (status == AltosMapTile.fetching)
 			return;
 
+		tile.remove_listener(this);
+
 		if (layers_loaded >= layers_total)
 			return;
 
 		++tiles_loaded_total;
 		++tiles_loaded_layer;
 
+		listener.debug("AltosMapLoader.notify_tile status %d total %d of %d layer %d of %d\n",
+			       status, tiles_loaded_total, tiles_total, tiles_loaded_layer, tiles_this_layer);
+
 		if (tiles_loaded_layer == tiles_this_layer) {
 			++layers_loaded;
 			listener.debug("%d layers loaded\n", layers_loaded);
-			if (layers_loaded == layers_total) {
-				listener.loader_done(tiles_total);
-				return;
-			} else {
-				do_next = true;
-			}
+			do_next = true;
 		}
-		listener.loader_notify(tiles_loaded_total,
-				       tiles_total, store.file.toString());
-		if (do_next)
-			next_load();
-	}
 
-	public synchronized void notify_tile(AltosMapTile tile, int status) {
-		notify_store(tile.store, status);
+		if (tiles_loaded_total == tiles_total)
+			listener.loader_done(tiles_total);
+		else {
+			listener.loader_notify(tiles_loaded_total,
+					       tiles_total, tile.store.file.toString());
+			if (do_next)
+				next_load();
+		}
 	}
 
-	public AltosMapCache cache() { return map.cache(); }
-
-	public AltosMapLoader(AltosMap map, AltosMapLoaderListener listener) {
+	public AltosMapLoader(AltosMap map, AltosMapLoaderListener listener,
+			      double latitude, double longitude, int min_z, int max_z, double radius, int all_types) {
+		listener.debug("lat %f lon %f min_z %d max_z %d radius %f all_types %d\n",
+			       latitude, longitude, min_z, max_z, radius, all_types);
 		this.map = map;
 		this.listener = listener;
+		this.latitude = latitude;
+		this.longitude = longitude;
+		this.min_z = min_z;
+		this.max_z = max_z;
+		this.radius = radius;
+		this.all_types = all_types;
+		start();
 	}
 }
diff --git a/altoslib/AltosMapStore.java b/altoslib/AltosMapStore.java
index eebef310..aed365ca 100644
--- a/altoslib/AltosMapStore.java
+++ b/altoslib/AltosMapStore.java
@@ -35,6 +35,7 @@ public class AltosMapStore {
 	public synchronized void add_listener(AltosMapStoreListener listener) {
 		if (!listeners.contains(listener))
 			listeners.add(listener);
+		listener.notify_store(this, status);
 	}
 
 	public synchronized void remove_listener(AltosMapStoreListener listener) {
@@ -110,7 +111,7 @@ public class AltosMapStore {
 				file.delete();
 			return AltosMapTile.bad_request;
 		}
-		return AltosMapTile.success;
+		return AltosMapTile.fetched;
 	}
 
 	static Object	fetch_lock = new Object();
@@ -118,42 +119,42 @@ public class AltosMapStore {
 	static final long	forbidden_interval = 60l * 1000l * 1000l * 1000l;
 	static final long 	google_maps_ratelimit_ms = 1200;
 
-	static Object	loader_lock = new Object();
+	static Object	fetcher_lock = new Object();
 
 	static LinkedList<AltosMapStore> waiting = new LinkedList<AltosMapStore>();
 	static LinkedList<AltosMapStore> running = new LinkedList<AltosMapStore>();
 
-	static final int concurrent_loaders = 128;
+	static final int concurrent_fetchers = 128;
 
-	static void start_loaders() {
-		while (!waiting.isEmpty() && running.size() < concurrent_loaders) {
+	static void start_fetchers() {
+		while (!waiting.isEmpty() && running.size() < concurrent_fetchers) {
 			AltosMapStore 	s = waiting.remove();
 			running.add(s);
-			Thread lt = s.make_loader_thread();
+			Thread lt = s.make_fetcher_thread();
 			lt.start();
 		}
 	}
 
-	void finish_loader() {
-		synchronized(loader_lock) {
+	void finish_fetcher() {
+		synchronized(fetcher_lock) {
 			running.remove(this);
-			start_loaders();
+			start_fetchers();
 		}
 	}
 
-	void add_loader() {
-		synchronized(loader_lock) {
+	void add_fetcher() {
+		synchronized(fetcher_lock) {
 			waiting.add(this);
-			start_loaders();
+			start_fetchers();
 		}
 	}
 
-	class loader implements Runnable {
+	class fetcher implements Runnable {
 
 		public void run() {
 			try {
 				if (file.exists()) {
-					notify_listeners(AltosMapTile.success);
+					notify_listeners(AltosMapTile.fetched);
 					return;
 				}
 
@@ -170,7 +171,7 @@ public class AltosMapStore {
 					synchronized (fetch_lock) {
 						long startTime = System.nanoTime();
 						new_status = fetch_url();
-						if (new_status == AltosMapTile.success) {
+						if (new_status == AltosMapTile.fetched) {
 							long duration_ms = (System.nanoTime() - startTime) / 1000000;
 							if (duration_ms < google_maps_ratelimit_ms) {
 								try {
@@ -186,17 +187,17 @@ public class AltosMapStore {
 				}
 				notify_listeners(new_status);
 			} finally {
-				finish_loader();
+				finish_fetcher();
 			}
 		}
 	}
 
-	private Thread make_loader_thread() {
-		return new Thread(new loader());
+	private Thread make_fetcher_thread() {
+		return new Thread(new fetcher());
 	}
 
-	private void load() {
-		add_loader();
+	private void fetch() {
+		add_fetcher();
 	}
 
 	private AltosMapStore (String url, File file) {
@@ -204,10 +205,10 @@ public class AltosMapStore {
 		this.file = file;
 
 		if (file.exists())
-			status = AltosMapTile.success;
+			status = AltosMapTile.fetched;
 		else {
-			status = AltosMapTile.loading;
-			load();
+			status = AltosMapTile.fetching;
+			fetch();
 		}
 	}
 
diff --git a/altoslib/AltosMapTile.java b/altoslib/AltosMapTile.java
index 076c5937..fdc8ff65 100644
--- a/altoslib/AltosMapTile.java
+++ b/altoslib/AltosMapTile.java
@@ -20,22 +20,23 @@ package org.altusmetrum.altoslib_10;
 import java.io.*;
 import java.util.*;
 
-public abstract class AltosMapTile implements AltosFontListener {
-	AltosMapTileListener	listener;
+public abstract class AltosMapTile implements AltosFontListener, AltosMapStoreListener {
+	LinkedList<AltosMapTileListener>	listeners = new LinkedList<AltosMapTileListener>();
 	public AltosLatLon	upper_left, center;
 	public int		px_size;
 	int		zoom;
 	int		maptype;
 	int		scale;
+	private AltosMapCache	cache;
 	public AltosMapStore	store;
-	public AltosMapCache	cache;
 	public int	status;
 
-	static public final int	success = 0;
-	static public final int	loading = 1;
-	static public final int	failed = 2;
-	static public final int	bad_request = 3;
-	static public final int	forbidden = 4;
+	static public final int	loaded = 0;	/* loaded from file */
+	static public final int	fetched = 1;	/* downloaded to file */
+	static public final int	fetching = 2;	/* downloading from net */
+	static public final int	failed = 3;	/* loading from file failed */
+	static public final int	bad_request = 4;/* downloading failed */
+	static public final int	forbidden = 5;	/* downloading failed */
 
 	private File map_file() {
 		double lat = center.lat;
@@ -79,33 +80,46 @@ public abstract class AltosMapTile implements AltosFontListener {
 	public void font_size_changed(int font_size) {
 	}
 
-	public void set_status(int status) {
+	private synchronized void notify_listeners(int status) {
 		this.status = status;
-		listener.notify_tile(this, status);
+		for (AltosMapTileListener listener : listeners)
+			listener.notify_tile(this, status);
 	}
 
-	public void notify_image(AltosImage image) {
-		listener.notify_tile(this, status);
+	public void notify_store(AltosMapStore store, int status) {
+//		System.out.printf("AltosMapTile.notify_store %d\n", status);
+		notify_listeners(status);
 	}
 
-	public int store_status() {
-		return store.status();
+	public void notify_image(AltosImage image) {
+		if (image == null)
+			status = failed;
+		else
+			status = loaded;
+		notify_listeners(status);
 	}
 
-	public void add_store_listener(AltosMapStoreListener listener) {
-		store.add_listener(listener);
+	public abstract void paint(AltosMapTransform t);
+
+	public AltosImage get_image() {
+		if (cache == null)
+			return null;
+		return cache.get(this);
 	}
 
-	public void remove_store_listener(AltosMapStoreListener listener) {
-		store.remove_listener(listener);
+	public synchronized void add_listener(AltosMapTileListener listener) {
+		if (!listeners.contains(listener))
+			listeners.add(listener);
+		listener.notify_tile(this, status);
 	}
 
-	public abstract void paint(AltosMapTransform t);
+	public synchronized void remove_listener(AltosMapTileListener listener) {
+		listeners.remove(listener);
+	}
 
-	public AltosMapTile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size, int scale) {
-		this.listener = listener;
+	public AltosMapTile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size, int scale) {
+		this.cache = cache;
 		this.upper_left = upper_left;
-		this.cache = listener.cache();
 
 		while (center.lon < -180.0)
 			center.lon += 360.0;
@@ -118,11 +132,11 @@ public abstract class AltosMapTile implements AltosFontListener {
 		this.px_size = px_size;
 		this.scale = scale;
 
-		status = AltosMapTile.loading;
 		store = AltosMapStore.get(map_url(), map_file());
+		store.add_listener(this);
 	}
 
-	public AltosMapTile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-		this(listener, upper_left, center, zoom, maptype, px_size, 1);
+	public AltosMapTile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+		this(cache, upper_left, center, zoom, maptype, px_size, 1);
 	}
 }
diff --git a/altoslib/AltosMapTileListener.java b/altoslib/AltosMapTileListener.java
index 6ab03638..6d78b205 100644
--- a/altoslib/AltosMapTileListener.java
+++ b/altoslib/AltosMapTileListener.java
@@ -19,6 +19,4 @@ package org.altusmetrum.altoslib_10;
 
 public interface AltosMapTileListener {
 	abstract public void notify_tile(AltosMapTile tile, int status);
-
-	abstract public AltosMapCache cache();
 }
diff --git a/altosuilib/AltosUIMapNew.java b/altosuilib/AltosUIMapNew.java
index c867bf2e..a90e8c91 100644
--- a/altosuilib/AltosUIMapNew.java
+++ b/altosuilib/AltosUIMapNew.java
@@ -241,8 +241,8 @@ public class AltosUIMapNew extends JComponent implements AltosFlightDisplay, Alt
 	}
 
 	class MapTile extends AltosMapTile {
-		public MapTile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-			super(listener, upper_left, center, zoom, maptype, px_size);
+		public MapTile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+			super(cache, upper_left, center, zoom, maptype, px_size);
 		}
 
 		public void paint(AltosMapTransform t) {
@@ -254,11 +254,9 @@ public class AltosUIMapNew extends JComponent implements AltosFlightDisplay, Alt
 			if (!g.hitClip(point.x, point.y, px_size, px_size))
 				return;
 
-			AltosImage altos_image = cache.get(this, store, px_size, px_size);
-
+			AltosImage	altos_image = get_image();
 			AltosUIImage	ui_image = (AltosUIImage) altos_image;
-
-			Image image = null;
+			Image		image = null;
 
 			if (ui_image != null)
 				image = ui_image.image;
@@ -272,8 +270,8 @@ public class AltosUIMapNew extends JComponent implements AltosFlightDisplay, Alt
 				if (t.has_location()) {
 					String	message = null;
 					switch (status) {
-					case AltosMapTile.loading:
-						message = "Loading...";
+					case AltosMapTile.fetching:
+						message = "Fetching...";
 						break;
 					case AltosMapTile.bad_request:
 						message = "Internal error";
@@ -334,8 +332,8 @@ public class AltosUIMapNew extends JComponent implements AltosFlightDisplay, Alt
 		return new MapMark(lat, lon, state);
 	}
 
-	public AltosMapTile new_tile(AltosMapTileListener listener, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
-		return new MapTile(listener, upper_left, center, zoom, maptype, px_size);
+	public AltosMapTile new_tile(AltosMapCache cache, AltosLatLon upper_left, AltosLatLon center, int zoom, int maptype, int px_size) {
+		return new MapTile(cache, upper_left, center, zoom, maptype, px_size);
 	}
 
 	public int width() {
diff --git a/altosuilib/AltosUIMapPreloadNew.java b/altosuilib/AltosUIMapPreloadNew.java
index b5f4dbf8..3269bbdd 100644
--- a/altosuilib/AltosUIMapPreloadNew.java
+++ b/altosuilib/AltosUIMapPreloadNew.java
@@ -127,8 +127,6 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 
 	JProgressBar	pbar;
 
-	AltosMapLoader	loader;
-
 	JLabel		site_list_label;
 	JComboBox<AltosLaunchSite>	site_list;
 
@@ -238,7 +236,10 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 						r = r * 1000;
 					loading = true;
 
-					loader.load(latitude, longitude, min_z, max_z, r, all_types());
+					new AltosMapLoader(map.map, this,
+							   latitude, longitude,
+							   min_z, max_z, r, all_types());
+
 				} catch (ParseException pe) {
 					load_button.setSelected(false);
 				}
@@ -271,8 +272,6 @@ public class AltosUIMapPreloadNew extends AltosUIFrame implements ActionListener
 
 		map = new AltosUIMapNew();
 
-		loader = new AltosMapLoader(map.map, this);
-
 		c.fill = GridBagConstraints.BOTH;
 		c.anchor = GridBagConstraints.CENTER;
 		c.insets = i;