Index: trunk/src/org/openstreetmap/josm/tools/OsmUrlToBounds.java
===================================================================
--- trunk/src/org/openstreetmap/josm/tools/OsmUrlToBounds.java	(revision 11301)
+++ trunk/src/org/openstreetmap/josm/tools/OsmUrlToBounds.java	(revision 11302)
@@ -191,16 +191,19 @@
     }
 
+    private static Dimension getScreenSize() {
+        if (Main.isDisplayingMapView()) {
+            return new Dimension(Main.map.mapView.getWidth(), Main.map.mapView.getHeight());
+        } else {
+            return GuiHelper.getScreenSize();
+        }
+    }
+
+    private static final int TILE_SIZE_IN_PIXELS = 256;
+
     public static Bounds positionToBounds(final double lat, final double lon, final int zoom) {
-        int tileSizeInPixels = 256;
-        Dimension screenSize = GuiHelper.getScreenSize();
-        int height = screenSize.height;
-        int width = screenSize.width;
-        if (Main.isDisplayingMapView()) {
-            height = Main.map.mapView.getHeight();
-            width = Main.map.mapView.getWidth();
-        }
-        double scale = (1 << zoom) * tileSizeInPixels / (2 * Math.PI * Ellipsoid.WGS84.a);
-        double deltaX = width / 2.0 / scale;
-        double deltaY = height / 2.0 / scale;
+        final Dimension screenSize = getScreenSize();
+        double scale = (1 << zoom) * TILE_SIZE_IN_PIXELS / (2 * Math.PI * Ellipsoid.WGS84.a);
+        double deltaX = screenSize.getWidth() / 2.0 / scale;
+        double deltaY = screenSize.getHeight() / 2.0 / scale;
         final Projection mercator = Projections.getProjectionByCode("EPSG:3857");
         final EastNorth projected = mercator.latlon2eastNorth(new LatLon(lat, lon));
@@ -210,17 +213,4 @@
     }
 
-    public static Pair<Double, Double> getTileOfLatLon(double lat, double lon, double zoom) {
-        double x = Math.floor((lon + 180) / 360 * Math.pow(2.0, zoom));
-        double y = Math.floor((1 - Math.log(Math.tan(Math.toRadians(lat)) + 1 / Math.cos(Math.toRadians(lat))) / Math.PI)
-                / 2 * Math.pow(2.0, zoom));
-        return new Pair<>(x, y);
-    }
-
-    public static LatLon getLatLonOfTile(double x, double y, double zoom) {
-        double lon = x / Math.pow(2.0, zoom) * 360.0 - 180;
-        double lat = Math.toDegrees(Math.atan(Math.sinh(Math.PI - (2.0 * Math.PI * y) / Math.pow(2.0, zoom))));
-        return new LatLon(lat, lon);
-    }
-
     /**
      * Return OSM Zoom level for a given area
@@ -230,17 +220,11 @@
      */
     public static int getZoom(Bounds b) {
-        // convert to mercator (for calculation of zoom only)
-        double latMin = Math.log(Math.tan(Math.PI/4.0+b.getMinLat()/180.0*Math.PI/2.0))*180.0/Math.PI;
-        double latMax = Math.log(Math.tan(Math.PI/4.0+b.getMaxLat()/180.0*Math.PI/2.0))*180.0/Math.PI;
-        double size = Math.max(Math.abs(latMax-latMin), Math.abs(b.getMaxLon()-b.getMinLon()));
-        int zoom = 0;
-        while (zoom <= 20) {
-            if (size >= 180) {
-                break;
-            }
-            size *= 2;
-            zoom++;
-        }
-        return zoom;
+        final Projection mercator = Projections.getProjectionByCode("EPSG:3857");
+        final EastNorth min = mercator.latlon2eastNorth(b.getMin());
+        final EastNorth max = mercator.latlon2eastNorth(b.getMax());
+        final double deltaX = max.getX() - min.getX();
+        final double scale = getScreenSize().getWidth() / deltaX;
+        final double x = scale * (2 * Math.PI * Ellipsoid.WGS84.a) / TILE_SIZE_IN_PIXELS;
+        return (int) Math.round(Math.log(x) / Math.log(2));
     }