// License: GPL. For details, see LICENSE file.
package org.openstreetmap.josm.tools;
import static org.openstreetmap.josm.tools.I18n.tr;
import java.awt.Dimension;
import java.util.HashMap;
import java.util.Map;
import org.openstreetmap.josm.Main;
import org.openstreetmap.josm.data.Bounds;
import org.openstreetmap.josm.data.coor.EastNorth;
import org.openstreetmap.josm.data.coor.LatLon;
import org.openstreetmap.josm.data.projection.Ellipsoid;
import org.openstreetmap.josm.data.projection.Projection;
import org.openstreetmap.josm.data.projection.Projections;
import org.openstreetmap.josm.gui.util.GuiHelper;
/**
* Parses various URL used in OpenStreetMap projects into {@link Bounds}.
*/
public final class OsmUrlToBounds {
private static final String SHORTLINK_PREFIX = "http://osm.org/go/";
private OsmUrlToBounds() {
// Hide default constructor for utils classes
}
/**
* Parses an URL into {@link Bounds}
* @param url the URL to be parsed
* @return the parsed {@link Bounds}, or {@code null}
*/
public static Bounds parse(String url) {
if (url.startsWith("geo:")) {
return GeoUrlToBounds.parse(url);
}
try {
// a percent sign indicates an encoded URL (RFC 1738).
if (url.contains("%")) {
url = Utils.decodeUrl(url);
}
} catch (IllegalArgumentException ex) {
Main.error(ex);
}
Bounds b = parseShortLink(url);
if (b != null)
return b;
if (url.contains("#map")) {
// probably it's a URL following the new scheme?
return parseHashURLs(url);
}
final int i = url.indexOf('?');
if (i == -1) {
return null;
}
String[] args = url.substring(i+1).split("&");
Map<String, String> map = new HashMap<>();
for (String arg : args) {
int eq = arg.indexOf('=');
if (eq != -1) {
map.put(arg.substring(0, eq), arg.substring(eq + 1));
}
}
try {
if (map.containsKey("bbox")) {
String[] bbox = map.get("bbox").split(",");
b = new Bounds(
Double.parseDouble(bbox[1]), Double.parseDouble(bbox[0]),
Double.parseDouble(bbox[3]), Double.parseDouble(bbox[2]));
} else if (map.containsKey("minlat")) {
double minlat = Double.parseDouble(map.get("minlat"));
double minlon = Double.parseDouble(map.get("minlon"));
double maxlat = Double.parseDouble(map.get("maxlat"));
double maxlon = Double.parseDouble(map.get("maxlon"));
b = new Bounds(minlat, minlon, maxlat, maxlon);
} else {
String z = map.get("zoom");
b = positionToBounds(parseDouble(map, "lat"), parseDouble(map, "lon"),
z == null ? 18 : Integer.parseInt(z));
}
} catch (IllegalArgumentException | ArrayIndexOutOfBoundsException ex) {
Main.error(ex, url);
}
return b;
}
/**
* Openstreetmap.org changed it's URL scheme in August 2013, which breaks the URL parsing.
* The following function, called by the old parse function if necessary, provides parsing new URLs
* the new URLs follow the scheme https://www.openstreetmap.org/#map=18/51.71873/8.76164&layers=CN
* @param url string for parsing
* @return Bounds if hashurl, {@code null} otherwise
*/
private static Bounds parseHashURLs(String url) {
int startIndex = url.indexOf("#map=");
if (startIndex == -1) return null;
int endIndex = url.indexOf('&', startIndex);
if (endIndex == -1) endIndex = url.length();
String coordPart = url.substring(startIndex+5, endIndex);
String[] parts = coordPart.split("/");
if (parts.length < 3) {
Main.warn(tr("URL does not contain {0}/{1}/{2}", tr("zoom"), tr("latitude"), tr("longitude")));
return null;
}
int zoom;
try {
zoom = Integer.parseInt(parts[0]);
} catch (NumberFormatException e) {
Main.warn(tr("URL does not contain valid {0}", tr("zoom")), e);
return null;
}
double lat, lon;
try {
lat = Double.parseDouble(parts[1]);
} catch (NumberFormatException e) {
Main.warn(tr("URL does not contain valid {0}", tr("latitude")), e);
return null;
}
try {
lon = Double.parseDouble(parts[2]);
} catch (NumberFormatException e) {
Main.warn(tr("URL does not contain valid {0}", tr("longitude")), e);
return null;
}
return positionToBounds(lat, lon, zoom);
}
private static double parseDouble(Map<String, String> map, String key) {
if (map.containsKey(key))
return Double.parseDouble(map.get(key));
if (map.containsKey('m'+key))
return Double.parseDouble(map.get('m'+key));
throw new IllegalArgumentException(map.toString() + " does not contain " + key);
}
private static final char[] SHORTLINK_CHARS = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '_', '@'
};
/**
* Parse OSM short link
*
* @param url string for parsing
* @return Bounds if shortlink, null otherwise
* @see <a href="http://trac.openstreetmap.org/browser/sites/rails_port/lib/short_link.rb">short_link.rb</a>
*/
private static Bounds parseShortLink(final String url) {
if (!url.startsWith(SHORTLINK_PREFIX))
return null;
final String shortLink = url.substring(SHORTLINK_PREFIX.length());
final Map<Character, Integer> array = new HashMap<>();
for (int i = 0; i < SHORTLINK_CHARS.length; ++i) {
array.put(SHORTLINK_CHARS[i], i);
}
// long is necessary (need 32 bit positive value is needed)
long x = 0;
long y = 0;
int zoom = 0;
int zoomOffset = 0;
for (final char ch : shortLink.toCharArray()) {
if (array.containsKey(ch)) {
int val = array.get(ch);
for (int i = 0; i < 3; ++i) {
x <<= 1;
if ((val & 32) != 0) {
x |= 1;
}
val <<= 1;
y <<= 1;
if ((val & 32) != 0) {
y |= 1;
}
val <<= 1;
}
zoom += 3;
} else {
zoomOffset--;
}
}
x <<= 32 - zoom;
y <<= 32 - zoom;
// 2**32 == 4294967296
return positionToBounds(y * 180.0 / 4294967296.0 - 90.0,
x * 360.0 / 4294967296.0 - 180.0,
// TODO: -2 was not in ruby code
zoom - 8 - (zoomOffset % 3) - 2);
}
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) {
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));
return new Bounds(
mercator.eastNorth2latlon(projected.add(-deltaX, -deltaY)),
mercator.eastNorth2latlon(projected.add(deltaX, deltaY)));
}
/**
* Return OSM Zoom level for a given area
*
* @param b bounds of the area
* @return matching zoom level for area
*/
public static int getZoom(Bounds b) {
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));
}
/**
* Return OSM URL for given area.
*
* @param b bounds of the area
* @return link to display that area in OSM map
*/
public static String getURL(Bounds b) {
return getURL(b.getCenter(), getZoom(b));
}
/**
* Return OSM URL for given position and zoom.
*
* @param pos center position of area
* @param zoom zoom depth of display
* @return link to display that area in OSM map
*/
public static String getURL(LatLon pos, int zoom) {
return getURL(pos.lat(), pos.lon(), zoom);
}
/**
* Return OSM URL for given lat/lon and zoom.
*
* @param dlat center latitude of area
* @param dlon center longitude of area
* @param zoom zoom depth of display
* @return link to display that area in OSM map
*
* @since 6453
*/
public static String getURL(double dlat, double dlon, int zoom) {
// Truncate lat and lon to something more sensible
int decimals = (int) Math.pow(10, zoom / 3d);
double lat = Math.round(dlat * decimals);
lat /= decimals;
double lon = Math.round(dlon * decimals);
lon /= decimals;
return Main.getOSMWebsite() + "/#map="+zoom+'/'+lat+'/'+lon;
}
}