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/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package net.java.html.geo;
import java.util.Collections;
import java.util.ServiceLoader;
import java.util.logging.Level;
import java.util.logging.Logger;
import net.java.html.BrwsrCtx;
import org.netbeans.html.context.spi.Contexts;
import org.netbeans.html.geo.impl.Accessor;
import org.netbeans.html.geo.impl.JsGLProvider;
import org.netbeans.html.geo.spi.GLProvider;
/** Class that represents a geolocation position provided as a callback
* to {@link Handle#onLocation(net.java.html.geo.Position)} method. The
* class getters mimic closely the structure of the position object as
* specified by
* W3C's Geolocation API.
*
* @author Jaroslav Tulach
*/
public final class Position {
static final Logger LOG = Logger.getLogger(Position.class.getName());
private final long timestamp;
private final Coordinates coords;
public Position(long timestamp, Coordinates coords) {
this.timestamp = timestamp;
this.coords = coords;
}
/** The actual location of the position.
* @return non-null coordinates
*/
public Coordinates getCoords() {
return coords;
}
/** The time when the position has been recorded.
* @return time in milliseconds since era (e.g. Jan 1, 1970).
*/
public long getTimestamp() {
return timestamp;
}
/** Actual location of a {@link Position}.
* Mimics closely
* W3C's Geolocation API.
*/
public static abstract class Coordinates {
protected Coordinates() {
if (!getClass().getName().equals("org.netbeans.html.geo.spi.CoordImpl")) {
throw new IllegalStateException();
}
}
/**
* @return geographic coordinate specified in decimal degrees.
*/
public abstract double getLatitude();
/**
* @return geographic coordinate specified in decimal degrees.
*/
public abstract double getLongitude();
/**
* The accuracy attribute denotes the accuracy level of the latitude
* and longitude coordinates. It is specified in meters.
* The value of the accuracy attribute must be a non-negative number.
*
* @return accuracy in meters
*/
public abstract double getAccuracy();
/** Denotes the height of the position, specified in meters above the ellipsoid.
* If the implementation cannot provide altitude information,
* the value of this attribute must be null.
* @return value in meters, may return null, if the information is not available
*/
public abstract Double getAltitude();
/** The altitude accuracy is specified in meters.
* If the implementation cannot provide altitude information,
* the value of this attribute must be null. Otherwise, the value
* must be a non-negative real number.
* @return value in meters; may return null, if the information is not available
*/
public abstract Double getAltitudeAccuracy();
/** Denotes the direction of travel of the device and
* is specified in degrees
* counting clockwise relative to the true north.
*
* @return value from 0 to 360 - may return null,
* if the information is not available
*/
public abstract Double getHeading();
/** Denotes the magnitude of the horizontal component of the
* device's current velocity and is specified in meters per second.
*
* @return may return null, if the information is not available
*/
public abstract Double getSpeed();
} // end of Coordinates
/** Rather than subclassing this class directly consider using {@link OnLocation}
* annotation. Such annotation will generate a subclass for you automatically
* with two static methods createQuery and createWatch
* which can be used to obtain instance of this class.
*/
public static abstract class Handle {
private final boolean oneTime;
private boolean enableHighAccuracy;
private long timeout;
private long maximumAge;
volatile JsH handle;
/** Creates new instance of this handle.
*
* @param oneTime true if the handle represents one time
* query. false if it represents a watch
*/
protected Handle(boolean oneTime) {
super();
this.oneTime = oneTime;
}
/** Callback from the implementation when a (new) position has been
* received and identified
* @param p the position
* @throws Throwable if an exception is thrown, it will be logged by the system
*/
protected abstract void onLocation(Position p) throws Throwable;
/** Callback when an error occurs.
* @param ex the exception describing what went wrong
* @throws Throwable if an exception is thrown, it will be logged by the system
*/
protected abstract void onError(Exception ex) throws Throwable;
/** Check whether the location API is supported.
* @return true, if one can call {@link #start}.
*/
public final boolean isSupported() {
JsH p = seekProviders(null, null);
if (p != null) {
p.stop();
return true;
}
return false;
}
/** Turns on high accuracy mode as specified by the
*
* W3C's Geolocation API. By default the mode is disabled.
* @param enable true or false
*/
public final void setHighAccuracy(boolean enable) {
this.enableHighAccuracy = enable;
}
/** The amount of milliseconds to wait for a result.
* By default infinity.
* @param timeout time in milliseconds to wait for a result.
*/
public final void setTimeout(long timeout) {
this.timeout = timeout;
}
/** Sets maximum age of cached results which are acceptable to be
* returned. By default maximum age is set to zero.
* @param age time in milliseconds of acceptable cached results
*/
public final void setMaximumAge(long age) {
this.maximumAge = age;
}
/** Initializes the query or watch request(s) and
* returns immediately. Has no effect if the query has already been
* started. If a problem appears while starting the system,
* it is immediately reported via the {@link #onError(java.lang.Exception)}
* callback. For example, if the {@link #isSupported()} method
* returns false an IllegalStateException is created
* and sent to the {@link #onError(java.lang.Exception) callback} method.
*/
public final void start() {
if (handle != null) {
return;
}
Exception[] problem = { null };
StringBuilder sb = new StringBuilder();
sb.append("[");
JsH h = seekProviders(sb, problem);
sb.append("\n]");
try {
if (problem[0] != null) {
onError(problem[0]);
return;
}
if (h == null) {
onError(new IllegalStateException("geolocation API not supported. Among providers: " + sb));
}
synchronized (this) {
if (handle != null) {
onError(new IllegalStateException("Parallel request"));
}
handle = h;
}
} catch (Throwable thr) {
LOG.log(Level.INFO, "Problems delivering onError report", thr);
}
}
private JsH seekProviders(StringBuilder sb, Exception[] problem) {
BrwsrCtx ctx = BrwsrCtx.findDefault(getClass());
JsH h = seekProviders(Contexts.find(ctx, GLProvider.class), null, sb, problem);
if (h == null) {
h = seekProviders(null, ServiceLoader.load(GLProvider.class), sb, problem);
}
if (h == null) {
h = seekProviders(new JsGLProvider(), null, sb, problem);
}
return h;
}
private JsH seekProviders(
GLProvider single, Iterable set,
StringBuilder sb, Exception[] problem
) {
if (set == null) {
if (single == null) {
return null;
}
set = Collections.singleton(single);
}
JsH h = null;
for (GLProvider p : set) {
if (sb != null) {
if (sb.length() > 1) {
sb.append(',');
}
sb.append("\n ").append(p.getClass().getName());
}
try {
h = createHandle(p);
} catch (Exception ex) {
LOG.log(Level.INFO, "Problems when starting " + p.getClass().getName(), ex);
if (problem != null && problem[0] == null) {
problem[0] = ex;
}
}
if (h != null) {
break;
}
}
return h;
}
/** Stops all pending requests. After this call no further callbacks
* can be obtained. Does nothing if no query or watch was in progress.
*/
public final void stop() {
JsH h;
synchronized (this) {
h = handle;
if (h == null) {
return;
}
handle = null;
}
h.stop();
}
private JsH createHandle(GLProvider p) {
JsH temp = new JsH(p);
return temp.watch == null ? null : temp;
}
private final class JsH extends Accessor {
private final Watch watch;
private final GLProvider provider;
public JsH(GLProvider p) {
super(true);
this.watch = Accessor.SPI.start(p, this, oneTime, enableHighAccuracy, timeout, maximumAge);
this.provider = p;
}
@Override
public void onLocation(Position position) {
if (handle != this) {
return;
}
if (oneTime) {
stop();
}
try {
Handle.this.onLocation(position);
} catch (Throwable ex) {
LOG.log(Level.SEVERE, null, ex);
}
}
@Override
public void onError(Exception err) {
if (handle != this) {
return;
}
if (oneTime) {
stop();
}
try {
Handle.this.onError(err);
} catch (Throwable ex) {
LOG.log(Level.SEVERE, null, ex);
}
}
protected final void stop() {
Accessor.SPI.stop(provider, watch);
}
@Override
public Watch start(
GLProvider p, Accessor peer,
boolean oneTime, boolean enableHighAccuracy,
long timeout, long maximumAge
) {
throw new UnsupportedOperationException();
}
@Override
public void stop(GLProvider p, Watch w) {
throw new UnsupportedOperationException();
}
} // end of JsH
}
}
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