Java tutorial
/* * Copyright (C) 2012 The Android Open Source Project * * Licensed 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 android.location; import android.annotation.UnsupportedAppUsage; import android.os.Parcel; import android.os.Parcelable; /** * Represents a geographical boundary, also known as a geofence. * * <p>Currently only circular geofences are supported and they do not support altitude changes. * * @hide */ public final class Geofence implements Parcelable { /** @hide */ public static final int TYPE_HORIZONTAL_CIRCLE = 1; private final int mType; private final double mLatitude; private final double mLongitude; private final float mRadius; /** * Create a circular geofence (on a flat, horizontal plane). * * @param latitude latitude in degrees, between -90 and +90 inclusive * @param longitude longitude in degrees, between -180 and +180 inclusive * @param radius radius in meters * @return a new geofence * @throws IllegalArgumentException if any parameters are out of range */ public static Geofence createCircle(double latitude, double longitude, float radius) { return new Geofence(latitude, longitude, radius); } private Geofence(double latitude, double longitude, float radius) { checkRadius(radius); checkLatLong(latitude, longitude); mType = TYPE_HORIZONTAL_CIRCLE; mLatitude = latitude; mLongitude = longitude; mRadius = radius; } /** @hide */ public int getType() { return mType; } /** @hide */ public double getLatitude() { return mLatitude; } /** @hide */ public double getLongitude() { return mLongitude; } /** @hide */ public float getRadius() { return mRadius; } private static void checkRadius(float radius) { if (radius <= 0) { throw new IllegalArgumentException("invalid radius: " + radius); } } private static void checkLatLong(double latitude, double longitude) { if (latitude > 90.0 || latitude < -90.0) { throw new IllegalArgumentException("invalid latitude: " + latitude); } if (longitude > 180.0 || longitude < -180.0) { throw new IllegalArgumentException("invalid longitude: " + longitude); } } private static void checkType(int type) { if (type != TYPE_HORIZONTAL_CIRCLE) { throw new IllegalArgumentException("invalid type: " + type); } } @UnsupportedAppUsage public static final Parcelable.Creator<Geofence> CREATOR = new Parcelable.Creator<Geofence>() { @Override public Geofence createFromParcel(Parcel in) { int type = in.readInt(); double latitude = in.readDouble(); double longitude = in.readDouble(); float radius = in.readFloat(); checkType(type); return Geofence.createCircle(latitude, longitude, radius); } @Override public Geofence[] newArray(int size) { return new Geofence[size]; } }; @Override public int describeContents() { return 0; } @Override public void writeToParcel(Parcel parcel, int flags) { parcel.writeInt(mType); parcel.writeDouble(mLatitude); parcel.writeDouble(mLongitude); parcel.writeFloat(mRadius); } private static String typeToString(int type) { switch (type) { case TYPE_HORIZONTAL_CIRCLE: return "CIRCLE"; default: checkType(type); return null; } } @Override public String toString() { return String.format("Geofence[%s %.6f, %.6f %.0fm]", typeToString(mType), mLatitude, mLongitude, mRadius); } @Override public int hashCode() { final int prime = 31; int result = 1; long temp; temp = Double.doubleToLongBits(mLatitude); result = prime * result + (int) (temp ^ (temp >>> 32)); temp = Double.doubleToLongBits(mLongitude); result = prime * result + (int) (temp ^ (temp >>> 32)); result = prime * result + Float.floatToIntBits(mRadius); result = prime * result + mType; return result; } /** * Two geofences are equal if they have identical properties. */ @Override public boolean equals(Object obj) { if (this == obj) return true; if (obj == null) return false; if (!(obj instanceof Geofence)) return false; Geofence other = (Geofence) obj; if (mRadius != other.mRadius) return false; if (mLatitude != other.mLatitude) return false; if (mLongitude != other.mLongitude) return false; if (mType != other.mType) return false; return true; } }