1/* 2 * Copyright (C) 2012 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 18package com.android.server.location; 19 20import android.app.PendingIntent; 21import android.location.Geofence; 22import android.location.Location; 23 24/** 25 * Represents state associated with a geofence 26 */ 27public class GeofenceState { 28 public final static int FLAG_ENTER = 0x01; 29 public final static int FLAG_EXIT = 0x02; 30 31 private static final int STATE_UNKNOWN = 0; 32 private static final int STATE_INSIDE = 1; 33 private static final int STATE_OUTSIDE = 2; 34 35 public final Geofence mFence; 36 private final Location mLocation; 37 public final long mExpireAt; 38 public final String mPackageName; 39 public final PendingIntent mIntent; 40 41 int mState; // current state 42 double mDistanceToCenter; // current distance to center of fence 43 44 public GeofenceState(Geofence fence, long expireAt, 45 String packageName, PendingIntent intent) { 46 mState = STATE_UNKNOWN; 47 mDistanceToCenter = Double.MAX_VALUE; 48 49 mFence = fence; 50 mExpireAt = expireAt; 51 mPackageName = packageName; 52 mIntent = intent; 53 54 mLocation = new Location(""); 55 mLocation.setLatitude(fence.getLatitude()); 56 mLocation.setLongitude(fence.getLongitude()); 57 } 58 59 /** 60 * Process a new location. 61 * @return FLAG_ENTER or FLAG_EXIT if the fence was crossed, 0 otherwise 62 */ 63 public int processLocation(Location location) { 64 mDistanceToCenter = mLocation.distanceTo(location); 65 66 int prevState = mState; 67 //TODO: inside/outside detection could be made more rigorous 68 boolean inside = mDistanceToCenter <= Math.max(mFence.getRadius(), location.getAccuracy()); 69 if (inside) { 70 mState = STATE_INSIDE; 71 if (prevState != STATE_INSIDE) { 72 return FLAG_ENTER; // return enter if previously exited or unknown 73 } 74 } else { 75 mState = STATE_OUTSIDE; 76 if (prevState == STATE_INSIDE) { 77 return FLAG_EXIT; // return exit only if previously entered 78 } 79 } 80 return 0; 81 } 82 83 /** 84 * Gets the distance from the current location to the fence's boundary. 85 * @return The distance or {@link Double#MAX_VALUE} if unknown. 86 */ 87 public double getDistanceToBoundary() { 88 if (Double.compare(mDistanceToCenter, Double.MAX_VALUE) == 0) { 89 return Double.MAX_VALUE; 90 } else { 91 return Math.abs(mFence.getRadius() - mDistanceToCenter); 92 } 93 } 94 95 @Override 96 public String toString() { 97 String state; 98 switch (mState) { 99 case STATE_INSIDE: 100 state = "IN"; 101 break; 102 case STATE_OUTSIDE: 103 state = "OUT"; 104 break; 105 default: 106 state = "?"; 107 } 108 return String.format("%s d=%.0f %s", mFence.toString(), mDistanceToCenter, state); 109 } 110} 111