Introduce a Lifecycle for system services

Provide an abstract class for system services to extend from,
similar to the android.app.Service.

This will allow services to receive events in a uniform way,
and will allow services to be created and started in the
correct order regardless of whether or not a particular
service exists.

Similar to android.app.Service, services are meant to implement
Binder interfaces as inner classes. This prevents services from
having incestuous access to each other and makes them use the
public API.

Change-Id: Iaacfee8d5f080a28d7cc606761f4624673ed390f
diff --git a/services/java/com/android/server/twilight/TwilightState.java b/services/java/com/android/server/twilight/TwilightState.java
new file mode 100644
index 0000000..91e24d7
--- /dev/null
+++ b/services/java/com/android/server/twilight/TwilightState.java
@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2013 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 com.android.server.twilight;
+
+import java.text.DateFormat;
+import java.util.Date;
+
+/**
+ * Describes whether it is day or night.
+ * This object is immutable.
+ */
+public class TwilightState {
+    private final boolean mIsNight;
+    private final long mYesterdaySunset;
+    private final long mTodaySunrise;
+    private final long mTodaySunset;
+    private final long mTomorrowSunrise;
+
+    TwilightState(boolean isNight,
+            long yesterdaySunset,
+            long todaySunrise, long todaySunset,
+            long tomorrowSunrise) {
+        mIsNight = isNight;
+        mYesterdaySunset = yesterdaySunset;
+        mTodaySunrise = todaySunrise;
+        mTodaySunset = todaySunset;
+        mTomorrowSunrise = tomorrowSunrise;
+    }
+
+    /**
+     * Returns true if it is currently night time.
+     */
+    public boolean isNight() {
+        return mIsNight;
+    }
+
+    /**
+     * Returns the time of yesterday's sunset in the System.currentTimeMillis() timebase,
+     * or -1 if the sun never sets.
+     */
+    public long getYesterdaySunset() {
+        return mYesterdaySunset;
+    }
+
+    /**
+     * Returns the time of today's sunrise in the System.currentTimeMillis() timebase,
+     * or -1 if the sun never rises.
+     */
+    public long getTodaySunrise() {
+        return mTodaySunrise;
+    }
+
+    /**
+     * Returns the time of today's sunset in the System.currentTimeMillis() timebase,
+     * or -1 if the sun never sets.
+     */
+    public long getTodaySunset() {
+        return mTodaySunset;
+    }
+
+    /**
+     * Returns the time of tomorrow's sunrise in the System.currentTimeMillis() timebase,
+     * or -1 if the sun never rises.
+     */
+    public long getTomorrowSunrise() {
+        return mTomorrowSunrise;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        return o instanceof TwilightState && equals((TwilightState)o);
+    }
+
+    public boolean equals(TwilightState other) {
+        return other != null
+                && mIsNight == other.mIsNight
+                && mYesterdaySunset == other.mYesterdaySunset
+                && mTodaySunrise == other.mTodaySunrise
+                && mTodaySunset == other.mTodaySunset
+                && mTomorrowSunrise == other.mTomorrowSunrise;
+    }
+
+    @Override
+    public int hashCode() {
+        return 0; // don't care
+    }
+
+    @Override
+    public String toString() {
+        DateFormat f = DateFormat.getDateTimeInstance();
+        return "{TwilightState: isNight=" + mIsNight
+                + ", mYesterdaySunset=" + f.format(new Date(mYesterdaySunset))
+                + ", mTodaySunrise=" + f.format(new Date(mTodaySunrise))
+                + ", mTodaySunset=" + f.format(new Date(mTodaySunset))
+                + ", mTomorrowSunrise=" + f.format(new Date(mTomorrowSunrise))
+                + "}";
+    }
+}