| /* |
| * Copyright (C) 2018 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.os; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| |
| import java.util.Objects; |
| |
| /** |
| * A value with an associated reference time. The reference time will typically be provided by the |
| * elapsed realtime clock. The elapsed realtime clock can be obtained using methods like |
| * {@link SystemClock#elapsedRealtime()} or {@link SystemClock#elapsedRealtimeClock()}. |
| * If a suitable clock is used the reference time can be used to identify the age of a value or |
| * ordering between values. |
| * |
| * <p>This class implements {@link Parcelable} for convenience but instances will only actually be |
| * parcelable if the value type held is {@code null}, {@link Parcelable}, or one of the other types |
| * supported by {@link Parcel#writeValue(Object)} / {@link Parcel#readValue(ClassLoader)}. |
| * |
| * @param <T> the type of the value with an associated timestamp |
| * @hide |
| */ |
| public final class TimestampedValue<T> implements Parcelable { |
| private final long mReferenceTimeMillis; |
| @Nullable |
| private final T mValue; |
| |
| public TimestampedValue(long referenceTimeMillis, @Nullable T value) { |
| mReferenceTimeMillis = referenceTimeMillis; |
| mValue = value; |
| } |
| |
| /** Returns the reference time value. See {@link TimestampedValue} for more information. */ |
| public long getReferenceTimeMillis() { |
| return mReferenceTimeMillis; |
| } |
| |
| /** |
| * Returns the value associated with the timestamp. See {@link TimestampedValue} for more |
| * information. |
| */ |
| @Nullable |
| public T getValue() { |
| return mValue; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (this == o) { |
| return true; |
| } |
| if (o == null || getClass() != o.getClass()) { |
| return false; |
| } |
| TimestampedValue<?> that = (TimestampedValue<?>) o; |
| return mReferenceTimeMillis == that.mReferenceTimeMillis |
| && Objects.equals(mValue, that.mValue); |
| } |
| |
| @Override |
| public int hashCode() { |
| return Objects.hash(mReferenceTimeMillis, mValue); |
| } |
| |
| @Override |
| public String toString() { |
| return "TimestampedValue{" |
| + "mReferenceTimeMillis=" + mReferenceTimeMillis |
| + ", mValue=" + mValue |
| + '}'; |
| } |
| |
| /** |
| * Returns the difference in milliseconds between two instance's reference times. |
| */ |
| public static long referenceTimeDifference( |
| @NonNull TimestampedValue<?> one, @NonNull TimestampedValue<?> two) { |
| return one.mReferenceTimeMillis - two.mReferenceTimeMillis; |
| } |
| |
| /** @hide */ |
| public static final @NonNull Parcelable.Creator<TimestampedValue<?>> CREATOR = |
| new Parcelable.ClassLoaderCreator<TimestampedValue<?>>() { |
| |
| @Override |
| public TimestampedValue<?> createFromParcel(@NonNull Parcel source) { |
| return createFromParcel(source, null); |
| } |
| |
| @Override |
| public TimestampedValue<?> createFromParcel( |
| @NonNull Parcel source, @Nullable ClassLoader classLoader) { |
| long referenceTimeMillis = source.readLong(); |
| Object value = source.readValue(classLoader); |
| return new TimestampedValue<>(referenceTimeMillis, value); |
| } |
| |
| @Override |
| public TimestampedValue[] newArray(int size) { |
| return new TimestampedValue[size]; |
| } |
| }; |
| |
| @Override |
| public int describeContents() { |
| return 0; |
| } |
| |
| @Override |
| public void writeToParcel(@NonNull Parcel dest, int flags) { |
| dest.writeLong(mReferenceTimeMillis); |
| dest.writeValue(mValue); |
| } |
| } |