| /* |
| * Copyright (C) 2014 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.util; |
| |
| import static com.android.internal.util.Preconditions.*; |
| |
| import android.hardware.camera2.impl.HashCodeHelpers; |
| |
| /** |
| * Immutable class for describing the range of two numeric values. |
| * <p> |
| * A range (or "interval") defines the inclusive boundaries around a contiguous span of |
| * values of some {@link Comparable} type; for example, |
| * "integers from 1 to 100 inclusive." |
| * </p> |
| * <p> |
| * All ranges are bounded, and the left side of the range is always {@code >=} |
| * the right side of the range. |
| * </p> |
| * |
| * <p>Although the implementation itself is immutable, there is no restriction that objects |
| * stored must also be immutable. If mutable objects are stored here, then the range |
| * effectively becomes mutable. </p> |
| */ |
| public final class Range<T extends Comparable<? super T>> { |
| /** |
| * Create a new immutable range. |
| * |
| * <p> |
| * The endpoints are {@code [lower, upper]}; that |
| * is the range is bounded. {@code lower} must be {@link Comparable#compareTo lesser or equal} |
| * to {@code upper}. |
| * </p> |
| * |
| * @param lower The lower endpoint (inclusive) |
| * @param upper The upper endpoint (inclusive) |
| * |
| * @throws NullPointerException if {@code lower} or {@code upper} is {@code null} |
| */ |
| public Range(final T lower, final T upper) { |
| mLower = checkNotNull(lower, "lower must not be null"); |
| mUpper = checkNotNull(upper, "upper must not be null"); |
| |
| if (lower.compareTo(upper) > 0) { |
| throw new IllegalArgumentException("lower must be less than or equal to upper"); |
| } |
| } |
| |
| /** |
| * Create a new immutable range, with the argument types inferred. |
| * |
| * <p> |
| * The endpoints are {@code [lower, upper]}; that |
| * is the range is bounded. {@code lower} must be {@link Comparable#compareTo lesser or equal} |
| * to {@code upper}. |
| * </p> |
| * |
| * @param lower The lower endpoint (inclusive) |
| * @param upper The upper endpoint (inclusive) |
| * |
| * @throws NullPointerException if {@code lower} or {@code upper} is {@code null} |
| */ |
| public static <T extends Comparable<? super T>> Range<T> create(final T lower, final T upper) { |
| return new Range<T>(lower, upper); |
| } |
| |
| /** |
| * Get the lower endpoint. |
| * |
| * @return a non-{@code null} {@code T} reference |
| */ |
| public T getLower() { |
| return mLower; |
| } |
| |
| /** |
| * Get the upper endpoint. |
| * |
| * @return a non-{@code null} {@code T} reference |
| */ |
| public T getUpper() { |
| return mUpper; |
| } |
| |
| /** |
| * Compare two ranges for equality. |
| * |
| * <p>A range is considered equal if and only if both the lower and upper endpoints |
| * are also equal.</p> |
| * |
| * @return {@code true} if the ranges are equal, {@code false} otherwise |
| */ |
| @Override |
| public boolean equals(final Object obj) { |
| if (obj == null) { |
| return false; |
| } |
| if (this == obj) { |
| return true; |
| } |
| if (obj instanceof Range) { |
| @SuppressWarnings("rawtypes") |
| final |
| Range other = (Range) obj; |
| return mLower.equals(other.mLower) && mUpper.equals(other.mUpper); |
| } |
| return false; |
| } |
| |
| /** |
| * Return the range as a string representation {@code "[lower, upper]"}. |
| * |
| * @return string representation of the range |
| */ |
| @Override |
| public String toString() { |
| return String.format("[%s, %s]", mLower, mUpper); |
| } |
| |
| /** |
| * {@inheritDoc} |
| */ |
| @Override |
| public int hashCode() { |
| return HashCodeHelpers.hashCode(mLower, mUpper); |
| } |
| |
| private final T mLower; |
| private final T mUpper; |
| }; |