StarRating.java
/*
* Copyright 2019 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 androidx.media2.session;
import androidx.annotation.IntRange;
import androidx.core.util.ObjectsCompat;
import androidx.media2.common.Rating;
import androidx.versionedparcelable.ParcelField;
import androidx.versionedparcelable.VersionedParcelize;
/**
* A class for rating expressed as the number of stars.
*/
@VersionedParcelize
public final class StarRating implements Rating {
private static final float RATING_NOT_RATED = -1.0f;
@ParcelField(1)
int mMaxStars;
@ParcelField(2)
float mStarRating;
// WARNING: Adding a new ParcelField may break old library users (b/152830728)
/*
* Used for VersionedParcelable
*/
StarRating() {
}
/**
* Creates a unrated StarRating instance with {@code maxStars}.
* If {@code maxStars} is not a positive integer, it will throw IllegalArgumentException.
*
* @param maxStars a range of this star rating from 0.0f to {@code maxStars}
*/
public StarRating(@IntRange(from = 1) int maxStars) {
if (maxStars <= 0) {
throw new IllegalArgumentException("maxStars should be a positive integer");
}
mMaxStars = maxStars;
mStarRating = RATING_NOT_RATED;
}
/**
* Creates a StarRating instance with {@code maxStars} and the given integer or fractional
* number of stars. Non integer values can for instance be used to represent an average rating
* value, which might not be an integer number of stars.
* If {@code maxStars} is not a positive integer or {@code starRating} has invalid value,
* it will throw IllegalArgumentException.
*
* @param maxStars the maximum number of stars which this rating can have.
* @param starRating a number ranging from 0.0f to {@code maxStars}
*/
public StarRating(@IntRange(from = 1) int maxStars, float starRating) {
if (maxStars <= 0) {
throw new IllegalArgumentException("maxStars should be a positive integer");
} else if (starRating < 0.0f || starRating > maxStars) {
throw new IllegalArgumentException("starRating is out of range [0, maxStars]");
}
mMaxStars = maxStars;
mStarRating = starRating;
}
@Override
public boolean isRated() {
return mStarRating >= 0.0f;
}
@Override
public int hashCode() {
return ObjectsCompat.hash(mMaxStars, mStarRating);
}
@Override
public boolean equals(Object obj) {
if (!(obj instanceof StarRating)) {
return false;
}
StarRating other = (StarRating) obj;
return mMaxStars == other.mMaxStars && mStarRating == other.mStarRating;
}
@Override
public String toString() {
return "StarRating: maxStars=" + mMaxStars
+ (isRated() ? ", starRating=" + mStarRating : ", unrated");
}
/**
* Returns the max stars.
*
* @return a max number of stars for this star rating.
*/
public int getMaxStars() {
return mMaxStars;
}
/**
* Returns the star-based rating value.
*
* @return a rating value greater or equal to 0.0f, or a negative value if it is unrated.
*/
public float getStarRating() {
return mStarRating;
}
}