Java tutorial
/* * Copyright (C) 2016 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.brotherpowers.cameraview; import android.support.v4.util.ArrayMap; import java.util.Set; import java.util.SortedSet; import java.util.TreeSet; /** * A collection class that automatically groups {@link Size}s by their {@link AspectRatio}s. */ class SizeMap { private final ArrayMap<AspectRatio, SortedSet<Size>> mRatios = new ArrayMap<>(); /** * Add a new {@link Size} to this collection. * * @param size The size to add. * @return {@code true} if it is added, {@code false} if it already exists and is not added. */ public boolean add(Size size) { for (AspectRatio ratio : mRatios.keySet()) { if (ratio.matches(size)) { final SortedSet<Size> sizes = mRatios.get(ratio); if (sizes.contains(size)) { return false; } else { sizes.add(size); return true; } } } // None of the existing ratio matches the provided size; add a new key SortedSet<Size> sizes = new TreeSet<>(); sizes.add(size); mRatios.put(AspectRatio.of(size.getWidth(), size.getHeight()), sizes); return true; } Set<AspectRatio> ratios() { return mRatios.keySet(); } SortedSet<Size> sizes(AspectRatio ratio) { return mRatios.get(ratio); } void clear() { mRatios.clear(); } boolean isEmpty() { return mRatios.isEmpty(); } }