content: /*
   * Copyright (C) 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 com.android.launcher3.util;
  
  import android.content.Context;
  import android.util.SparseArray;
  import android.view.LayoutInflater;
  import android.view.View;
  import android.view.ViewGroup;
  
  /**
   * Utility class to cache views at an activity level
   */
  public class ViewCache {
  
      protected final SparseArray<CacheEntry> mCache = new SparseArray();
  
      public void setCacheSize(int layoutId, int size) {
          mCache.put(layoutId, new CacheEntry(size));
      }
  
      public <T extends View> T getView(int layoutId, Context context, ViewGroup parent) {
          CacheEntry entry = mCache.get(layoutId);
          if (entry == null) {
              entry = new CacheEntry(1);
              mCache.put(layoutId, entry);
          }
  
          if (entry.mCurrentSize > 0) {
              entry.mCurrentSize --;
              T result = (T) entry.mViews[entry.mCurrentSize];
              entry.mViews[entry.mCurrentSize] = null;
              return result;
          }
  
          return (T) LayoutInflater.from(context).inflate(layoutId, parent, false);
      }
  
      public void recycleView(int layoutId, View view) {
          CacheEntry entry = mCache.get(layoutId);
          if (entry != null && entry.mCurrentSize < entry.mMaxSize) {
              entry.mViews[entry.mCurrentSize] = view;
              entry.mCurrentSize++;
          }
      }
  
      private static class CacheEntry {
  
          final int mMaxSize;
          final View[] mViews;
  
          int mCurrentSize;
  
          public CacheEntry(int maxSize) {
              mMaxSize = maxSize;
              mViews = new View[maxSize];
              mCurrentSize = 0;
          }
      }
  }
  