| /* |
| * 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 com.android.systemui.recents.views; |
| |
| import android.content.Context; |
| |
| import java.util.Iterator; |
| import java.util.LinkedList; |
| import java.util.List; |
| |
| |
| /* A view pool to manage more views than we can visibly handle */ |
| public class ViewPool<V, T> { |
| |
| /* An interface to the consumer of a view pool */ |
| public interface ViewPoolConsumer<V, T> { |
| public V createView(Context context); |
| public void onReturnViewToPool(V v); |
| public void onPickUpViewFromPool(V v, T prepareData, boolean isNewView); |
| public boolean hasPreferredData(V v, T preferredData); |
| } |
| |
| Context mContext; |
| ViewPoolConsumer<V, T> mViewCreator; |
| LinkedList<V> mPool = new LinkedList<V>(); |
| |
| /** Initializes the pool with a fixed predetermined pool size */ |
| public ViewPool(Context context, ViewPoolConsumer<V, T> viewCreator) { |
| mContext = context; |
| mViewCreator = viewCreator; |
| } |
| |
| /** Returns a view into the pool */ |
| void returnViewToPool(V v) { |
| mViewCreator.onReturnViewToPool(v); |
| mPool.push(v); |
| } |
| |
| /** Gets a view from the pool and prepares it */ |
| V pickUpViewFromPool(T preferredData, T prepareData) { |
| V v = null; |
| boolean isNewView = false; |
| if (mPool.isEmpty()) { |
| v = mViewCreator.createView(mContext); |
| isNewView = true; |
| } else { |
| // Try and find a preferred view |
| Iterator<V> iter = mPool.iterator(); |
| while (iter.hasNext()) { |
| V vpv = iter.next(); |
| if (mViewCreator.hasPreferredData(vpv, preferredData)) { |
| v = vpv; |
| iter.remove(); |
| break; |
| } |
| } |
| // Otherwise, just grab the first view |
| if (v == null) { |
| v = mPool.pop(); |
| } |
| } |
| mViewCreator.onPickUpViewFromPool(v, prepareData, isNewView); |
| return v; |
| } |
| |
| /** |
| * Returns the list of views in the pool. |
| */ |
| List<V> getViews() { |
| return mPool; |
| } |
| } |