Alexander Lucas | 97842ff | 2014-03-07 14:56:55 -0800 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright (C) 2013 The Android Open Source Project |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | package com.example.android.displayingbitmaps.util; |
| 18 | |
| 19 | import android.content.res.Resources; |
| 20 | import android.graphics.Bitmap; |
| 21 | import android.graphics.drawable.BitmapDrawable; |
| 22 | |
| 23 | import com.example.android.common.logger.Log; |
| 24 | import com.example.android.displayingbitmaps.BuildConfig; |
| 25 | |
| 26 | /** |
| 27 | * A BitmapDrawable that keeps track of whether it is being displayed or cached. |
| 28 | * When the drawable is no longer being displayed or cached, |
| 29 | * {@link android.graphics.Bitmap#recycle() recycle()} will be called on this drawable's bitmap. |
| 30 | */ |
| 31 | public class RecyclingBitmapDrawable extends BitmapDrawable { |
| 32 | |
| 33 | static final String TAG = "CountingBitmapDrawable"; |
| 34 | |
| 35 | private int mCacheRefCount = 0; |
| 36 | private int mDisplayRefCount = 0; |
| 37 | |
| 38 | private boolean mHasBeenDisplayed; |
| 39 | |
| 40 | public RecyclingBitmapDrawable(Resources res, Bitmap bitmap) { |
| 41 | super(res, bitmap); |
| 42 | } |
| 43 | |
| 44 | /** |
| 45 | * Notify the drawable that the displayed state has changed. Internally a |
| 46 | * count is kept so that the drawable knows when it is no longer being |
| 47 | * displayed. |
| 48 | * |
| 49 | * @param isDisplayed - Whether the drawable is being displayed or not |
| 50 | */ |
| 51 | public void setIsDisplayed(boolean isDisplayed) { |
| 52 | //BEGIN_INCLUDE(set_is_displayed) |
| 53 | synchronized (this) { |
| 54 | if (isDisplayed) { |
| 55 | mDisplayRefCount++; |
| 56 | mHasBeenDisplayed = true; |
| 57 | } else { |
| 58 | mDisplayRefCount--; |
| 59 | } |
| 60 | } |
| 61 | |
| 62 | // Check to see if recycle() can be called |
| 63 | checkState(); |
| 64 | //END_INCLUDE(set_is_displayed) |
| 65 | } |
| 66 | |
| 67 | /** |
| 68 | * Notify the drawable that the cache state has changed. Internally a count |
| 69 | * is kept so that the drawable knows when it is no longer being cached. |
| 70 | * |
| 71 | * @param isCached - Whether the drawable is being cached or not |
| 72 | */ |
| 73 | public void setIsCached(boolean isCached) { |
| 74 | //BEGIN_INCLUDE(set_is_cached) |
| 75 | synchronized (this) { |
| 76 | if (isCached) { |
| 77 | mCacheRefCount++; |
| 78 | } else { |
| 79 | mCacheRefCount--; |
| 80 | } |
| 81 | } |
| 82 | |
| 83 | // Check to see if recycle() can be called |
| 84 | checkState(); |
| 85 | //END_INCLUDE(set_is_cached) |
| 86 | } |
| 87 | |
| 88 | private synchronized void checkState() { |
| 89 | //BEGIN_INCLUDE(check_state) |
| 90 | // If the drawable cache and display ref counts = 0, and this drawable |
| 91 | // has been displayed, then recycle |
| 92 | if (mCacheRefCount <= 0 && mDisplayRefCount <= 0 && mHasBeenDisplayed |
| 93 | && hasValidBitmap()) { |
| 94 | if (BuildConfig.DEBUG) { |
| 95 | Log.d(TAG, "No longer being used or cached so recycling. " |
| 96 | + toString()); |
| 97 | } |
| 98 | |
| 99 | getBitmap().recycle(); |
| 100 | } |
| 101 | //END_INCLUDE(check_state) |
| 102 | } |
| 103 | |
| 104 | private synchronized boolean hasValidBitmap() { |
| 105 | Bitmap bitmap = getBitmap(); |
| 106 | return bitmap != null && !bitmap.isRecycled(); |
| 107 | } |
| 108 | |
| 109 | } |