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      1 /*
      2  * Copyright 2013 Google Inc.
      3  *
      4  * Use of this source code is governed by a BSD-style license that can be
      5  * found in the LICENSE file.
      6  */
      7 
      8 #include "SkCachingPixelRef.h"
      9 #include "SkBitmapCache.h"
     10 #include "SkRect.h"
     11 
     12 bool SkCachingPixelRef::Install(SkImageGenerator* generator,
     13                                 SkBitmap* dst) {
     14     SkImageInfo info;
     15     SkASSERT(dst != NULL);
     16     if ((NULL == generator)
     17         || !(generator->getInfo(&info))
     18         || !dst->setInfo(info)) {
     19         SkDELETE(generator);
     20         return false;
     21     }
     22     SkAutoTUnref<SkCachingPixelRef> ref(SkNEW_ARGS(SkCachingPixelRef,
     23                                            (info, generator, dst->rowBytes())));
     24     dst->setPixelRef(ref);
     25     return true;
     26 }
     27 
     28 SkCachingPixelRef::SkCachingPixelRef(const SkImageInfo& info,
     29                                      SkImageGenerator* generator,
     30                                      size_t rowBytes)
     31     : INHERITED(info)
     32     , fImageGenerator(generator)
     33     , fErrorInDecoding(false)
     34     , fRowBytes(rowBytes) {
     35     SkASSERT(fImageGenerator != NULL);
     36 }
     37 SkCachingPixelRef::~SkCachingPixelRef() {
     38     SkDELETE(fImageGenerator);
     39     // Assert always unlock before unref.
     40 }
     41 
     42 bool SkCachingPixelRef::onNewLockPixels(LockRec* rec) {
     43     if (fErrorInDecoding) {
     44         return false;  // don't try again.
     45     }
     46 
     47     const SkImageInfo& info = this->info();
     48     if (!SkBitmapCache::Find(this->getGenerationID(),
     49                              SkIRect::MakeWH(info.width(), info.height()),
     50                              &fLockedBitmap)) {
     51         // Cache has been purged, must re-decode.
     52         if (!fLockedBitmap.tryAllocPixels(info, fRowBytes)) {
     53             fErrorInDecoding = true;
     54             return false;
     55         }
     56         if (!fImageGenerator->getPixels(info, fLockedBitmap.getPixels(), fRowBytes)) {
     57             fErrorInDecoding = true;
     58             return false;
     59         }
     60         fLockedBitmap.setImmutable();
     61         SkBitmapCache::Add(this->getGenerationID(),
     62                            SkIRect::MakeWH(info.width(), info.height()),
     63                            fLockedBitmap);
     64     }
     65 
     66     // Now bitmap should contain a concrete PixelRef of the decoded image.
     67     void* pixels = fLockedBitmap.getPixels();
     68     SkASSERT(pixels != NULL);
     69     rec->fPixels = pixels;
     70     rec->fColorTable = NULL;
     71     rec->fRowBytes = fLockedBitmap.rowBytes();
     72     return true;
     73 }
     74 
     75 void SkCachingPixelRef::onUnlockPixels() {
     76     fLockedBitmap.reset();
     77 }
     78