src/third_party/skia/src/lazy/SkCachingPixelRef.cpp

   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(
  49                 this->getGenerationID(), info.bounds(), &fLockedBitmap)) {
  50         // Cache has been purged, must re-decode.
  51         if (!fLockedBitmap.tryAllocPixels(info, fRowBytes)) {
  52             fErrorInDecoding = true;
  53             return false;
  54         }
  55         if (!fImageGenerator->getPixels(info, fLockedBitmap.getPixels(), fRowBytes)) {
  56             fErrorInDecoding = true;
  57             return false;
  58         }
  59         fLockedBitmap.setImmutable();
  60         SkBitmapCache::Add(
  61                 this->getGenerationID(), info.bounds(), fLockedBitmap);
  62     }
  63
  64     // Now bitmap should contain a concrete PixelRef of the decoded image.
  65     void* pixels = fLockedBitmap.getPixels();
  66     SkASSERT(pixels != NULL);
  67     rec->fPixels = pixels;
  68     rec->fColorTable = NULL;
  69     rec->fRowBytes = fLockedBitmap.rowBytes();
  70     return true;
  71 }
  72
  73 void SkCachingPixelRef::onUnlockPixels() {
  74     fLockedBitmap.reset();
  75 }