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 
Install(SkImageGenerator * generator,SkBitmap * dst)12 bool SkCachingPixelRef::Install(SkImageGenerator* generator,
13                                 SkBitmap* dst) {
14     SkASSERT(dst != NULL);
15     if (NULL == generator) {
16         return false;
17     }
18     const SkImageInfo info = generator->getInfo();
19     if (!dst->setInfo(info)) {
20         SkDELETE(generator);
21         return false;
22     }
23     SkAutoTUnref<SkCachingPixelRef> ref(SkNEW_ARGS(SkCachingPixelRef,
24                                            (info, generator, dst->rowBytes())));
25     dst->setPixelRef(ref);
26     return true;
27 }
28 
SkCachingPixelRef(const SkImageInfo & info,SkImageGenerator * generator,size_t rowBytes)29 SkCachingPixelRef::SkCachingPixelRef(const SkImageInfo& info,
30                                      SkImageGenerator* generator,
31                                      size_t rowBytes)
32     : INHERITED(info)
33     , fImageGenerator(generator)
34     , fErrorInDecoding(false)
35     , fRowBytes(rowBytes) {
36     SkASSERT(fImageGenerator != NULL);
37 }
~SkCachingPixelRef()38 SkCachingPixelRef::~SkCachingPixelRef() {
39     SkDELETE(fImageGenerator);
40     // Assert always unlock before unref.
41 }
42 
onNewLockPixels(LockRec * rec)43 bool SkCachingPixelRef::onNewLockPixels(LockRec* rec) {
44     if (fErrorInDecoding) {
45         return false;  // don't try again.
46     }
47 
48     const SkImageInfo& info = this->info();
49     if (!SkBitmapCache::Find(
50                 this->getGenerationID(), info.bounds(), &fLockedBitmap)) {
51         // Cache has been purged, must re-decode.
52         if (!fLockedBitmap.tryAllocPixels(info, fRowBytes)) {
53             fErrorInDecoding = true;
54             return false;
55         }
56         const SkImageGenerator::Result result = fImageGenerator->getPixels(info,
57                 fLockedBitmap.getPixels(), fRowBytes);
58         switch (result) {
59             case SkImageGenerator::kIncompleteInput:
60             case SkImageGenerator::kSuccess:
61                 break;
62             default:
63                 fErrorInDecoding = true;
64                 return false;
65         }
66         fLockedBitmap.setImmutable();
67         SkBitmapCache::Add(this, info.bounds(), fLockedBitmap);
68     }
69 
70     // Now bitmap should contain a concrete PixelRef of the decoded image.
71     void* pixels = fLockedBitmap.getPixels();
72     SkASSERT(pixels != NULL);
73     rec->fPixels = pixels;
74     rec->fColorTable = NULL;
75     rec->fRowBytes = fLockedBitmap.rowBytes();
76     return true;
77 }
78 
onUnlockPixels()79 void SkCachingPixelRef::onUnlockPixels() {
80     fLockedBitmap.reset();
81 }
82