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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 
      9 #include "SkData.h"
     10 #include "SkFlate.h"
     11 #include "SkPDFCatalog.h"
     12 #include "SkPDFImageStream.h"
     13 #include "SkStream.h"
     14 
     15 #define kNoColorTransform 0
     16 
     17 static bool skip_compression(SkPDFCatalog* catalog) {
     18     return SkToBool(catalog->getDocumentFlags() &
     19                     SkPDFDocument::kFavorSpeedOverSize_Flags);
     20 }
     21 
     22 // TODO(edisonn): Use SkData (after removing deprecated constructor in SkPDFStream).
     23 SkPDFImageStream::SkPDFImageStream(SkStream* stream,
     24                                    const SkBitmap& bitmap,
     25                                    const SkIRect& srcRect,
     26                                    EncodeToDCTStream encoder)
     27     : SkPDFStream(stream),
     28       fBitmap(bitmap),
     29       fSrcRect(srcRect),
     30       fEncoder(encoder) {
     31 }
     32 
     33 SkPDFImageStream::SkPDFImageStream(const SkPDFImageStream& pdfStream)
     34         : SkPDFStream(pdfStream),
     35           fBitmap(pdfStream.fBitmap),
     36           fSrcRect(pdfStream.fSrcRect),
     37           fEncoder(pdfStream.fEncoder) {
     38 }
     39 
     40 SkPDFImageStream::~SkPDFImageStream() {}
     41 
     42 bool SkPDFImageStream::populate(SkPDFCatalog* catalog) {
     43     if (getState() == kUnused_State) {
     44         if (!skip_compression(catalog)) {
     45             SkDynamicMemoryWStream dctCompressedWStream;
     46             if (!fEncoder || !fEncoder(&dctCompressedWStream, fBitmap, fSrcRect)) {
     47                 return INHERITED::populate(catalog);
     48             }
     49 
     50             if (dctCompressedWStream.getOffset() < getData()->getLength()) {
     51                 SkData* data = dctCompressedWStream.copyToData();
     52                 SkMemoryStream* stream = SkNEW_ARGS(SkMemoryStream, (data));
     53                 setData(stream);
     54                 stream->unref();
     55                 if (data) {
     56                     // copyToData and new SkMemoryStream both call ref(), supress one.
     57                     data->unref();
     58                 }
     59 
     60                 insertName("Filter", "DCTDecode");
     61                 insertInt("ColorTransform", kNoColorTransform);
     62                 setState(kCompressed_State);
     63             }
     64         }
     65         setState(kNoCompression_State);
     66         insertInt("Length", getData()->getLength());
     67     } else if (getState() == kNoCompression_State && !skip_compression(catalog) &&
     68                (SkFlate::HaveFlate() || fEncoder)) {
     69         // Compression has not been requested when the stream was first created.
     70         // But a new Catalog would want it compressed.
     71         if (!getSubstitute()) {
     72             SkPDFImageStream* substitute = SkNEW_ARGS(SkPDFImageStream, (*this));
     73             setSubstitute(substitute);
     74             catalog->setSubstitute(this, substitute);
     75         }
     76         return false;
     77     }
     78     return true;
     79 }
     80