Merge SkCodec with SkScanlineDecoder

src/codec/SkBmpCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBmpCodec.h"
 #include "SkBmpMaskCodec.h"
 #include "SkBmpRLECodec.h"
@@ skipping 244 matching lines @@
         height = (int) get_short(iBuffer.get(), 2);
         bitsPerPixel = get_short(iBuffer.get(), 6);
         bytesPerColor = 3;
     } else {
         // There are no valid bmp headers
         SkCodecPrintf("Error: second bitmap header size is invalid.\n");
         return false;
     }
 
     // Check for valid dimensions from header
-    SkScanlineDecoder::SkScanlineOrder rowOrder = SkScanlineDecoder::kBottomUp_SkScanlineOrder;
+    SkCodec::SkScanlineOrder rowOrder = SkCodec::kBottomUp_SkScanlineOrder;
     if (height < 0) {
         height = -height;
-        rowOrder = SkScanlineDecoder::kTopDown_SkScanlineOrder;
+        rowOrder = SkCodec::kTopDown_SkScanlineOrder;
     }
     // The height field for bmp in ico is double the actual height because they
     // contain an XOR mask followed by an AND mask
     if (inIco) {
         height /= 2;
     }
     if (width <= 0 || height <= 0) {
         // TODO: Decide if we want to disable really large bmps as well.
         // https://code.google.com/p/skia/issues/detail?id=3617
         SkCodecPrintf("Error: invalid bitmap dimensions.\n");
@@ skipping 245 matching lines @@
         // codec has taken ownership of stream, so we do not need to
         // delete it.
         SkASSERT(codec);
         streamDeleter.detach();
         return codec;
     }
     return nullptr;
 }
 
 SkBmpCodec::SkBmpCodec(const SkImageInfo& info, SkStream* stream,
-        uint16_t bitsPerPixel, SkScanlineDecoder::SkScanlineOrder rowOrder)
+        uint16_t bitsPerPixel, SkCodec::SkScanlineOrder rowOrder)
     : INHERITED(info, stream)
     , fBitsPerPixel(bitsPerPixel)
     , fRowOrder(rowOrder)
 {}
 
 bool SkBmpCodec::onRewind() {
     return SkBmpCodec::ReadHeader(this->stream(), this->inIco(), nullptr);
 }
 
-int32_t SkBmpCodec::getDstRow(int32_t y, int32_t height) {
-    if (SkScanlineDecoder::kTopDown_SkScanlineOrder == fRowOrder) {
+int32_t SkBmpCodec::getDstRow(int32_t y, int32_t height) const {
+    if (SkCodec::kTopDown_SkScanlineOrder == fRowOrder) {
         return y;
     }
-    SkASSERT(SkScanlineDecoder::kBottomUp_SkScanlineOrder == fRowOrder);
+    SkASSERT(SkCodec::kBottomUp_SkScanlineOrder == fRowOrder);
     return height - y - 1;
 }
 
 /*
  * Get the destination row to start filling from
  * Used to fill the remainder of the image on incomplete input for bmps
  * This is tricky since bmps may be kTopDown or kBottomUp.  For kTopDown,
  * we start filling from where we left off, but for kBottomUp we start
  * filling at the top of the image.
  */
 void* SkBmpCodec::getDstStartRow(void* dst, size_t dstRowBytes, int32_t y) const {
-    return (SkScanlineDecoder::kTopDown_SkScanlineOrder == fRowOrder) ?
+    return (SkCodec::kTopDown_SkScanlineOrder == fRowOrder) ?
             SkTAddOffset<void*>(dst, y * dstRowBytes) : dst;
 }
 
 /*
  * Compute the number of colors in the color table
  */
 uint32_t SkBmpCodec::computeNumColors(uint32_t numColors) {
     // Zero is a default for maxColors
     // Also set numColors to maxColors when it is too large
     uint32_t maxColors = 1 << fBitsPerPixel;
     if (numColors == 0 || numColors >= maxColors) {
         return maxColors;
     }
     return numColors;
 }
 
-/*
- * Scanline decoder for bmps
- */
-class SkBmpScanlineDecoder : public SkScanlineDecoder {
-public:
-    SkBmpScanlineDecoder(SkBmpCodec* codec)
-        : INHERITED(codec->getInfo())
-        , fCodec(codec)
-    {}
-
-    SkEncodedFormat onGetEncodedFormat() const override {
-        return kBMP_SkEncodedFormat;
+SkCodec::Result SkBmpCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
+        const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
+    if (!this->rewindIfNeeded()) {
+        return kCouldNotRewind;
+    }
+    if (options.fSubset) {
+        // Subsets are not supported.
+        return kUnimplemented;
+    }
+    if (dstInfo.dimensions() != this->getInfo().dimensions()) {
+        if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) {
+            return SkCodec::kInvalidScale;
+        }
+    }
+    if (!conversion_possible(dstInfo, this->getInfo())) {
+        SkCodecPrintf("Error: cannot convert input type to output type.\n");
+        return kInvalidConversion;
     }
 
-    SkCodec::Result onStart(const SkImageInfo& dstInfo, const SkCodec::Options& options,
-                            SkPMColor inputColorPtr[], int* inputColorCount) override {
-        if (!fCodec->rewindIfNeeded()) {
-            return SkCodec::kCouldNotRewind;
-        }
-        if (options.fSubset) {
-            // Subsets are not supported.
-            return SkCodec::kUnimplemented;
-        }
-        if (dstInfo.dimensions() != this->getInfo().dimensions()) {
-            if (!SkScaledCodec::DimensionsSupportedForSampling(this->getInfo(), dstInfo)) {
-                return SkCodec::kInvalidScale;
-            }
-        }
-        if (!conversion_possible(dstInfo, this->getInfo())) {
-            SkCodecPrintf("Error: cannot convert input type to output type.\n");
-            return SkCodec::kInvalidConversion;
-        }
+    return prepareToDecode(dstInfo, options, inputColorPtr, inputColorCount);
+}
 
-        return fCodec->prepareToDecode(dstInfo, options, inputColorPtr, inputColorCount);
-    }
+SkCodec::Result SkBmpCodec::onGetScanlines(void* dst, int count, size_t rowBytes) {
+    // Create a new image info representing the portion of the image to decode
+    SkImageInfo rowInfo = this->dstInfo().makeWH(this->dstInfo().width(), count);
 
-    SkCodec::Result onGetScanlines(void* dst, int count, size_t rowBytes) override {
-        // Create a new image info representing the portion of the image to decode
-        SkImageInfo rowInfo = this->dstInfo().makeWH(this->dstInfo().width(), count);
+    // Decode the requested rows
+    return this->decodeRows(rowInfo, dst, rowBytes, this->options());
+}
 
-        // Decode the requested rows
-        return fCodec->decodeRows(rowInfo, dst, rowBytes, this->options());
-    }
-
-    SkScanlineOrder onGetScanlineOrder() const override {
-        return fCodec->fRowOrder;
-    }
-
-    int onGetY() const override {
-        return fCodec->getDstRow(this->INHERITED::onGetY(), this->dstInfo().height());
-    }
-
-    // TODO(msarett): Override default skipping with something more clever.
-
-private:
-    SkAutoTDelete<SkBmpCodec> fCodec;
-
-    typedef SkScanlineDecoder INHERITED;
-};
-
-SkScanlineDecoder* SkBmpCodec::NewSDFromStream(SkStream* stream) {
-    SkAutoTDelete<SkBmpCodec> codec(static_cast<SkBmpCodec*>(SkBmpCodec::NewFromStream(stream)));
-    if (!codec) {
-        return NULL;
-    }
-
-    return new SkBmpScanlineDecoder(codec.detach());
+int SkBmpCodec::onNextScanline() const {
+    return this->getDstRow(this->INHERITED::onNextScanline(), this->dstInfo().height());
 }