Split SkBmpCodec into three separate classes

src/codec/SkBmpStandardCodec.h

+/*
+ * 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 "SkCodec.h"
+#include "SkColorTable.h"
+#include "SkImageInfo.h"
+#include "SkMaskSwizzler.h"

[scroggo, 2015/07/31 15:05:44]

This is not used by this class.

[msarett, 2015/08/03 22:52:35]

Done.

+#include "SkStream.h"

[scroggo, 2015/07/31 15:05:44]

I think this can be forward declared.

[msarett, 2015/08/03 22:52:35]

Acknowledged.

+#include "SkSwizzler.h"
+#include "SkTypes.h"
+
+/*
+ * This class implements the decoding for bmp images

[scroggo, 2015/07/31 15:05:44]

Which kind?

[msarett, 2015/08/03 22:52:35]

Improved this description

+ */
+class SkBmpStandardCodec : public SkCodec {
+protected:
+
+    /*
+     * Initiates the bmp decode
+     */
+    Result onGetPixels(const SkImageInfo& dstInfo, void* dst,
+                       size_t dstRowBytes, const Options&, SkPMColor*,
+                       int*) override;
+
+    SkEncodedFormat onGetEncodedFormat() const override { return kBMP_SkEncodedFormat; }
+
+private:
+
+    /*
+     * Creates the color table
+     * Sets colorCount to the new color count if it is non-NULL
+     */
+    bool createColorTable(SkAlphaType alphaType, int* colorCount);
+
+    /*
+     * Initialize swizzler
+     */
+    bool initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts);
+
+    /*
+     * Performs the bitmap decoding for standard input format
+     */
+    Result decode(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes, const Options& opts);
+
+    /*
+     * Creates an instance of the decoder
+     * Called only by NewFromStream
+     *
+     * @param srcInfo contains the source width and height
+     * @param stream the stream of image data
+     * @param bitsPerPixel the number of bits used to store each pixel
+     * @param format the format of the bmp file
+     * @param numColors the number of colors in the color table
+     * @param bytesPerColor the number of bytes in the stream used to represent
+                            each color in the color table
+     * @param offset the offset of the image pixel data from the end of the
+     *               headers
+     * @param rowOrder indicates whether rows are ordered top-down or bottom-up
+     */
+    SkBmpStandardCodec(const SkImageInfo& srcInfo, SkStream* stream,
+               uint16_t bitsPerPixel, uint32_t numColors, uint32_t bytesPerColor,
+               uint32_t offset, SkBmpCodec::RowOrder rowOrder, bool isIco);
+
+    // Fields

[scroggo, 2015/07/31 15:05:44]

comment not needed.

[msarett, 2015/08/03 22:52:35]

Done.

+    const uint16_t                      fBitsPerPixel;

[scroggo, 2015/07/31 15:05:44]

This looks to be used by all three codecs.

You can put it in a base class, and then add a protected accessor. Then you
won't have to duplicate this field.

(Maybe some of the others can be shared?)

[msarett, 2015/08/03 22:52:35]

Done.  fRowOrder can also be shared.

+    SkAutoTUnref<SkColorTable>          fColorTable;     // owned
+    uint32_t                            fNumColors;
+    const uint32_t                      fBytesPerColor;
+    const uint32_t                      fOffset;
+    const SkBmpCodec::RowOrder          fRowOrder;
+    SkAutoTDelete<SkSwizzler>           fSwizzler;
+    SkAutoTDeleteArray<uint8_t>         fSrcBuffer;
+    const bool                          fIsIco;
+    bool                                fIsTransparent;
+
+    friend class SkBmpCodec;
+
+    typedef SkCodec INHERITED;
+};