skia2/tools/SkBitmapRegionCanvas.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 "SkBitmap.h"
#include "SkBitmapRegionDecoder.h"
#include "SkCodec.h"

/*
 * This class implements SkBitmapRegionDecoder using an SkCodec and
 * an SkCanvas.  It uses the scanline decoder to subset the height.  It then
 * will subset the width and scale by drawing to an SkCanvas.
 */
// FIXME (msarett): This implementation does not support WEBP, because WEBP
// does not have a scanline decoder.
class SkBitmapRegionCanvas : public SkBitmapRegionDecoder {
public:

    /*
     * Takes ownership of pointer to decoder
     */
    SkBitmapRegionCanvas(SkCodec* decoder);

    bool decodeRegion(SkBitmap* bitmap, SkBitmap::Allocator* allocator,
                      const SkIRect& desiredSubset, int sampleSize,
                      SkColorType colorType, bool requireUnpremul) override;

    bool conversionSupported(SkColorType colorType) override;

    SkEncodedFormat getEncodedFormat() override { return fDecoder->getEncodedFormat(); }

private:

    SkAutoTDelete<SkCodec> fDecoder;

    typedef SkBitmapRegionDecoder INHERITED;

};