SkDecodingImageGenerator now uses SkStreamRewindable

src/images/SkImageDecoder.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
 #include "SkBitmap.h"
@@ skipping 264 matching lines @@
                           SkBitmap::Config pref, Mode mode, Format* format) {
     if (0 == size) {
         return false;
     }
     SkASSERT(buffer);
 
     SkMemoryStream  stream(buffer, size);
     return SkImageDecoder::DecodeStream(&stream, bm, pref, mode, format);
 }
 
-/**
- *  Special allocator used by DecodeMemoryToTarget. Uses preallocated memory
- *  provided if the bm is 8888. Otherwise, uses a heap allocator. The same
- *  allocator will be used again for a copy to 8888, when the preallocated
- *  memory will be used.
- */
-class TargetAllocator : public SkBitmap::HeapAllocator {
-
-public:
-    TargetAllocator(void* target)
-        : fTarget(target) {}
-
-    virtual bool allocPixelRef(SkBitmap* bm, SkColorTable* ct) SK_OVERRIDE {
-        // If the config is not 8888, allocate a pixelref using the heap.
-        // fTarget will be used to store the final pixels when copied to
-        // 8888.
-        if (bm->config() != SkBitmap::kARGB_8888_Config) {
-            return INHERITED::allocPixelRef(bm, ct);
-        }
-        // In kARGB_8888_Config, there is no colortable.
-        SkASSERT(NULL == ct);
-        bm->setPixels(fTarget);
-        return true;
-    }
-
-private:
-    void* fTarget;
-    typedef SkBitmap::HeapAllocator INHERITED;
-};
-
-/**
- *  Helper function for DecodeMemoryToTarget. DecodeMemoryToTarget wants
- *  8888, so set the config to it. All parameters must not be null.
- *  @param decoder Decoder appropriate for this stream.
- *  @param stream Rewound stream to the encoded data.
- *  @param bitmap On success, will have its bounds set to the bounds of the
- *      encoded data, and its config set to 8888.
- *  @return True if the bounds were decoded and the bitmap is 8888 or can be
- *      copied to 8888.
- */
-static bool decode_bounds_to_8888(SkImageDecoder* decoder, SkStream* stream,
-                                  SkBitmap* bitmap) {
-    SkASSERT(decoder != NULL);
-    SkASSERT(stream != NULL);
-    SkASSERT(bitmap != NULL);
-
-    if (!decoder->decode(stream, bitmap, SkImageDecoder::kDecodeBounds_Mode)) {
-        return false;
-    }
-
-    if (bitmap->config() == SkBitmap::kARGB_8888_Config) {
-        return true;
-    }
-
-    if (!bitmap->canCopyTo(SkBitmap::kARGB_8888_Config)) {
-        return false;
-    }
-
-    bitmap->setConfig(SkBitmap::kARGB_8888_Config, bitmap->width(), bitmap->height());
-    return true;
-}
-
-/**
- *  Helper function for DecodeMemoryToTarget. Decodes the stream into bitmap, and if
- *  the bitmap is not 8888, then it is copied to 8888. Either way, the end result has
- *  its pixels stored in target. All parameters must not be null.
- *  @param decoder Decoder appropriate for this stream.
- *  @param stream Rewound stream to the encoded data.
- *  @param bitmap On success, will contain the decoded image, with its pixels stored
- *      at target.
- *  @param target Preallocated memory for storing pixels.
- *  @return bool Whether the decode (and copy, if necessary) succeeded.
- */
-static bool decode_pixels_to_8888(SkImageDecoder* decoder, SkStream* stream,
-                                  SkBitmap* bitmap, void* target) {
-    SkASSERT(decoder != NULL);
-    SkASSERT(stream != NULL);
-    SkASSERT(bitmap != NULL);
-    SkASSERT(target != NULL);
-
-    TargetAllocator allocator(target);
-    decoder->setAllocator(&allocator);
-
-    bool success = decoder->decode(stream, bitmap, SkImageDecoder::kDecodePixels_Mode);
-    decoder->setAllocator(NULL);
-
-    if (!success) {
-        return false;
-    }
-
-    if (bitmap->config() == SkBitmap::kARGB_8888_Config) {
-        return true;
-    }
-
-    SkBitmap bm8888;
-    if (!bitmap->copyTo(&bm8888, SkBitmap::kARGB_8888_Config, &allocator)) {
-        return false;
-    }
-
-    bitmap->swap(bm8888);
-    return true;
-}
-
-bool SkImageDecoder::DecodeMemoryToTarget(const void* buffer, size_t size,
-                                          SkImageInfo* info,
-                                          const SkImageDecoder::Target* target) {
-    // FIXME: Just to get this working, implement in terms of existing
-    // ImageDecoder calls.
-    SkBitmap bm;
-    SkMemoryStream stream(buffer, size);
-    SkAutoTDelete<SkImageDecoder> decoder(SkImageDecoder::Factory(&stream));
-    if (NULL == decoder.get()) {
-        return false;
-    }
-
-    if (!decode_bounds_to_8888(decoder.get(), &stream, &bm)) {
-        return false;
-    }
-
-    SkASSERT(bm.config() == SkBitmap::kARGB_8888_Config);
-
-    // Now set info properly.
-    // Since Config is SkBitmap::kARGB_8888_Config, SkBitmapToImageInfo
-    // will always succeed.
-    if (info) {
-        SkAssertResult(SkBitmapToImageInfo(bm, info));
-    }
-
-    if (NULL == target) {
-        return true;
-    }
-
-    if (target->fRowBytes != SkToU32(bm.rowBytes())) {
-        size_t minRB = SkBitmap::ComputeRowBytes(bm.config(), bm.width());
-        if (target->fRowBytes < minRB) {
-            SkDEBUGFAIL("Desired row bytes is too small");
-            return false;
-        }
-        bm.setConfig(bm.config(), bm.width(), bm.height(), target->fRowBytes);
-    }
-
-    // SkMemoryStream.rewind() will always return true.
-    SkAssertResult(stream.rewind());
-    return decode_pixels_to_8888(decoder.get(), &stream, &bm, target->fAddr);
-}
-
-
 bool SkImageDecoder::DecodeStream(SkStreamRewindable* stream, SkBitmap* bm,
                                   SkBitmap::Config pref, Mode mode,
                                   Format* format) {
     SkASSERT(stream);
     SkASSERT(bm);
 
     bool success = false;
     SkImageDecoder* codec = SkImageDecoder::Factory(stream);
 
     if (NULL != codec) {
         success = codec->decode(stream, bm, pref, mode);
         if (success && format) {
             *format = codec->getFormat();
             if (kUnknown_Format == *format) {
                 if (stream->rewind()) {
                     *format = GetStreamFormat(stream);
                 }
             }
         }
         delete codec;
     }
     return success;
 }