3 files changed, 614 insertions, 0 deletions
diff --git a/image/encoders/ico/moz.build b/image/encoders/ico/moz.build
new file mode 100644
index 0000000000..27e41489fd
--- /dev/null
+++ b/image/encoders/ico/moz.build
@@ -0,0 +1,20 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+SOURCES += [
+    "nsICOEncoder.cpp",
+]
+
+# Decoders need RasterImage.h
+LOCAL_INCLUDES += [
+    "/image",
+    "/image/encoders/bmp",
+    "/image/encoders/png",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
diff --git a/image/encoders/ico/nsICOEncoder.cpp b/image/encoders/ico/nsICOEncoder.cpp
new file mode 100644
index 0000000000..518acc9a0b
--- /dev/null
+++ b/image/encoders/ico/nsICOEncoder.cpp
@@ -0,0 +1,499 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsCRT.h"
+#include "mozilla/EndianUtils.h"
+#include "nsBMPEncoder.h"
+#include "BMPHeaders.h"
+#include "nsPNGEncoder.h"
+#include "nsICOEncoder.h"
+#include "nsString.h"
+#include "nsStreamUtils.h"
+#include "nsTArray.h"
+
+using namespace mozilla;
+using namespace mozilla::image;
+
+NS_IMPL_ISUPPORTS(nsICOEncoder, imgIEncoder, nsIInputStream,
+                  nsIAsyncInputStream)
+
+nsICOEncoder::nsICOEncoder()
+    : mICOFileHeader{},
+      mICODirEntry{},
+      mImageBufferStart(nullptr),
+      mImageBufferCurr(0),
+      mImageBufferSize(0),
+      mImageBufferReadPoint(0),
+      mFinished(false),
+      mUsePNG(true),
+      mNotifyThreshold(0) {}
+
+nsICOEncoder::~nsICOEncoder() {
+  if (mImageBufferStart) {
+    free(mImageBufferStart);
+    mImageBufferStart = nullptr;
+    mImageBufferCurr = nullptr;
+  }
+}
+
+// nsICOEncoder::InitFromData
+// Two output options are supported: format=<png|bmp>;bpp=<bpp_value>
+// format specifies whether to use png or bitmap format
+// bpp specifies the bits per pixel to use where bpp_value can be 24 or 32
+NS_IMETHODIMP
+nsICOEncoder::InitFromData(const uint8_t* aData, uint32_t aLength,
+                           uint32_t aWidth, uint32_t aHeight, uint32_t aStride,
+                           uint32_t aInputFormat,
+                           const nsAString& aOutputOptions) {
+  // validate input format
+  if (aInputFormat != INPUT_FORMAT_RGB && aInputFormat != INPUT_FORMAT_RGBA &&
+      aInputFormat != INPUT_FORMAT_HOSTARGB) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // Stride is the padded width of each row, so it better be longer
+  if ((aInputFormat == INPUT_FORMAT_RGB && aStride < aWidth * 3) ||
+      ((aInputFormat == INPUT_FORMAT_RGBA ||
+        aInputFormat == INPUT_FORMAT_HOSTARGB) &&
+       aStride < aWidth * 4)) {
+    NS_WARNING("Invalid stride for InitFromData");
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsresult rv;
+  rv = StartImageEncode(aWidth, aHeight, aInputFormat, aOutputOptions);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = AddImageFrame(aData, aLength, aWidth, aHeight, aStride, aInputFormat,
+                     aOutputOptions);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = EndImageEncode();
+  return rv;
+}
+
+// Returns the number of bytes in the image buffer used
+// For an ICO file, this is all bytes in the buffer.
+NS_IMETHODIMP
+nsICOEncoder::GetImageBufferUsed(uint32_t* aOutputSize) {
+  NS_ENSURE_ARG_POINTER(aOutputSize);
+  *aOutputSize = mImageBufferSize;
+  return NS_OK;
+}
+
+// Returns a pointer to the start of the image buffer
+NS_IMETHODIMP
+nsICOEncoder::GetImageBuffer(char** aOutputBuffer) {
+  NS_ENSURE_ARG_POINTER(aOutputBuffer);
+  *aOutputBuffer = reinterpret_cast<char*>(mImageBufferStart);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::AddImageFrame(const uint8_t* aData, uint32_t aLength,
+                            uint32_t aWidth, uint32_t aHeight, uint32_t aStride,
+                            uint32_t aInputFormat,
+                            const nsAString& aFrameOptions) {
+  if (mUsePNG) {
+    mContainedEncoder = new nsPNGEncoder();
+    nsresult rv;
+    nsAutoString noParams;
+    rv = mContainedEncoder->InitFromData(aData, aLength, aWidth, aHeight,
+                                         aStride, aInputFormat, noParams);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t PNGImageBufferSize;
+    mContainedEncoder->GetImageBufferUsed(&PNGImageBufferSize);
+    mImageBufferSize =
+        ICONFILEHEADERSIZE + ICODIRENTRYSIZE + PNGImageBufferSize;
+    mImageBufferStart = static_cast<uint8_t*>(malloc(mImageBufferSize));
+    if (!mImageBufferStart) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    mImageBufferCurr = mImageBufferStart;
+    mICODirEntry.mBytesInRes = PNGImageBufferSize;
+
+    EncodeFileHeader();
+    EncodeInfoHeader();
+
+    char* imageBuffer;
+    rv = mContainedEncoder->GetImageBuffer(&imageBuffer);
+    NS_ENSURE_SUCCESS(rv, rv);
+    memcpy(mImageBufferCurr, imageBuffer, PNGImageBufferSize);
+    mImageBufferCurr += PNGImageBufferSize;
+  } else {
+    mContainedEncoder = new nsBMPEncoder();
+    nsresult rv;
+
+    nsAutoString params;
+    params.AppendLiteral("bpp=");
+    params.AppendInt(mICODirEntry.mBitCount);
+
+    rv = mContainedEncoder->InitFromData(aData, aLength, aWidth, aHeight,
+                                         aStride, aInputFormat, params);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    uint32_t andMaskSize = ((GetRealWidth() + 31) / 32) * 4 *  // row AND mask
+                           GetRealHeight();                    // num rows
+
+    uint32_t BMPImageBufferSize;
+    mContainedEncoder->GetImageBufferUsed(&BMPImageBufferSize);
+    mImageBufferSize =
+        ICONFILEHEADERSIZE + ICODIRENTRYSIZE + BMPImageBufferSize + andMaskSize;
+    mImageBufferStart = static_cast<uint8_t*>(malloc(mImageBufferSize));
+    if (!mImageBufferStart) {
+      return NS_ERROR_OUT_OF_MEMORY;
+    }
+    mImageBufferCurr = mImageBufferStart;
+
+    // Icon files that wrap a BMP file must not include the BITMAPFILEHEADER
+    // section at the beginning of the encoded BMP data, so we must skip over
+    // bmp::FILE_HEADER_LENGTH bytes when adding the BMP content to the icon
+    // file.
+    mICODirEntry.mBytesInRes =
+        BMPImageBufferSize - bmp::FILE_HEADER_LENGTH + andMaskSize;
+
+    // Encode the icon headers
+    EncodeFileHeader();
+    EncodeInfoHeader();
+
+    char* imageBuffer;
+    rv = mContainedEncoder->GetImageBuffer(&imageBuffer);
+    NS_ENSURE_SUCCESS(rv, rv);
+    memcpy(mImageBufferCurr, imageBuffer + bmp::FILE_HEADER_LENGTH,
+           BMPImageBufferSize - bmp::FILE_HEADER_LENGTH);
+    // We need to fix the BMP height to be *2 for the AND mask
+    uint32_t fixedHeight = GetRealHeight() * 2;
+    NativeEndian::swapToLittleEndianInPlace(&fixedHeight, 1);
+    // The height is stored at an offset of 8 from the DIB header
+    memcpy(mImageBufferCurr + 8, &fixedHeight, sizeof(fixedHeight));
+    mImageBufferCurr += BMPImageBufferSize - bmp::FILE_HEADER_LENGTH;
+
+    // Calculate rowsize in DWORD's
+    uint32_t rowSize = ((GetRealWidth() + 31) / 32) * 4;  // + 31 to round up
+    int32_t currentLine = GetRealHeight();
+
+    // Write out the AND mask
+    while (currentLine > 0) {
+      currentLine--;
+      uint8_t* encoded = mImageBufferCurr + currentLine * rowSize;
+      uint8_t* encodedEnd = encoded + rowSize;
+      while (encoded != encodedEnd) {
+        *encoded = 0;  // make everything visible
+        encoded++;
+      }
+    }
+
+    mImageBufferCurr += andMaskSize;
+  }
+
+  return NS_OK;
+}
+
+// See ::InitFromData for other info.
+NS_IMETHODIMP
+nsICOEncoder::StartImageEncode(uint32_t aWidth, uint32_t aHeight,
+                               uint32_t aInputFormat,
+                               const nsAString& aOutputOptions) {
+  // can't initialize more than once
+  if (mImageBufferStart || mImageBufferCurr) {
+    return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  // validate input format
+  if (aInputFormat != INPUT_FORMAT_RGB && aInputFormat != INPUT_FORMAT_RGBA &&
+      aInputFormat != INPUT_FORMAT_HOSTARGB) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // Icons are only 1 byte, so make sure our bitmap is in range
+  if (aWidth > 256 || aHeight > 256) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  // parse and check any provided output options
+  uint16_t bpp = 24;
+  bool usePNG = true;
+  nsresult rv = ParseOptions(aOutputOptions, bpp, usePNG);
+  NS_ENSURE_SUCCESS(rv, rv);
+  MOZ_ASSERT(bpp <= 32);
+
+  mUsePNG = usePNG;
+
+  InitFileHeader();
+  // The width and height are stored as 0 when we have a value of 256
+  InitInfoHeader(bpp, aWidth == 256 ? 0 : (uint8_t)aWidth,
+                 aHeight == 256 ? 0 : (uint8_t)aHeight);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::EndImageEncode() {
+  // must be initialized
+  if (!mImageBufferStart || !mImageBufferCurr) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+
+  mFinished = true;
+  NotifyListener();
+
+  // if output callback can't get enough memory, it will free our buffer
+  if (!mImageBufferStart || !mImageBufferCurr) {
+    return NS_ERROR_OUT_OF_MEMORY;
+  }
+
+  return NS_OK;
+}
+
+// Parses the encoder options and sets the bits per pixel to use and PNG or BMP
+// See InitFromData for a description of the parse options
+nsresult nsICOEncoder::ParseOptions(const nsAString& aOptions,
+                                    uint16_t& aBppOut, bool& aUsePNGOut) {
+  // If no parsing options just use the default of 24BPP and PNG yes
+  if (aOptions.Length() == 0) {
+    aUsePNGOut = true;
+    aBppOut = 24;
+  }
+
+  // Parse the input string into a set of name/value pairs.
+  // From format: format=<png|bmp>;bpp=<bpp_value>
+  // to format: [0] = format=<png|bmp>, [1] = bpp=<bpp_value>
+  nsTArray<nsCString> nameValuePairs;
+  ParseString(NS_ConvertUTF16toUTF8(aOptions), ';', nameValuePairs);
+
+  // For each name/value pair in the set
+  for (unsigned i = 0; i < nameValuePairs.Length(); ++i) {
+    // Split the name value pair [0] = name, [1] = value
+    nsTArray<nsCString> nameValuePair;
+    ParseString(nameValuePairs[i], '=', nameValuePair);
+    if (nameValuePair.Length() != 2) {
+      return NS_ERROR_INVALID_ARG;
+    }
+
+    // Parse the format portion of the string format=<png|bmp>;bpp=<bpp_value>
+    if (nameValuePair[0].Equals("format", nsCaseInsensitiveCStringComparator)) {
+      if (nameValuePair[1].Equals("png", nsCaseInsensitiveCStringComparator)) {
+        aUsePNGOut = true;
+      } else if (nameValuePair[1].Equals("bmp",
+                                         nsCaseInsensitiveCStringComparator)) {
+        aUsePNGOut = false;
+      } else {
+        return NS_ERROR_INVALID_ARG;
+      }
+    }
+
+    // Parse the bpp portion of the string format=<png|bmp>;bpp=<bpp_value>
+    if (nameValuePair[0].Equals("bpp", nsCaseInsensitiveCStringComparator)) {
+      if (nameValuePair[1].EqualsLiteral("24")) {
+        aBppOut = 24;
+      } else if (nameValuePair[1].EqualsLiteral("32")) {
+        aBppOut = 32;
+      } else {
+        return NS_ERROR_INVALID_ARG;
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::Close() {
+  if (mImageBufferStart) {
+    free(mImageBufferStart);
+    mImageBufferStart = nullptr;
+    mImageBufferSize = 0;
+    mImageBufferReadPoint = 0;
+    mImageBufferCurr = nullptr;
+  }
+
+  return NS_OK;
+}
+
+// Obtains the available bytes to read
+NS_IMETHODIMP
+nsICOEncoder::Available(uint64_t* _retval) {
+  if (!mImageBufferStart || !mImageBufferCurr) {
+    return NS_BASE_STREAM_CLOSED;
+  }
+
+  *_retval = GetCurrentImageBufferOffset() - mImageBufferReadPoint;
+  return NS_OK;
+}
+
+// Obtains the stream's status
+NS_IMETHODIMP
+nsICOEncoder::StreamStatus() {
+  return mImageBufferStart && mImageBufferCurr ? NS_OK : NS_BASE_STREAM_CLOSED;
+}
+
+// [noscript] Reads bytes which are available
+NS_IMETHODIMP
+nsICOEncoder::Read(char* aBuf, uint32_t aCount, uint32_t* _retval) {
+  return ReadSegments(NS_CopySegmentToBuffer, aBuf, aCount, _retval);
+}
+
+// [noscript] Reads segments
+NS_IMETHODIMP
+nsICOEncoder::ReadSegments(nsWriteSegmentFun aWriter, void* aClosure,
+                           uint32_t aCount, uint32_t* _retval) {
+  uint32_t maxCount = GetCurrentImageBufferOffset() - mImageBufferReadPoint;
+  if (maxCount == 0) {
+    *_retval = 0;
+    return mFinished ? NS_OK : NS_BASE_STREAM_WOULD_BLOCK;
+  }
+
+  if (aCount > maxCount) {
+    aCount = maxCount;
+  }
+
+  nsresult rv = aWriter(
+      this, aClosure,
+      reinterpret_cast<const char*>(mImageBufferStart + mImageBufferReadPoint),
+      0, aCount, _retval);
+  if (NS_SUCCEEDED(rv)) {
+    NS_ASSERTION(*_retval <= aCount, "bad write count");
+    mImageBufferReadPoint += *_retval;
+  }
+  // errors returned from the writer end here!
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::IsNonBlocking(bool* _retval) {
+  *_retval = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::AsyncWait(nsIInputStreamCallback* aCallback, uint32_t aFlags,
+                        uint32_t aRequestedCount, nsIEventTarget* aTarget) {
+  if (aFlags != 0) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+
+  if (mCallback || mCallbackTarget) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  mCallbackTarget = aTarget;
+  // 0 means "any number of bytes except 0"
+  mNotifyThreshold = aRequestedCount;
+  if (!aRequestedCount) {
+    mNotifyThreshold = 1024;  // We don't want to notify incessantly
+  }
+
+  // We set the callback absolutely last, because NotifyListener uses it to
+  // determine if someone needs to be notified.  If we don't set it last,
+  // NotifyListener might try to fire off a notification to a null target
+  // which will generally cause non-threadsafe objects to be used off the
+  // main thread
+  mCallback = aCallback;
+
+  // What we are being asked for may be present already
+  NotifyListener();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsICOEncoder::CloseWithStatus(nsresult aStatus) { return Close(); }
+
+void nsICOEncoder::NotifyListener() {
+  if (mCallback && (GetCurrentImageBufferOffset() - mImageBufferReadPoint >=
+                        mNotifyThreshold ||
+                    mFinished)) {
+    nsCOMPtr<nsIInputStreamCallback> callback;
+    if (mCallbackTarget) {
+      callback = NS_NewInputStreamReadyEvent("nsICOEncoder::NotifyListener",
+                                             mCallback, mCallbackTarget);
+    } else {
+      callback = mCallback;
+    }
+
+    NS_ASSERTION(callback, "Shouldn't fail to make the callback");
+    // Null the callback first because OnInputStreamReady could reenter
+    // AsyncWait
+    mCallback = nullptr;
+    mCallbackTarget = nullptr;
+    mNotifyThreshold = 0;
+
+    callback->OnInputStreamReady(this);
+  }
+}
+
+// Initializes the icon file header mICOFileHeader
+void nsICOEncoder::InitFileHeader() {
+  memset(&mICOFileHeader, 0, sizeof(mICOFileHeader));
+  mICOFileHeader.mReserved = 0;
+  mICOFileHeader.mType = 1;
+  mICOFileHeader.mCount = 1;
+}
+
+// Initializes the icon directory info header mICODirEntry
+void nsICOEncoder::InitInfoHeader(uint16_t aBPP, uint8_t aWidth,
+                                  uint8_t aHeight) {
+  memset(&mICODirEntry, 0, sizeof(mICODirEntry));
+  mICODirEntry.mBitCount = aBPP;
+  mICODirEntry.mBytesInRes = 0;
+  mICODirEntry.mColorCount = 0;
+  mICODirEntry.mWidth = aWidth;
+  mICODirEntry.mHeight = aHeight;
+  mICODirEntry.mImageOffset = ICONFILEHEADERSIZE + ICODIRENTRYSIZE;
+  mICODirEntry.mPlanes = 1;
+  mICODirEntry.mReserved = 0;
+}
+
+// Encodes the icon file header mICOFileHeader
+void nsICOEncoder::EncodeFileHeader() {
+  IconFileHeader littleEndianIFH = mICOFileHeader;
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mReserved, 1);
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mType, 1);
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianIFH.mCount, 1);
+
+  memcpy(mImageBufferCurr, &littleEndianIFH.mReserved,
+         sizeof(littleEndianIFH.mReserved));
+  mImageBufferCurr += sizeof(littleEndianIFH.mReserved);
+  memcpy(mImageBufferCurr, &littleEndianIFH.mType,
+         sizeof(littleEndianIFH.mType));
+  mImageBufferCurr += sizeof(littleEndianIFH.mType);
+  memcpy(mImageBufferCurr, &littleEndianIFH.mCount,
+         sizeof(littleEndianIFH.mCount));
+  mImageBufferCurr += sizeof(littleEndianIFH.mCount);
+}
+
+// Encodes the icon directory info header mICODirEntry
+void nsICOEncoder::EncodeInfoHeader() {
+  IconDirEntry littleEndianmIDE = mICODirEntry;
+
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mPlanes, 1);
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mBitCount, 1);
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mBytesInRes, 1);
+  NativeEndian::swapToLittleEndianInPlace(&littleEndianmIDE.mImageOffset, 1);
+
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mWidth,
+         sizeof(littleEndianmIDE.mWidth));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mWidth);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mHeight,
+         sizeof(littleEndianmIDE.mHeight));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mHeight);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mColorCount,
+         sizeof(littleEndianmIDE.mColorCount));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mColorCount);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mReserved,
+         sizeof(littleEndianmIDE.mReserved));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mReserved);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mPlanes,
+         sizeof(littleEndianmIDE.mPlanes));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mPlanes);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mBitCount,
+         sizeof(littleEndianmIDE.mBitCount));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mBitCount);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mBytesInRes,
+         sizeof(littleEndianmIDE.mBytesInRes));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mBytesInRes);
+  memcpy(mImageBufferCurr, &littleEndianmIDE.mImageOffset,
+         sizeof(littleEndianmIDE.mImageOffset));
+  mImageBufferCurr += sizeof(littleEndianmIDE.mImageOffset);
+}
diff --git a/image/encoders/ico/nsICOEncoder.h b/image/encoders/ico/nsICOEncoder.h
new file mode 100644
index 0000000000..ef601ba97e
--- /dev/null
+++ b/image/encoders/ico/nsICOEncoder.h
@@ -0,0 +1,95 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_image_encoders_ico_nsICOEncoder_h
+#define mozilla_image_encoders_ico_nsICOEncoder_h
+
+#include "mozilla/Attributes.h"
+#include "mozilla/ReentrantMonitor.h"
+#include "mozilla/image/ICOFileHeaders.h"
+
+#include "imgIEncoder.h"
+
+#include "nsCOMPtr.h"
+
+#define NS_ICOENCODER_CID                            \
+  { /*92AE3AB2-8968-41B1-8709-B6123BCEAF21 */        \
+    0x92ae3ab2, 0x8968, 0x41b1, {                    \
+      0x87, 0x09, 0xb6, 0x12, 0x3b, 0Xce, 0xaf, 0x21 \
+    }                                                \
+  }
+
+// Provides ICO encoding functionality. Use InitFromData() to do the
+// encoding. See that function definition for encoding options.
+
+class nsICOEncoder final : public imgIEncoder {
+  typedef mozilla::ReentrantMonitor ReentrantMonitor;
+
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_IMGIENCODER
+  NS_DECL_NSIINPUTSTREAM
+  NS_DECL_NSIASYNCINPUTSTREAM
+
+  nsICOEncoder();
+
+  // Obtains the width of the icon directory entry
+  uint32_t GetRealWidth() const {
+    return mICODirEntry.mWidth == 0 ? 256 : mICODirEntry.mWidth;
+  }
+
+  // Obtains the height of the icon directory entry
+  uint32_t GetRealHeight() const {
+    return mICODirEntry.mHeight == 0 ? 256 : mICODirEntry.mHeight;
+  }
+
+ protected:
+  ~nsICOEncoder();
+
+  nsresult ParseOptions(const nsAString& aOptions, uint16_t& aBppOut,
+                        bool& aUsePNGOut);
+  void NotifyListener();
+
+  // Initializes the icon file header mICOFileHeader
+  void InitFileHeader();
+  // Initializes the icon directory info header mICODirEntry
+  void InitInfoHeader(uint16_t aBPP, uint8_t aWidth, uint8_t aHeight);
+  // Encodes the icon file header mICOFileHeader
+  void EncodeFileHeader();
+  // Encodes the icon directory info header mICODirEntry
+  void EncodeInfoHeader();
+  // Obtains the current offset filled up to for the image buffer
+  inline int32_t GetCurrentImageBufferOffset() {
+    return static_cast<int32_t>(mImageBufferCurr - mImageBufferStart);
+  }
+
+  // Holds either a PNG or a BMP depending on the encoding options specified
+  // or if no encoding options specified will use the default (PNG)
+  nsCOMPtr<imgIEncoder> mContainedEncoder;
+
+  // These headers will always contain endian independent stuff.
+  // Don't trust the width and height of mICODirEntry directly,
+  // instead use the accessors GetRealWidth() and GetRealHeight().
+  mozilla::image::IconFileHeader mICOFileHeader;
+  mozilla::image::IconDirEntry mICODirEntry;
+
+  // Keeps track of the start of the image buffer
+  uint8_t* mImageBufferStart;
+  // Keeps track of the current position in the image buffer
+  uint8_t* mImageBufferCurr;
+  // Keeps track of the image buffer size
+  uint32_t mImageBufferSize;
+  // Keeps track of the number of bytes in the image buffer which are read
+  uint32_t mImageBufferReadPoint;
+  // Stores true if the image is done being encoded
+  bool mFinished;
+  // Stores true if the contained image is a PNG
+  bool mUsePNG;
+
+  nsCOMPtr<nsIInputStreamCallback> mCallback;
+  nsCOMPtr<nsIEventTarget> mCallbackTarget;
+  uint32_t mNotifyThreshold;
+};
+
+#endif  // mozilla_image_encoders_ico_nsICOEncoder_h