DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (a81015259a98)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * the Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2010.
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Bobby Holley <bobbyholley@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#ifndef MOZILLA_IMAGELIB_DECODER_H_
#define MOZILLA_IMAGELIB_DECODER_H_

#include "RasterImage.h"

#include "imgIDecoderObserver.h"

namespace mozilla {
namespace imagelib {

class Decoder
{
public:

  Decoder(RasterImage& aImage, imgIDecoderObserver* aObserver);
  virtual ~Decoder();

  /**
   * Initialize an image decoder. Decoders may not be re-initialized.
   *
   * @param aContainer The image container to decode to.
   * @param aObserver The observer for decode notification events.
   *
   * Notifications Sent: TODO
   */
  void Init();


  /**
   * Initializes a decoder whose aImage and aObserver is already being used by a
   * parent decoder. Decoders may not be re-initialized.
   *
   * @param aContainer The image container to decode to.
   * @param aObserver The observer for decode notification events.
   *
   * Notifications Sent: TODO
   */
  void InitSharedDecoder();

  /**
   * Writes data to the decoder.
   *
   * @param aBuffer buffer containing the data to be written
   * @param aCount the number of bytes to write
   *
   * Any errors are reported by setting the appropriate state on the decoder.
   *
   * Notifications Sent: TODO
   */
  void Write(const char* aBuffer, PRUint32 aCount);

  /**
   * Informs the decoder that all the data has been written.
   *
   * Notifications Sent: TODO
   */
  void Finish();

  /**
   * Informs the shared decoder that all the data has been written.
   * Should only be used if InitSharedDecoder was useed
   *
   * Notifications Sent: TODO
   */
  void FinishSharedDecoder();

  /**
   * Tells the decoder to flush any pending invalidations. This informs the image
   * frame of its decoded region, and sends the appropriate OnDataAvailable call
   * to consumers.
   *
   * This can be called any time when we're midway through decoding a frame,
   * and must be called after finishing a frame (before starting a new one).
   */
  void FlushInvalidations();

  // We're not COM-y, so we don't get refcounts by default
  NS_INLINE_DECL_REFCOUNTING(Decoder)

  /*
   * State.
   */

  // If we're doing a "size decode", we more or less pass through the image
  // data, stopping only to scoop out the image dimensions. A size decode
  // must be enabled by SetSizeDecode() _before_calling Init().
  bool IsSizeDecode() { return mSizeDecode; };
  void SetSizeDecode(bool aSizeDecode)
  {
    NS_ABORT_IF_FALSE(!mInitialized, "Can't set size decode after Init()!");
    mSizeDecode = aSizeDecode;
  }

  // The number of frames we have, including anything in-progress. Thus, this
  // is only 0 if we haven't begun any frames.
  PRUint32 GetFrameCount() { return mFrameCount; }

  // The number of complete frames we have (ie, not including anything in-progress).
  PRUint32 GetCompleteFrameCount() { return mInFrame ? mFrameCount - 1 : mFrameCount; }

  // Error tracking
  bool HasError() { return HasDataError() || HasDecoderError(); };
  bool HasDataError() { return mDataError; };
  bool HasDecoderError() { return NS_FAILED(mFailCode); };
  nsresult GetDecoderError() { return mFailCode; };
  void PostResizeError() { PostDataError(); }
  bool GetDecodeDone() const {
    return mDecodeDone;
  }

  // flags.  Keep these in sync with imgIContainer.idl.
  // SetDecodeFlags must be called before Init(), otherwise
  // default flags are assumed.
  enum {
    DECODER_NO_PREMULTIPLY_ALPHA = 0x2,
    DECODER_NO_COLORSPACE_CONVERSION = 0x4
  };
  void SetDecodeFlags(PRUint32 aFlags) { mDecodeFlags = aFlags; }
  PRUint32 GetDecodeFlags() { return mDecodeFlags; }

  // Use HistogramCount as an invalid Histogram ID
  virtual Telemetry::ID SpeedHistogram() { return Telemetry::HistogramCount; }

protected:

  /*
   * Internal hooks. Decoder implementations may override these and
   * only these methods.
   */
  virtual void InitInternal();
  virtual void WriteInternal(const char* aBuffer, PRUint32 aCount);
  virtual void FinishInternal();

  /*
   * Progress notifications.
   */

  // Called by decoders when they determine the size of the image. Informs
  // the image of its size and sends notifications.
  void PostSize(PRInt32 aWidth, PRInt32 aHeight);

  // Called by decoders when they begin/end a frame. Informs the image, sends
  // notifications, and does internal book-keeping.
  void PostFrameStart();
  void PostFrameStop();

  // Called by the decoders when they have a region to invalidate. We may not
  // actually pass these invalidations on right away.
  void PostInvalidation(nsIntRect& aRect);

  // Called by the decoders when they have successfully decoded the image. This
  // may occur as the result of the decoder getting to the appropriate point in
  // the stream, or by us calling FinishInternal().
  //
  // May not be called mid-frame.
  void PostDecodeDone();

  // Data errors are the fault of the source data, decoder errors are our fault
  void PostDataError();
  void PostDecoderError(nsresult aFailCode);

  /*
   * Member variables.
   *
   */
  RasterImage &mImage;
  nsCOMPtr<imgIDecoderObserver> mObserver;

  PRUint32 mDecodeFlags;
  bool mDecodeDone;
  bool mDataError;

private:
  PRUint32 mFrameCount; // Number of frames, including anything in-progress

  nsIntRect mInvalidRect; // Tracks an invalidation region in the current frame.

  nsresult mFailCode;

  bool mInitialized;
  bool mSizeDecode;
  bool mInFrame;
};

} // namespace imagelib
} // namespace mozilla

#endif // MOZILLA_IMAGELIB_DECODER_H_