image/imgIRequest.idl

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  *
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "nsISupports.idl"
   8 #include "nsIRequest.idl"
   9
  10 interface imgIContainer;
  11 interface imgINotificationObserver;
  12 interface nsIURI;
  13 interface nsIPrincipal;
  14
  15 /**
  16  * imgIRequest interface
  17  *
  18  * @author Stuart Parmenter <stuart@mozilla.com>
  19  * @version 0.1
  20  * @see imagelib2
  21  */
  22 [scriptable, builtinclass, uuid(db0a945c-3883-424a-98d0-2ee0523b0255)]
  23 interface imgIRequest : nsIRequest
  24 {
  25   /**
  26    * the image container...
  27    * @return the image object associated with the request.
  28    * @attention NEED DOCS
  29    */
  30   readonly attribute imgIContainer image;
  31
  32   /**
  33    * Producer ID for image containers created by this image.
  34    */
  35   [infallible] readonly attribute unsigned long producerId;
  36
  37   /**
  38    * Bits set in the return value from imageStatus
  39    * @name statusflags
  40    *
  41    * Meanings:
  42    *
  43    * STATUS_NONE: Nothing to report.
  44    *
  45    * STATUS_SIZE_AVAILABLE: We received enough image data
  46    * from the network or filesystem that we know the width
  47    * and height of the image, and have thus called SetSize()
  48    * on the container.
  49    *
  50    * STATUS_LOAD_COMPLETE: The data has been fully loaded
  51    * to memory, but not necessarily fully decoded.
  52    *
  53    * STATUS_ERROR: An error occurred loading the image.
  54    *
  55    * STATUS_FRAME_COMPLETE: The first frame has been
  56    * completely decoded.
  57    *
  58    * STATUS_DECODE_COMPLETE: The whole image has been decoded.
  59    *
  60    * STATUS_IS_ANIMATED: The image is animated.
  61    *
  62    * STATUS_HAS_TRANSPARENCY: The image is partially or completely transparent.
  63    */
  64   //@{
  65   const long STATUS_NONE             = 0x0;
  66   const long STATUS_SIZE_AVAILABLE   = 0x1;
  67   const long STATUS_LOAD_COMPLETE    = 0x2;
  68   const long STATUS_ERROR            = 0x4;
  69   const long STATUS_FRAME_COMPLETE   = 0x8;
  70   const long STATUS_DECODE_COMPLETE  = 0x10;
  71   const long STATUS_IS_ANIMATED      = 0x20;
  72   const long STATUS_HAS_TRANSPARENCY = 0x40;
  73   //@}
  74
  75   /**
  76    * Status flags of the STATUS_* variety.
  77    */
  78   readonly attribute unsigned long imageStatus;
  79
  80   /*
  81    * Actual error code that generated a STATUS_ERROR imageStatus
  82    * (see xpcom/base/ErrorList.h)
  83    */
  84   [noscript] readonly attribute nsresult imageErrorCode;
  85
  86   /**
  87    * The URI the image load was started with.  Note that this might not be the
  88    * actual URI for the image (e.g. if HTTP redirects happened during the
  89    * load).
  90    */
  91   readonly attribute nsIURI URI;
  92
  93   /**
  94    * The URI of the resource we ended up loading after all redirects, etc.
  95    */
  96   readonly attribute nsIURI finalURI;
  97
  98   readonly attribute imgINotificationObserver notificationObserver;
  99
 100   readonly attribute string mimeType;
 101
 102   /**
 103    * Clone this request; the returned request will have aObserver as the
 104    * observer.  aObserver will be notified synchronously (before the clone()
 105    * call returns) with all the notifications that have already been dispatched
 106    * for this image load.
 107    */
 108   imgIRequest clone(in imgINotificationObserver aObserver);
 109
 110   /**
 111    * The principal gotten from the channel the image was loaded from.
 112    */
 113   readonly attribute nsIPrincipal imagePrincipal;
 114
 115   /**
 116    * true if the loading of the image required cross-origin redirects.
 117    */
 118   readonly attribute bool hadCrossOriginRedirects;
 119
 120   /**
 121    * Whether the request is multipart (ie, multipart/x-mixed-replace)
 122    */
 123   readonly attribute bool multipart;
 124
 125   /**
 126    * CORS modes images can be loaded with.
 127    *
 128    * By default, all images are loaded with CORS_NONE and cannot be used
 129    * cross-origin in context like WebGL.
 130    *
 131    * If an HTML img element has the crossorigin attribute set, the imgIRequest
 132    * will be validated for cross-origin usage with CORS, and, if successful,
 133    * will have its CORS mode set to the relevant type.
 134    */
 135   //@{
 136   const long CORS_NONE = 1;
 137   const long CORS_ANONYMOUS = 2;
 138   const long CORS_USE_CREDENTIALS = 3;
 139   //@}
 140
 141   /**
 142    * The CORS mode that this image was loaded with.
 143    */
 144   readonly attribute long CORSMode;
 145
 146   /**
 147    * Cancels this request as in nsIRequest::Cancel(); further, also nulls out
 148    * decoderObserver so it gets no further notifications from us.
 149    *
 150    * NOTE: You should not use this in any new code; instead, use cancel(). Note
 151    * that cancel() is asynchronous, which means that some time after you call
 152    * it, the listener/observer will get an OnStopRequest(). This means that, if
 153    * you're the observer, you can't call cancel() from your destructor.
 154    */
 155   void cancelAndForgetObserver(in nsresult aStatus);
 156
 157   /**
 158    * Requests a synchronous decode for the image.
 159    *
 160    * imgIContainer has a startDecoding() method, but callers may want to request
 161    * a decode before the container has necessarily been instantiated. Calling
 162    * startDecoding() on the imgIRequest simply forwards along the request if the
 163    * container already exists, or calls it once the container becomes available
 164    * if it does not yet exist.
 165    */
 166   void startDecoding(in uint32_t aFlags);
 167
 168   /**
 169    * Exactly like startDecoding above except returns whether the current frame
 170    * of the image is complete or not.
 171    *
 172    * @param aFlags Flags of the FLAG_* variety. Only FLAG_ASYNC_NOTIFY
 173    *               is accepted; all others are ignored.
 174    */
 175   [noscript, notxpcom] boolean startDecodingWithResult(in uint32_t aFlags);
 176
 177   /**
 178    * This method triggers decoding for an image, but unlike startDecoding() it
 179    * enables the caller to provide more detailed information about the decode
 180    * request.
 181    *
 182    * @param aFlags Flags of the FLAG_* variety.
 183    * @return True there is a surface that satisfies the request and it is
 184    *         fully decoded, else false.
 185    */
 186   [noscript, notxpcom] boolean requestDecodeWithResult(in uint32_t aFlags);
 187
 188   /**
 189    * Locks an image. If the image does not exist yet, locks it once it becomes
 190    * available. The lock persists for the lifetime of the imgIRequest (until
 191    * unlockImage is called) even if the underlying image changes.
 192    *
 193    * If you don't call unlockImage() by the time this imgIRequest goes away, it
 194    * will be called for you automatically.
 195    *
 196    * @see imgIContainer::lockImage for documentation of the underlying call.
 197    */
 198   void lockImage();
 199
 200   /**
 201    * Unlocks an image.
 202    *
 203    * @see imgIContainer::unlockImage for documentation of the underlying call.
 204    */
 205   void unlockImage();
 206
 207   /**
 208    * If this image is unlocked, discard the image's decoded data.  If the image
 209    * is locked or is already discarded, do nothing.
 210    */
 211   void requestDiscard();
 212
 213   /**
 214    * If this request is for an animated image, the method creates a new
 215    * request which contains the current frame of the image.
 216    * Otherwise returns the same request.
 217    */
 218   imgIRequest getStaticRequest();
 219
 220   /**
 221    * Requests that the image animate (if it has an animation).
 222    *
 223    * @see Image::IncrementAnimationConsumers for documentation of the
 224    * underlying call.
 225    */
 226   void incrementAnimationConsumers();
 227
 228   /**
 229    * Tell the image it can forget about a request that the image animate.
 230    *
 231    * @see Image::DecrementAnimationConsumers for documentation of the
 232    * underlying call.
 233    */
 234   void decrementAnimationConsumers();
 235
 236   /**
 237    * Request loading priority boost to requested category, each category
 238    * of request increases priority only one time.
 239    *
 240    * CATEGORY_FRAME_INIT: increase priority when the imgRequest is associated
 241    * with an nsImageFrame.
 242    *
 243    * CATEGORY_FRAME_STYLE: increase priority when the imgRequest is for a CSS
 244    * background-image, list-style-image, etc. on a ComputedStyle, and a frame
 245    * has been assigned this ComputedStyle.
 246    *
 247    * CATEGORY_SIZE_QUERY: increase priority when size decoding is necessary to
 248    * determine the layout size of an associated nsImageFrame.
 249    *
 250    * CATEGORY_DISPLAY: increase priority when the image is about to be displayed
 251    * in the viewport.
 252    */
 253   const uint32_t CATEGORY_FRAME_INIT  = 1 << 0;
 254   const uint32_t CATEGORY_FRAME_STYLE = 1 << 1;
 255   const uint32_t CATEGORY_SIZE_QUERY  = 1 << 2;
 256   const uint32_t CATEGORY_DISPLAY     = 1 << 3;
 257   void boostPriority(in uint32_t aCategory);
 258 };
 259