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