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    * Bits set in the return value from imageStatus
  34    * @name statusflags
  35    *
  36    * Meanings:
  37    *
  38    * STATUS_NONE: Nothing to report.
  39    *
  40    * STATUS_SIZE_AVAILABLE: We received enough image data
  41    * from the network or filesystem that we know the width
  42    * and height of the image, and have thus called SetSize()
  43    * on the container.
  44    *
  45    * STATUS_LOAD_COMPLETE: The data has been fully loaded
  46    * to memory, but not necessarily fully decoded.
  47    *
  48    * STATUS_ERROR: An error occurred loading the image.
  49    *
  50    * STATUS_FRAME_COMPLETE: The first frame has been
  51    * completely decoded.
  52    *
  53    * STATUS_DECODE_COMPLETE: The whole image has been decoded.
  54    *
  55    * STATUS_IS_ANIMATED: The image is animated.
  56    *
  57    * STATUS_HAS_TRANSPARENCY: The image is partially or completely transparent.
  58    */
  59   //@{
  60   const long STATUS_NONE             = 0x0;
  61   const long STATUS_SIZE_AVAILABLE   = 0x1;
  62   const long STATUS_LOAD_COMPLETE    = 0x2;
  63   const long STATUS_ERROR            = 0x4;
  64   const long STATUS_FRAME_COMPLETE   = 0x8;
  65   const long STATUS_DECODE_COMPLETE  = 0x10;
  66   const long STATUS_IS_ANIMATED      = 0x20;
  67   const long STATUS_HAS_TRANSPARENCY = 0x40;
  68   //@}
  69
  70   /**
  71    * Status flags of the STATUS_* variety.
  72    */
  73   readonly attribute unsigned long imageStatus;
  74
  75   /*
  76    * Actual error code that generated a STATUS_ERROR imageStatus
  77    * (see xpcom/base/ErrorList.h)
  78    */
  79   [noscript] readonly attribute nsresult imageErrorCode;
  80
  81   /**
  82    * The URI the image load was started with.  Note that this might not be the
  83    * actual URI for the image (e.g. if HTTP redirects happened during the
  84    * load).
  85    */
  86   readonly attribute nsIURI URI;
  87
  88   /**
  89    * The URI of the resource we ended up loading after all redirects, etc.
  90    */
  91   readonly attribute nsIURI finalURI;
  92
  93   readonly attribute imgINotificationObserver notificationObserver;
  94
  95   readonly attribute string mimeType;
  96
  97   /**
  98    * Clone this request; the returned request will have aObserver as the
  99    * observer.  aObserver will be notified synchronously (before the clone()
 100    * call returns) with all the notifications that have already been dispatched
 101    * for this image load.
 102    */
 103   imgIRequest clone(in imgINotificationObserver aObserver);
 104
 105   /**
 106    * The principal gotten from the channel the image was loaded from.
 107    */
 108   readonly attribute nsIPrincipal imagePrincipal;
 109
 110   /**
 111    * Whether the request is multipart (ie, multipart/x-mixed-replace)
 112    */
 113   readonly attribute bool multipart;
 114
 115   /**
 116    * CORS modes images can be loaded with.
 117    *
 118    * By default, all images are loaded with CORS_NONE and cannot be used
 119    * cross-origin in context like WebGL.
 120    *
 121    * If an HTML img element has the crossorigin attribute set, the imgIRequest
 122    * will be validated for cross-origin usage with CORS, and, if successful,
 123    * will have its CORS mode set to the relevant type.
 124    */
 125   //@{
 126   const long CORS_NONE = 1;
 127   const long CORS_ANONYMOUS = 2;
 128   const long CORS_USE_CREDENTIALS = 3;
 129   //@}
 130
 131   /**
 132    * The CORS mode that this image was loaded with.
 133    */
 134   readonly attribute long CORSMode;
 135
 136   /**
 137    * Cancels this request as in nsIRequest::Cancel(); further, also nulls out
 138    * decoderObserver so it gets no further notifications from us.
 139    *
 140    * NOTE: You should not use this in any new code; instead, use cancel(). Note
 141    * that cancel() is asynchronous, which means that some time after you call
 142    * it, the listener/observer will get an OnStopRequest(). This means that, if
 143    * you're the observer, you can't call cancel() from your destructor.
 144    */
 145   void cancelAndForgetObserver(in nsresult aStatus);
 146
 147   /**
 148    * Requests a synchronous decode for the image.
 149    *
 150    * imgIContainer has a startDecoding() method, but callers may want to request
 151    * a decode before the container has necessarily been instantiated. Calling
 152    * startDecoding() on the imgIRequest simply forwards along the request if the
 153    * container already exists, or calls it once the container becomes available
 154    * if it does not yet exist.
 155    */
 156   void startDecoding(in uint32_t aFlags);
 157
 158   /**
 159    * Exactly like startDecoding above except returns whether the current frame
 160    * of the image is complete or not.
 161    */
 162   [noscript, notxpcom] boolean startDecodingWithResult(in uint32_t aFlags);
 163
 164   /**
 165    * Locks an image. If the image does not exist yet, locks it once it becomes
 166    * available. The lock persists for the lifetime of the imgIRequest (until
 167    * unlockImage is called) even if the underlying image changes.
 168    *
 169    * If you don't call unlockImage() by the time this imgIRequest goes away, it
 170    * will be called for you automatically.
 171    *
 172    * @see imgIContainer::lockImage for documentation of the underlying call.
 173    */
 174   void lockImage();
 175
 176   /**
 177    * Unlocks an image.
 178    *
 179    * @see imgIContainer::unlockImage for documentation of the underlying call.
 180    */
 181   void unlockImage();
 182
 183   /**
 184    * If this image is unlocked, discard the image's decoded data.  If the image
 185    * is locked or is already discarded, do nothing.
 186    */
 187   void requestDiscard();
 188
 189   /**
 190    * If this request is for an animated image, the method creates a new
 191    * request which contains the current frame of the image.
 192    * Otherwise returns the same request.
 193    */
 194   imgIRequest getStaticRequest();
 195
 196   /**
 197    * Requests that the image animate (if it has an animation).
 198    *
 199    * @see Image::IncrementAnimationConsumers for documentation of the
 200    * underlying call.
 201    */
 202   void incrementAnimationConsumers();
 203
 204   /**
 205    * Tell the image it can forget about a request that the image animate.
 206    *
 207    * @see Image::DecrementAnimationConsumers for documentation of the
 208    * underlying call.
 209    */
 210   void decrementAnimationConsumers();
 211
 212   /**
 213    * Request loading priority boost to requested category, each category
 214    * of request increases priority only one time..
 215    *
 216    * CATEGORY_FRAME_INIT: increase priority when the imgRequest is associated
 217    * with an nsImageFrame.
 218    *
 219    * CATEGORY_SIZE_QUERY: increase priority when size decoding is necessary to
 220    * determine the layout size of the associated nsImageFrame.
 221    *
 222    * CATEGORY_DISPLAY: increase priority when the image is about to be displayed
 223    * in the viewport.
 224    */
 225   const uint32_t CATEGORY_FRAME_INIT = 1 << 0;
 226   const uint32_t CATEGORY_SIZE_QUERY = 1 << 1;
 227   const uint32_t CATEGORY_DISPLAY    = 1 << 2;
 228   void boostPriority(in uint32_t aCategory);
 229 };
 230