imgILoader 编辑

modules/libpr0n/public/imgILoader.idlScriptable Please add a summary to this article. Inherits from: nsISupports Last changed in Gecko 8.0 (Firefox 8.0 / Thunderbird 8.0 / SeaMonkey 2.5)

Implemented by @mozilla.org/image/loader;1 as a service:

var imgILoader = Components.classes["@mozilla.org/image/loader;1"]
                 .getService(Components.interfaces.imgILoader);

Method overview

imgIRequest loadImage(in nsIURI aURI, in nsIURI aInitialDocumentURL, in nsIURI aReferrerURI, in nsIPrincipal aLoadingPrincipal, in nsILoadGroup aLoadGroup, in imgIDecoderObserver aObserver, in nsISupports aCX, in nsLoadFlags aLoadFlags, in nsISupports cacheKey, in imgIRequest aRequest, in nsIChannelPolicy channelPolicy);

imgIRequest loadImageWithChannel(in nsIChannel aChannel, in imgIDecoderObserver aObserver, in nsISupports cx, out nsIStreamListener aListener);

boolean supportImageWithMimeType(in string mimeType);

Constants

Constant	Value	Description
LOAD_CORS_ANONYMOUS	1 << 16
LOAD_CORS_USE_CREDENTIALS	1 << 17

Methods

loadImage()

Start the load and decode of an image.

imgIRequest loadImage(
  in nsIURI aURI,
  in nsIURI aInitialDocumentURL,
  in nsIURI aReferrerURI,
  in nsIPrincipal aLoadingPrincipal,
  in nsILoadGroup aLoadGroup,
  in imgIDecoderObserver aObserver,
  in nsISupports aCX,
  in nsLoadFlags aLoadFlags,
  in nsISupports cacheKey,
  in imgIRequest aRequest,
  in nsIChannelPolicy channelPolicy
);

Parameters

aURI

The URI to load.

aInitialDocumentURL

aReferrerURI

The 'referring' URI.

aLoadingPrincipal

The principal of the loading document.

aLoadGroup

Loadgroup to put the image load into.

aObserver

The observer (may be null)

aCX

Some random data.

aLoadFlags

Load flags for the request.

cacheKey

aRequest

A newly created, unused imgIRequest object or null for one to be created for you. libpr0n does NOT keep a strong ref to the observer; this prevents reference cycles. This means that callers of loadImage should make sure to Cancel() the resulting request before the observer goes away.

channelPolicy

Return value

loadImageWithChannel()

Start the load and decode of an image.

libpr0n does NOT keep a strong ref to the observer; this prevents reference cycles. This means that callers of loadImageWithChannel should make sure to Cancel() the resulting request before the observer goes away.

imgIRequest loadImageWithChannel(
  in nsIChannel aChannel,
  in imgIDecoderObserver aObserver,
  in nsISupports cx,
  out nsIStreamListener aListener
);

Parameters

aChannel

The channel to load the image from. This must already be opened before this method is called, and there must have been no OnDataAvailable calls for it yet.

aObserver

The observer (may be null)

cx

Some random data.

aListener

A listener that you must send the channel's notifications and data to. Can be null, in which case imagelib has found a cached image and is not interested in the data. aChannel will be canceled for you in this case.

Return value

 

supportImageWithMimeType()

Checks if a decoder for the an image with the given mime type is available.

boolean supportImageWithMimeType(
  in string mimeType
);

Parameters

mimeType

The type to find a decoder for.

Return value

true if a decoder is available, false otherwise.