gecko-dev/image/imgITools.idl
Agi Sferro a076d6d45e Bug 1530402 - Provide imgTools.decodeFromChannelAsync. r=aosmond,snorp
This method allows consumers to decode images from a |nsIChannel| instance.

This method also supports vector images (e.g. SVGs), which other decode methods don't.

Differential Revision: https://phabricator.services.mozilla.com/D49037

--HG--
extra : moz-landing-system : lando
2019-11-18 16:48:53 +00:00

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsISupports.idl"
interface nsIChannel;
interface nsIEventTarget;
interface nsIInputStream;
interface nsIURI;
interface imgIContainer;
interface imgILoader;
interface imgICache;
interface imgIScriptedNotificationObserver;
interface imgINotificationObserver;
interface imgIContainerCallback;
webidl Document;
[scriptable, builtinclass, uuid(4c2383a4-931c-484d-8c4a-973590f66e3f)]
interface imgITools : nsISupports
{
/**
* decodeImageFromBuffer
* Caller provides an buffer, a buffer size and a mimetype. We read from
* the stream and decompress it (according to the specified mime type) and
* return the resulting imgIContainer.
*
* @param aBuffer
* Data in memory.
* @param aSize
* Buffer size.
* @param aMimeType
* Type of image in the stream.
*/
imgIContainer decodeImageFromBuffer(in string aBuffer,
in unsigned long aSize,
in ACString aMimeType);
/**
* decodeImageFromArrayBuffer
* Caller provides an ArrayBuffer and a mimetype. We read from
* the stream and decompress it (according to the specified mime type) and
* return the resulting imgIContainer.
*
* @param aArrayBuffer
* An ArrayBuffer.
* @param aMimeType
* Type of image in the stream.
*/
[implicit_jscontext]
imgIContainer decodeImageFromArrayBuffer(in jsval aArrayBuffer,
in ACString aMimeType);
/**
* decodeImageFromChannelAsync
* See decodeImage. The main difference between this method and decodeImage
* is that here the operation is done async on a thread from the decode
* pool. When the operation is completed, the callback is executed with the
* result.
*
* @param aURI
* The original URI of the image
* @param aChannel
* Channel to the image to be decoded.
* @param aCallback
* The callback is executed when the imgContainer is fully created.
* @param aObserver
* Optional observer for the decoded image, the caller should make
* sure the observer is kept alive as long as necessary, as ImageLib
* does not keep a strong reference to the observer.
*/
void decodeImageFromChannelAsync(in nsIURI aURI,
in nsIChannel aChannel,
in imgIContainerCallback aCallback,
in imgINotificationObserver aObserver);
/**
* decodeImageAsync
* See decodeImage. The main difference between this method and decodeImage
* is that here the operation is done async on a thread from the decode
* pool. When the operation is completed, the callback is executed with the
* result.
*
* @param aStream
* An input stream for an encoded image file.
* @param aMimeType
* Type of image in the stream.
* @param aCallback
* The callback is executed when the imgContainer is fully created.
* @param aEventTarget
* This eventTarget is used to execute aCallback
*/
void decodeImageAsync(in nsIInputStream aStream,
in ACString aMimeType,
in imgIContainerCallback aCallback,
in nsIEventTarget aEventTarget);
/**
* encodeImage
* Caller provides an image container, and the mime type it should be
* encoded to. We return an input stream for the encoded image data.
*
* @param aContainer
* An image container.
* @param aMimeType
* Type of encoded image desired (eg "image/png").
* @param outputOptions
* Encoder-specific output options.
*/
nsIInputStream encodeImage(in imgIContainer aContainer,
in ACString aMimeType,
[optional] in AString outputOptions);
/**
* encodeScaledImage
* Caller provides an image container, and the mime type it should be
* encoded to. We return an input stream for the encoded image data.
* The encoded image is scaled to the specified dimensions.
*
* @param aContainer
* An image container.
* @param aMimeType
* Type of encoded image desired (eg "image/png").
* @param aWidth, aHeight
* The size (in pixels) desired for the resulting image. Specify 0 to
* use the given image's width or height. Values must be >= 0.
* @param outputOptions
* Encoder-specific output options.
*/
nsIInputStream encodeScaledImage(in imgIContainer aContainer,
in ACString aMimeType,
in long aWidth,
in long aHeight,
[optional] in AString outputOptions);
/**
* getImgLoaderForDocument
* Retrieve an image loader that reflects the privacy status of the given
* document.
*
* @param doc
* A document. Must not be null.
*/
imgILoader getImgLoaderForDocument(in Document doc);
/**
* getImgLoaderForDocument
* Retrieve an image cache that reflects the privacy status of the given
* document.
*
* @param doc
* A document. Null is allowed, but must _only_ be passed
* when there is no way to obtain a relevant document for
* the current context in which a cache is desired.
*/
imgICache getImgCacheForDocument(in Document doc);
/**
* encodeCroppedImage
* Caller provides an image container, and the mime type it should be
* encoded to. We return an input stream for the encoded image data.
* The encoded image is cropped to the specified dimensions.
*
* The given offset and size must not exceed the image bounds.
*
* @param aContainer
* An image container.
* @param aMimeType
* Type of encoded image desired (eg "image/png").
* @param aOffsetX, aOffsetY
* The crop offset (in pixels). Values must be >= 0.
* @param aWidth, aHeight
* The size (in pixels) desired for the resulting image. Specify 0 to
* use the given image's width or height. Values must be >= 0.
* @param outputOptions
* Encoder-specific output options.
*/
nsIInputStream encodeCroppedImage(in imgIContainer aContainer,
in ACString aMimeType,
in long aOffsetX,
in long aOffsetY,
in long aWidth,
in long aHeight,
[optional] in AString outputOptions);
/**
* Create a wrapper around a scripted notification observer (ordinarily
* imgINotificationObserver cannot be implemented from scripts).
*
* @param aObserver The scripted observer to wrap
*/
imgINotificationObserver
createScriptedObserver(in imgIScriptedNotificationObserver aObserver);
};
/**
* This is a companion interface for nsIAsyncInputStream::asyncWait.
*/
[function, scriptable, uuid(f195772c-a4c0-47ae-80ca-211e001c67be)]
interface imgIContainerCallback : nsISupports
{
/* If the operation fails, aStatus will contain the error value */
void onImageReady(in imgIContainer aImage, in nsresult aStatus);
};