gecko/image/public/imgITools.idl

/* -*- 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 nsIInputStream;
interface imgIContainer;
interface imgILoader;
interface imgICache;
interface nsIDOMDocument;
interface imgIScriptedNotificationObserver;
interface imgINotificationObserver;

[scriptable, uuid(98bd5bf9-87eb-4d92-81b1-4cd10c64f7b2)]
interface imgITools : nsISupports
{
    /**
     * decodeImageData
     * Caller provides an input stream and mimetype. We read from the stream
     * and decompress it (according to the specified mime type) and return
     * the resulting imgIContainer. (If the caller already has a container,
     * it can be provided as input to be reused).
     *
     * @param aStream
     *        An input stream for an encoded image file.
     * @param aMimeType
     *        Type of image in the stream.
     * @param aContainer
     *        An imgIContainer holding the decoded image. Specify |null| when
     *        calling to have one created, otherwise specify a container to
     *        be used. It is an error to pass an already-initialized container
     *        as aContainer.
     */
    void decodeImageData(in nsIInputStream aStream,
                         in ACString aMimeType,
                         inout imgIContainer aContainer);

    /**
     * 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 nsIDOMDocument 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 nsIDOMDocument 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);
};