gecko-dev/image/imgIContainer.idl
2016-08-23 22:57:10 -07:00

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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"
%{C++
#include "DrawResult.h"
#include "gfxContext.h"
#include "gfxMatrix.h"
#include "gfxRect.h"
#include "mozilla/gfx/2D.h"
#include "mozilla/Maybe.h"
#include "mozilla/RefPtr.h"
#include "nsRect.h"
#include "nsSize.h"
#include "limits.h"
class nsIDocument;
namespace mozilla {
namespace layers {
class LayerManager;
class ImageContainer;
}
}
class nsIFrame;
namespace mozilla {
class TimeStamp;
class SVGImageContext;
}
namespace mozilla {
namespace image {
class ImageRegion;
struct Orientation;
}
}
%}
native DrawResult(mozilla::image::DrawResult);
[ptr] native gfxContext(gfxContext);
[ref] native gfxMatrix(gfxMatrix);
[ref] native gfxRect(gfxRect);
[ref] native gfxSize(gfxSize);
native SamplingFilter(mozilla::gfx::SamplingFilter);
[ref] native nsIntRect(nsIntRect);
native nsIntRectByVal(nsIntRect);
[ref] native nsIntSize(nsIntSize);
native nsSize(nsSize);
[ptr] native nsIFrame(nsIFrame);
native TempRefImageContainer(already_AddRefed<mozilla::layers::ImageContainer>);
[ref] native ImageRegion(mozilla::image::ImageRegion);
[ptr] native LayerManager(mozilla::layers::LayerManager);
native Orientation(mozilla::image::Orientation);
[ref] native TimeStamp(mozilla::TimeStamp);
[ref] native MaybeSVGImageContext(mozilla::Maybe<mozilla::SVGImageContext>);
native TempRefSourceSurface(already_AddRefed<mozilla::gfx::SourceSurface>);
native TempRefImgIContainer(already_AddRefed<imgIContainer>);
native nsIntSizeByVal(nsIntSize);
[ptr] native nsIDocument(nsIDocument);
/**
* imgIContainer is the interface that represents an image. It allows
* access to frames as Thebes surfaces. It also allows drawing of images
* onto Thebes contexts.
*
* Internally, imgIContainer also manages animation of images.
*/
[scriptable, builtinclass, uuid(a8dbee24-ff86-4755-b40e-51175caf31af)]
interface imgIContainer : nsISupports
{
/**
* The width of the container rectangle. In the case of any error,
* zero is returned, and an exception will be thrown.
*/
readonly attribute int32_t width;
/**
* The height of the container rectangle. In the case of any error,
* zero is returned, and an exception will be thrown.
*/
readonly attribute int32_t height;
/**
* The intrinsic size of this image in appunits. If the image has no intrinsic
* size in a dimension, -1 will be returned for that dimension. In the case of
* any error, an exception will be thrown.
*/
[noscript] readonly attribute nsSize intrinsicSize;
/**
* The (dimensionless) intrinsic ratio of this image. In the case of any
* error, an exception will be thrown.
*/
[noscript] readonly attribute nsSize intrinsicRatio;
/**
* Given a size at which this image will be displayed, and the drawing
* parameters affecting how it will be drawn, returns the image size which
* should be used to draw to produce the highest quality result. This is the
* appropriate size, for example, to use as an input to the pixel snapping
* algorithm.
*
* For best results the size returned by this method should not be cached. It
* can change over time due to changes in the internal state of the image.
*
* @param aDest The size of the destination rect into which this image will be
* drawn, in device pixels.
* @param aWhichFrame Frame specifier of the FRAME_* variety.
* @param aSamplingFilter The filter to be used if we're scaling the image.
* @param aFlags Flags of the FLAG_* variety
*/
[notxpcom, nostdcall] nsIntSizeByVal
optimalImageSizeForDest([const] in gfxSize aDest, in uint32_t aWhichFrame,
in SamplingFilter aSamplingFilter, in uint32_t aFlags);
/**
* Enumerated values for the 'type' attribute (below).
*/
const unsigned short TYPE_RASTER = 0;
const unsigned short TYPE_VECTOR = 1;
/**
* The type of this image (one of the TYPE_* values above).
*/
[infallible] readonly attribute unsigned short type;
/**
* Whether this image is animated. You can only be guaranteed that querying
* this will not throw if STATUS_DECODE_COMPLETE is set on the imgIRequest.
*
* @throws NS_ERROR_NOT_AVAILABLE if the animated state cannot be determined.
*/
readonly attribute boolean animated;
/**
* Flags for imgIContainer operations.
*
* Meanings:
*
* FLAG_NONE: Lack of flags.
*
* FLAG_SYNC_DECODE: Forces synchronous/non-progressive decode of all
* available data before the call returns.
*
* FLAG_SYNC_DECODE_IF_FAST: Like FLAG_SYNC_DECODE, but requests a sync decode
* be performed only if ImageLib estimates it can be completed very quickly.
*
* FLAG_ASYNC_NOTIFY: Send notifications asynchronously, even if we decode
* synchronously beause of FLAG_SYNC_DECODE or FLAG_SYNC_DECODE_IF_FAST.
*
* FLAG_DECODE_NO_PREMULTIPLY_ALPHA: Do not premultiply alpha if
* it's not already premultiplied in the image data.
*
* FLAG_DECODE_NO_COLORSPACE_CONVERSION: Do not do any colorspace conversion;
* ignore any embedded profiles, and don't convert to any particular
* destination space.
*
* FLAG_CLAMP: Extend the image to the fill area by clamping image sample
* coordinates instead of by tiling. This only affects 'draw'.
*
* FLAG_HIGH_QUALITY_SCALING: A hint as to whether this image should be
* scaled using the high quality scaler. Do not set this if not drawing to
* a window or not listening to invalidations. Passing this flag will do two
* things: 1) request a decode of the image at the size asked for by the
* caller if one isn't already started or complete, and 2) allows a decoded
* frame of any size (it could be neither the requested size, nor the
* intrinsic size) to be substituted.
*
* FLAG_WANT_DATA_SURFACE: Can be passed to GetFrame when the caller wants a
* DataSourceSurface instead of a hardware accelerated surface. This can be
* important for performance (by avoiding an upload to/readback from the GPU)
* when the caller knows they want a SourceSurface of type DATA.
*
* FLAG_BYPASS_SURFACE_CACHE: Forces drawing to happen rather than taking
* cached rendering from the surface cache. This is used when we are printing,
* for example, where we want the vector commands from VectorImages to end up
* in the PDF output rather than a cached rendering at screen resolution.
*
* FLAG_FORCE_PRESERVEASPECTRATIO_NONE: Force scaling this image
* non-uniformly if necessary. This flag is for vector image only. A raster
* image should ignore this flag. While drawing a vector image with this
* flag, do not force uniform scaling even if its root <svg> node has a
* preserveAspectRatio attribute that would otherwise require uniform
* scaling , such as xMinYMin/ xMidYMin. Always scale the graphic content of
* the given image non-uniformly if necessary such that the image's
* viewBox (if specified or implied by height/width attributes) exactly
* matches the viewport rectangle.
*
* FLAG_FORCE_UNIFORM_SCALING: Signal to ClippedImage::OptimalSizeForDest that
* its returned size can only scale the image's size *uniformly* (by the same
* factor in each dimension). We need this flag when painting border-image
* section with SVG image source-data, if the SVG image has no viewBox and no
* intrinsic size. In such a case, we synthesize a viewport for the SVG image
* (a "window into SVG space") based on the border image area, and we need to
* be sure we don't subsequently scale that viewport in a way that distorts
* its contents by stretching them more in one dimension than the other.
*/
const unsigned long FLAG_NONE = 0x0;
const unsigned long FLAG_SYNC_DECODE = 0x1;
const unsigned long FLAG_SYNC_DECODE_IF_FAST = 0x2;
const unsigned long FLAG_ASYNC_NOTIFY = 0x4;
const unsigned long FLAG_DECODE_NO_PREMULTIPLY_ALPHA = 0x8;
const unsigned long FLAG_DECODE_NO_COLORSPACE_CONVERSION = 0x10;
const unsigned long FLAG_CLAMP = 0x20;
const unsigned long FLAG_HIGH_QUALITY_SCALING = 0x40;
const unsigned long FLAG_WANT_DATA_SURFACE = 0x80;
const unsigned long FLAG_BYPASS_SURFACE_CACHE = 0x100;
const unsigned long FLAG_FORCE_PRESERVEASPECTRATIO_NONE = 0x200;
const unsigned long FLAG_FORCE_UNIFORM_SCALING = 0x400;
/**
* A constant specifying the default set of decode flags (i.e., the default
* values for FLAG_DECODE_*).
*/
const unsigned long DECODE_FLAGS_DEFAULT = 0;
/**
* Constants for specifying various "special" frames.
*
* FRAME_FIRST: The first frame
* FRAME_CURRENT: The current frame
*
* FRAME_MAX_VALUE should be set to the value of the maximum constant above,
* as it is used for ensuring that a valid value was passed in.
*/
const unsigned long FRAME_FIRST = 0;
const unsigned long FRAME_CURRENT = 1;
const unsigned long FRAME_MAX_VALUE = 1;
/**
* Get a surface for the given frame. This may be a platform-native,
* optimized surface, so you cannot inspect its pixel data. If you
* need that, use SourceSurface::GetDataSurface.
*
* @param aWhichFrame Frame specifier of the FRAME_* variety.
* @param aFlags Flags of the FLAG_* variety
*/
[noscript, notxpcom] TempRefSourceSurface getFrame(in uint32_t aWhichFrame,
in uint32_t aFlags);
/**
* Get a surface for the given frame at the specified size. Matching the
* requested size is best effort; it's not guaranteed that the surface you get
* will be a perfect match. (Some reasons you may get a surface of a different
* size include: if you requested upscaling, if downscale-during-decode is
* disabled, or if you didn't request the first frame.)
*
* @param aSize The desired size.
* @param aWhichFrame Frame specifier of the FRAME_* variety.
* @param aFlags Flags of the FLAG_* variety
*/
[noscript, notxpcom] TempRefSourceSurface getFrameAtSize([const] in nsIntSize aSize,
in uint32_t aWhichFrame,
in uint32_t aFlags);
/**
* Returns true if this image will draw opaquely right now if asked to draw
* with FLAG_HIGH_QUALITY_SCALING and otherwise default flags. If this image
* (when decoded) is opaque but no decoded frames are available then
* willDrawOpaqueNow will return false.
*/
[noscript, notxpcom] boolean willDrawOpaqueNow();
/**
* @return true if getImageContainer() is expected to return a valid
* ImageContainer when passed the given @Manager and @Flags
* parameters.
*/
[noscript, notxpcom] boolean isImageContainerAvailable(in LayerManager aManager,
in uint32_t aFlags);
/**
* Attempts to create an ImageContainer (and Image) containing the current
* frame.
*
* Avoid calling this unless you're actually going to layerize this image.
*
* @param aManager The LayerManager which will be used to create the
* ImageContainer.
* @param aFlags Decoding / drawing flags (in other words, FLAG_* flags).
* Currently only FLAG_SYNC_DECODE and FLAG_SYNC_DECODE_IF_FAST
* are supported.
* @return An ImageContainer for the current frame, or nullptr if one could
* not be created.
*/
[noscript, notxpcom] TempRefImageContainer getImageContainer(in LayerManager aManager,
in uint32_t aFlags);
/**
* Draw the requested frame of this image onto the context specified.
*
* Drawing an image involves scaling it to a certain size (which may be
* implemented as a "smart" scale by substituting an HQ-scaled frame or
* rendering at a high DPI), and then selecting a region of that image to
* draw. That region is drawn onto the graphics context and in the process
* transformed by the context matrix, which determines the final area that is
* filled. The basic process looks like this:
*
* +------------------+
* | Image |
* | |
* | intrinsic width |
* | X |
* | intrinsic height |
* +------------------+
* / \
* / \
* / (scale to aSize) \
* / \
* +----------------------------+
* | |
* | Scaled Image |
* | aSize.width X aSize.height |
* | |
* | +---------+ |
* | | aRegion | |
* | +---------+ |
* +-------(---------(----------+
* | |
* / \
* | (transform |
* / by aContext \
* | matrix) |
* / \
* +---------------------+
* | |
* | Fill Rect |
* | |
* +---------------------+
*
* The region may extend outside of the scaled image's boundaries. It's
* actually a region in tiled image space, which is formed by tiling the
* scaled image infinitely in every direction. Drawing with a region larger
* than the scaled image thus causes the filled area to contain multiple tiled
* copies of the image, which looks like this:
*
* ....................................................
* : : : :
* : Tile : Tile : Tile :
* : +------------[aRegion]------------+ :
* :........|.......:................:........|.......:
* : | : : | :
* : Ti|le : Scaled Image : Ti|le :
* : | : : | :
* :........|.......:................:........|.......:
* : +---------------------------------+ :
* : Ti|le : Tile : Ti|le :
* : / : : \ :
* :......(.........:................:..........).....:
* | |
* / \
* | (transform by aContext matrix) |
* / \
* +---------------------------------------------+
* | : : |
* |.....:.................................:.....|
* | : : |
* | : Tiled Fill : |
* | : : |
* |.....:.................................:.....|
* | : : |
* +---------------------------------------------+
*
*
* @param aContext The Thebes context to draw the image to.
* @param aSize The size to which the image should be scaled before drawing.
* This requirement may be satisfied using HQ scaled frames,
* selecting from different resolution layers, drawing at a
* higher DPI, or just performing additional scaling on the
* graphics context. Callers can use optimalImageSizeForDest()
* to determine the best choice for this parameter if they have
* no special size requirements.
* @param aRegion The region in tiled image space which will be drawn onto the
* graphics context. aRegion is in the coordinate space of the
* image after it has been scaled to aSize - that is, the image
* is scaled first, and then aRegion is applied. When aFlags
* includes FLAG_CLAMP, the image will be extended to this area
* by clamping image sample coordinates. Otherwise, the image
* will be automatically tiled as necessary. aRegion can also
* optionally contain a second region which restricts the set
* of pixels we're allowed to sample from when drawing; this
* is only of use to callers which need to draw with pixel
* snapping.
* @param aWhichFrame Frame specifier of the FRAME_* variety.
* @param aSamplingFilter The filter to be used if we're scaling the image.
* @param aSVGContext If specified, SVG-related rendering context, such as
* overridden attributes on the image document's root <svg>
* node, and the size of the viewport that the full image
* would occupy. Ignored for raster images.
* @param aFlags Flags of the FLAG_* variety
* @return A DrawResult value indicating whether and to what degree the
* drawing operation was successful.
*/
[noscript, notxpcom] DrawResult
draw(in gfxContext aContext,
[const] in nsIntSize aSize,
[const] in ImageRegion aRegion,
in uint32_t aWhichFrame,
in SamplingFilter aSamplingFilter,
[const] in MaybeSVGImageContext aSVGContext,
in uint32_t aFlags);
/*
* Ensures that an image is decoding. Calling this function guarantees that
* the image will at some point fire off decode notifications. Images that
* can be decoded "quickly" according to some heuristic will be decoded
* synchronously.
*/
[noscript] void startDecoding();
/*
* This method triggers decoding for an image, but unlike startDecoding() it
* enables the caller to provide more detailed information about the decode
* request.
*
* @param aSize The size to which the image should be scaled while decoding,
* if possible. If the image cannot be scaled to this size while
* being decoded, it will be decoded at its intrinsic size.
* @param aFlags Flags of the FLAG_* variety. Only the decode flags
* (FLAG_DECODE_*) and FLAG_SYNC_DECODE (which will
* synchronously decode images that can be decoded "quickly",
* just like startDecoding() does) are accepted; others will be
* ignored.
*/
[noscript] void requestDecodeForSize([const] in nsIntSize aSize,
in uint32_t aFlags);
/**
* Increments the lock count on the image. An image will not be discarded
* as long as the lock count is nonzero. Note that it is still possible for
* the image to be undecoded if decode-on-draw is enabled and the image
* was never drawn.
*
* Upon instantiation images have a lock count of zero.
*/
void lockImage();
/**
* Decreases the lock count on the image. If the lock count drops to zero,
* the image is allowed to discard its frame data to save memory.
*
* Upon instantiation images have a lock count of zero. It is an error to
* call this method without first having made a matching lockImage() call.
* In other words, the lock count is not allowed to be negative.
*/
void unlockImage();
/**
* If this image is unlocked, discard its decoded data. If the image is
* locked or has already been discarded, do nothing.
*/
void requestDiscard();
/**
* Indicates that this imgIContainer has been triggered to update
* its internal animation state. Likely this should only be called
* from within nsImageFrame or objects of similar type.
*/
[notxpcom] void requestRefresh([const] in TimeStamp aTime);
/**
* Animation mode Constants
* 0 = normal
* 1 = don't animate
* 2 = loop once
*/
const short kNormalAnimMode = 0;
const short kDontAnimMode = 1;
const short kLoopOnceAnimMode = 2;
attribute unsigned short animationMode;
/* Methods to control animation */
void resetAnimation();
/*
* Returns an index for the requested animation frame (either FRAME_FIRST or
* FRAME_CURRENT).
*
* The units of the index aren't specified, and may vary between different
* types of images. What you can rely on is that on all occasions when
* getFrameIndex(FRAME_CURRENT) returns a certain value,
* draw(..FRAME_CURRENT..) will draw the same frame. The same holds for
* FRAME_FIRST as well.
*
* @param aWhichFrame Frame specifier of the FRAME_* variety.
*/
[notxpcom] float getFrameIndex(in uint32_t aWhichFrame);
/*
* Returns the inherent orientation of the image, as described in the image's
* metadata (e.g. EXIF).
*/
[notxpcom] Orientation getOrientation();
/*
* Returns the delay, in ms, between the first and second frame. If this
* returns 0, there is no delay between first and second frame (i.e., this
* image could render differently whenever it draws).
*
* If this image is not animated, or not known to be animated (see attribute
* animated), returns -1.
*/
[notxpcom] int32_t getFirstFrameDelay();
/*
* If this is an animated image that hasn't started animating already, this
* sets the animation's start time to the indicated time.
*
* This has no effect if the image isn't animated or it has started animating
* already; it also has no effect if the image format doesn't care about
* animation start time.
*
* In all cases, animation does not actually begin until startAnimation(),
* resetAnimation(), or requestRefresh() is called for the first time.
*/
[notxpcom] void setAnimationStartTime([const] in TimeStamp aTime);
/*
* Given an invalidation rect in the coordinate system used by the decoder,
* returns an invalidation rect in image space.
*
* This is the identity transformation in most cases, but the result can
* differ if the image is wrapped by an ImageWrapper that changes its size
* or orientation.
*/
[notxpcom] nsIntRectByVal
getImageSpaceInvalidationRect([const] in nsIntRect aRect);
/*
* Removes any ImageWrappers and returns the unwrapped base image.
*/
[notxpcom, nostdcall] TempRefImgIContainer unwrap();
/*
* Propagate the use counters (if any) from this container to the passed in
* document.
*/
[noscript, notxpcom] void propagateUseCounters(in nsIDocument aDocument);
};