gecko-dev/layout/painting/nsImageRenderer.h
Morris Tseng 506acb1953 Bug 1376855 - Support nsDisplayBackgroundImage in layers free mode. r=kats
MozReview-Commit-ID: KaIAVfNB4E5

--HG--
extra : rebase_source : a7797ce7ef8439780c2f61f7edf68f26c654c9ae
2017-06-28 15:07:45 -07:00

339 lines
14 KiB
C++

/* -*- 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/. */
#ifndef nsImageRenderer_h__
#define nsImageRenderer_h__
#include "nsLayoutUtils.h"
#include "nsStyleStruct.h"
#include "Units.h"
class gfxDrawable;
namespace mozilla {
namespace layers {
class StackingContextHelper;
class WebRenderParentCommand;
class WebRenderDisplayItemLayer;
class WebRenderLayerManager;
} // namespace layers
namespace wr {
class DisplayListBuilder;
} // namespace wr
// A CSSSizeOrRatio represents a (possibly partially specified) size for use
// in computing image sizes. Either or both of the width and height might be
// given. A ratio of width to height may also be given. If we at least two
// of these then we can compute a concrete size, that is a width and height.
struct CSSSizeOrRatio
{
CSSSizeOrRatio()
: mRatio(0, 0)
, mHasWidth(false)
, mHasHeight(false) {}
bool CanComputeConcreteSize() const
{
return mHasWidth + mHasHeight + HasRatio() >= 2;
}
bool IsConcrete() const { return mHasWidth && mHasHeight; }
bool HasRatio() const { return mRatio.width > 0 && mRatio.height > 0; }
bool IsEmpty() const
{
return (mHasWidth && mWidth <= 0) ||
(mHasHeight && mHeight <= 0) ||
mRatio.width <= 0 || mRatio.height <= 0;
}
// CanComputeConcreteSize must return true when ComputeConcreteSize is
// called.
nsSize ComputeConcreteSize() const;
void SetWidth(nscoord aWidth)
{
mWidth = aWidth;
mHasWidth = true;
if (mHasHeight) {
mRatio = nsSize(mWidth, mHeight);
}
}
void SetHeight(nscoord aHeight)
{
mHeight = aHeight;
mHasHeight = true;
if (mHasWidth) {
mRatio = nsSize(mWidth, mHeight);
}
}
void SetSize(const nsSize& aSize)
{
mWidth = aSize.width;
mHeight = aSize.height;
mHasWidth = true;
mHasHeight = true;
mRatio = aSize;
}
void SetRatio(const nsSize& aRatio)
{
MOZ_ASSERT(!mHasWidth || !mHasHeight,
"Probably shouldn't be setting a ratio if we have a concrete size");
mRatio = aRatio;
}
nsSize mRatio;
nscoord mWidth;
nscoord mHeight;
bool mHasWidth;
bool mHasHeight;
};
/**
* This is a small wrapper class to encapsulate image drawing that can draw an
* nsStyleImage image, which may internally be a real image, a sub image, or a
* CSS gradient.
*
* @note Always call the member functions in the order of PrepareImage(),
* SetSize(), and Draw*().
*/
class nsImageRenderer {
public:
typedef mozilla::image::DrawResult DrawResult;
typedef mozilla::layers::LayerManager LayerManager;
typedef mozilla::layers::ImageContainer ImageContainer;
enum {
FLAG_SYNC_DECODE_IMAGES = 0x01,
FLAG_PAINTING_TO_WINDOW = 0x02
};
enum FitType
{
CONTAIN,
COVER
};
nsImageRenderer(nsIFrame* aForFrame, const nsStyleImage* aImage, uint32_t aFlags);
~nsImageRenderer();
/**
* Populates member variables to get ready for rendering.
* @return true iff the image is ready, and there is at least a pixel to
* draw.
*/
bool PrepareImage();
/**
* The three Compute*Size functions correspond to the sizing algorthms and
* definitions from the CSS Image Values and Replaced Content spec. See
* http://dev.w3.org/csswg/css-images-3/#sizing .
*/
/**
* Compute the intrinsic size of the image as defined in the CSS Image Values
* spec. The intrinsic size is the unscaled size which the image would ideally
* like to be in app units.
*/
mozilla::CSSSizeOrRatio ComputeIntrinsicSize();
/**
* Computes the placement for a background image, or for the image data
* inside of a replaced element.
*
* @param aPos The CSS <position> value that specifies the image's position.
* @param aOriginBounds The box to which the tiling position should be
* relative. For background images, this should correspond to
* 'background-origin' for the frame, except when painting on the
* canvas, in which case the origin bounds should be the bounds
* of the root element's frame. For a replaced element, this should
* be the element's content-box.
* @param aTopLeft [out] The top-left corner where an image tile should be
* drawn.
* @param aAnchorPoint [out] A point which should be pixel-aligned by
* nsLayoutUtils::DrawImage. This is the same as aTopLeft, unless
* CSS specifies a percentage (including 'right' or 'bottom'), in
* which case it's that percentage within of aOriginBounds. So
* 'right' would set aAnchorPoint.x to aOriginBounds.XMost().
*
* Points are returned relative to aOriginBounds.
*/
static void ComputeObjectAnchorPoint(const mozilla::Position& aPos,
const nsSize& aOriginBounds,
const nsSize& aImageSize,
nsPoint* aTopLeft,
nsPoint* aAnchorPoint);
/**
* Compute the size of the rendered image using either the 'cover' or
* 'contain' constraints (aFitType).
* aIntrinsicRatio may be an invalid ratio, that is one or both of its
* dimensions can be less than or equal to zero.
*/
static nsSize ComputeConstrainedSize(const nsSize& aConstrainingSize,
const nsSize& aIntrinsicRatio,
FitType aFitType);
/**
* Compute the size of the rendered image (the concrete size) where no cover/
* contain constraints are given. The 'default algorithm' from the CSS Image
* Values spec.
*/
static nsSize ComputeConcreteSize(const mozilla::CSSSizeOrRatio& aSpecifiedSize,
const mozilla::CSSSizeOrRatio& aIntrinsicSize,
const nsSize& aDefaultSize);
/**
* Set this image's preferred size. This will be its intrinsic size where
* specified and the default size where it is not. Used as the unscaled size
* when rendering the image.
*/
void SetPreferredSize(const mozilla::CSSSizeOrRatio& aIntrinsicSize,
const nsSize& aDefaultSize);
/**
* Draws the image to the target rendering context using
* {background|mask}-specific arguments.
* @see nsLayoutUtils::DrawImage() for parameters.
*/
DrawResult DrawLayer(nsPresContext* aPresContext,
gfxContext& aRenderingContext,
const nsRect& aDest,
const nsRect& aFill,
const nsPoint& aAnchor,
const nsRect& aDirty,
const nsSize& aRepeatSize,
float aOpacity);
/**
* Builds WebRender DisplayItems for an image using
* {background|mask}-specific arguments.
* @see nsLayoutUtils::DrawImage() for parameters.
*/
DrawResult BuildWebRenderDisplayItemsForLayer(nsPresContext* aPresContext,
mozilla::wr::DisplayListBuilder& aBuilder,
const mozilla::layers::StackingContextHelper& aSc,
nsTArray<layers::WebRenderParentCommand>& aParentCommands,
mozilla::layers::WebRenderDisplayItemLayer* aLayer,
mozilla::layers::WebRenderLayerManager* aManager,
nsDisplayItem* aItem,
const nsRect& aDest,
const nsRect& aFill,
const nsPoint& aAnchor,
const nsRect& aDirty,
const nsSize& aRepeatSize,
float aOpacity);
/**
* Draw the image to a single component of a border-image style rendering.
* aFill The destination rect to be drawn into
* aSrc is the part of the image to be rendered into a tile (aUnitSize in
* aFill), if aSrc and the dest tile are different sizes, the image will be
* scaled to map aSrc onto the dest tile.
* aHFill and aVFill are the repeat patterns for the component -
* NS_STYLE_BORDER_IMAGE_REPEAT_*
* aUnitSize The scaled size of a single source rect (in destination coords)
* aIndex identifies the component: 0 1 2
* 3 4 5
* 6 7 8
* aSVGViewportSize The image size evaluated by default sizing algorithm.
* Pass Nothing() if we can read a valid viewport size or aspect-ratio from
* the drawing image directly, otherwise, pass Some() with viewport size
* evaluated from default sizing algorithm.
* aHasIntrinsicRatio is used to record if the source image has fixed
* intrinsic ratio.
*/
DrawResult
DrawBorderImageComponent(nsPresContext* aPresContext,
gfxContext& aRenderingContext,
const nsRect& aDirtyRect,
const nsRect& aFill,
const mozilla::CSSIntRect& aSrc,
uint8_t aHFill,
uint8_t aVFill,
const nsSize& aUnitSize,
uint8_t aIndex,
const mozilla::Maybe<nsSize>& aSVGViewportSize,
const bool aHasIntrinsicRatio);
bool IsRasterImage();
bool IsAnimatedImage();
/// Retrieves the image associated with this nsImageRenderer, if there is one.
already_AddRefed<imgIContainer> GetImage();
bool IsImageContainerAvailable(layers::LayerManager* aManager, uint32_t aFlags);
bool IsReady() const { return mPrepareResult == DrawResult::SUCCESS; }
DrawResult PrepareResult() const { return mPrepareResult; }
void SetExtendMode(mozilla::gfx::ExtendMode aMode) { mExtendMode = aMode; }
void SetMaskOp(uint8_t aMaskOp) { mMaskOp = aMaskOp; }
void PurgeCacheForViewportChange(const mozilla::Maybe<nsSize>& aSVGViewportSize,
const bool aHasRatio);
nsStyleImageType GetType() const { return mType; }
already_AddRefed<nsStyleGradient> GetGradientData();
private:
/**
* Draws the image to the target rendering context.
* aSrc is a rect on the source image which will be mapped to aDest; it's
* currently only used for gradients.
*
* @see nsLayoutUtils::DrawImage() for other parameters.
*/
DrawResult Draw(nsPresContext* aPresContext,
gfxContext& aRenderingContext,
const nsRect& aDirtyRect,
const nsRect& aDest,
const nsRect& aFill,
const nsPoint& aAnchor,
const nsSize& aRepeatSize,
const mozilla::CSSIntRect& aSrc,
float aOpacity = 1.0);
/**
* Builds WebRender DisplayItems for the image.
* aSrc is a rect on the source image which will be mapped to aDest; it's
* currently only used for gradients.
*
* @see nsLayoutUtils::DrawImage() for other parameters.
*/
DrawResult BuildWebRenderDisplayItems(nsPresContext* aPresContext,
mozilla::wr::DisplayListBuilder& aBuilder,
const mozilla::layers::StackingContextHelper& aSc,
nsTArray<layers::WebRenderParentCommand>& aParentCommands,
mozilla::layers::WebRenderDisplayItemLayer* aLayer,
mozilla::layers::WebRenderLayerManager* aManager,
nsDisplayItem* aItem,
const nsRect& aDirtyRect,
const nsRect& aDest,
const nsRect& aFill,
const nsPoint& aAnchor,
const nsSize& aRepeatSize,
const mozilla::CSSIntRect& aSrc,
float aOpacity = 1.0);
/**
* Helper method for creating a gfxDrawable from mPaintServerFrame or
* mImageElementSurface.
* Requires mType is eStyleImageType_Element.
* Returns null if we cannot create the drawable.
*/
already_AddRefed<gfxDrawable> DrawableForElement(const nsRect& aImageRect,
gfxContext& aContext);
nsIFrame* mForFrame;
const nsStyleImage* mImage;
nsStyleImageType mType;
nsCOMPtr<imgIContainer> mImageContainer;
RefPtr<nsStyleGradient> mGradientData;
nsIFrame* mPaintServerFrame;
nsLayoutUtils::SurfaceFromElementResult mImageElementSurface;
DrawResult mPrepareResult;
nsSize mSize; // unscaled size of the image, in app units
uint32_t mFlags;
mozilla::gfx::ExtendMode mExtendMode;
uint8_t mMaskOp;
};
} // namespace mozilla
#endif /* nsImageRenderer_h__ */