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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/. */
+
+/* utility functions for drawing borders and backgrounds */
+
+#ifndef nsCSSRendering_h___
+#define nsCSSRendering_h___
+
+#include "gfxBlur.h"
+#include "gfxContext.h"
+#include "imgIContainer.h"
+#include "mozilla/gfx/PathHelpers.h"
+#include "mozilla/gfx/Rect.h"
+#include "mozilla/TypedEnumBits.h"
+#include "nsLayoutUtils.h"
+#include "nsStyleStruct.h"
+#include "nsIFrame.h"
+
+class gfxDrawable;
+class nsStyleContext;
+class nsPresContext;
+class nsRenderingContext;
+
+namespace mozilla {
+
+namespace gfx {
+struct Color;
+class DrawTarget;
+} // namespace gfx
+
+namespace layers {
+class ImageContainer;
+} // namespace layers
+
+// 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;
+};
+
+enum class PaintBorderFlags : uint8_t
+{
+ SYNC_DECODE_IMAGES = 1 << 0
+};
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(PaintBorderFlags)
+
+} // namespace mozilla
+
+/**
+ * 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-specific
+ * arguments.
+ * @see nsLayoutUtils::DrawImage() for parameters.
+ */
+ DrawResult DrawBackground(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ const nsRect& aDest,
+ const nsRect& aFill,
+ const nsPoint& aAnchor,
+ const nsRect& aDirty,
+ const nsSize& aRepeatSize);
+
+ /**
+ * 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,
+ nsRenderingContext& 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 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);
+
+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,
+ nsRenderingContext& aRenderingContext,
+ const nsRect& aDirtyRect,
+ const nsRect& aDest,
+ const nsRect& aFill,
+ const nsPoint& aAnchor,
+ const nsSize& aRepeatSize,
+ const mozilla::CSSIntRect& aSrc);
+
+ /**
+ * 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,
+ nsRenderingContext& aRenderingContext);
+
+ 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;
+};
+
+/**
+ * A struct representing all the information needed to paint a background
+ * image to some target, taking into account all CSS background-* properties.
+ * See PrepareImageLayer.
+ */
+struct nsBackgroundLayerState {
+ typedef mozilla::gfx::CompositionOp CompositionOp;
+
+ /**
+ * @param aFlags some combination of nsCSSRendering::PAINTBG_* flags
+ */
+ nsBackgroundLayerState(nsIFrame* aForFrame, const nsStyleImage* aImage,
+ uint32_t aFlags)
+ : mImageRenderer(aForFrame, aImage, aFlags)
+ {}
+
+ /**
+ * The nsImageRenderer that will be used to draw the background.
+ */
+ nsImageRenderer mImageRenderer;
+ /**
+ * A rectangle that one copy of the image tile is mapped onto. Same
+ * coordinate system as aBorderArea/aBGClipRect passed into
+ * PrepareImageLayer.
+ */
+ nsRect mDestArea;
+ /**
+ * The actual rectangle that should be filled with (complete or partial)
+ * image tiles. Same coordinate system as aBorderArea/aBGClipRect passed into
+ * PrepareImageLayer.
+ */
+ nsRect mFillArea;
+ /**
+ * The anchor point that should be snapped to a pixel corner. Same
+ * coordinate system as aBorderArea/aBGClipRect passed into
+ * PrepareImageLayer.
+ */
+ nsPoint mAnchor;
+ /**
+ * The background-repeat property space keyword computes the
+ * repeat size which is image size plus spacing.
+ */
+ nsSize mRepeatSize;
+};
+
+struct nsCSSRendering {
+ typedef mozilla::gfx::CompositionOp CompositionOp;
+ typedef mozilla::gfx::DrawTarget DrawTarget;
+ typedef mozilla::gfx::Float Float;
+ typedef mozilla::gfx::Point Point;
+ typedef mozilla::gfx::Rect Rect;
+ typedef mozilla::gfx::Size Size;
+ typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
+ typedef mozilla::image::DrawResult DrawResult;
+ typedef nsIFrame::Sides Sides;
+
+ /**
+ * Initialize any static variables used by nsCSSRendering.
+ */
+ static void Init();
+
+ /**
+ * Clean up any static variables used by nsCSSRendering.
+ */
+ static void Shutdown();
+
+ static void PaintBoxShadowInner(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsIFrame* aForFrame,
+ const nsRect& aFrameArea);
+
+ static void PaintBoxShadowOuter(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsIFrame* aForFrame,
+ const nsRect& aFrameArea,
+ const nsRect& aDirtyRect,
+ float aOpacity = 1.0);
+
+ static void ComputePixelRadii(const nscoord *aAppUnitsRadii,
+ nscoord aAppUnitsPerPixel,
+ RectCornerRadii *oBorderRadii);
+
+ /**
+ * Render the border for an element using css rendering rules
+ * for borders. aSkipSides says which sides to skip
+ * when rendering, the default is to skip none.
+ */
+ static DrawResult PaintBorder(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsIFrame* aForFrame,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ nsStyleContext* aStyleContext,
+ mozilla::PaintBorderFlags aFlags,
+ Sides aSkipSides = Sides());
+
+ /**
+ * Like PaintBorder, but taking an nsStyleBorder argument instead of
+ * getting it from aStyleContext. aSkipSides says which sides to skip
+ * when rendering, the default is to skip none.
+ */
+ static DrawResult PaintBorderWithStyleBorder(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsIFrame* aForFrame,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ const nsStyleBorder& aBorderStyle,
+ nsStyleContext* aStyleContext,
+ mozilla::PaintBorderFlags aFlags,
+ Sides aSkipSides = Sides());
+
+
+ /**
+ * Render the outline for an element using css rendering rules
+ * for borders.
+ */
+ static void PaintOutline(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsIFrame* aForFrame,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ nsStyleContext* aStyleContext);
+
+ /**
+ * Render keyboard focus on an element.
+ * |aFocusRect| is the outer rectangle of the focused element.
+ * Uses a fixed style equivalent to "1px dotted |aColor|".
+ * Not used for controls, because the native theme may differ.
+ */
+ static void PaintFocus(nsPresContext* aPresContext,
+ DrawTarget* aDrawTarget,
+ const nsRect& aFocusRect,
+ nscolor aColor);
+
+ /**
+ * Render a gradient for an element.
+ * aDest is the rect for a single tile of the gradient on the destination.
+ * aFill is the rect on the destination to be covered by repeated tiling of
+ * the gradient.
+ * aSrc is the part of the gradient to be rendered into a tile (aDest), if
+ * aSrc and aDest are different sizes, the image will be scaled to map aSrc
+ * onto aDest.
+ * aIntrinsicSize is the size of the source gradient.
+ */
+ static void PaintGradient(nsPresContext* aPresContext,
+ nsRenderingContext& aRenderingContext,
+ nsStyleGradient* aGradient,
+ const nsRect& aDirtyRect,
+ const nsRect& aDest,
+ const nsRect& aFill,
+ const nsSize& aRepeatSize,
+ const mozilla::CSSIntRect& aSrc,
+ const nsSize& aIntrinsiceSize);
+
+ /**
+ * Find the frame whose background style should be used to draw the
+ * canvas background. aForFrame must be the frame for the root element
+ * whose background style should be used. This function will return
+ * aForFrame unless the <body> background should be propagated, in
+ * which case we return the frame associated with the <body>'s background.
+ */
+ static nsIFrame* FindBackgroundStyleFrame(nsIFrame* aForFrame);
+
+ /**
+ * @return true if |aFrame| is a canvas frame, in the CSS sense.
+ */
+ static bool IsCanvasFrame(nsIFrame* aFrame);
+
+ /**
+ * Fill in an aBackgroundSC to be used to paint the background
+ * for an element. This applies the rules for propagating
+ * backgrounds between BODY, the root element, and the canvas.
+ * @return true if there is some meaningful background.
+ */
+ static bool FindBackground(nsIFrame* aForFrame,
+ nsStyleContext** aBackgroundSC);
+
+ /**
+ * As FindBackground, but the passed-in frame is known to be a root frame
+ * (returned from nsCSSFrameConstructor::GetRootElementStyleFrame())
+ * and there is always some meaningful background returned.
+ */
+ static nsStyleContext* FindRootFrameBackground(nsIFrame* aForFrame);
+
+ /**
+ * Returns background style information for the canvas.
+ *
+ * @param aForFrame
+ * the frame used to represent the canvas, in the CSS sense (i.e.
+ * nsCSSRendering::IsCanvasFrame(aForFrame) must be true)
+ * @param aRootElementFrame
+ * the frame representing the root element of the document
+ * @param aBackground
+ * contains background style information for the canvas on return
+ */
+ static nsStyleContext*
+ FindCanvasBackground(nsIFrame* aForFrame, nsIFrame* aRootElementFrame)
+ {
+ MOZ_ASSERT(IsCanvasFrame(aForFrame), "not a canvas frame");
+ if (aRootElementFrame)
+ return FindRootFrameBackground(aRootElementFrame);
+
+ // This should always give transparent, so we'll fill it in with the
+ // default color if needed. This seems to happen a bit while a page is
+ // being loaded.
+ return aForFrame->StyleContext();
+ }
+
+ /**
+ * Find a frame which draws a non-transparent background,
+ * for various table-related and HR-related backwards-compatibility hacks.
+ * This function will also stop if it finds themed frame which might draw
+ * background.
+ *
+ * Be very hesitant if you're considering calling this function -- it's
+ * usually not what you want.
+ */
+ static nsIFrame*
+ FindNonTransparentBackgroundFrame(nsIFrame* aFrame,
+ bool aStartAtParent = false);
+
+ /**
+ * Determine the background color to draw taking into account print settings.
+ */
+ static nscolor
+ DetermineBackgroundColor(nsPresContext* aPresContext,
+ nsStyleContext* aStyleContext,
+ nsIFrame* aFrame,
+ bool& aDrawBackgroundImage,
+ bool& aDrawBackgroundColor);
+
+ static nsRect
+ ComputeImageLayerPositioningArea(nsPresContext* aPresContext,
+ nsIFrame* aForFrame,
+ const nsRect& aBorderArea,
+ const nsStyleImageLayers::Layer& aLayer,
+ nsIFrame** aAttachedToFrame,
+ bool* aOutTransformedFixed);
+
+ static nsBackgroundLayerState
+ PrepareImageLayer(nsPresContext* aPresContext,
+ nsIFrame* aForFrame,
+ uint32_t aFlags,
+ const nsRect& aBorderArea,
+ const nsRect& aBGClipRect,
+ const nsStyleImageLayers::Layer& aLayer,
+ bool* aOutIsTransformedFixed = nullptr);
+
+ struct ImageLayerClipState {
+ nsRect mBGClipArea; // Affected by mClippedRadii
+ nsRect mAdditionalBGClipArea; // Not affected by mClippedRadii
+ nsRect mDirtyRect;
+ gfxRect mDirtyRectGfx;
+
+ nscoord mRadii[8];
+ RectCornerRadii mClippedRadii;
+ bool mHasRoundedCorners;
+ bool mHasAdditionalBGClipArea;
+
+ // Whether we are being asked to draw with a caller provided background
+ // clipping area. If this is true we also disable rounded corners.
+ bool mCustomClip;
+ };
+
+ static void
+ GetImageLayerClip(const nsStyleImageLayers::Layer& aLayer,
+ nsIFrame* aForFrame, const nsStyleBorder& aBorder,
+ const nsRect& aBorderArea, const nsRect& aCallerDirtyRect,
+ bool aWillPaintBorder, nscoord aAppUnitsPerPixel,
+ /* out */ ImageLayerClipState* aClipState);
+
+ /**
+ * Render the background for an element using css rendering rules
+ * for backgrounds or mask.
+ */
+ enum {
+ /**
+ * When this flag is passed, the element's nsDisplayBorder will be
+ * painted immediately on top of this background.
+ */
+ PAINTBG_WILL_PAINT_BORDER = 0x01,
+ /**
+ * When this flag is passed, images are synchronously decoded.
+ */
+ PAINTBG_SYNC_DECODE_IMAGES = 0x02,
+ /**
+ * When this flag is passed, painting will go to the screen so we can
+ * take advantage of the fact that it will be clipped to the viewport.
+ */
+ PAINTBG_TO_WINDOW = 0x04,
+ /**
+ * When this flag is passed, painting will read properties of mask-image
+ * style, instead of background-image.
+ */
+ PAINTBG_MASK_IMAGE = 0x08
+ };
+
+ struct PaintBGParams {
+ nsPresContext& presCtx;
+ nsRenderingContext& renderingCtx;
+ nsRect dirtyRect;
+ nsRect borderArea;
+ nsIFrame* frame;
+ uint32_t paintFlags;
+ nsRect* bgClipRect = nullptr;
+ int32_t layer; // -1 means painting all layers; other
+ // value means painting one specific
+ // layer only.
+ CompositionOp compositionOp;
+
+ static PaintBGParams ForAllLayers(nsPresContext& aPresCtx,
+ nsRenderingContext& aRenderingCtx,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ nsIFrame *aFrame,
+ uint32_t aPaintFlags);
+ static PaintBGParams ForSingleLayer(nsPresContext& aPresCtx,
+ nsRenderingContext& aRenderingCtx,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ nsIFrame *aFrame,
+ uint32_t aPaintFlags,
+ int32_t aLayer,
+ CompositionOp aCompositionOp = CompositionOp::OP_OVER);
+
+ private:
+ PaintBGParams(nsPresContext& aPresCtx,
+ nsRenderingContext& aRenderingCtx,
+ const nsRect& aDirtyRect,
+ const nsRect& aBorderArea,
+ nsIFrame* aFrame,
+ uint32_t aPaintFlags,
+ int32_t aLayer,
+ CompositionOp aCompositionOp)
+ : presCtx(aPresCtx),
+ renderingCtx(aRenderingCtx),
+ dirtyRect(aDirtyRect),
+ borderArea(aBorderArea),
+ frame(aFrame),
+ paintFlags(aPaintFlags),
+ layer(aLayer),
+ compositionOp(aCompositionOp) {}
+ };
+
+ static DrawResult PaintBackground(const PaintBGParams& aParams);
+
+
+ /**
+ * Same as |PaintBackground|, except using the provided style structs.
+ * This short-circuits the code that ensures that the root element's
+ * background is drawn on the canvas.
+ * The aLayer parameter allows you to paint a single layer of the background.
+ * The default value for aLayer, -1, means that all layers will be painted.
+ * The background color will only be painted if the back-most layer is also
+ * being painted.
+ * aCompositionOp is only respected if a single layer is specified (aLayer != -1).
+ * If all layers are painted, the image layer's blend mode (or the mask
+ * layer's composition mode) will be used.
+ */
+ static DrawResult PaintBackgroundWithSC(const PaintBGParams& aParams,
+ nsStyleContext *mBackgroundSC,
+ const nsStyleBorder& aBorder);
+
+ /**
+ * Returns the rectangle covered by the given background layer image, taking
+ * into account background positioning, sizing, and repetition, but not
+ * clipping.
+ */
+ static nsRect GetBackgroundLayerRect(nsPresContext* aPresContext,
+ nsIFrame* aForFrame,
+ const nsRect& aBorderArea,
+ const nsRect& aClipRect,
+ const nsStyleImageLayers::Layer& aLayer,
+ uint32_t aFlags);
+
+ /**
+ * Called when we start creating a display list. The frame tree will not
+ * change until a matching EndFrameTreeLocked is called.
+ */
+ static void BeginFrameTreesLocked();
+ /**
+ * Called when we've finished using a display list. When all
+ * BeginFrameTreeLocked calls have been balanced by an EndFrameTreeLocked,
+ * the frame tree may start changing again.
+ */
+ static void EndFrameTreesLocked();
+
+ // Draw a border segment in the table collapsing border model without
+ // beveling corners
+ static void DrawTableBorderSegment(DrawTarget& aDrawTarget,
+ uint8_t aBorderStyle,
+ nscolor aBorderColor,
+ const nsStyleBackground* aBGColor,
+ const nsRect& aBorderRect,
+ int32_t aAppUnitsPerDevPixel,
+ int32_t aAppUnitsPerCSSPixel,
+ uint8_t aStartBevelSide = 0,
+ nscoord aStartBevelOffset = 0,
+ uint8_t aEndBevelSide = 0,
+ nscoord aEndBevelOffset = 0);
+
+ // NOTE: pt, dirtyRect, lineSize, ascent, offset in the following
+ // structs are non-rounded device pixels, not app units.
+ struct DecorationRectParams
+ {
+ // The width [length] and the height [thickness] of the decoration
+ // line. This is a "logical" size in textRun orientation, so that
+ // for a vertical textrun, width will actually be a physical height;
+ // and conversely, height will be a physical width.
+ Size lineSize;
+ // The ascent of the text.
+ Float ascent = 0.0f;
+ // The offset of the decoration line from the baseline of the text
+ // (if the value is positive, the line is lifted up).
+ Float offset = 0.0f;
+ // If descentLimit is zero or larger and the underline overflows
+ // from the descent space, the underline should be lifted up as far
+ // as possible. Note that this does not mean the underline never
+ // overflows from this limitation, because if the underline is
+ // positioned to the baseline or upper, it causes unreadability.
+ // Note that if this is zero or larger, the underline rect may be
+ // shrunken if it's possible. Therefore, this value is used for
+ // strikeout line and overline too.
+ Float descentLimit = -1.0f;
+ // Which line will be painted. The value can be
+ // NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE or
+ // NS_STYLE_TEXT_DECORATION_LINE_OVERLINE or
+ // NS_STYLE_TEXT_DECORATION_LINE_LINE_THROUGH.
+ uint8_t decoration = NS_STYLE_TEXT_DECORATION_LINE_UNDERLINE;
+ // The style of the decoration line such as
+ // NS_STYLE_TEXT_DECORATION_STYLE_*.
+ uint8_t style = NS_STYLE_TEXT_DECORATION_STYLE_NONE;
+ bool vertical = false;
+ };
+ struct PaintDecorationLineParams : DecorationRectParams
+ {
+ // No need to paint outside this rect.
+ Rect dirtyRect;
+ // The top/left edge of the text.
+ Point pt;
+ // The color of the decoration line.
+ nscolor color = NS_RGBA(0, 0, 0, 0);
+ // The distance between the left edge of the given frame and the
+ // position of the text as positioned without offset of the shadow.
+ Float icoordInFrame = 0.0f;
+ };
+
+ /**
+ * Function for painting the decoration lines for the text.
+ *
+ * input:
+ * @param aFrame the frame which needs the decoration line
+ * @param aGfxContext
+ */
+ static void PaintDecorationLine(nsIFrame* aFrame, DrawTarget& aDrawTarget,
+ const PaintDecorationLineParams& aParams);
+
+ /**
+ * Returns a Rect corresponding to the outline of the decoration line for the
+ * given text metrics. Arguments have the same meaning as for
+ * PaintDecorationLine. Currently this only works for solid
+ * decorations; for other decoration styles the returned Rect will be empty.
+ */
+ static Rect DecorationLineToPath(const PaintDecorationLineParams& aParams);
+
+ /**
+ * Function for getting the decoration line rect for the text.
+ * NOTE: aLineSize, aAscent and aOffset are non-rounded device pixels,
+ * not app units.
+ * input:
+ * @param aPresContext
+ * output:
+ * @return the decoration line rect for the input,
+ * the each values are app units.
+ */
+ static nsRect GetTextDecorationRect(nsPresContext* aPresContext,
+ const DecorationRectParams& aParams);
+
+ static CompositionOp GetGFXBlendMode(uint8_t mBlendMode) {
+ switch (mBlendMode) {
+ case NS_STYLE_BLEND_NORMAL: return CompositionOp::OP_OVER;
+ case NS_STYLE_BLEND_MULTIPLY: return CompositionOp::OP_MULTIPLY;
+ case NS_STYLE_BLEND_SCREEN: return CompositionOp::OP_SCREEN;
+ case NS_STYLE_BLEND_OVERLAY: return CompositionOp::OP_OVERLAY;
+ case NS_STYLE_BLEND_DARKEN: return CompositionOp::OP_DARKEN;
+ case NS_STYLE_BLEND_LIGHTEN: return CompositionOp::OP_LIGHTEN;
+ case NS_STYLE_BLEND_COLOR_DODGE: return CompositionOp::OP_COLOR_DODGE;
+ case NS_STYLE_BLEND_COLOR_BURN: return CompositionOp::OP_COLOR_BURN;
+ case NS_STYLE_BLEND_HARD_LIGHT: return CompositionOp::OP_HARD_LIGHT;
+ case NS_STYLE_BLEND_SOFT_LIGHT: return CompositionOp::OP_SOFT_LIGHT;
+ case NS_STYLE_BLEND_DIFFERENCE: return CompositionOp::OP_DIFFERENCE;
+ case NS_STYLE_BLEND_EXCLUSION: return CompositionOp::OP_EXCLUSION;
+ case NS_STYLE_BLEND_HUE: return CompositionOp::OP_HUE;
+ case NS_STYLE_BLEND_SATURATION: return CompositionOp::OP_SATURATION;
+ case NS_STYLE_BLEND_COLOR: return CompositionOp::OP_COLOR;
+ case NS_STYLE_BLEND_LUMINOSITY: return CompositionOp::OP_LUMINOSITY;
+ default: MOZ_ASSERT(false); return CompositionOp::OP_OVER;
+ }
+ }
+
+ static CompositionOp GetGFXCompositeMode(uint8_t aCompositeMode) {
+ switch (aCompositeMode) {
+ case NS_STYLE_MASK_COMPOSITE_ADD: return CompositionOp::OP_OVER;
+ case NS_STYLE_MASK_COMPOSITE_SUBTRACT: return CompositionOp::OP_OUT;
+ case NS_STYLE_MASK_COMPOSITE_INTERSECT: return CompositionOp::OP_IN;
+ case NS_STYLE_MASK_COMPOSITE_EXCLUDE: return CompositionOp::OP_XOR;
+ default: MOZ_ASSERT(false); return CompositionOp::OP_OVER;
+ }
+ }
+protected:
+ static gfxRect GetTextDecorationRectInternal(
+ const Point& aPt, const DecorationRectParams& aParams);
+
+ /**
+ * Returns inflated rect for painting a decoration line.
+ * Complex style decoration lines should be painted from leftmost of nearest
+ * ancestor block box because that makes better look of connection of lines
+ * for different nodes. ExpandPaintingRectForDecorationLine() returns
+ * a rect for actual painting rect for the clipped rect.
+ *
+ * input:
+ * @param aFrame the frame which needs the decoration line.
+ * @param aStyle the style of the complex decoration line
+ * NS_STYLE_TEXT_DECORATION_STYLE_DOTTED or
+ * NS_STYLE_TEXT_DECORATION_STYLE_DASHED or
+ * NS_STYLE_TEXT_DECORATION_STYLE_WAVY.
+ * @param aClippedRect the clipped rect for the decoration line.
+ * in other words, visible area of the line.
+ * @param aICoordInFrame the distance between inline-start edge of aFrame
+ * and aClippedRect.pos.
+ * @param aCycleLength the width of one cycle of the line style.
+ */
+ static Rect ExpandPaintingRectForDecorationLine(
+ nsIFrame* aFrame,
+ const uint8_t aStyle,
+ const Rect &aClippedRect,
+ const Float aICoordInFrame,
+ const Float aCycleLength,
+ bool aVertical);
+};
+
+/*
+ * nsContextBoxBlur
+ * Creates an 8-bit alpha channel context for callers to draw in, blurs the
+ * contents of that context and applies it as a 1-color mask on a
+ * different existing context. Uses gfxAlphaBoxBlur as its back end.
+ *
+ * You must call Init() first to create a suitable temporary surface to draw
+ * on. You must then draw any desired content onto the given context, then
+ * call DoPaint() to apply the blurred content as a single-color mask. You
+ * can only call Init() once, so objects cannot be reused.
+ *
+ * This is very useful for creating drop shadows or silhouettes.
+ */
+class nsContextBoxBlur {
+ typedef mozilla::gfx::Color Color;
+ typedef mozilla::gfx::DrawTarget DrawTarget;
+ typedef mozilla::gfx::RectCornerRadii RectCornerRadii;
+
+public:
+ enum {
+ FORCE_MASK = 0x01
+ };
+ /**
+ * Prepares a gfxContext to draw on. Do not call this twice; if you want
+ * to get the gfxContext again use GetContext().
+ *
+ * @param aRect The coordinates of the surface to create.
+ * All coordinates must be in app units.
+ * This must not include the blur radius, pass
+ * it as the second parameter and everything
+ * is taken care of.
+ *
+ * @param aBlurRadius The blur radius in app units.
+ *
+ * @param aAppUnitsPerDevPixel The number of app units in a device pixel,
+ * for conversion. Most of the time you'll
+ * pass this from the current PresContext if
+ * available.
+ *
+ * @param aDestinationCtx The graphics context to apply the blurred
+ * mask to when you call DoPaint(). Make sure
+ * it is not destroyed before you call
+ * DoPaint(). To set the color of the
+ * resulting blurred graphic mask, you must
+ * set the color on this context before
+ * calling Init().
+ *
+ * @param aDirtyRect The absolute dirty rect in app units. Used to
+ * optimize the temporary surface size and speed up blur.
+ *
+ * @param aSkipRect An area in device pixels (NOT app units!) to avoid
+ * blurring over, to prevent unnecessary work.
+ *
+ * @param aFlags FORCE_MASK to ensure that the content drawn to the
+ * returned gfxContext is used as a mask, and not
+ * drawn directly to aDestinationCtx.
+ *
+ * @return A blank 8-bit alpha-channel-only graphics context to
+ * draw on, or null on error. Must not be freed. The
+ * context has a device offset applied to it given by
+ * aRect. This means you can use coordinates as if it
+ * were at the desired position at aRect and you don't
+ * need to worry about translating any coordinates to
+ * draw on this temporary surface.
+ *
+ * If aBlurRadius is 0, the returned context is aDestinationCtx and
+ * DoPaint() does nothing, because no blurring is required. Therefore, you
+ * should prepare the destination context as if you were going to draw
+ * directly on it instead of any temporary surface created in this class.
+ */
+ gfxContext* Init(const nsRect& aRect, nscoord aSpreadRadius,
+ nscoord aBlurRadius,
+ int32_t aAppUnitsPerDevPixel, gfxContext* aDestinationCtx,
+ const nsRect& aDirtyRect, const gfxRect* aSkipRect,
+ uint32_t aFlags = 0);
+
+ /**
+ * Does the actual blurring and mask applying. Users of this object *must*
+ * have called Init() first, then have drawn whatever they want to be
+ * blurred onto the internal gfxContext before calling this.
+ */
+ void DoPaint();
+
+ /**
+ * Gets the internal gfxContext at any time. Must not be freed. Avoid
+ * calling this before calling Init() since the context would not be
+ * constructed at that point.
+ */
+ gfxContext* GetContext();
+
+
+ /**
+ * Get the margin associated with the given blur radius, i.e., the
+ * additional area that might be painted as a result of it. (The
+ * margin for a spread radius is itself, on all sides.)
+ */
+ static nsMargin GetBlurRadiusMargin(nscoord aBlurRadius,
+ int32_t aAppUnitsPerDevPixel);
+
+ /**
+ * Blurs a coloured rectangle onto aDestinationCtx. This is equivalent
+ * to calling Init(), drawing a rectangle onto the returned surface
+ * and then calling DoPaint, but may let us optimize better in the
+ * backend.
+ *
+ * @param aDestinationCtx The destination to blur to.
+ * @param aRect The rectangle to blur in app units.
+ * @param aAppUnitsPerDevPixel The number of app units in a device pixel,
+ * for conversion. Most of the time you'll
+ * pass this from the current PresContext if
+ * available.
+ * @param aCornerRadii Corner radii for aRect, if it is a rounded
+ * rectangle.
+ * @param aBlurRadius The blur radius in app units.
+ * @param aShadowColor The color to draw the blurred shadow.
+ * @param aDirtyRect The absolute dirty rect in app units. Used to
+ * optimize the temporary surface size and speed up blur.
+ * @param aSkipRect An area in device pixels (NOT app units!) to avoid
+ * blurring over, to prevent unnecessary work.
+ */
+ static void BlurRectangle(gfxContext* aDestinationCtx,
+ const nsRect& aRect,
+ int32_t aAppUnitsPerDevPixel,
+ RectCornerRadii* aCornerRadii,
+ nscoord aBlurRadius,
+ const Color& aShadowColor,
+ const nsRect& aDirtyRect,
+ const gfxRect& aSkipRect);
+
+ /**
+ * Draws a blurred inset box shadow shape onto the destination surface.
+ * Like BlurRectangle, this is equivalent to calling Init(),
+ * drawing a rectangle onto the returned surface
+ * and then calling DoPaint, but may let us optimize better in the
+ * backend.
+ *
+ * @param aDestinationCtx The destination to blur to.
+ * @param aDestinationRect The rectangle to blur in app units.
+ * @param aShadowClipRect The inside clip rect that creates the path.
+ * @param aShadowColor The color of the blur
+ * @param aBlurRadiusAppUnits The blur radius in app units
+ * @param aSpreadRadiusAppUnits The spread radius in app units.
+ * @param aAppUnitsPerDevPixel The number of app units in a device pixel,
+ * for conversion. Most of the time you'll
+ * pass this from the current PresContext if
+ * available.
+ * @param aHasBorderRadius If this inset box blur has a border radius
+ * @param aInnerClipRectRadii The clip rect radii used for the inside rect's path.
+ * @param aSkipRect An area in device pixels (NOT app units!) to avoid
+ * blurring over, to prevent unnecessary work.
+ */
+ bool InsetBoxBlur(gfxContext* aDestinationCtx,
+ mozilla::gfx::Rect aDestinationRect,
+ mozilla::gfx::Rect aShadowClipRect,
+ mozilla::gfx::Color& aShadowColor,
+ nscoord aBlurRadiusAppUnits,
+ nscoord aSpreadRadiusAppUnits,
+ int32_t aAppUnitsPerDevPixel,
+ bool aHasBorderRadius,
+ RectCornerRadii& aInnerClipRectRadii,
+ mozilla::gfx::Rect aSkipRect,
+ mozilla::gfx::Point aShadowOffset);
+
+protected:
+ static void GetBlurAndSpreadRadius(DrawTarget* aDestDrawTarget,
+ int32_t aAppUnitsPerDevPixel,
+ nscoord aBlurRadius,
+ nscoord aSpreadRadius,
+ mozilla::gfx::IntSize& aOutBlurRadius,
+ mozilla::gfx::IntSize& aOutSpreadRadius,
+ bool aConstrainSpreadRadius = true);
+
+ gfxAlphaBoxBlur mAlphaBoxBlur;
+ RefPtr<gfxContext> mContext;
+ gfxContext* mDestinationCtx;
+
+ /* This is true if the blur already has it's content transformed
+ * by mDestinationCtx's transform */
+ bool mPreTransformed;
+};
+
+#endif /* nsCSSRendering_h___ */