gecko-dev/layout/style/nsComputedDOMStyle.h
Emilio Cobos Álvarez 011d524740 Bug 1646336 - Don't unnecessarily lose precision in nsComputedDOMStyle. r=hiro
We're converting to nscoord in some places unnecessarily, reducing the
precision of the computed value we return.

This makes some tests unnecessarily fail if we change the base of
nscoord.

Differential Revision: https://phabricator.services.mozilla.com/D79996
2020-06-18 00:42:47 +00:00

391 lines
14 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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/. */
/* DOM object returned from element.getComputedStyle() */
#ifndef nsComputedDOMStyle_h__
#define nsComputedDOMStyle_h__
#include "mozilla/Attributes.h"
#include "mozilla/StyleColorInlines.h"
#include "mozilla/UniquePtr.h"
#include "mozilla/dom/Element.h"
#include "nsCOMPtr.h"
#include "nsContentUtils.h"
#include "nscore.h"
#include "nsDOMCSSDeclaration.h"
#include "mozilla/ComputedStyle.h"
#include "nsIWeakReferenceUtils.h"
#include "mozilla/gfx/Types.h"
#include "nsCoord.h"
#include "nsColor.h"
#include "nsStyleStruct.h"
#include "mozilla/WritingModes.h"
namespace mozilla {
namespace dom {
class DocGroup;
class Element;
} // namespace dom
class PresShell;
struct ComputedGridTrackInfo;
} // namespace mozilla
struct ComputedStyleMap;
struct nsCSSKTableEntry;
class nsIFrame;
class nsDOMCSSValueList;
struct nsMargin;
class nsROCSSPrimitiveValue;
class nsStyleGradient;
class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
public nsStubMutationObserver {
private:
// Convenience typedefs:
template <typename T>
using Span = mozilla::Span<T>;
using KTableEntry = nsCSSKTableEntry;
using CSSValue = mozilla::dom::CSSValue;
using StyleGeometryBox = mozilla::StyleGeometryBox;
using Element = mozilla::dom::Element;
using Document = mozilla::dom::Document;
using StyleFlexBasis = mozilla::StyleFlexBasis;
using StyleSize = mozilla::StyleSize;
using StyleMaxSize = mozilla::StyleMaxSize;
using LengthPercentage = mozilla::LengthPercentage;
using LengthPercentageOrAuto = mozilla::LengthPercentageOrAuto;
using StyleExtremumLength = mozilla::StyleExtremumLength;
using ComputedStyle = mozilla::ComputedStyle;
public:
NS_DECL_CYCLE_COLLECTING_ISUPPORTS
NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS_AMBIGUOUS(
nsComputedDOMStyle, nsICSSDeclaration)
NS_DECL_NSIDOMCSSSTYLEDECLARATION_HELPER
nsresult GetPropertyValue(const nsCSSPropertyID aPropID,
nsAString& aValue) override;
void SetPropertyValue(const nsCSSPropertyID aPropID, const nsACString& aValue,
nsIPrincipal* aSubjectPrincipal,
mozilla::ErrorResult& aRv) override;
void IndexedGetter(uint32_t aIndex, bool& aFound,
nsACString& aPropName) final;
enum StyleType {
eDefaultOnly, // Only includes UA and user sheets
eAll // Includes all stylesheets
};
nsComputedDOMStyle(Element* aElement, const nsAString& aPseudoElt,
Document* aDocument, StyleType aStyleType);
nsINode* GetParentObject() override { return mElement; }
static already_AddRefed<ComputedStyle> GetComputedStyle(
Element* aElement, nsAtom* aPseudo, StyleType aStyleType = eAll);
static already_AddRefed<ComputedStyle> GetComputedStyleNoFlush(
Element* aElement, nsAtom* aPseudo, StyleType aStyleType = eAll) {
return DoGetComputedStyleNoFlush(
aElement, aPseudo, nsContentUtils::GetPresShellForContent(aElement),
aStyleType);
}
static already_AddRefed<ComputedStyle> GetUnanimatedComputedStyleNoFlush(
Element* aElement, nsAtom* aPseudo);
// Helper for nsDOMWindowUtils::GetVisitedDependentComputedStyle
void SetExposeVisitedStyle(bool aExpose) {
NS_ASSERTION(aExpose != mExposeVisitedStyle, "should always be changing");
mExposeVisitedStyle = aExpose;
}
void GetCSSImageURLs(const nsACString& aPropertyName,
nsTArray<nsCString>& aImageURLs,
mozilla::ErrorResult& aRv) final;
// nsDOMCSSDeclaration abstract methods which should never be called
// on a nsComputedDOMStyle object, but must be defined to avoid
// compile errors.
mozilla::DeclarationBlock* GetOrCreateCSSDeclaration(
Operation aOperation, mozilla::DeclarationBlock** aCreated) final;
virtual nsresult SetCSSDeclaration(mozilla::DeclarationBlock*,
mozilla::MutationClosureData*) override;
virtual mozilla::dom::Document* DocToUpdate() override;
nsDOMCSSDeclaration::ParsingEnvironment GetParsingEnvironment(
nsIPrincipal* aSubjectPrincipal) const final;
static already_AddRefed<nsROCSSPrimitiveValue> MatrixToCSSValue(
const mozilla::gfx::Matrix4x4& aMatrix);
static void SetToRGBAColor(nsROCSSPrimitiveValue* aValue, nscolor aColor);
static void RegisterPrefChangeCallbacks();
static void UnregisterPrefChangeCallbacks();
// nsIMutationObserver
NS_DECL_NSIMUTATIONOBSERVER_PARENTCHAINCHANGED
private:
virtual ~nsComputedDOMStyle();
void AssertFlushedPendingReflows() {
NS_ASSERTION(mFlushedPendingReflows,
"property getter should have been marked layout-dependent");
}
nsMargin GetAdjustedValuesForBoxSizing();
// This indicates error by leaving mComputedStyle null.
void UpdateCurrentStyleSources(nsCSSPropertyID);
void ClearCurrentStyleSources();
// Helper functions called by UpdateCurrentStyleSources.
void ClearComputedStyle();
void SetResolvedComputedStyle(RefPtr<ComputedStyle>&& aContext,
uint64_t aGeneration);
void SetFrameComputedStyle(ComputedStyle* aStyle, uint64_t aGeneration);
static already_AddRefed<ComputedStyle> DoGetComputedStyleNoFlush(
Element* aElement, nsAtom* aPseudo, mozilla::PresShell* aPresShell,
StyleType aStyleType);
#define STYLE_STRUCT(name_) \
const nsStyle##name_* Style##name_() { \
return mComputedStyle->Style##name_(); \
}
#include "nsStyleStructList.h"
#undef STYLE_STRUCT
/**
* A method to get a percentage base for a percentage value. Returns true
* if a percentage base value was determined, false otherwise.
*/
typedef bool (nsComputedDOMStyle::*PercentageBaseGetter)(nscoord&);
already_AddRefed<CSSValue> GetOffsetWidthFor(mozilla::Side);
already_AddRefed<CSSValue> GetAbsoluteOffset(mozilla::Side);
nscoord GetUsedAbsoluteOffset(mozilla::Side);
already_AddRefed<CSSValue> GetNonStaticPositionOffset(
mozilla::Side aSide, bool aResolveAuto, PercentageBaseGetter aWidthGetter,
PercentageBaseGetter aHeightGetter);
already_AddRefed<CSSValue> GetStaticOffset(mozilla::Side aSide);
already_AddRefed<CSSValue> GetPaddingWidthFor(mozilla::Side aSide);
already_AddRefed<CSSValue> GetBorderWidthFor(mozilla::Side aSide);
already_AddRefed<CSSValue> GetMarginWidthFor(mozilla::Side aSide);
already_AddRefed<CSSValue> GetTransformValue(const mozilla::StyleTransform&);
already_AddRefed<nsROCSSPrimitiveValue> GetGridTrackSize(
const mozilla::StyleTrackSize&);
already_AddRefed<nsROCSSPrimitiveValue> GetGridTrackBreadth(
const mozilla::StyleTrackBreadth&);
void SetValueToTrackBreadth(nsROCSSPrimitiveValue*,
const mozilla::StyleTrackBreadth&);
already_AddRefed<CSSValue> GetGridTemplateColumnsRows(
const mozilla::StyleGridTemplateComponent& aTrackList,
const mozilla::ComputedGridTrackInfo& aTrackInfo);
bool GetLineHeightCoord(nscoord& aCoord);
bool ShouldHonorMinSizeAutoInAxis(mozilla::PhysicalAxis aAxis);
/* Properties queryable as CSSValues.
* To avoid a name conflict with nsIDOM*CSS2Properties, these are all
* DoGetXXX instead of GetXXX.
*/
/* Box properties */
already_AddRefed<CSSValue> DoGetWidth();
already_AddRefed<CSSValue> DoGetHeight();
already_AddRefed<CSSValue> DoGetMaxHeight();
already_AddRefed<CSSValue> DoGetMaxWidth();
already_AddRefed<CSSValue> DoGetMinHeight();
already_AddRefed<CSSValue> DoGetMinWidth();
already_AddRefed<CSSValue> DoGetLeft();
already_AddRefed<CSSValue> DoGetTop();
already_AddRefed<CSSValue> DoGetRight();
already_AddRefed<CSSValue> DoGetBottom();
/* Font properties */
already_AddRefed<CSSValue> DoGetOsxFontSmoothing();
/* Grid properties */
already_AddRefed<CSSValue> DoGetGridTemplateColumns();
already_AddRefed<CSSValue> DoGetGridTemplateRows();
/* StyleImageLayer properties */
already_AddRefed<CSSValue> DoGetImageLayerPosition(
const nsStyleImageLayers& aLayers);
/* Mask properties */
already_AddRefed<CSSValue> DoGetMask();
/* Padding properties */
already_AddRefed<CSSValue> DoGetPaddingTop();
already_AddRefed<CSSValue> DoGetPaddingBottom();
already_AddRefed<CSSValue> DoGetPaddingLeft();
already_AddRefed<CSSValue> DoGetPaddingRight();
/* Table Properties */
already_AddRefed<CSSValue> DoGetBorderSpacing();
/* Border Properties */
already_AddRefed<CSSValue> DoGetBorderTopWidth();
already_AddRefed<CSSValue> DoGetBorderBottomWidth();
already_AddRefed<CSSValue> DoGetBorderLeftWidth();
already_AddRefed<CSSValue> DoGetBorderRightWidth();
/* Margin Properties */
already_AddRefed<CSSValue> DoGetMarginTopWidth();
already_AddRefed<CSSValue> DoGetMarginBottomWidth();
already_AddRefed<CSSValue> DoGetMarginLeftWidth();
already_AddRefed<CSSValue> DoGetMarginRightWidth();
/* Text Properties */
already_AddRefed<CSSValue> DoGetLineHeight();
already_AddRefed<CSSValue> DoGetTextDecoration();
/* Display properties */
already_AddRefed<CSSValue> DoGetTransform();
already_AddRefed<CSSValue> DoGetTransformOrigin();
already_AddRefed<CSSValue> DoGetPerspectiveOrigin();
/* Column properties */
already_AddRefed<CSSValue> DoGetColumnRuleWidth();
// For working around a MSVC bug. See related comment in
// GenerateComputedDOMStyleGenerated.py.
already_AddRefed<CSSValue> DummyGetter();
/* Helper functions */
void SetValueFromComplexColor(nsROCSSPrimitiveValue* aValue,
const mozilla::StyleColor& aColor);
void SetValueToPosition(const mozilla::Position& aPosition,
nsDOMCSSValueList* aValueList);
void SetValueToURLValue(const mozilla::StyleComputedUrl* aURL,
nsROCSSPrimitiveValue* aValue);
void SetValueToSize(nsROCSSPrimitiveValue* aValue, const mozilla::StyleSize&);
void SetValueToLengthPercentageOrAuto(nsROCSSPrimitiveValue* aValue,
const LengthPercentageOrAuto&,
bool aClampNegativeCalc);
void SetValueToLengthPercentage(nsROCSSPrimitiveValue* aValue,
const LengthPercentage&,
bool aClampNegativeCalc);
void SetValueToMaxSize(nsROCSSPrimitiveValue* aValue, const StyleMaxSize&);
void SetValueToExtremumLength(nsROCSSPrimitiveValue* aValue,
StyleExtremumLength);
bool GetCBContentWidth(nscoord& aWidth);
bool GetCBContentHeight(nscoord& aHeight);
bool GetCBPaddingRectWidth(nscoord& aWidth);
bool GetCBPaddingRectHeight(nscoord& aHeight);
bool GetScrollFrameContentWidth(nscoord& aWidth);
bool GetScrollFrameContentHeight(nscoord& aHeight);
bool GetFrameBorderRectWidth(nscoord& aWidth);
bool GetFrameBorderRectHeight(nscoord& aHeight);
// Find out if we can safely skip flushing (i.e. pending restyles do not
// affect our element).
bool NeedsToFlushStyle(nsCSSPropertyID) const;
// Find out if we need to flush layout of the document, depending on the
// property that was requested.
bool NeedsToFlushLayout(nsCSSPropertyID) const;
// Flushes the given document, which must be our document, and potentially the
// mElement's document.
void Flush(Document&, mozilla::FlushType);
nsIFrame* GetOuterFrame() const;
static ComputedStyleMap* GetComputedStyleMap();
// We don't really have a good immutable representation of "presentation".
// Given the way GetComputedStyle is currently used, we should just grab the
// presshell, if any, from the document.
nsWeakPtr mDocumentWeak;
RefPtr<Element> mElement;
/**
* Strong reference to the ComputedStyle we access data from. This can be
* either a ComputedStyle we resolved ourselves or a ComputedStyle we got
* from our frame.
*
* If we got the ComputedStyle from the frame, we clear out mComputedStyle
* in ClearCurrentStyleSources. If we resolved one ourselves, then
* ClearCurrentStyleSources leaves it in mComputedStyle for use the next
* time this nsComputedDOMStyle object is queried. UpdateCurrentStyleSources
* in this case will check that the ComputedStyle is still valid to be used,
* by checking whether flush styles results in any restyles having been
* processed.
*/
RefPtr<ComputedStyle> mComputedStyle;
RefPtr<nsAtom> mPseudo;
/*
* While computing style data, the primary frame for mContent --- named
* "outer" because we should use it to compute positioning data. Null
* otherwise.
*/
nsIFrame* mOuterFrame;
/*
* While computing style data, the "inner frame" for mContent --- the frame
* which we should use to compute margin, border, padding and content data.
* Null otherwise.
*/
nsIFrame* mInnerFrame;
/*
* While computing style data, the presshell we're working with. Null
* otherwise.
*/
mozilla::PresShell* mPresShell;
/*
* The kind of styles we should be returning.
*/
StyleType mStyleType;
/**
* The nsComputedDOMStyle generation at the time we last resolved a style
* context and stored it in mComputedStyle, and the pres shell we got the
* style from. Should only be used together.
*/
uint64_t mComputedStyleGeneration = 0;
uint32_t mPresShellId = 0;
bool mExposeVisitedStyle;
/**
* Whether we resolved a ComputedStyle last time we called
* UpdateCurrentStyleSources. Initially false.
*/
bool mResolvedComputedStyle;
#ifdef DEBUG
bool mFlushedPendingReflows = false;
#endif
friend struct ComputedStyleMap;
};
already_AddRefed<nsComputedDOMStyle> NS_NewComputedDOMStyle(
mozilla::dom::Element* aElement, const nsAString& aPseudoElt,
mozilla::dom::Document* aDocument,
nsComputedDOMStyle::StyleType aStyleType = nsComputedDOMStyle::eAll);
#endif /* nsComputedDOMStyle_h__ */