layout/style/nsComputedDOMStyle.h
author Emilio Cobos Álvarez <emilio@crisal.io>
Thu, 27 Jun 2019 20:24:02 +0200
changeset 543425 2086a08e77feeeaddcff0399deef434ac2e8c17e
parent 543354 e0af0c6328746dd6eefa01c51c502ef583c99953
child 546634 0edb7e82846534f22e0116825e28f8d96e62c20f
permissions -rw-r--r--
Bug 1562269 - Serialize grid-auto-rows / grid-auto-columns with Servo. r=boris Two less properties, now that we're not using nsStyleCoord for them we can do this. Unfortunately the grid resolved value code needs to serialize it still, so this doesn't remove as much code. Also fix the script since the generated file was renamed. Differential Revision: https://phabricator.services.mozilla.com/D36349

/* -*- 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;
struct nsStyleImage;

class nsComputedDOMStyle final : public nsDOMCSSDeclaration,
                                 public nsStubMutationObserver {
 private:
  // Convenience typedefs:
  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;
  nsresult SetPropertyValue(const nsCSSPropertyID aPropID,
                            const nsAString& aValue,
                            nsIPrincipal* aSubjectPrincipal) override;

  void IndexedGetter(uint32_t aIndex, bool& aFound, nsAString& 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 nsAString& aPropertyName,
                       nsTArray<nsString>& 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(bool aNeedsLayoutFlush);
  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> GetBorderStyleFor(mozilla::Side aSide);

  already_AddRefed<CSSValue> GetBorderWidthFor(mozilla::Side aSide);

  already_AddRefed<CSSValue> GetBorderColorFor(mozilla::Side aSide);

  already_AddRefed<CSSValue> GetMarginWidthFor(mozilla::Side aSide);

  already_AddRefed<CSSValue> GetTransformValue(const mozilla::StyleTransform&);

  // Appends all aLineNames (may be empty) space-separated to aResult.
  void AppendGridLineNames(nsString& aResult,
                           const nsTArray<RefPtr<nsAtom>>& aLineNames);
  // Appends aLineNames as a CSSValue* to aValueList.  If aLineNames is empty
  // a value ("[]") is only appended if aSuppressEmptyList is false.
  void AppendGridLineNames(nsDOMCSSValueList* aValueList,
                           const nsTArray<RefPtr<nsAtom>>& aLineNames,
                           bool aSuppressEmptyList = true);
  // Appends aLineNames1/2 (if non-empty) as a CSSValue* to aValueList.
  void AppendGridLineNames(nsDOMCSSValueList* aValueList,
                           const nsTArray<RefPtr<nsAtom>>& aLineNames1,
                           const nsTArray<RefPtr<nsAtom>>& aLineNames2);
  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 nsStyleGridTemplate& 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();
  already_AddRefed<CSSValue> DoGetTextDecorationColor();
  already_AddRefed<CSSValue> DoGetTextDecorationStyle();

  /* 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);

  /**
   * If aCoord is a eStyleUnit_Coord returns the nscoord.  If it's
   * eStyleUnit_Percent, attempts to resolve the percentage base and returns
   * the resulting nscoord.  If it's some other unit or a percentage base can't
   * be determined, returns aDefaultValue.
   */
  nscoord StyleCoordToNSCoord(const LengthPercentage& aCoord,
                              PercentageBaseGetter aPercentageBaseGetter,
                              nscoord aDefaultValue, bool aClampNegativeCalc);
  template <typename LengthPercentageLike>
  nscoord StyleCoordToNSCoord(const LengthPercentageLike& aCoord,
                              PercentageBaseGetter aPercentageBaseGetter,
                              nscoord aDefaultValue, bool aClampNegativeCalc) {
    if (aCoord.IsLengthPercentage()) {
      return StyleCoordToNSCoord(aCoord.AsLengthPercentage(),
                                 aPercentageBaseGetter, aDefaultValue,
                                 aClampNegativeCalc);
    }
    return aDefaultValue;
  }

  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 mElement).
  bool NeedsToFlush() 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;
#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__ */