firefox-main/layout/mathml/nsMathMLChar.h (file symbol)

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/* 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 nsMathMLChar_h_
#define nsMathMLChar_h_
#include "gfxTextRun.h"
#include "mozilla/EnumSet.h"
#include "nsBoundingMetrics.h"
#include "nsColor.h"
#include "nsMathMLOperators.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsString.h"
class gfxContext;
class nsGlyphTable;
class nsIFrame;
class nsPresContext;
struct nsBoundingMetrics;
struct nsFont;
namespace mozilla {
class nsDisplayListBuilder;
class nsDisplayListSet;
class ComputedStyle;
} // namespace mozilla
// Hints for Stretch() to indicate criteria for stretching
enum class MathMLStretchFlag : uint8_t {
Normal, // try to stretch to requested size.
Nearer, // Stretch very close to requested size.
Smaller, // Don't stretch more than requested size.
Larger, // Don't stretch less than requested size.
LargeOperator, // Draw as a large operator in displaystyle.
MaxWidth, // Find the widest metrics returned from a vertical stretch.
};
using MathMLStretchFlags = mozilla::EnumSet<MathMLStretchFlag>;
constexpr MathMLStretchFlags kMathMLStretchVariableSet(
MathMLStretchFlag::Normal, MathMLStretchFlag::Nearer,
MathMLStretchFlag::Smaller, MathMLStretchFlag::Larger);
constexpr MathMLStretchFlags kMathMLStretchSet =
kMathMLStretchVariableSet + MathMLStretchFlag::LargeOperator;
// A single glyph in our internal representation is either
// 1) a code pair from the mathfontFONTFAMILY.properties table, interpreted
// as a Unicode point.
// 2) a glyph index from the Open Type MATH table.
struct nsGlyphCode {
union {
char16_t code;
uint32_t glyphID;
};
bool isGlyphID = true;
bool Exists() const { return isGlyphID ? glyphID != 0 : code != 0; }
bool operator==(const nsGlyphCode& other) const {
return (other.isGlyphID == isGlyphID &&
(isGlyphID ? other.glyphID == glyphID : other.code == code));
}
bool operator!=(const nsGlyphCode&) const = default;
};
// Class used to handle stretchy symbols (accent, delimiter and boundary
// symbols).
class nsMathMLChar {
public:
typedef gfxTextRun::Range Range;
typedef mozilla::gfx::DrawTarget DrawTarget;
// constructor and destructor
nsMathMLChar() : mDirection(StretchDirection::Default) {
MOZ_COUNT_CTOR(nsMathMLChar);
mComputedStyle = nullptr;
mUnscaledAscent = 0;
mScaleX = mScaleY = 1.0;
mDrawingMethod = DrawingMethod::Normal;
mMirroringMethod = MirroringMethod::None;
}
// not a virtual destructor: this class is not intended to be subclassed
~nsMathMLChar();
void Display(mozilla::nsDisplayListBuilder* aBuilder, nsIFrame* aForFrame,
const mozilla::nsDisplayListSet& aLists, uint32_t aIndex,
const nsRect* aSelectedRect = nullptr);
void PaintForeground(nsIFrame* aForFrame, gfxContext& aRenderingContext,
nsPoint aPt, bool aIsSelected);
// This is the method called to ask the char to stretch itself.
// @param aContainerSize - IN - suggested size for the stretched char
// @param aDesiredStretchSize - OUT - the size that the char wants
nsresult Stretch(nsIFrame* aForFrame, DrawTarget* aDrawTarget,
float aFontSizeInflation, StretchDirection aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
MathMLStretchFlags aStretchFlags, bool aRTL);
void SetData(nsString& aData);
void GetData(nsString& aData) { aData = mData; }
int32_t Length() { return mData.Length(); }
StretchDirection GetStretchDirection() { return mDirection; }
// Sometimes we only want to pass the data to another routine,
// this function helps to avoid copying
const char16_t* get() { return mData.get(); }
void GetRect(nsRect& aRect) { aRect = mRect; }
void SetRect(const nsRect& aRect) { mRect = aRect; }
// Get the maximum width that the character might have after a vertical
// Stretch().
//
// @param aStretchHint can be the value that will be passed to Stretch().
// It is used to determine whether the operator is stretchy or a largeop.
nscoord GetMaxWidth(
nsIFrame* aForFrame, DrawTarget* aDrawTarget, float aFontSizeInflation,
MathMLStretchFlags aStretchFlags = MathMLStretchFlag::Normal);
// Metrics that _exactly_ enclose the char. The char *must* have *already*
// being stretched before you can call the GetBoundingMetrics() method.
// IMPORTANT: since chars have their own ComputedStyles, and may be rendered
// with glyphs that are not in the parent font, just calling the default
// aRenderingContext.GetBoundingMetrics(aChar) can give incorrect results.
void GetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {
aBoundingMetrics = mBoundingMetrics;
}
void SetBoundingMetrics(nsBoundingMetrics& aBoundingMetrics) {
mBoundingMetrics = aBoundingMetrics;
}
void SetComputedStyle(mozilla::ComputedStyle* aComputedStyle);
nscoord ItalicCorrection() const { return mItalicCorrection; }
protected:
friend class nsGlyphTable;
friend class nsPropertiesTable;
friend class nsOpenTypeTable;
nsString mData;
private:
nsRect mRect;
StretchDirection mDirection;
nsBoundingMetrics mBoundingMetrics;
RefPtr<mozilla::ComputedStyle> mComputedStyle;
// mGlyphs/mBmData are arrays describing the glyphs used to draw the operator.
// See the drawing methods below.
RefPtr<gfxTextRun> mGlyphs[4];
nsBoundingMetrics mBmData[4];
// mUnscaledAscent is the actual ascent of the char.
nscoord mUnscaledAscent;
// mScaleX, mScaleY are the factors by which we scale the char.
float mScaleX, mScaleY;
// mDrawingMethod indicates how we draw the stretchy operator:
// - Normal: we render the mData string normally.
// - Variant: we draw a larger size variant given by mGlyphs[0].
// - Parts: we assemble several parts given by mGlyphs[0], ... mGlyphs[4]
// XXXfredw: the MATH table can have any numbers of parts and extenders.
enum class DrawingMethod : uint8_t { Normal, Variant, Parts };
DrawingMethod mDrawingMethod;
// mMirroringMethod indicates whether the character is mirrored.
// - None: shouldn't be mirrored.
// - Character: using unicode character mirroring.
// - Glyph: using rtlm glyph mirroring.
// - ScaleFallback: the font doesn't support this character, fall back
// to applying a scale of -1 on the X axis and a scale
// of 1 on the Y axis.
enum class MirroringMethod : uint8_t {
None,
Character,
Glyph,
ScaleFallback,
};
MirroringMethod mMirroringMethod;
nscoord mItalicCorrection = 0;
class StretchEnumContext;
friend class StretchEnumContext;
// helper methods
bool SetFontFamily(nsPresContext* aPresContext,
const nsGlyphTable* aGlyphTable,
const nsGlyphCode& aGlyphCode,
const mozilla::StyleFontFamilyList& aDefaultFamily,
nsFont& aFont, RefPtr<gfxFontGroup>* aFontGroup);
nsresult StretchInternal(nsIFrame* aForFrame, DrawTarget* aDrawTarget,
float aFontSizeInflation,
StretchDirection& aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
MathMLStretchFlags aStretchFlags,
float aMaxSize = kMathMLOperatorSizeInfinity,
bool aMaxSizeIsAbsolute = false);
nsresult PaintVertically(nsPresContext* aPresContext,
gfxContext* aThebesContext, nsRect& aRect,
nscolor aColor);
nsresult PaintHorizontally(nsPresContext* aPresContext,
gfxContext* aThebesContext, nsRect& aRect,
nscolor aColor);
void ApplyTransforms(gfxContext* aThebesContext, int32_t aAppUnitsPerGfxUnit,
nsRect& r);
};
#endif /* nsMathMLChar_h_ */