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/* -*- 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 */
#ifndef nsMathMLChar_h___
#define nsMathMLChar_h___
#include "nsColor.h"
#include "nsMathMLOperators.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsString.h"
#include "nsBoundingMetrics.h"
#include "gfxTextRun.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 {
// Don't stretch
// Variable size stretches
NS_STRETCH_NORMAL = 0x01, // try to stretch to requested size
NS_STRETCH_NEARER = 0x02, // stretch very close to requested size
NS_STRETCH_SMALLER = 0x04, // don't stretch more than requested size
NS_STRETCH_LARGER = 0x08, // don't stretch less than requested size
// A largeop in displaystyle
// Intended for internal use:
// Find the widest metrics that might be returned from a vertical stretch
// A single glyph in our internal representation is either
// 1) a 'code@font' pair from the table. The
// 'code' is interpreted as a Unicode point. The 'font' is a numeric
// identifier given to the font to which the glyph belongs, which is 0 for the
// FONTFAMILY and > 0 for 'external' fonts.
// 2) a glyph index from the Open Type MATH table. In that case, all the glyphs
// come from the font containing that table and 'font' is just set to -1.
struct nsGlyphCode {
union {
char16_t code[2];
uint32_t glyphID;
int8_t font;
bool IsGlyphID() const { return font == -1; }
int32_t Length() const {
return (IsGlyphID() || code[1] == char16_t('\0') ? 1 : 2);
bool Exists() const { return IsGlyphID() ? glyphID != 0 : code[0] != 0; }
bool operator==(const nsGlyphCode& other) const {
return (other.font == font && ((IsGlyphID() && other.glyphID == glyphID) ||
(!IsGlyphID() && other.code[0] == code[0] &&
other.code[1] == code[1])));
bool operator!=(const nsGlyphCode& other) const { return !operator==(other); }
// Class used to handle stretchy symbols (accent, delimiter and boundary
// symbols).
class nsMathMLChar {
typedef gfxTextRun::Range Range;
typedef mozilla::gfx::DrawTarget DrawTarget;
// constructor and destructor
mComputedStyle = nullptr;
mUnscaledAscent = 0;
mScaleX = mScaleY = 1.0;
mMirrored = false;
// not a virtual destructor: this class is not intended to be subclassed
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,
nsStretchDirection aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
uint32_t aStretchHint, bool aRTL);
void SetData(nsString& aData);
void GetData(nsString& aData) { aData = mData; }
int32_t Length() { return mData.Length(); }
nsStretchDirection 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,
uint32_t aStretchHint = NS_STRETCH_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;
// Hooks to access the extra leaf ComputedStyles given to the MathMLChars.
// They provide an interface to make them accessible to the Style System via
// the Get/Set AdditionalComputedStyle() APIs. Owners of MathMLChars
// should honor these APIs.
mozilla::ComputedStyle* GetComputedStyle() const;
void SetComputedStyle(mozilla::ComputedStyle* aComputedStyle);
friend class nsGlyphTable;
friend class nsPropertiesTable;
friend class nsOpenTypeTable;
nsString mData;
nsRect mRect;
nsStretchDirection 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;
// mDraw indicates how we draw the stretchy operator:
// - DRAW_NORMAL: we render the mData string normally.
// - DRAW_VARIANT: we draw a larger size variant given by mGlyphs[0].
// - DRAW_PARTS: we assemble several parts given by mGlyphs[0], ... mGlyphs[4]
// XXXfredw: the MATH table can have any numbers of parts and extenders.
DrawingMethod mDraw;
// mMirrored indicates whether the character is mirrored.
bool mMirrored;
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,
nsStretchDirection& aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
uint32_t aStretchHint,
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___ */