gecko-dev/layout/mathml/nsMathMLChar.h

269 lines
8.7 KiB
C++

/* -*- 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/. */
#ifndef nsMathMLChar_h___
#define nsMathMLChar_h___
#include "nsAutoPtr.h"
#include "nsMathMLOperators.h"
#include "nsPoint.h"
#include "nsRect.h"
#include "nsString.h"
#include "nsBoundingMetrics.h"
#include "gfxFont.h"
class nsGlyphTable;
class nsIFrame;
class nsDisplayListBuilder;
class nsDisplayListSet;
class nsPresContext;
class nsRenderingContext;
class nsBoundingMetrics;
class nsStyleContext;
class nsFont;
// Hints for Stretch() to indicate criteria for stretching
enum {
// Don't stretch
NS_STRETCH_NONE = 0x00,
// Variable size stretches
NS_STRETCH_VARIABLE_MASK = 0x0F,
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
NS_STRETCH_LARGEOP = 0x10,
NS_STRETCH_INTEGRAL = 0x20,
// Intended for internal use:
// Find the widest metrics that might be returned from a vertical stretch
NS_STRETCH_MAXWIDTH = 0x40
};
// A single glyph in our internal representation is either
// 1) a 'code@font' pair from the mathfontFONTFAMILY.properties 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] == PRUnichar('\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
{
public:
// constructor and destructor
nsMathMLChar() {
MOZ_COUNT_CTOR(nsMathMLChar);
mStyleContext = nullptr;
mUnscaledAscent = 0;
mScaleX = mScaleY = 1.0;
mDraw = DRAW_NORMAL;
mMirrored = false;
}
// not a virtual destructor: this class is not intended to be subclassed
~nsMathMLChar();
void Display(nsDisplayListBuilder* aBuilder,
nsIFrame* aForFrame,
const nsDisplayListSet& aLists,
uint32_t aIndex,
const nsRect* aSelectedRect = nullptr);
void PaintForeground(nsPresContext* aPresContext,
nsRenderingContext& 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(nsPresContext* aPresContext,
nsRenderingContext& aRenderingContext,
nsStretchDirection aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
uint32_t aStretchHint,
bool aRTL);
void
SetData(nsPresContext* aPresContext,
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.
// @param aMaxSize is the value of the "maxsize" attribute.
// @param aMaxSizeIsAbsolute indicates whether the aMaxSize is an absolute
// value in app units (true) or a multiplier of the base size (false).
nscoord
GetMaxWidth(nsPresContext* aPresContext,
nsRenderingContext& aRenderingContext,
uint32_t aStretchHint = NS_STRETCH_NORMAL,
float aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY,
// Perhaps just nsOperatorFlags aFlags.
// But need DisplayStyle for largeOp,
// or remove the largeop bit from flags.
bool aMaxSizeIsAbsolute = false);
// 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 style contexts, 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 style contexts given to the MathMLChars.
// They provide an interface to make them accessible to the Style System via
// the Get/Set AdditionalStyleContext() APIs. Owners of MathMLChars
// should honor these APIs.
nsStyleContext* GetStyleContext() const;
void SetStyleContext(nsStyleContext* aStyleContext);
protected:
friend class nsGlyphTable;
nsString mData;
private:
nsRect mRect;
nsStretchDirection mDirection;
nsBoundingMetrics mBoundingMetrics;
nsStyleContext* mStyleContext;
// mGlyphs/mBmData are arrays describing the glyphs used to draw the operator.
// See the drawing methods below.
nsAutoPtr<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.
enum DrawingMethod {
DRAW_NORMAL, DRAW_VARIANT, DRAW_PARTS
};
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 nsAString& aDefaultFamily,
nsFont& aFont,
nsRefPtr<gfxFontGroup>* aFontGroup);
nsresult
StretchInternal(nsPresContext* aPresContext,
gfxContext* aThebesContext,
nsStretchDirection& aStretchDirection,
const nsBoundingMetrics& aContainerSize,
nsBoundingMetrics& aDesiredStretchSize,
uint32_t aStretchHint,
float aMaxSize = NS_MATHML_OPERATOR_SIZE_INFINITY,
bool aMaxSizeIsAbsolute = false);
nsresult
PaintVertically(nsPresContext* aPresContext,
gfxContext* aThebesContext,
nsRect& aRect);
nsresult
PaintHorizontally(nsPresContext* aPresContext,
gfxContext* aThebesContext,
nsRect& aRect);
void
ApplyTransforms(gfxContext* aThebesContext, int32_t aAppUnitsPerGfxUnit,
nsRect &r);
};
#endif /* nsMathMLChar_h___ */