gecko-dev/layout/generic/nsTextRunTransformations.h

176 lines
7.3 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 NSTEXTRUNTRANSFORMATIONS_H_
#define NSTEXTRUNTRANSFORMATIONS_H_
#include "mozilla/Attributes.h"
#include "mozilla/MemoryReporting.h"
#include "gfxFont.h"
class nsTransformedTextRun;
class nsStyleContext;
class nsTransformingTextRunFactory {
public:
virtual ~nsTransformingTextRunFactory() {}
// Default 8-bit path just transforms to Unicode and takes that path
nsTransformedTextRun* MakeTextRun(const uint8_t* aString, uint32_t aLength,
const gfxFontGroup::Parameters* aParams,
gfxFontGroup* aFontGroup, uint32_t aFlags,
nsStyleContext** aStyles, bool aOwnsFactory = true);
nsTransformedTextRun* MakeTextRun(const PRUnichar* aString, uint32_t aLength,
const gfxFontGroup::Parameters* aParams,
gfxFontGroup* aFontGroup, uint32_t aFlags,
nsStyleContext** aStyles, bool aOwnsFactory = true);
virtual void RebuildTextRun(nsTransformedTextRun* aTextRun, gfxContext* aRefContext) = 0;
};
/**
* Builds textruns that render their text using a font-variant (i.e.,
* smallcaps).
*/
class nsFontVariantTextRunFactory : public nsTransformingTextRunFactory {
public:
virtual void RebuildTextRun(nsTransformedTextRun* aTextRun, gfxContext* aRefContext) MOZ_OVERRIDE;
};
/**
* Builds textruns that transform the text in some way (e.g., capitalize)
* and then render the text using some other textrun implementation.
*/
class nsCaseTransformTextRunFactory : public nsTransformingTextRunFactory {
public:
// We could add an optimization here so that when there is no inner
// factory, no title-case conversion, and no upper-casing of SZLIG, we override
// MakeTextRun (after making it virtual in the superclass) and have it
// just convert the string to uppercase or lowercase and create the textrun
// via the fontgroup.
// Takes ownership of aInnerTransformTextRunFactory
nsCaseTransformTextRunFactory(nsTransformingTextRunFactory* aInnerTransformingTextRunFactory,
bool aAllUppercase = false)
: mInnerTransformingTextRunFactory(aInnerTransformingTextRunFactory),
mAllUppercase(aAllUppercase) {}
virtual void RebuildTextRun(nsTransformedTextRun* aTextRun, gfxContext* aRefContext) MOZ_OVERRIDE;
protected:
nsAutoPtr<nsTransformingTextRunFactory> mInnerTransformingTextRunFactory;
bool mAllUppercase;
};
/**
* So that we can reshape as necessary, we store enough information
* to fully rebuild the textrun contents.
*/
class nsTransformedTextRun : public gfxTextRun {
public:
static nsTransformedTextRun *Create(const gfxTextRunFactory::Parameters* aParams,
nsTransformingTextRunFactory* aFactory,
gfxFontGroup* aFontGroup,
const PRUnichar* aString, uint32_t aLength,
const uint32_t aFlags, nsStyleContext** aStyles,
bool aOwnsFactory);
~nsTransformedTextRun() {
if (mOwnsFactory) {
delete mFactory;
}
}
void SetCapitalization(uint32_t aStart, uint32_t aLength,
bool* aCapitalization,
gfxContext* aRefContext);
virtual bool SetPotentialLineBreaks(uint32_t aStart, uint32_t aLength,
uint8_t* aBreakBefore,
gfxContext* aRefContext);
/**
* Called after SetCapitalization and SetPotentialLineBreaks
* are done and before we request any data from the textrun. Also always
* called after a Create.
*/
void FinishSettingProperties(gfxContext* aRefContext)
{
if (mNeedsRebuild) {
mNeedsRebuild = false;
mFactory->RebuildTextRun(this, aRefContext);
}
}
// override the gfxTextRun impls to account for additional members here
virtual size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) MOZ_MUST_OVERRIDE;
virtual size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) MOZ_MUST_OVERRIDE;
nsTransformingTextRunFactory *mFactory;
nsTArray<nsRefPtr<nsStyleContext> > mStyles;
nsTArray<bool> mCapitalize;
nsString mString;
bool mOwnsFactory;
bool mNeedsRebuild;
private:
nsTransformedTextRun(const gfxTextRunFactory::Parameters* aParams,
nsTransformingTextRunFactory* aFactory,
gfxFontGroup* aFontGroup,
const PRUnichar* aString, uint32_t aLength,
const uint32_t aFlags, nsStyleContext** aStyles,
bool aOwnsFactory)
: gfxTextRun(aParams, aLength, aFontGroup, aFlags),
mFactory(aFactory), mString(aString, aLength),
mOwnsFactory(aOwnsFactory), mNeedsRebuild(true)
{
mCharacterGlyphs = reinterpret_cast<CompressedGlyph*>(this + 1);
uint32_t i;
for (i = 0; i < aLength; ++i) {
mStyles.AppendElement(aStyles[i]);
}
}
};
/**
* Copy a given textrun, but merge certain characters into a single logical
* character. Glyphs for a character are added to the glyph list for the previous
* character and then the merged character is eliminated. Visually the results
* are identical.
*
* This is used for text-transform:uppercase when we encounter a SZLIG,
* whose uppercase form is "SS", or other ligature or precomposed form
* that expands to multiple codepoints during case transformation,
* and for Greek text when combining diacritics have been deleted.
*
* This function is unable to merge characters when they occur in different
* glyph runs. This only happens in tricky edge cases where a character was
* decomposed by case-mapping (e.g. there's no precomposed uppercase version
* of an accented lowercase letter), and then font-matching caused the
* diacritics to be assigned to a different font than the base character.
* In this situation, the diacritic(s) get discarded, which is less than
* ideal, but they probably weren't going to render very well anyway.
* Bug 543200 will improve this by making font-matching operate on entire
* clusters instead of individual codepoints.
*
* For simplicity, this produces a textrun containing all DetailedGlyphs,
* no simple glyphs. So don't call it unless you really have merging to do.
*
* @param aCharsToMerge when aCharsToMerge[i] is true, this character in aSrc
* is merged into the previous character
*
* @param aDeletedChars when aDeletedChars[i] is true, the character at this
* position in aDest was deleted (has no corresponding char in aSrc)
*/
void
MergeCharactersInTextRun(gfxTextRun* aDest, gfxTextRun* aSrc,
const bool* aCharsToMerge, const bool* aDeletedChars);
gfxTextRunFactory::Parameters
GetParametersForInner(nsTransformedTextRun* aTextRun, uint32_t* aFlags,
gfxContext* aRefContext);
#endif /*NSTEXTRUNTRANSFORMATIONS_H_*/