diff options
Diffstat (limited to 'layout/generic/nsTextRunTransformations.h')
| -rw-r--r-- | layout/generic/nsTextRunTransformations.h | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/layout/generic/nsTextRunTransformations.h b/layout/generic/nsTextRunTransformations.h new file mode 100644 index 0000000000..77e661df56 --- /dev/null +++ b/layout/generic/nsTextRunTransformations.h @@ -0,0 +1,248 @@ +/* -*- 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/. */ + +#ifndef NSTEXTRUNTRANSFORMATIONS_H_ +#define NSTEXTRUNTRANSFORMATIONS_H_ + +#include "mozilla/Attributes.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/UniquePtr.h" +#include "gfxTextRun.h" +#include "mozilla/ComputedStyle.h" +#include "nsPresContext.h" +#include "nsStyleStruct.h" + +class nsTransformedTextRun; + +struct nsTransformedCharStyle final { + NS_INLINE_DECL_REFCOUNTING(nsTransformedCharStyle) + + explicit nsTransformedCharStyle(mozilla::ComputedStyle* aStyle, + nsPresContext* aPresContext) + : mFont(aStyle->StyleFont()->mFont), + mLanguage(aStyle->StyleFont()->mLanguage), + mPresContext(aPresContext), + mScriptSizeMultiplier(aStyle->StyleFont()->mScriptSizeMultiplier), + mTextTransform(aStyle->StyleText()->mTextTransform), + mMathVariant(aStyle->StyleFont()->mMathVariant), + mExplicitLanguage(aStyle->StyleFont()->mExplicitLanguage) {} + + nsFont mFont; + RefPtr<nsAtom> mLanguage; + RefPtr<nsPresContext> mPresContext; + float mScriptSizeMultiplier; + mozilla::StyleTextTransform mTextTransform; + mozilla::StyleMathVariant mMathVariant; + bool mExplicitLanguage; + bool mForceNonFullWidth = false; + bool mMaskPassword = false; + + private: + ~nsTransformedCharStyle() = default; + nsTransformedCharStyle(const nsTransformedCharStyle& aOther) = delete; + nsTransformedCharStyle& operator=(const nsTransformedCharStyle& aOther) = + delete; +}; + +class nsTransformingTextRunFactory { + public: + virtual ~nsTransformingTextRunFactory() = default; + + // Default 8-bit path just transforms to Unicode and takes that path + already_AddRefed<nsTransformedTextRun> MakeTextRun( + const uint8_t* aString, uint32_t aLength, + const gfxFontGroup::Parameters* aParams, gfxFontGroup* aFontGroup, + mozilla::gfx::ShapedTextFlags aFlags, nsTextFrameUtils::Flags aFlags2, + nsTArray<RefPtr<nsTransformedCharStyle>>&& aStyles, bool aOwnsFactory); + + already_AddRefed<nsTransformedTextRun> MakeTextRun( + const char16_t* aString, uint32_t aLength, + const gfxFontGroup::Parameters* aParams, gfxFontGroup* aFontGroup, + mozilla::gfx::ShapedTextFlags aFlags, nsTextFrameUtils::Flags aFlags2, + nsTArray<RefPtr<nsTransformedCharStyle>>&& aStyles, bool aOwnsFactory); + + virtual void RebuildTextRun(nsTransformedTextRun* aTextRun, + mozilla::gfx::DrawTarget* aRefDrawTarget, + gfxMissingFontRecorder* aMFR) = 0; +}; + +/** + * Builds textruns that transform the text in some way (e.g., capitalize) + * and then render the text using some other textrun implementation. + * This factory also supports "text-security" transforms that convert all + * characters to a single symbol. + */ +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(mozilla::UniquePtr<nsTransformingTextRunFactory> + aInnerTransformingTextRunFactory, + bool aAllUppercase, char16_t aMaskChar) + : mInnerTransformingTextRunFactory( + std::move(aInnerTransformingTextRunFactory)), + mAllUppercase(aAllUppercase), + mMaskChar(aMaskChar) {} + + virtual void RebuildTextRun(nsTransformedTextRun* aTextRun, + mozilla::gfx::DrawTarget* aRefDrawTarget, + gfxMissingFontRecorder* aMFR) override; + + // Perform a transformation on the given string, writing the result into + // aConvertedString. If aGlobalTransform is passed, the transform is global + // and aLanguage is used to determine any language-specific behavior; + // otherwise, an nsTransformedTextRun should be passed in as aTextRun and its + // styles will be used to determine the transform(s) to be applied. + // If such an input textrun is provided, then its line-breaks and styles + // will be copied to the output arrays, which must also be provided by + // the caller. For the global transform usage (no input textrun), these are + // ignored. + // If aMaskChar is non-zero, it is used as a "masking" character to replace + // all characters in the text (for -webkit-text-security). + // If aCaseTransformsOnly is true, then only the upper/lower/capitalize + // transformations are performed; full-width and full-size-kana are ignored. + // If `aTextRun` is not nullptr and characters which are styled with setting + // `nsTransformedCharStyle::mMaskPassword` to true, they are replaced with + // password mask characters and are not transformed (i.e., won't be added + // or merged for the specified transform). However, unmasked characters + // whose `nsTransformedCharStyle::mMaskPassword` is set to false are + // transformed normally. + // Note that "masking" behavior may be triggered either by + // -webkit-text-security, resulting in a non-zero aMaskChar being passed, + // or by <input type=password>, which results in the editor code setting + // nsTransformedCharStyle::mMaskPassword. (The latter mechanism enables the + // editor to temporarily reveal the just-entered character during typing, + // whereas simply setting aMaskChar would unconditionally mask all the text.) + static bool TransformString( + const nsAString& aString, nsString& aConvertedString, + const mozilla::Maybe<mozilla::StyleTextTransform>& aGlobalTransform, + char16_t aMaskChar, bool aCaseTransformsOnly, const nsAtom* aLanguage, + nsTArray<bool>& aCharsToMergeArray, nsTArray<bool>& aDeletedCharsArray, + const nsTransformedTextRun* aTextRun = nullptr, + uint32_t aOffsetInTextRun = 0, + nsTArray<uint8_t>* aCanBreakBeforeArray = nullptr, + nsTArray<RefPtr<nsTransformedCharStyle>>* aStyleArray = nullptr); + + protected: + mozilla::UniquePtr<nsTransformingTextRunFactory> + mInnerTransformingTextRunFactory; + bool mAllUppercase; + char16_t mMaskChar; +}; + +/** + * So that we can reshape as necessary, we store enough information + * to fully rebuild the textrun contents. + */ +class nsTransformedTextRun final : public gfxTextRun { + public: + static already_AddRefed<nsTransformedTextRun> Create( + const gfxTextRunFactory::Parameters* aParams, + nsTransformingTextRunFactory* aFactory, gfxFontGroup* aFontGroup, + const char16_t* aString, uint32_t aLength, + const mozilla::gfx::ShapedTextFlags aFlags, + const nsTextFrameUtils::Flags aFlags2, + nsTArray<RefPtr<nsTransformedCharStyle>>&& aStyles, bool aOwnsFactory); + + ~nsTransformedTextRun() { + if (mOwnsFactory) { + delete mFactory; + } + } + + void SetCapitalization(uint32_t aStart, uint32_t aLength, + bool* aCapitalization); + virtual bool SetPotentialLineBreaks(Range aRange, + const uint8_t* aBreakBefore) override; + /** + * Called after SetCapitalization and SetPotentialLineBreaks + * are done and before we request any data from the textrun. Also always + * called after a Create. + */ + void FinishSettingProperties(mozilla::gfx::DrawTarget* aRefDrawTarget, + gfxMissingFontRecorder* aMFR) { + if (mNeedsRebuild) { + mNeedsRebuild = false; + mFactory->RebuildTextRun(this, aRefDrawTarget, aMFR); + } + } + + // override the gfxTextRun impls to account for additional members here + virtual size_t SizeOfExcludingThis( + mozilla::MallocSizeOf aMallocSizeOf) override; + virtual size_t SizeOfIncludingThis( + mozilla::MallocSizeOf aMallocSizeOf) override; + + nsTransformingTextRunFactory* mFactory; + nsTArray<RefPtr<nsTransformedCharStyle>> mStyles; + nsTArray<bool> mCapitalize; + nsString mString; + bool mOwnsFactory; + bool mNeedsRebuild; + + private: + nsTransformedTextRun(const gfxTextRunFactory::Parameters* aParams, + nsTransformingTextRunFactory* aFactory, + gfxFontGroup* aFontGroup, const char16_t* aString, + uint32_t aLength, + const mozilla::gfx::ShapedTextFlags aFlags, + const nsTextFrameUtils::Flags aFlags2, + nsTArray<RefPtr<nsTransformedCharStyle>>&& aStyles, + bool aOwnsFactory) + : gfxTextRun(aParams, aLength, aFontGroup, aFlags, aFlags2), + mFactory(aFactory), + mStyles(std::move(aStyles)), + mString(aString, aLength), + mOwnsFactory(aOwnsFactory), + mNeedsRebuild(true) { + mCharacterGlyphs = reinterpret_cast<CompressedGlyph*>(this + 1); + } +}; + +/** + * 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, mozilla::gfx::ShapedTextFlags* aFlags, + mozilla::gfx::DrawTarget* aRefDrawTarget); + +#endif /*NSTEXTRUNTRANSFORMATIONS_H_*/ |