1 files changed, 248 insertions, 0 deletions
diff --git a/layout/generic/nsTextRunTransformations.h b/layout/generic/nsTextRunTransformations.h
new file mode 100644
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+++ b/layout/generic/nsTextRunTransformations.h
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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 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_*/