gecko-dev/gfx/thebes/gfxFcPlatformFontList.h

/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
 * 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 GFXFCPLATFORMFONTLIST_H_
#define GFXFCPLATFORMFONTLIST_H_

#include "gfxFont.h"
#include "gfxFontEntry.h"
#include "gfxFT2FontBase.h"
#include "gfxPlatformFontList.h"
#include "mozilla/FontPropertyTypes.h"
#include "mozilla/mozalloc.h"
#include "nsAutoRef.h"
#include "nsClassHashtable.h"

#include <fontconfig/fontconfig.h>
#include "ft2build.h"
#include FT_FREETYPE_H
#include FT_TRUETYPE_TABLES_H
#include FT_MULTIPLE_MASTERS_H
#include <cairo.h>
#include <cairo-ft.h>

#if defined(MOZ_CONTENT_SANDBOX) && defined (XP_LINUX)
#include "mozilla/SandboxBroker.h"
#endif

namespace mozilla {
    namespace dom {
        class SystemFontListEntry;
    };
};

template <>
class nsAutoRefTraits<FcPattern> : public nsPointerRefTraits<FcPattern>
{
public:
    static void Release(FcPattern *ptr) { FcPatternDestroy(ptr); }
    static void AddRef(FcPattern *ptr) { FcPatternReference(ptr); }
};

template <>
class nsAutoRefTraits<FcConfig> : public nsPointerRefTraits<FcConfig>
{
public:
    static void Release(FcConfig *ptr) { FcConfigDestroy(ptr); }
    static void AddRef(FcConfig *ptr) { FcConfigReference(ptr); }
};

// Helper classes used for clearning out user font data when cairo font
// face is destroyed. Since multiple faces may use the same data, be
// careful to assure that the data is only cleared out when all uses
// expire. The font entry object contains a refptr to FTUserFontData and
// each cairo font created from that font entry contains a
// FTUserFontDataRef with a refptr to that same FTUserFontData object.

class FTUserFontData {
public:
    NS_INLINE_DECL_THREADSAFE_REFCOUNTING(FTUserFontData)

    explicit FTUserFontData(FT_Face aFace, const uint8_t* aData)
        : mFace(aFace), mFontData(aData)
    {
    }

    const uint8_t *FontData() const { return mFontData; }

private:
    ~FTUserFontData()
    {
        mozilla::gfx::Factory::ReleaseFTFace(mFace);
        if (mFontData) {
            free((void*)mFontData);
        }
    }

    FT_Face        mFace;
    const uint8_t *mFontData;
};

// The names for the font entry and font classes should really
// the common 'Fc' abbreviation but the gfxPangoFontGroup code already
// defines versions of these, so use the verbose name for now.

class gfxFontconfigFontEntry : public gfxFontEntry {
public:
    // used for system fonts with explicit patterns
    explicit gfxFontconfigFontEntry(const nsAString& aFaceName,
                                    FcPattern* aFontPattern,
                                    bool aIgnoreFcCharmap);

    // used for data fonts where the fontentry takes ownership
    // of the font data and the FT_Face
    explicit gfxFontconfigFontEntry(const nsAString& aFaceName,
                                    WeightRange aWeight,
                                    StretchRange aStretch,
                                    SlantStyleRange aStyle,
                                    const uint8_t *aData,
                                    uint32_t aLength,
                                    FT_Face aFace);

    // used for @font-face local system fonts with explicit patterns
    explicit gfxFontconfigFontEntry(const nsAString& aFaceName,
                                    FcPattern* aFontPattern,
                                    WeightRange aWeight,
                                    StretchRange aStretch,
                                    SlantStyleRange aStyle);

    gfxFontEntry* Clone() const override;

    FcPattern* GetPattern() { return mFontPattern; }

    nsresult ReadCMAP(FontInfoData *aFontInfoData = nullptr) override;
    bool TestCharacterMap(uint32_t aCh) override;

    FT_Face GetFTFace();

    FT_MM_Var* GetMMVar() override;

    bool HasVariations() override;
    void GetVariationAxes(nsTArray<gfxFontVariationAxis>& aAxes) override;
    void GetVariationInstances(nsTArray<gfxFontVariationInstance>& aInstances) override;

    hb_blob_t* GetFontTable(uint32_t aTableTag) override;

    void ForgetHBFace() override;
    void ReleaseGrFace(gr_face* aFace) override;

    double GetAspect();

protected:
    virtual ~gfxFontconfigFontEntry();

    gfxFont *CreateFontInstance(const gfxFontStyle *aFontStyle) override;

    // helper method for creating cairo font from pattern
    cairo_scaled_font_t*
    CreateScaledFont(FcPattern* aRenderPattern,
                     gfxFloat aAdjustedSize,
                     const gfxFontStyle *aStyle,
                     FT_Face aFTFace);

    // override to pull data from FTFace
    virtual nsresult
    CopyFontTable(uint32_t aTableTag,
                  nsTArray<uint8_t>& aBuffer) override;

    // if HB or GR faces are gone, close down the FT_Face
    void MaybeReleaseFTFace();

    // pattern for a single face of a family
    nsCountedRef<FcPattern> mFontPattern;

    // user font data, when needed
    RefPtr<FTUserFontData> mUserFontData;

    // FTFace - initialized when needed
    FT_Face   mFTFace;
    bool      mFTFaceInitialized;

    // Whether TestCharacterMap should check the actual cmap rather than asking
    // fontconfig about character coverage.
    // We do this for app-bundled (rather than system) fonts, as they may
    // include color glyphs that fontconfig would overlook, and for fonts
    // loaded via @font-face.
    bool      mIgnoreFcCharmap;

    // Whether the face supports variations. For system-installed fonts, we
    // query fontconfig for this (so they will only work if fontconfig is
    // recent enough to include support); for downloaded user-fonts we query
    // the FreeType face.
    bool      mHasVariations;
    bool      mHasVariationsInitialized;

    double    mAspect;

    // data font
    const uint8_t* mFontData;
    uint32_t       mLength;

    class UnscaledFontCache
    {
    public:
        already_AddRefed<mozilla::gfx::UnscaledFontFontconfig>
        Lookup(const char* aFile, uint32_t aIndex);

        void Add(const RefPtr<mozilla::gfx::UnscaledFontFontconfig>& aUnscaledFont) {
            mUnscaledFonts[kNumEntries-1] = aUnscaledFont;
            MoveToFront(kNumEntries-1);
        }

    private:
        void MoveToFront(size_t aIndex);

        static const size_t kNumEntries = 3;
        mozilla::ThreadSafeWeakPtr<mozilla::gfx::UnscaledFontFontconfig> mUnscaledFonts[kNumEntries];
    };

    UnscaledFontCache mUnscaledFontCache;

    // Because of FreeType bug 52955, we keep the FT_MM_Var struct when it is
    // first loaded, rather than releasing it and re-fetching it as needed.
    FT_MM_Var* mMMVar = nullptr;
    bool mMMVarInitialized = false;
};

class gfxFontconfigFontFamily : public gfxFontFamily {
public:
    explicit gfxFontconfigFontFamily(const nsAString& aName) :
        gfxFontFamily(aName),
        mContainsAppFonts(false),
        mHasNonScalableFaces(false),
        mForceScalable(false)
    { }

    template<typename Func>
    void AddFacesToFontList(Func aAddPatternFunc);

    void FindStyleVariations(FontInfoData *aFontInfoData = nullptr) override;

    // Families are constructed initially with just references to patterns.
    // When necessary, these are enumerated within FindStyleVariations.
    void AddFontPattern(FcPattern* aFontPattern);

    void SetFamilyContainsAppFonts(bool aContainsAppFonts)
    {
        mContainsAppFonts = aContainsAppFonts;
    }

    void
    FindAllFontsForStyle(const gfxFontStyle& aFontStyle,
                         nsTArray<gfxFontEntry*>& aFontEntryList,
                         bool aIgnoreSizeTolerance) override;

    bool FilterForFontList(nsAtom* aLangGroup,
                           const nsACString& aGeneric) const final {
        return SupportsLangGroup(aLangGroup);
    }

protected:
    virtual ~gfxFontconfigFontFamily();

    // helper for FilterForFontList
    bool SupportsLangGroup(nsAtom *aLangGroup) const;

    nsTArray<nsCountedRef<FcPattern> > mFontPatterns;

    bool      mContainsAppFonts;
    bool      mHasNonScalableFaces;
    bool      mForceScalable;
};

class gfxFontconfigFont : public gfxFT2FontBase {
public:
    gfxFontconfigFont(const RefPtr<mozilla::gfx::UnscaledFontFontconfig> &aUnscaledFont,
                      cairo_scaled_font_t *aScaledFont,
                      FcPattern *aPattern,
                      gfxFloat aAdjustedSize,
                      gfxFontEntry *aFontEntry,
                      const gfxFontStyle *aFontStyle);

    virtual FontType GetType() const override { return FONT_TYPE_FONTCONFIG; }
    virtual FcPattern *GetPattern() const { return mPattern; }

    virtual already_AddRefed<mozilla::gfx::ScaledFont>
    GetScaledFont(DrawTarget *aTarget) override;

private:
    virtual ~gfxFontconfigFont();

    nsCountedRef<FcPattern> mPattern;
};

class gfxFcPlatformFontList : public gfxPlatformFontList {
public:
    gfxFcPlatformFontList();

    static gfxFcPlatformFontList* PlatformFontList() {
        return static_cast<gfxFcPlatformFontList*>(sPlatformFontList);
    }

    // initialize font lists
    virtual nsresult InitFontListForPlatform() override;

    void GetFontList(nsAtom *aLangGroup,
                     const nsACString& aGenericFamily,
                     nsTArray<nsString>& aListOfFonts) override;

    void ReadSystemFontList(
        InfallibleTArray<mozilla::dom::SystemFontListEntry>* retValue);

    gfxFontEntry*
    LookupLocalFont(const nsAString& aFontName,
                    WeightRange aWeightForEntry,
                    StretchRange aStretchForEntry,
                    SlantStyleRange aStyleForEntry) override;

    gfxFontEntry*
    MakePlatformFont(const nsAString& aFontName,
                     WeightRange aWeightForEntry,
                     StretchRange aStretchForEntry,
                     SlantStyleRange aStyleForEntry,
                     const uint8_t* aFontData,
                     uint32_t aLength) override;

    bool FindAndAddFamilies(const nsAString& aFamily,
                            nsTArray<FamilyAndGeneric>* aOutput,
                            FindFamiliesFlags aFlags,
                            gfxFontStyle* aStyle = nullptr,
                            gfxFloat aDevToCssSize = 1.0) override;

    bool GetStandardFamilyName(const nsAString& aFontName,
                               nsAString& aFamilyName) override;

    FcConfig* GetLastConfig() const { return mLastConfig; }

    // override to use fontconfig lookup for generics
    void AddGenericFonts(mozilla::FontFamilyType aGenericType,
                         nsAtom* aLanguage,
                         nsTArray<FamilyAndGeneric>& aFamilyList) override;

    void ClearLangGroupPrefFonts() override;

    // clear out cached generic-lang ==> family-list mappings
    void ClearGenericMappings() {
        mGenericMappings.Clear();
    }

    // map lang group ==> lang string
    // When aForFontEnumerationThread is true, this method will avoid using
    // LanguageService::LookupLanguage, because it is not safe for off-main-
    // thread use (except by stylo traversal, which does the necessary locking)
    void GetSampleLangForGroup(nsAtom* aLanguage, nsACString& aLangStr,
                               bool aForFontEnumerationThread = false);

    static FT_Library GetFTLibrary();

protected:
    virtual ~gfxFcPlatformFontList();

#if defined(MOZ_CONTENT_SANDBOX) && defined(XP_LINUX)
    typedef mozilla::SandboxBroker::Policy SandboxPolicy;
#else
    // Dummy type just so we can still have a SandboxPolicy* parameter.
    struct SandboxPolicy {};
#endif

    // Add all the font families found in a font set.
    // aAppFonts indicates whether this is the system or application fontset.
    void AddFontSetFamilies(FcFontSet* aFontSet, const SandboxPolicy* aPolicy,
                            bool aAppFonts);

    // Helper for above, to add a single font pattern.
    void AddPatternToFontList(FcPattern* aFont, FcChar8*& aLastFamilyName,
                              nsAString& aFamilyName,
                              RefPtr<gfxFontconfigFontFamily>& aFontFamily,
                              bool aAppFonts);

    // figure out which families fontconfig maps a generic to
    // (aGeneric assumed already lowercase)
    PrefFontList* FindGenericFamilies(const nsAString& aGeneric,
                                      nsAtom* aLanguage);

    // are all pref font settings set to use fontconfig generics?
    bool PrefFontListsUseOnlyGenerics();

    static void CheckFontUpdates(nsITimer *aTimer, void *aThis);

    virtual gfxFontFamily*
    GetDefaultFontForPlatform(const gfxFontStyle* aStyle) override;

    gfxFontFamily* CreateFontFamily(const nsAString& aName) const override;

    // helper method for finding an appropriate lang string
    bool TryLangForGroup(const nsACString& aOSLang, nsAtom* aLangGroup,
                         nsACString& aLang, bool aForFontEnumerationThread);

#ifdef MOZ_BUNDLED_FONTS
    void ActivateBundledFonts();
    nsCString mBundledFontsPath;
    bool mBundledFontsInitialized;
#endif

    // to avoid enumerating all fonts, maintain a mapping of local font
    // names to family
    nsBaseHashtable<nsStringHashKey,
                    nsCountedRef<FcPattern>,
                    FcPattern*> mLocalNames;

    // caching generic/lang ==> font family list
    nsClassHashtable<nsCStringHashKey,
                     PrefFontList> mGenericMappings;

    // Caching family lookups as found by FindAndAddFamilies after resolving
    // substitutions. The gfxFontFamily objects cached here are owned by the
    // gfxFcPlatformFontList via its mFamilies table; note that if the main
    // font list is rebuilt (e.g. due to a fontconfig configuration change),
    // these pointers will be invalidated. InitFontList() flushes the cache
    // in this case.
    nsDataHashtable<nsCStringHashKey,
                    nsTArray<FamilyAndGeneric>> mFcSubstituteCache;

    nsCOMPtr<nsITimer> mCheckFontUpdatesTimer;
    nsCountedRef<FcConfig> mLastConfig;

    // By default, font prefs under Linux are set to simply lookup
    // via fontconfig the appropriate font for serif/sans-serif/monospace.
    // Rather than check each time a font pref is used, check them all at startup
    // and set a boolean to flag the case that non-default user font prefs exist
    // Note: langGroup == x-math is handled separately
    bool mAlwaysUseFontconfigGenerics;

    static FT_Library sCairoFTLibrary;
};

#endif /* GFXPLATFORMFONTLIST_H_ */