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#include "qtextengine_p.h"

QT_BEGIN_NAMESPACE

// set the glyph attributes heuristically. Assumes a 1 to 1 relationship between chars and glyphs

// and no reordering.

// also computes logClusters heuristically

static void heuristicSetGlyphAttributes(const QChar *uc, int length, QGlyphLayout *glyphs, unsigned short *logClusters, int num_glyphs)

{

    // ### zeroWidth and justification are missing here!!!!!

    Q_UNUSED(num_glyphs);

//     qDebug("QScriptEngine::heuristicSetGlyphAttributes, num_glyphs=%d", item->num_glyphs);

    const bool symbolFont = false; // ####

    glyphs->attributes[0].mark = false;

    glyphs->attributes[0].clusterStart = true;

    glyphs->attributes[0].dontPrint = (!symbolFont && uc[0].unicode() == 0x00ad) || qIsControlChar(uc[0].unicode());

    int pos = 0;

    int lastCat = QChar::category(uc[0].unicode());

    for (int i = 1; i < length; ++i) {

        if (logClusters[i] == pos)

            // same glyph

            continue;

        ++pos;

        while (pos < logClusters[i]) {

            ++pos;

        }

        // hide soft-hyphens by default

        if ((!symbolFont && uc[i].unicode() == 0x00ad) || qIsControlChar(uc[i].unicode()))

            glyphs->attributes[pos].dontPrint = true;

        const QUnicodeTables::Properties *prop = QUnicodeTables::properties(uc[i].unicode());

        int cat = prop->category;

        // one gets an inter character justification point if the current char is not a non spacing mark.

        // as then the current char belongs to the last one and one gets a space justification point

        // after the space char.

        if (lastCat == QChar::Separator_Space)

            glyphs->attributes[pos-1].justification = HB_Space;

        else if (cat != QChar::Mark_NonSpacing)

            glyphs->attributes[pos-1].justification = HB_Character;

        else

            glyphs->attributes[pos-1].justification = HB_NoJustification;

        lastCat = cat;

    }

    pos = logClusters[length-1];

    if (lastCat == QChar::Separator_Space)

        glyphs->attributes[pos].justification = HB_Space;

    else

        glyphs->attributes[pos].justification = HB_Character;

}

struct QArabicProperties {

    unsigned char shape;

    unsigned char justification;

};

Q_DECLARE_TYPEINFO(QArabicProperties, Q_PRIMITIVE_TYPE);

enum QArabicShape {

    XIsolated,

    XFinal,

    XInitial,

    XMedial,

    // intermediate state

    XCausing

};

// these groups correspond to the groups defined in the Unicode standard.

// Some of these groups are equal with regards to both joining and line breaking behaviour,

// and thus have the same enum value

//

// I'm not sure the mapping of syriac to arabic enums is correct with regards to justification, but as

// I couldn't find any better document I'll hope for the best.

enum ArabicGroup {

    // NonJoining

    ArabicNone,

    ArabicSpace,

    // Transparent

    Transparent,

    // Causing

    Center,

    Kashida,

    // Arabic

    // Dual

    Beh,

    Noon,

    Meem = Noon,

    Heh = Noon,

    KnottedHeh = Noon,

    HehGoal = Noon,

    SwashKaf = Noon,

    Yeh,

    Hah,

    Seen,

    Sad = Seen,

    Tah,

    Kaf = Tah,

    Gaf = Tah,

    Lam = Tah,

    Ain,

    Feh = Ain,

    Qaf = Ain,

    // Right

    Alef,

    Waw,

    Dal,

    TehMarbuta = Dal,

    Reh,

    HamzaOnHehGoal,

    YehWithTail = HamzaOnHehGoal,

    YehBarre = HamzaOnHehGoal,

    // Syriac

    // Dual

    Beth = Beh,

    Gamal = Ain,

    Heth = Noon,

    Teth = Hah,

    Yudh = Noon,

    Kaph = Noon,

    Lamadh = Lam,

    Mim = Noon,

    Nun = Noon,

    Semakh = Noon,

    FinalSemakh = Noon,

    SyriacE = Ain,

    Pe = Ain,

    ReversedPe = Hah,

    Qaph = Noon,

    Shin = Noon,

    Fe = Ain,

    // Right

    Alaph = Alef,

    Dalath = Dal,

    He = Dal,

    SyriacWaw = Waw,

    Zain = Alef,

    YudhHe = Waw,

    Sadhe = HamzaOnHehGoal,

    Taw = Dal,

    // Compiler bug? Otherwise ArabicGroupsEnd would be equal to Dal + 1.

    Dummy = HamzaOnHehGoal,

    ArabicGroupsEnd

};

static const unsigned char arabic_group[0x150] = {

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, Alef, Alef,

    Waw, Alef, Yeh, Alef,

    Beh, TehMarbuta, Beh, Beh,

    Hah, Hah, Hah, Dal,

    Dal, Reh, Reh, Seen,

    Seen, Sad, Sad, Tah,

    Tah, Ain, Ain, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    // 0x640

    Kashida, Feh, Qaf, Kaf,

    Lam, Meem, Noon, Heh,

    Waw, Yeh, Yeh, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, Beh, Qaf,

    Transparent, Alef, Alef, Alef,

    ArabicNone, Alef, Waw, Waw,

    Yeh, Beh, Beh, Beh,

    Beh, Beh, Beh, Beh,

    // 0x680

    Beh, Hah, Hah, Hah,

    Hah, Hah, Hah, Hah,

    Dal, Dal, Dal, Dal,

    Dal, Dal, Dal, Dal,

    Dal, Reh, Reh, Reh,

    Reh, Reh, Reh, Reh,

    Reh, Reh, Seen, Seen,

    Seen, Sad, Sad, Tah,

    Ain, Feh, Feh, Feh,

    Feh, Feh, Feh, Qaf,

    Qaf, Gaf, SwashKaf, Gaf,

    Kaf, Kaf, Kaf, Gaf,

    Gaf, Gaf, Gaf, Gaf,

    Gaf, Lam, Lam, Lam,

    Lam, Noon, Noon, Noon,

    Noon, Noon, KnottedHeh, Hah,

    // 0x6c0

    TehMarbuta, HehGoal, HamzaOnHehGoal, HamzaOnHehGoal,

    Waw, Waw, Waw, Waw,

    Waw, Waw, Waw, Waw,

    Yeh, YehWithTail, Yeh, Waw,

    Yeh, Yeh, YehBarre, YehBarre,

    ArabicNone, TehMarbuta, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, ArabicNone, ArabicNone, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, ArabicNone, ArabicNone, Transparent,

    Transparent, ArabicNone, Transparent, Transparent,

    Transparent, Transparent, Dal, Reh,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, Seen, Sad,

    Ain, ArabicNone, ArabicNone, KnottedHeh,

    // 0x700

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    ArabicNone, ArabicNone, ArabicNone, ArabicNone,

    Alaph, Transparent, Beth, Gamal,

    Gamal, Dalath, Dalath, He,

    SyriacWaw, Zain, Heth, Teth,

    Teth, Yudh, YudhHe, Kaph,

    Lamadh, Mim, Nun, Semakh,

    FinalSemakh, SyriacE, Pe, ReversedPe,

    Sadhe, Qaph, Dalath, Shin,

    Taw, Beth, Gamal, Dalath,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, Transparent,

    Transparent, Transparent, Transparent, ArabicNone,

    ArabicNone, Zain, Kaph, Fe,

};

static inline ArabicGroup arabicGroup(unsigned short uc)

{

    if (uc >= 0x0600 && uc < 0x750)

        return (ArabicGroup) arabic_group[uc-0x600];

    else if (uc == 0x200d)

        return Center;

    else if (QChar::category(uc) == QChar::Separator_Space)

        return ArabicSpace;

    else

        return ArabicNone;

}

/*

   Arabic shaping obeys a number of rules according to the joining classes (see Unicode book, section on

   arabic).

   Each unicode char has a joining class (right, dual (left&right), center (joincausing) or transparent).

   transparent joining is not encoded in QChar::joining(), but applies to all combining marks and format marks.

   Right join-causing: dual + center

   Left join-causing: dual + right + center

   Rules are as follows (for a string already in visual order, as we have it here):

   R1 Transparent characters do not affect joining behaviour.

   R2 A right joining character, that has a right join-causing char on the right will get form XRight

   (R3 A left joining character, that has a left join-causing char on the left will get form XLeft)

   Note: the above rule is meaningless, as there are no pure left joining characters defined in Unicode

   R4 A dual joining character, that has a left join-causing char on the left and a right join-causing char on

             the right will get form XMedial

   R5  A dual joining character, that has a right join causing char on the right, and no left join causing char on the left

         will get form XRight

   R6 A dual joining character, that has a  left join causing char on the left, and no right join causing char on the right

         will get form XLeft

   R7 Otherwise the character will get form XIsolated

   Additionally we have to do the minimal ligature support for lam-alef ligatures:

   L1 Transparent characters do not affect ligature behaviour.

   L2 Any sequence of Alef(XRight) + Lam(XMedial) will form the ligature Alef.Lam(XLeft)

   L3 Any sequence of Alef(XRight) + Lam(XLeft) will form the ligature Alef.Lam(XIsolated)

   The state table below handles rules R1-R7.

*/

enum Joining {

    JNone,

    JCausing,

    JDual,

    JRight,

    JTransparent

};

static const Joining joining_for_group[ArabicGroupsEnd] = {

    // NonJoining

    JNone, // ArabicNone

    JNone, // ArabicSpace

    // Transparent

    JTransparent, // Transparent

    // Causing

    JCausing, // Center

    JCausing, // Kashida

    // Dual

    JDual, // Beh

    JDual, // Noon

    JDual, // Yeh

    JDual, // Hah

    JDual, // Seen

    JDual, // Tah

    JDual, // Ain

    // Right

    JRight, // Alef

    JRight, // Waw

    JRight, // Dal

    JRight, // Reh

    JRight  // HamzaOnHehGoal

};

struct JoiningPair {

    QArabicShape form1;

    QArabicShape form2;

};

static const JoiningPair joining_table[5][4] =

// None, Causing, Dual, Right

{

    { { XIsolated, XIsolated }, { XIsolated, XCausing }, { XIsolated, XInitial }, { XIsolated, XIsolated } }, // XIsolated

    { { XFinal, XIsolated }, { XFinal, XCausing }, { XFinal, XInitial }, { XFinal, XIsolated } }, // XFinal

    { { XIsolated, XIsolated }, { XInitial, XCausing }, { XInitial, XMedial }, { XInitial, XFinal } }, // XInitial

    { { XFinal, XIsolated }, { XMedial, XCausing }, { XMedial, XMedial }, { XMedial, XFinal } }, // XMedial

    { { XIsolated, XIsolated }, { XIsolated, XCausing }, { XIsolated, XMedial }, { XIsolated, XFinal } }, // XCausing

};

/*

According to http://www.microsoft.com/middleeast/Arabicdev/IE6/KBase.asp

1. Find the priority of the connecting opportunities in each word

2. Add expansion at the highest priority connection opportunity

3. If more than one connection opportunity have the same highest value,

   use the opportunity closest to the end of the word.

Following is a chart that provides the priority for connection

opportunities and where expansion occurs. The character group names

are those in table 6.6 of the UNICODE 2.0 book.

PrioritY        Glyph                   Condition                                       Kashida Location

Arabic_Kashida        User inserted Kashida   The user entered a Kashida in a position.       After the user

                (Shift+j or Shift+[E with hat])    Thus, it is the highest priority to insert an   inserted kashida

                                        automatic kashida.

Arabic_Seen        Seen, Sad               Connecting to the next character.               After the character.

                                        (Initial or medial form).

Arabic_HaaDal        Teh Marbutah, Haa, Dal  Connecting to previous character.               Before the final form

                                                                                        of these characters.

Arabic_Alef     Alef, Tah, Lam,         Connecting to previous character.               Before the final form

                Kaf and Gaf                                                             of these characters.

Arabic_BaRa     Reh, Yeh                Connected to medial Beh                         Before preceding medial Baa

Arabic_Waw        Waw, Ain, Qaf, Feh      Connecting to previous character.               Before the final form of

                                                                                        these characters.

Arabic_Normal   Other connecting        Connecting to previous character.               Before the final form

                characters                                                              of these characters.

This seems to imply that we have at most one kashida point per arabic word.

*/

void qt_getArabicProperties(const unsigned short *chars, int len, QArabicProperties *properties)

{

//     qDebug("arabicSyriacOpenTypeShape: properties:");

    int lastPos = 0;

    int lastGroup = ArabicNone;

    ArabicGroup group = arabicGroup(chars[0]);

    Joining j = joining_for_group[group];

    QArabicShape shape = joining_table[XIsolated][j].form2;

    properties[0].justification = HB_NoJustification;

    for (int i = 1; i < len; ++i) {

        // #### fix handling for spaces and punktuation

        properties[i].justification = HB_NoJustification;

        group = arabicGroup(chars[i]);

        j = joining_for_group[group];

        if (j == JTransparent) {

            properties[i].shape = XIsolated;

            continue;

        }

        properties[lastPos].shape = joining_table[shape][j].form1;

        shape = joining_table[shape][j].form2;

        switch(lastGroup) {

        case Seen:

            if (properties[lastPos].shape == XInitial || properties[lastPos].shape == XMedial)

                properties[i-1].justification = HB_Arabic_Seen;

            break;

        case Hah:

            if (properties[lastPos].shape == XFinal)

                properties[lastPos-1].justification = HB_Arabic_HaaDal;

            break;

        case Alef:

            if (properties[lastPos].shape == XFinal)

                properties[lastPos-1].justification = HB_Arabic_Alef;

            break;

        case Ain:

            if (properties[lastPos].shape == XFinal)

                properties[lastPos-1].justification = HB_Arabic_Waw;

            break;

        case Noon:

            if (properties[lastPos].shape == XFinal)

                properties[lastPos-1].justification = HB_Arabic_Normal;

            break;

        case ArabicNone:

            break;

        default:

            Q_ASSERT(false);

        }

        lastGroup = ArabicNone;

        switch(group) {

        case ArabicNone:

        case Transparent:

        // ### Center should probably be treated as transparent when it comes to justification.

        case Center:

            break;

        case ArabicSpace:

            properties[i].justification = HB_Arabic_Space;

            break;

        case Kashida:

            properties[i].justification = HB_Arabic_Kashida;

            break;

        case Seen:

            lastGroup = Seen;

            break;

        case Hah:

        case Dal:

            lastGroup = Hah;

            break;

        case Alef:

        case Tah:

            lastGroup = Alef;

            break;

        case Yeh:

        case Reh:

            if (properties[lastPos].shape == XMedial && arabicGroup(chars[lastPos]) == Beh)

                properties[lastPos-1].justification = HB_Arabic_BaRa;