src/gui/text/qtextengine_p.h
changeset 0 1918ee327afb
child 3 41300fa6a67c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/gui/text/qtextengine_p.h	Mon Jan 11 14:00:40 2010 +0000
@@ -0,0 +1,609 @@
+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the QtGui module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the Technology Preview License Agreement accompanying
+** this package.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights.  These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at qt-info@nokia.com.
+**
+**
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QTEXTENGINE_P_H
+#define QTEXTENGINE_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists for the convenience
+// of other Qt classes.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include "QtCore/qglobal.h"
+#include "QtCore/qstring.h"
+#include "QtCore/qvarlengtharray.h"
+#include "QtCore/qnamespace.h"
+#include "QtGui/qtextlayout.h"
+#include "private/qtextformat_p.h"
+#include "private/qfont_p.h"
+#include "QtCore/qvector.h"
+#include "QtGui/qpaintengine.h"
+#include "QtGui/qtextobject.h"
+#include "QtGui/qtextoption.h"
+#include "QtCore/qset.h"
+#include "QtCore/qdebug.h"
+#ifndef QT_BUILD_COMPAT_LIB
+#include "private/qtextdocument_p.h"
+#endif
+#include "private/qharfbuzz_p.h"
+#include "private/qfixed_p.h"
+
+#include <stdlib.h>
+
+QT_BEGIN_NAMESPACE
+
+class QFontPrivate;
+class QFontEngine;
+
+class QString;
+class QPainter;
+
+class QAbstractTextDocumentLayout;
+
+
+// this uses the same coordinate system as Qt, but a different one to freetype.
+// * y is usually negative, and is equal to the ascent.
+// * negative yoff means the following stuff is drawn higher up.
+// the characters bounding rect is given by QRect(x,y,width,height), its advance by
+// xoo and yoff
+struct glyph_metrics_t
+{
+    inline glyph_metrics_t()
+        : x(100000),  y(100000) {}
+    inline glyph_metrics_t(QFixed _x, QFixed _y, QFixed _width, QFixed _height, QFixed _xoff, QFixed _yoff)
+        : x(_x),
+          y(_y),
+          width(_width),
+          height(_height),
+          xoff(_xoff),
+          yoff(_yoff)
+        {}
+    QFixed x;
+    QFixed y;
+    QFixed width;
+    QFixed height;
+    QFixed xoff;
+    QFixed yoff;
+
+    glyph_metrics_t transformed(const QTransform &xform) const;
+    inline bool isValid() const {return x != 100000 && y != 100000;}
+};
+Q_DECLARE_TYPEINFO(glyph_metrics_t, Q_PRIMITIVE_TYPE);
+
+struct Q_AUTOTEST_EXPORT QScriptAnalysis
+{
+    enum Flags {
+        None = 0,
+        Lowercase = 1,
+        Uppercase = 2,
+        SmallCaps = 3,
+        LineOrParagraphSeparator = 4,
+        Space = 5,
+        SpaceTabOrObject = Space,
+        Tab = 6,
+        TabOrObject = Tab,
+        Object = 7
+    };
+    unsigned short script    : 8;
+    unsigned short bidiLevel : 6;  // Unicode Bidi algorithm embedding level (0-61)
+    unsigned short flags     : 3;
+    inline bool operator == (const QScriptAnalysis &other) const {
+        return script == other.script && bidiLevel == other.bidiLevel && flags == other.flags;
+    }
+};
+Q_DECLARE_TYPEINFO(QScriptAnalysis, Q_PRIMITIVE_TYPE);
+
+struct QGlyphJustification
+{
+    inline QGlyphJustification()
+        : type(0), nKashidas(0), space_18d6(0)
+    {}
+
+    enum JustificationType {
+        JustifyNone,
+        JustifySpace,
+        JustifyKashida
+    };
+
+    uint type :2;
+    uint nKashidas : 6; // more do not make sense...
+    uint space_18d6 : 24;
+};
+Q_DECLARE_TYPEINFO(QGlyphJustification, Q_PRIMITIVE_TYPE);
+
+struct QGlyphLayoutInstance
+{
+    QFixedPoint offset;
+    QFixedPoint advance;
+    HB_Glyph glyph;
+    QGlyphJustification justification;
+    HB_GlyphAttributes attributes;
+};
+
+struct QGlyphLayout
+{
+    // init to 0 not needed, done when shaping
+    QFixedPoint *offsets; // 8 bytes per element
+    HB_Glyph *glyphs; // 4 bytes per element
+    QFixed *advances_x; // 4 bytes per element
+    QFixed *advances_y; // 4 bytes per element
+    QGlyphJustification *justifications; // 4 bytes per element
+    HB_GlyphAttributes *attributes; // 2 bytes per element
+
+    int numGlyphs;
+
+    inline QGlyphLayout() : numGlyphs(0) {}
+
+    inline explicit QGlyphLayout(char *address, int totalGlyphs)
+    {
+        offsets = reinterpret_cast<QFixedPoint *>(address);
+        int offset = totalGlyphs * sizeof(HB_FixedPoint);
+        glyphs = reinterpret_cast<HB_Glyph *>(address + offset);
+        offset += totalGlyphs * sizeof(HB_Glyph);
+        advances_x = reinterpret_cast<QFixed *>(address + offset);
+        offset += totalGlyphs * sizeof(QFixed);
+        advances_y = reinterpret_cast<QFixed *>(address + offset);
+        offset += totalGlyphs * sizeof(QFixed);
+        justifications = reinterpret_cast<QGlyphJustification *>(address + offset);
+        offset += totalGlyphs * sizeof(QGlyphJustification);
+        attributes = reinterpret_cast<HB_GlyphAttributes *>(address + offset);
+        numGlyphs = totalGlyphs;
+    }
+
+    inline QGlyphLayout mid(int position, int n = -1) const {
+        QGlyphLayout copy = *this;
+        copy.glyphs += position;
+        copy.advances_x += position;
+        copy.advances_y += position;
+        copy.offsets += position;
+        copy.justifications += position;
+        copy.attributes += position;
+        if (n == -1)
+            copy.numGlyphs -= position;
+        else
+            copy.numGlyphs = n;
+        return copy;
+    }
+
+    static inline int spaceNeededForGlyphLayout(int totalGlyphs) {
+        return totalGlyphs * (sizeof(HB_Glyph) + sizeof(HB_GlyphAttributes)
+                + sizeof(QFixed) + sizeof(QFixed) + sizeof(QFixedPoint)
+                + sizeof(QGlyphJustification));
+    }
+
+    inline QFixed effectiveAdvance(int item) const
+    { return (advances_x[item] + QFixed::fromFixed(justifications[item].space_18d6)) * !attributes[item].dontPrint; }
+
+    inline QGlyphLayoutInstance instance(int position) const {
+        QGlyphLayoutInstance g;
+        g.offset.x = offsets[position].x;
+        g.offset.y = offsets[position].y;
+        g.glyph = glyphs[position];
+        g.advance.x = advances_x[position];
+        g.advance.y = advances_y[position];
+        g.justification = justifications[position];
+        g.attributes = attributes[position];
+        return g;
+    }
+
+    inline void setInstance(int position, const QGlyphLayoutInstance &g) {
+        offsets[position].x = g.offset.x;
+        offsets[position].y = g.offset.y;
+        glyphs[position] = g.glyph;
+        advances_x[position] = g.advance.x;
+        advances_y[position] = g.advance.y;
+        justifications[position] = g.justification;
+        attributes[position] = g.attributes;
+    }
+
+    inline void clear(int first = 0, int last = -1) {
+        if (last == -1)
+            last = numGlyphs;
+        if (first == 0 && last == numGlyphs
+            && reinterpret_cast<char *>(offsets + numGlyphs) == reinterpret_cast<char *>(glyphs)) {
+            memset(offsets, 0, spaceNeededForGlyphLayout(numGlyphs));
+        } else {
+            const int num = last - first;
+            memset(offsets + first, 0, num * sizeof(QFixedPoint));
+            memset(glyphs + first, 0, num * sizeof(HB_Glyph));
+            memset(advances_x + first, 0, num * sizeof(QFixed));
+            memset(advances_y + first, 0, num * sizeof(QFixed));
+            memset(justifications + first, 0, num * sizeof(QGlyphJustification));
+            memset(attributes + first, 0, num * sizeof(HB_GlyphAttributes));
+        }
+    }
+
+    inline char *data() {
+        return reinterpret_cast<char *>(offsets);
+    }
+
+    void grow(char *address, int totalGlyphs);
+};
+
+class QVarLengthGlyphLayoutArray : private QVarLengthArray<void *>, public QGlyphLayout
+{
+private:
+    typedef QVarLengthArray<void *> Array;
+public:
+    QVarLengthGlyphLayoutArray(int totalGlyphs)
+        : Array(spaceNeededForGlyphLayout(totalGlyphs) / sizeof(void *) + 1)
+        , QGlyphLayout(reinterpret_cast<char *>(Array::data()), totalGlyphs)
+    {
+        memset(Array::data(), 0, Array::size() * sizeof(void *));
+    }
+
+    void resize(int totalGlyphs)
+    {
+        Array::resize(spaceNeededForGlyphLayout(totalGlyphs) / sizeof(void *) + 1);
+
+        *((QGlyphLayout *)this) = QGlyphLayout(reinterpret_cast<char *>(Array::data()), totalGlyphs);
+        memset(Array::data(), 0, Array::size() * sizeof(void *));
+    }
+};
+
+template <int N> struct QGlyphLayoutArray : public QGlyphLayout
+{
+public:
+    QGlyphLayoutArray()
+        : QGlyphLayout(reinterpret_cast<char *>(buffer), N)
+    {
+        memset(buffer, 0, sizeof(buffer));
+    }
+
+private:
+    void *buffer[(N * (sizeof(HB_Glyph) + sizeof(HB_GlyphAttributes)
+                + sizeof(QFixed) + sizeof(QFixed) + sizeof(QFixedPoint)
+                + sizeof(QGlyphJustification)))
+                    / sizeof(void *) + 1];
+};
+
+struct QScriptItem;
+/// Internal QTextItem
+class QTextItemInt : public QTextItem
+{
+public:
+    inline QTextItemInt()
+        : justified(false), underlineStyle(QTextCharFormat::NoUnderline), num_chars(0), chars(0),
+          logClusters(0), f(0), fontEngine(0)
+    {}
+    QTextItemInt(const QScriptItem &si, QFont *font, const QTextCharFormat &format = QTextCharFormat());
+
+    /// copy the structure items, adjusting the glyphs arrays to the right subarrays.
+    /// the width of the returned QTextItemInt is not adjusted, for speed reasons
+    QTextItemInt midItem(QFontEngine *fontEngine, int firstGlyphIndex, int numGlyphs) const;
+
+    QFixed descent;
+    QFixed ascent;
+    QFixed width;
+
+    RenderFlags flags;
+    bool justified;
+    QTextCharFormat::UnderlineStyle underlineStyle;
+    const QTextCharFormat charFormat;
+    int num_chars;
+    const QChar *chars;
+    const unsigned short *logClusters;
+    const QFont *f;
+
+    QGlyphLayout glyphs;
+    QFontEngine *fontEngine;
+};
+
+inline bool qIsControlChar(ushort uc)
+{
+    return uc >= 0x200b && uc <= 0x206f
+        && (uc <= 0x200f /* ZW Space, ZWNJ, ZWJ, LRM and RLM */
+            || (uc >= 0x2028 && uc <= 0x202f /* LS, PS, LRE, RLE, PDF, LRO, RLO, NNBSP */)
+            || uc >= 0x206a /* ISS, ASS, IAFS, AFS, NADS, NODS */);
+}
+
+struct Q_AUTOTEST_EXPORT QScriptItem
+{
+    inline QScriptItem()
+        : position(0),
+          num_glyphs(0), descent(-1), ascent(-1), width(-1),
+          glyph_data_offset(0) {}
+    inline QScriptItem(int p, const QScriptAnalysis &a)
+        : position(p), analysis(a),
+          num_glyphs(0), descent(-1), ascent(-1), width(-1),
+          glyph_data_offset(0) {}
+
+    int position;
+    QScriptAnalysis analysis;
+    unsigned short num_glyphs;
+    QFixed descent;
+    QFixed ascent;
+    QFixed width;
+    int glyph_data_offset;
+    QFixed height() const { return ascent + descent + 1; }
+};
+
+
+Q_DECLARE_TYPEINFO(QScriptItem, Q_MOVABLE_TYPE);
+
+typedef QVector<QScriptItem> QScriptItemArray;
+
+struct Q_AUTOTEST_EXPORT QScriptLine
+{
+    // created and filled in QTextLine::layout_helper
+    QScriptLine()
+        : from(0), length(0),
+        justified(0), gridfitted(0),
+        hasTrailingSpaces(0) {}
+    QFixed descent;
+    QFixed ascent;
+    QFixed x;
+    QFixed y;
+    QFixed width;
+    QFixed textWidth;
+    int from;
+    signed int length : 29;
+    mutable uint justified : 1;
+    mutable uint gridfitted : 1;
+    uint hasTrailingSpaces : 1;
+    QFixed height() const { return ascent + descent + 1; }
+    void setDefaultHeight(QTextEngine *eng);
+    void operator+=(const QScriptLine &other);
+};
+Q_DECLARE_TYPEINFO(QScriptLine, Q_PRIMITIVE_TYPE);
+
+
+inline void QScriptLine::operator+=(const QScriptLine &other)
+{
+    descent = qMax(descent, other.descent);
+    ascent = qMax(ascent, other.ascent);
+    textWidth += other.textWidth;
+    length += other.length;
+}
+
+typedef QVector<QScriptLine> QScriptLineArray;
+
+class QFontPrivate;
+class QTextFormatCollection;
+
+class Q_GUI_EXPORT QTextEngine {
+public:
+    struct LayoutData {
+        LayoutData(const QString &str, void **stack_memory, int mem_size);
+        LayoutData();
+        ~LayoutData();
+        mutable QScriptItemArray items;
+        int allocated;
+        int available_glyphs;
+        void **memory;
+        unsigned short *logClustersPtr;
+        QGlyphLayout glyphLayout;
+        mutable int used;
+        uint hasBidi : 1;
+        uint inLayout : 1;
+        uint memory_on_stack : 1;
+        bool haveCharAttributes;
+        QString string;
+        void reallocate(int totalGlyphs);
+    };
+
+    QTextEngine(LayoutData *data);
+    QTextEngine();
+    QTextEngine(const QString &str, const QFont &f);
+    ~QTextEngine();
+
+    enum Mode {
+        WidthOnly = 0x07
+    };
+
+    // keep in sync with QAbstractFontEngine::TextShapingFlag!!
+    enum ShaperFlag {
+        RightToLeft = 0x0001,
+        DesignMetrics = 0x0002,
+        GlyphIndicesOnly = 0x0004
+    };
+    Q_DECLARE_FLAGS(ShaperFlags, ShaperFlag)
+
+    void invalidate();
+    void clearLineData();
+
+    void validate() const;
+    void itemize() const;
+
+    static void bidiReorder(int numRuns, const quint8 *levels, int *visualOrder);
+
+    const HB_CharAttributes *attributes() const;
+
+    void shape(int item) const;
+
+    void justify(const QScriptLine &si);
+
+    QFixed width(int charFrom, int numChars) const;
+    glyph_metrics_t boundingBox(int from,  int len) const;
+    glyph_metrics_t tightBoundingBox(int from,  int len) const;
+
+    int length(int item) const {
+        const QScriptItem &si = layoutData->items[item];
+        int from = si.position;
+        item++;
+        return (item < layoutData->items.size() ? layoutData->items[item].position : layoutData->string.length()) - from;
+    }
+    int length(const QScriptItem *si) const {
+        int end;
+        if (si + 1 < layoutData->items.constData()+ layoutData->items.size())
+            end = (si+1)->position;
+        else
+            end = layoutData->string.length();
+        return end - si->position;
+    }
+
+    QFontEngine *fontEngine(const QScriptItem &si, QFixed *ascent = 0, QFixed *descent = 0) const;
+    QFont font(const QScriptItem &si) const;
+    inline QFont font() const { return fnt; }
+
+    /**
+     * Returns a pointer to an array of log clusters, offset at the script item.
+     * Each item in the array is a unsigned short.  For each character in the original string there is an entry in the table
+     * so there is a one to one correlation in indexes between the original text and the index in the logcluster.
+     * The value of each item is the position in the glyphs array. Multiple similar pointers in the logclusters array imply
+     * that one glyph is used for more than one character.
+     * \sa glyphs()
+     */
+    inline unsigned short *logClusters(const QScriptItem *si) const
+        { return layoutData->logClustersPtr+si->position; }
+    /**
+     * Returns an array of QGlyphLayout items, offset at the script item.
+     * Each item in the array matches one glyph in the text, storing the advance, position etc.
+     * The returned item's length equals to the number of available glyphs. This may be more
+     * than what was actually shaped.
+     * \sa logClusters()
+     */
+    inline QGlyphLayout availableGlyphs(const QScriptItem *si) const {
+        return layoutData->glyphLayout.mid(si->glyph_data_offset);
+    }
+    /**
+     * Returns an array of QGlyphLayout items, offset at the script item.
+     * Each item in the array matches one glyph in the text, storing the advance, position etc.
+     * The returned item's length equals to the number of shaped glyphs.
+     * \sa logClusters()
+     */
+    inline QGlyphLayout shapedGlyphs(const QScriptItem *si) const {
+        return layoutData->glyphLayout.mid(si->glyph_data_offset, si->num_glyphs);
+    }
+
+    inline void ensureSpace(int nGlyphs) const {
+        if (layoutData->glyphLayout.numGlyphs - layoutData->used < nGlyphs)
+            layoutData->reallocate((((layoutData->used + nGlyphs)*3/2 + 15) >> 4) << 4);
+    }
+
+    void freeMemory();
+
+    int findItem(int strPos) const;
+    inline QTextFormatCollection *formats() const {
+#ifdef QT_BUILD_COMPAT_LIB
+        return 0; // Compat should never reference this symbol
+#else
+        return block.docHandle()->formatCollection();
+#endif
+    }
+    QTextCharFormat format(const QScriptItem *si) const;
+    inline QAbstractTextDocumentLayout *docLayout() const {
+#ifdef QT_BUILD_COMPAT_LIB
+        return 0; // Compat should never reference this symbol
+#else
+        return block.docHandle()->document()->documentLayout();
+#endif
+    }
+    int formatIndex(const QScriptItem *si) const;
+
+    /// returns the width of tab at index (in the tabs array) with the tab-start at position x
+    QFixed calculateTabWidth(int index, QFixed x) const;
+
+    mutable QScriptLineArray lines;
+
+    QString text;
+    QFont fnt;
+    QTextBlock block;
+
+    QTextOption option;
+
+    QFixed minWidth;
+    QFixed maxWidth;
+    QPointF position;
+    uint ignoreBidi : 1;
+    uint cacheGlyphs : 1;
+    uint stackEngine : 1;
+    uint forceJustification : 1;
+
+    int *underlinePositions;
+
+    mutable LayoutData *layoutData;
+
+    inline bool hasFormats() const { return (block.docHandle() || specialData); }
+
+    struct SpecialData {
+        int preeditPosition;
+        QString preeditText;
+        QList<QTextLayout::FormatRange> addFormats;
+        QVector<int> addFormatIndices;
+        QVector<int> resolvedFormatIndices;
+    };
+    SpecialData *specialData;
+
+    bool atWordSeparator(int position) const;
+    bool atSpace(int position) const;
+    void indexAdditionalFormats();
+
+    QString elidedText(Qt::TextElideMode mode, const QFixed &width, int flags = 0) const;
+
+    void shapeLine(const QScriptLine &line);
+
+private:
+    void setBoundary(int strPos) const;
+    void addRequiredBoundaries() const;
+    void shapeText(int item) const;
+    void shapeTextWithHarfbuzz(int item) const;
+#if defined(Q_WS_WINCE)
+    void shapeTextWithCE(int item) const;
+#endif
+#if defined(Q_WS_MAC)
+    void shapeTextMac(int item) const;
+#endif
+    void splitItem(int item, int pos) const;
+
+    void resolveAdditionalFormats() const;
+};
+
+class QStackTextEngine : public QTextEngine {
+public:
+    enum { MemSize = 256*40/sizeof(void *) };
+    QStackTextEngine(const QString &string, const QFont &f);
+    LayoutData _layoutData;
+    void *_memory[MemSize];
+};
+
+
+Q_DECLARE_OPERATORS_FOR_FLAGS(QTextEngine::ShaperFlags)
+
+QT_END_NAMESPACE
+
+#endif // QTEXTENGINE_P_H