qfont.cpp

qt-x11-opensource-src-4.1.4.tar.gz源码

{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
    return engine->fontDef.style != QFont::StyleNormal;
}

/*!
    Returns the style value of the matched window system font.

    \sa QFont::style()
*/
QFont::Style QFontInfo::style() const
{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
    return (QFont::Style)engine->fontDef.style;
}

/*!
    Returns the weight of the matched window system font.

    \sa QFont::weight(), bold()
*/
int QFontInfo::weight() const
{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
    return engine->fontDef.weight;

}

/*!
    \fn bool QFontInfo::bold() const

    Returns true if weight() would return a value greater than
    QFont::Normal; otherwise returns false.

    \sa weight(), QFont::bold()
*/

/*!
    Returns the underline value of the matched window system font.

  \sa QFont::underline()

  \internal

  Here we read the underline flag directly from the QFont.
  This is OK for X11 and for Windows because we always get what we want.
*/
bool QFontInfo::underline() const
{
    return d->underline;
}

/*!
    Returns the overline value of the matched window system font.

    \sa QFont::overline()

    \internal

    Here we read the overline flag directly from the QFont.
    This is OK for X11 and for Windows because we always get what we want.
*/
bool QFontInfo::overline() const
{
    return d->overline;
}

/*!
    Returns the strikeout value of the matched window system font.

  \sa QFont::strikeOut()

  \internal Here we read the strikeOut flag directly from the QFont.
  This is OK for X11 and for Windows because we always get what we want.
*/
bool QFontInfo::strikeOut() const
{
    return d->strikeOut;
}

/*!
    Returns the fixed pitch value of the matched window system font.

    \sa QFont::fixedPitch()
*/
bool QFontInfo::fixedPitch() const
{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
#ifdef Q_OS_MAC
    if (!engine->fontDef.fixedPitchComputed) {
        QChar ch[2] = { QChar('i'), QChar('m') };
        QGlyphLayout g[2];
        int l = 2;
        engine->stringToCMap(ch, 2, g, &l, 0);
        engine->fontDef.fixedPitch = g[0].advance.x == g[1].advance.x;
        engine->fontDef.fixedPitchComputed = true;
    }
#endif
    return engine->fontDef.fixedPitch;
}

/*!
    Returns the style of the matched window system font.

    Currently only returns the style hint set in QFont.

    \sa QFont::styleHint() QFont::StyleHint
*/
QFont::StyleHint QFontInfo::styleHint() const
{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
    return (QFont::StyleHint) engine->fontDef.styleHint;
}

/*!
    Returns true if the font is a raw mode font; otherwise returns
    false.

    If it is a raw mode font, all other functions in QFontInfo will
    return the same values set in the QFont, regardless of the font
    actually used.

    \sa QFont::rawMode()
*/
bool QFontInfo::rawMode() const
{
    return d->rawMode;
}

/*!
    Returns true if the matched window system font is exactly the same
    as the one specified by the font; otherwise returns false.

    \sa QFont::exactMatch()
*/
bool QFontInfo::exactMatch() const
{
    QFontEngine *engine = d->engineForScript(QUnicodeTables::Common);
    Q_ASSERT(engine != 0);
    return (d->rawMode
            ? engine->type() != QFontEngine::Box
            : d->request.exactMatch(engine->fontDef));
}




// **********************************************************************
// QFontCache
// **********************************************************************

#ifdef QFONTCACHE_DEBUG
// fast timeouts for debugging
static const int fast_timeout =   1000;  // 1s
static const int slow_timeout =   5000;  // 5s
#else
static const int fast_timeout =  10000; // 10s
static const int slow_timeout = 300000; //  5m
#endif // QFONTCACHE_DEBUG

QFontCache *QFontCache::instance = 0;
const uint QFontCache::min_cost = 4*1024; // 4mb


QFontCache::QFontCache()
    : QObject(qApp), total_cost(0), max_cost(min_cost),
      current_timestamp(0), fast(false), timer_id(-1)
{
    Q_ASSERT(instance == 0);
    instance = this;
}

QFontCache::~QFontCache()
{
    {
        EngineDataCache::Iterator it = engineDataCache.begin(),
                                 end = engineDataCache.end();
        while (it != end) {
            if (it.value()->ref == 0)
                delete it.value();
            else
                FC_DEBUG("QFontCache::~QFontCache: engineData %p still has refcount %d",
                         it.value(), it.value()->ref.atomic);
            ++it;
        }
    }
    EngineCache::Iterator it = engineCache.begin(),
                         end = engineCache.end();
    while (it != end) {
        if (--it.value().data->cache_count == 0) {
            if (it.value().data->ref == 0) {
                FC_DEBUG("QFontCache::~QFontCache: deleting engine %p key=(%d / %g %d %d %d %d)",
                         it.value().data, it.key().script, it.key().def.pointSize,
                         it.key().def.pixelSize, it.key().def.weight, it.key().def.style,
                         it.key().def.fixedPitch);

                delete it.value().data;
            } else {
                FC_DEBUG("QFontCache::~QFontCache: engine = %p still has refcount %d",
                         it.value().data, it.value().data->ref.atomic);
            }
        }
        ++it;
    }
    instance = 0;
}

#ifdef Q_WS_QWS
void QFontCache::clear()
{
    {
        EngineDataCache::Iterator it = engineDataCache.begin(),
                                 end = engineDataCache.end();
        while (it != end) {
            QFontEngineData *data = it.value();
            if (data->engine)
                data->engine->ref.deref();
            data->engine = 0;
            ++it;
        }
    }

    EngineCache::Iterator it = engineCache.begin(),
                         end = engineCache.end();
    while (it != end) {
        if (--it.value().data->cache_count == 0) {
            if (it.value().data->ref == 0) {
                FC_DEBUG("QFontCache::~QFontCache: deleting engine %p key=(%d / %g %d %d %d %d)",
                         it.value().data, it.key().script, it.key().def.pointSize,
                         it.key().def.pixelSize, it.key().def.weight, it.key().def.style,
                         it.key().def.fixedPitch);
                delete it.value().data;
            } else {
                FC_DEBUG("QFontCache::~QFontCache: engine = %p still has refcount %d",
                         it.value().data, it.value().data->ref.atomic);
            }
        }
        ++it;
    }
}
#endif

QFontEngineData *QFontCache::findEngineData(const Key &key) const
{
    EngineDataCache::ConstIterator it = engineDataCache.find(key),
                                  end = engineDataCache.end();
    if (it == end) return 0;

    // found
    return it.value();
}

void QFontCache::insertEngineData(const Key &key, QFontEngineData *engineData)
{
    FC_DEBUG("QFontCache: inserting new engine data %p", engineData);

    engineDataCache.insert(key, engineData);
    increaseCost(sizeof(QFontEngineData));
}

QFontEngine *QFontCache::findEngine(const Key &key)
{
    EngineCache::Iterator it = engineCache.find(key),
                         end = engineCache.end();
    if (it == end) return 0;

    // found... update the hitcount and timestamp
    it.value().hits++;
    it.value().timestamp = ++current_timestamp;

    FC_DEBUG("QFontCache: found font engine\n"
            "  %p: timestamp %4u hits %3u ref %2d/%2d, type '%s'",
            it.value().data, it.value().timestamp, it.value().hits,
            it.value().data->ref.atomic, it.value().data->cache_count,
            it.value().data->name());

    return it.value().data;
}

void QFontCache::insertEngine(const Key &key, QFontEngine *engine)
{
    FC_DEBUG("QFontCache: inserting new engine %p", engine);

    Engine data(engine);
    data.timestamp = ++current_timestamp;

    engineCache.insert(key, data);

    // only increase the cost if this is the first time we insert the engine
    if (engine->cache_count == 0)
        increaseCost(engine->cache_cost);

    ++engine->cache_count;
}

void QFontCache::increaseCost(uint cost)
{
    cost = (cost + 512) / 1024; // store cost in kb
    cost = cost > 0 ? cost : 1;
    total_cost += cost;

    FC_DEBUG("  COST: increased %u kb, total_cost %u kb, max_cost %u kb",
            cost, total_cost, max_cost);

    if (total_cost > max_cost) {
        max_cost = total_cost;

        if (timer_id == -1 || ! fast) {
            FC_DEBUG("  TIMER: starting fast timer (%d ms)", fast_timeout);

            if (timer_id != -1) killTimer(timer_id);
            timer_id = startTimer(fast_timeout);
            fast = true;
        }
    }
}

void QFontCache::decreaseCost(uint cost)
{
    cost = (cost + 512) / 1024; // cost is stored in kb
    cost = cost > 0 ? cost : 1;
    Q_ASSERT(cost <= total_cost);
    total_cost -= cost;

    FC_DEBUG("  COST: decreased %u kb, total_cost %u kb, max_cost %u kb",
            cost, total_cost, max_cost);
}

#if defined(Q_WS_WIN) || defined (Q_WS_QWS)
void QFontCache::cleanupPrinterFonts()
{
    FC_DEBUG("QFontCache::cleanupPrinterFonts");

    {
        FC_DEBUG("  CLEAN engine data:");

        // clean out all unused engine datas
        EngineDataCache::Iterator it = engineDataCache.begin(),
                                 end = engineDataCache.end();
        while (it != end) {
            if (it.key().screen == 0) {
                ++it;
                continue;
            }

            if(it.value()->ref != 0) {
#ifdef Q_WS_WIN
                for(int i = 0; i < QUnicodeTables::ScriptCount; ++i) {
                    if(it.value()->engines[i]) {
                        it.value()->engines[i]->ref.deref();
                        it.value()->engines[i] = 0;
                    }
                }
#else
                if (it.value()->engine) {
                    it.value()->engine->ref.deref();
                    it.value()->engine = 0;
                }
#endif
                ++it;
            } else {

                EngineDataCache::Iterator rem = it++;

                decreaseCost(sizeof(QFontEngineData));

                FC_DEBUG("    %p", rem.value());

                delete rem.value();
                engineDataCache.erase(rem);
            }
        }
    }

    EngineCache::Iterator it = engineCache.begin(),
                         end = engineCache.end();
    while(it != end) {
        if (it.value().data->ref != 0 || it.key().screen == 0) {
            ++it;
            continue;
        }

        FC_DEBUG("    %p: timestamp %4u hits %2u ref %2d/%2d, type '%s'",
                  it.value().data, it.value().timestamp, it.value().hits,
                  it.value().data->ref.atomic, it.value().data->cache_count,
                  it.value().data->name());

        if (--it.value().data->cache_count == 0) {
            FC_DEBUG("    DELETE: last occurence in cache");

            decreaseCost(it.value().data->cache_cost);
            delete it.value().data;
        }

        engineCache.erase(it++);
    }
}
#endif

void QFontCache::timerEvent(QTimerEvent *)
{
    FC_DEBUG("QFontCache::timerEvent: performing cache maintenance (timestamp %u)",
              current_timestamp);

    if (total_cost <= max_cost && max_cost <= min_cost) {
        FC_DEBUG("  cache redused sufficiently, stopping timer");

        killTimer(timer_id);
        timer_id = -1;
        fast = false;

        return;
    }

    // go through the cache and count up everything in use
    uint in_use_cost = 0;

    {
        FC_DEBUG("  SWEEP engine data:");

        // make sure the cost of each engine data is at least 1kb
        const uint engine_data_cost =
            sizeof(QFontEngineData) > 1024 ? sizeof(QFontEngineData) : 1024;

        EngineDataCache::ConstIterator it = engineDataCache.begin(),
                                      end = engineDataCache.end();
        for (; it != end; ++it) {
#ifdef QFONTCACHE_DEBUG
            FC_DEBUG("    %p: ref %2d", it.value(), int(it.value()->ref));

#  if defined(Q_WS_X11) || defined(Q_WS_WIN)
            // print out all engines
            for (int i = 0; i < QUnicodeTables::ScriptCount; ++i) {
                if (! it.value()->engines[i])
                    continue;
                FC_DEBUG("      contains %p", it.value()->engines[i]);
            }
#  endif // Q_WS_X11 || Q_WS_WIN
#endif // QFONTCACHE_DEBUG

            if (it.value()->ref != 0)
                in_use_cost += engine_data_cost;
        }
    }

    {
        FC_DEBUG("  SWEEP engine:");

        EngineCache::ConstIterator it = engineCache.begin(),
                                  end = engineCache.end();
        for (; it != end; ++it) {
            FC_DEBUG("    %p: timestamp %4u hits %2u ref %2d/%2d, cost %u bytes",
                      it.value().data, it.value().timestamp, it.value().hits,
                      it.value().data->ref.atomic, it.value().data->cache_count,
                      it.value().data->cache_cost);

            if (it.value().data->ref != 0)
                in_use_cost += it.value().data->cache_cost / it.value().data->cache_count;
        }

        // attempt to make up for rounding errors
        in_use_cost += engineCache.size();
    }

    in_use_cost = (in_use_cost + 512) / 1024; // cost is stored in kb

    /*
      calculate the new maximum cost for the cache

      NOTE: in_use_cost is *not* correct due to rounding errors in the
      above algorithm.  instead of worrying about getting the
      calculation correct, we are more interested in spe