Exemple #1
0
void QFontDatabase::load(const QFontPrivate *d, int script)
{
    // sanity checks
    if (!qApp)
        qWarning("QFontDatabase::load: Must construct QApplication first");
    Q_ASSERT(script >= 0 && script < QUnicodeTables::ScriptCount);

    // normalize the request to get better caching
    QFontDef req = d->request;
    if (req.pixelSize <= 0)
        req.pixelSize = floor((100.0 * req.pointSize * d->dpi) / 72. + 0.5) / 100;
    if (req.pixelSize < 1)
        req.pixelSize = 1;
    if (req.weight == 0)
        req.weight = QFont::Normal;
    if (req.stretch == 0)
        req.stretch = 100;

    QFontCache::Key key(req, d->rawMode ? QUnicodeTables::Common : script, d->screen);
    if (!d->engineData)
        getEngineData(d, key);

    // the cached engineData could have already loaded the engine we want
    if (d->engineData->engines[script])
        return;

    QFontEngine *fe = QFontCache::instance()->findEngine(key);

    // set it to the actual pointsize, so QFontInfo will do the right thing
    if (req.pointSize < 0)
        req.pointSize = req.pixelSize*72./d->dpi;

    if (!fe) {
        if (qt_enable_test_font && req.family == QLatin1String("__Qt__Box__Engine__")) {
            fe = new QTestFontEngine(req.pixelSize);
            fe->fontDef = req;
        } else {
            QMutexLocker locker(fontDatabaseMutex());
            if (!privateDb()->count)
                initializeDb();
            fe = loadWin(d, script, req);
        }
        if (!fe) {
            fe = new QFontEngineBox(req.pixelSize);
            fe->fontDef = QFontDef();
        }
    }
    d->engineData->engines[script] = fe;
    fe->ref.ref();
    QFontCache::instance()->insertEngine(key, fe);
}
void tst_QFontCache::clear()
{
#ifdef QT_BUILD_INTERNAL
    QFontEngine_startCollectingEngines();
#else
    // must not crash, at very least ;)
#endif

    QFontEngine *fontEngine = 0;

    {
        // we're never caching the box (and the "test") font engines
        // let's ensure we're not leaking them as well as the cached ones
        qt_setQtEnableTestFont(true);

        QFont f;
        f.setFamily("__Qt__Box__Engine__");
        f.exactMatch(); // loads engine
    }
    {
        QFontDatabase db;

        QFont f;
        f.setStyleHint(QFont::Serif);
        const QString familyForHint(f.defaultFamily());

        // it should at least return a family that is available
        QVERIFY(db.hasFamily(familyForHint));
        f.exactMatch(); // loads engine

        fontEngine = QFontPrivate::get(f)->engineForScript(QChar::Script_Common);
        QVERIFY(fontEngine);
        QVERIFY(QFontCache::instance()->engineCacheCount.value(fontEngine) > 0); // ensure it is cached

        // acquire the engine to use it somewhere else:
        // (e.g. like the we do in QFontSubset() or like QRawFont does in fromFont())
        fontEngine->ref.ref();

        // cache the engine once again; there is a special case when the engine is cached more than once
        QFontCache::instance()->insertEngine(QFontCache::Key(QFontDef(), 0, 0), fontEngine);
    }

    // use it:
    // e.g. fontEngine->stringToCMap(..);

    // and whilst it is alive, don't hesitate to add/remove the app-local fonts:
    // (QFontDatabase::{add,remove}ApplicationFont() clears the cache)
    QFontCache::instance()->clear();

    // release the acquired engine:
    if (fontEngine) {
        if (!fontEngine->ref.deref())
            delete fontEngine;
        fontEngine = 0;
    }

    // we may even exit the application now:
    QFontCache::instance()->cleanup();

#ifdef QT_BUILD_INTERNAL
    QList<QFontEngine *> leakedEngines = QFontEngine_stopCollectingEngines();
    for (int i = 0; i < leakedEngines.size(); ++i) qWarning() << i << leakedEngines.at(i) << leakedEngines.at(i)->ref.load();
    // and we are not leaking!
    QCOMPARE(leakedEngines.size(), 0);
#endif
}