qfontcombobox.cpp

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#include "qfontcombobox.h"

#ifndef QT_NO_FONTCOMBOBOX

#include <qstringlistmodel.h>
#include <qitemdelegate.h>
#include <qlistview.h>
#include <qpainter.h>
#include <qevent.h>
#include <qapplication.h>
#include <private/qcombobox_p.h>
#include <qdebug.h>

QT_BEGIN_NAMESPACE

static QFontDatabase::WritingSystem writingSystemForFont(const QFont &font, bool *hasLatin)
{
    *hasLatin = true;

    QList<QFontDatabase::WritingSystem> writingSystems = QFontDatabase().writingSystems(font.family());
//     qDebug() << font.family() << writingSystems;

    // this just confuses the algorithm below. Vietnamese is Latin with lots of special chars
    writingSystems.removeAll(QFontDatabase::Vietnamese);

    QFontDatabase::WritingSystem system = QFontDatabase::Any;

    if (!writingSystems.contains(QFontDatabase::Latin)) {
        *hasLatin = false;
        // we need to show something
        if (writingSystems.count())
            system = writingSystems.last();
    } else {
        writingSystems.removeAll(QFontDatabase::Latin);
    }

    if (writingSystems.isEmpty())
        return system;

    if (writingSystems.count() == 1 && writingSystems.at(0) > QFontDatabase::Cyrillic) {
        system = writingSystems.at(0);
        return system;
    }

    if (writingSystems.count() <= 2
        && writingSystems.last() > QFontDatabase::Armenian
        && writingSystems.last() < QFontDatabase::Vietnamese) {
        system = writingSystems.last();
        return system;
    }

    if (writingSystems.count() <= 5
        && writingSystems.last() >= QFontDatabase::SimplifiedChinese
        && writingSystems.last() <= QFontDatabase::Korean)
        system = writingSystems.last();

    return system;
}

class QFontFamilyDelegate : public QAbstractItemDelegate
{
    Q_OBJECT
public:
    explicit QFontFamilyDelegate(QObject *parent);

    // painting
    void paint(QPainter *painter,
               const QStyleOptionViewItem &option,
               const QModelIndex &index) const;

    QSize sizeHint(const QStyleOptionViewItem &option,
                   const QModelIndex &index) const;

    QIcon truetype;
    QIcon bitmap;
    QFontDatabase::WritingSystem writingSystem;
};

QFontFamilyDelegate::QFontFamilyDelegate(QObject *parent)
    : QAbstractItemDelegate(parent)
{
    truetype = QIcon(QLatin1String(":/trolltech/styles/commonstyle/images/fonttruetype-16.png"));
    bitmap = QIcon(QLatin1String(":/trolltech/styles/commonstyle/images/fontbitmap-16.png"));
    writingSystem = QFontDatabase::Any;
}

void QFontFamilyDelegate::paint(QPainter *painter,
                                const QStyleOptionViewItem &option,
                                const QModelIndex &index) const
{
    QString text = index.data(Qt::DisplayRole).toString();
    QFont font(option.font);
    font.setPointSize(QFontInfo(font).pointSize() * 3 / 2);
    QFont font2 = font;
    font2.setFamily(text);

    bool hasLatin;
    QFontDatabase::WritingSystem system = writingSystemForFont(font2, &hasLatin);
    if (hasLatin)
        font = font2;

    QRect r = option.rect;

    if (option.state & QStyle::State_Selected) {
        painter->save();
        painter->setBrush(option.palette.highlight());
        painter->setPen(Qt::NoPen);
        painter->drawRect(option.rect);
        painter->setPen(QPen(option.palette.highlightedText(), 0));
    }

    const QIcon *icon = &bitmap;
    if (QFontDatabase().isSmoothlyScalable(text)) {
        icon = &truetype;
    }
    QSize actualSize = icon->actualSize(r.size());

    icon->paint(painter, r, Qt::AlignLeft|Qt::AlignVCenter);
    if (option.direction == Qt::RightToLeft)
        r.setRight(r.right() - actualSize.width() - 4);
    else
        r.setLeft(r.left() + actualSize.width() + 4);

    QFont old = painter->font();
    painter->setFont(font);

    // If the ascent of the font is larger than the height of the rect,
    // we will clip the text, so it's better to align the tight bounding rect in this case
    // This is specifically for fonts where the ascent is very large compared to
    // the descent, like certain of the Stix family.
    QFontMetricsF fontMetrics(font);
    if (fontMetrics.ascent() > r.height()) {
        QRectF tbr = fontMetrics.tightBoundingRect(text);
        painter->drawText(r.x(), r.y() + (r.height() + tbr.height()) / 2.0, text);
    } else {
        painter->drawText(r, Qt::AlignVCenter|Qt::AlignLeading|Qt::TextSingleLine, text);
    }

    if (writingSystem != QFontDatabase::Any)
        system = writingSystem;

    if (system != QFontDatabase::Any) {
        int w = painter->fontMetrics().width(text + QLatin1String("  "));
        painter->setFont(font2);
        QString sample = QFontDatabase().writingSystemSample(system);
        if (option.direction == Qt::RightToLeft)
            r.setRight(r.right() - w);
        else
            r.setLeft(r.left() + w);
        painter->drawText(r, Qt::AlignVCenter|Qt::AlignLeading|Qt::TextSingleLine, sample);
    }
    painter->setFont(old);

    if (option.state & QStyle::State_Selected)
        painter->restore();

}

QSize QFontFamilyDelegate::sizeHint(const QStyleOptionViewItem &option,
                                    const QModelIndex &index) const
{
    QString text = index.data(Qt::DisplayRole).toString();
    QFont font(option.font);
//     font.setFamily(text);
    font.setPointSize(QFontInfo(font).pointSize() * 3/2);
    QFontMetrics fontMetrics(font);
    return QSize(fontMetrics.width(text), fontMetrics.height());
}


class QFontComboBoxPrivate : public QComboBoxPrivate
{
public:
    inline QFontComboBoxPrivate() { filters = QFontComboBox::AllFonts; }

    QFontComboBox::FontFilters filters;
    QFont currentFont;

    void _q_updateModel();
    void _q_currentChanged(const QString &);

    Q_DECLARE_PUBLIC(QFontComboBox)
};


void QFontComboBoxPrivate::_q_updateModel()
{
    Q_Q(QFontComboBox);
    const int scalableMask = (QFontComboBox::ScalableFonts | QFontComboBox::NonScalableFonts);
    const int spacingMask = (QFontComboBox::ProportionalFonts | QFontComboBox::MonospacedFonts);

    QStringListModel *m = qobject_cast<QStringListModel *>(q->model());
    if (!m)
        return;
    QFontFamilyDelegate *delegate = qobject_cast<QFontFamilyDelegate *>(q->view()->itemDelegate());
    QFontDatabase::WritingSystem system = delegate ? delegate->writingSystem : QFontDatabase::Any;

    QFontDatabase fdb;
    QStringList list = fdb.families(system);
    QStringList result;

    int offset = 0;
    QFontInfo fi(currentFont);

    for (int i = 0; i < list.size(); ++i) {
        if ((filters & scalableMask) && (filters & scalableMask) != scalableMask) {
            if (bool(filters & QFontComboBox::ScalableFonts) != fdb.isSmoothlyScalable(list.at(i)))
                continue;
        }
        if ((filters & spacingMask) && (filters & spacingMask) != spacingMask) {
            if (bool(filters & QFontComboBox::MonospacedFonts) != fdb.isFixedPitch(list.at(i)))
                continue;
        }
        result += list.at(i);
        if (list.at(i) == fi.family() || list.at(i).startsWith(fi.family() + QLatin1String(" [")))
            offset = result.count() - 1;
    }
    list = result;

    //we need to block the signals so that the model doesn't emit reset
    //this prevents the current index from changing
    //it will be updated just after this
    const bool old = m->blockSignals(true);
    m->setStringList(list);
    m->blockSignals(old);

    if (list.isEmpty()) {
        if (currentFont != QFont()) {
            currentFont = QFont();
            emit q->currentFontChanged(currentFont);
        }
    } else {
        q->setCurrentIndex(offset);
    }
}


void QFontComboBoxPrivate::_q_currentChanged(const QString &text)
{
    Q_Q(QFontComboBox);
    if (currentFont.family() != text) {
        currentFont.setFamily(text);
        emit q->currentFontChanged(currentFont);
    }
}

QFontComboBox::QFontComboBox(QWidget *parent)
    : QComboBox(*new QFontComboBoxPrivate, parent)
{
    Q_D(QFontComboBox);
    d->currentFont = font();
    setEditable(true);

    QStringListModel *m = new QStringListModel(this);
    setModel(m);
    setItemDelegate(new QFontFamilyDelegate(this));
    QListView *lview = qobject_cast<QListView*>(view());
    if (lview)
        lview->setUniformItemSizes(true);
    setWritingSystem(QFontDatabase::Any);

    connect(this, SIGNAL(currentIndexChanged(QString)),
            this, SLOT(_q_currentChanged(QString)));

    connect(qApp, SIGNAL(fontDatabaseChanged()),
            this, SLOT(_q_updateModel()));
}


QFontComboBox::~QFontComboBox()
{
}

void QFontComboBox::setWritingSystem(QFontDatabase::WritingSystem script)
{
    Q_D(QFontComboBox);
    QFontFamilyDelegate *delegate = qobject_cast<QFontFamilyDelegate *>(view()->itemDelegate());
    if (delegate)
        delegate->writingSystem = script;
    d->_q_updateModel();
}

QFontDatabase::WritingSystem QFontComboBox::writingSystem() const
{
    QFontFamilyDelegate *delegate = qobject_cast<QFontFamilyDelegate *>(view()->itemDelegate());
    if (delegate)
        return delegate->writingSystem;
    return QFontDatabase::Any;
}


void QFontComboBox::setFontFilters(FontFilters filters)
{
    Q_D(QFontComboBox);
    d->filters = filters;
    d->_q_updateModel();
}

QFontComboBox::FontFilters QFontComboBox::fontFilters() const
{
    Q_D(const QFontComboBox);
    return d->filters;
}

QFont QFontComboBox::currentFont() const
{
    Q_D(const QFontComboBox);
    return d->currentFont;
}

void QFontComboBox::setCurrentFont(const QFont &font)
{
    Q_D(QFontComboBox);
    if (font != d->currentFont) {
        d->currentFont = font;
        d->_q_updateModel();
        if (d->currentFont == font) { //else the signal has already be emitted by _q_updateModel
            emit currentFontChanged(d->currentFont);
        }
    }
}

bool QFontComboBox::event(QEvent *e)
{
    if (e->type() == QEvent::Resize) {
        QListView *lview = qobject_cast<QListView*>(view());
        if (lview)
            lview->window()->setFixedWidth(width() * 5 / 3);
    }
    return QComboBox::event(e);
}

QSize QFontComboBox::sizeHint() const
{
    QSize sz = QComboBox::sizeHint();
    QFontMetrics fm(font());
    sz.setWidth(fm.width(QLatin1Char('m'))*14);
    return sz;
}

QT_END_NAMESPACE

#include "qfontcombobox.moc"
#include "moc_qfontcombobox.cpp"

#endif // QT_NO_FONTCOMBOBOX