src/gui/itemviews/qitemdelegate.cpp

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/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
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#include "qitemdelegate.h"

#ifndef QT_NO_ITEMVIEWS
#include <qabstractitemmodel.h>
#include <qapplication.h>
#include <qbrush.h>
#include <qlineedit.h>
#include <qpainter.h>
#include <qpalette.h>
#include <qpoint.h>
#include <qrect.h>
#include <qsize.h>
#include <qstyle.h>
#include <qstyleoption.h>
#include <qevent.h>
#include <qpixmap.h>
#include <qbitmap.h>
#include <qpixmapcache.h>
#include <qitemeditorfactory.h>
#include <qmetaobject.h>
#include <qtextlayout.h>
#include <private/qobject_p.h>
#include <private/qdnd_p.h>
#include <qdebug.h>
#include <qlocale.h>

#include <limits.h>

class QItemDelegatePrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QItemDelegate)

public:
    QItemDelegatePrivate() : f(0), clipPainting(false) {}

    inline const QItemEditorFactory *editorFactory() const
        { return f ? f : QItemEditorFactory::defaultFactory(); }

    inline QIcon::Mode iconMode(QStyle::State state) const
        {
            if (!(state & QStyle::State_Enabled)) return QIcon::Disabled;
            if (state & QStyle::State_Selected) return QIcon::Selected;
            return QIcon::Normal;
        }

    inline QIcon::State iconState(QStyle::State state) const
        { return state & QStyle::State_Open ? QIcon::On : QIcon::Off; }

    inline static QString replaceNewLine(QString text)
        {
            const QChar nl = QLatin1Char('\n');
            for (int i = 0; i < text.count(); ++i)
                if (text.at(i) == nl)
                    text[i] = QChar::LineSeparator;
            return text;
        }

    void _q_commitDataAndCloseEditor(QWidget *editor);

    QItemEditorFactory *f;
    bool clipPainting;

    QRect textLayoutBounds(const QStyleOptionViewItemV2 &options) const;
    QSizeF doTextLayout(int lineWidth) const;
    mutable QTextLayout textLayout;
    mutable QTextOption textOption;
};

void QItemDelegatePrivate::_q_commitDataAndCloseEditor(QWidget *editor)
{
    Q_Q(QItemDelegate);
    emit q->commitData(editor);
    emit q->closeEditor(editor, QAbstractItemDelegate::SubmitModelCache);
}

QRect QItemDelegatePrivate::textLayoutBounds(const QStyleOptionViewItemV2 &option) const
{
    QRect rect = option.rect;
    const bool wrapText = option.features & QStyleOptionViewItemV2::WrapText;
    switch (option.decorationPosition) {
    case QStyleOptionViewItem::Left:
    case QStyleOptionViewItem::Right:
        rect.setWidth(INT_MAX >> 6);
        break;
    case QStyleOptionViewItem::Top:
    case QStyleOptionViewItem::Bottom:
        rect.setWidth(wrapText ? option.decorationSize.width() : (INT_MAX >> 6));
        break;
    }

    return rect;
}

QSizeF QItemDelegatePrivate::doTextLayout(int lineWidth) const
{
    QFontMetrics fontMetrics(textLayout.font());
    int leading = fontMetrics.leading();
    qreal height = 0;
    qreal widthUsed = 0;
    textLayout.beginLayout();
    while (true) {
        QTextLine line = textLayout.createLine();
        if (!line.isValid())
            break;
        line.setLineWidth(lineWidth);
        height += leading;
        line.setPosition(QPointF(0, height));
        height += line.height();
        widthUsed = qMax(widthUsed, line.naturalTextWidth());
    }
    textLayout.endLayout();
    return QSizeF(widthUsed, height);
}

QItemDelegate::QItemDelegate(QObject *parent)
    : QAbstractItemDelegate(*new QItemDelegatePrivate(), parent)
{

}

QItemDelegate::~QItemDelegate()
{
}

bool QItemDelegate::hasClipping() const
{
    Q_D(const QItemDelegate);
    return d->clipPainting;
}

void QItemDelegate::setClipping(bool clip)
{
    Q_D(QItemDelegate);
    d->clipPainting = clip;
}

void QItemDelegate::paint(QPainter *painter,
                          const QStyleOptionViewItem &option,
                          const QModelIndex &index) const
{
    Q_D(const QItemDelegate);
    Q_ASSERT(index.isValid());
    QStyleOptionViewItemV2 opt = setOptions(index, option);
    const QStyleOptionViewItemV2 *v2 = qstyleoption_cast<const QStyleOptionViewItemV2 *>(&option);
    opt.features = v2 ? v2->features : QStyleOptionViewItemV2::ViewItemFeatures(QStyleOptionViewItemV2::None);

    // prepare
    painter->save();
    if (d->clipPainting)
        painter->setClipRect(opt.rect);

    // get the data and the rectangles

    QVariant value;

    QIcon icon;
    QIcon::Mode iconMode = d->iconMode(option.state);
    QIcon::State iconState = d->iconState(option.state);

    QPixmap pixmap;
    QRect decorationRect;
    value = index.data(Qt::DecorationRole);
    if (value.isValid()) {
        if (value.type() == QVariant::Icon) {
            icon = qvariant_cast<QIcon>(value);
            decorationRect = QRect(QPoint(0, 0),
                                   icon.actualSize(option.decorationSize, iconMode, iconState));
        } else {
            pixmap = decoration(opt, value);
            decorationRect = QRect(QPoint(0, 0), pixmap.size());
        }
    }

    QString text;
    QRect displayRect;
    value = index.data(Qt::DisplayRole);
    if (value.isValid()) {
        if (value.type() == QVariant::Double)
            text = QLocale().toString(value.toDouble());
        else
            text = QItemDelegatePrivate::replaceNewLine(value.toString());

        displayRect = textRectangle(painter, d->textLayoutBounds(opt), opt.font, text);
    }

    QRect checkRect;
    Qt::CheckState checkState = Qt::Unchecked;
    value = index.data(Qt::CheckStateRole);
    if (value.isValid()) {
        checkState = static_cast<Qt::CheckState>(value.toInt());
        checkRect = check(opt, opt.rect, value);
    }

    // do the layout

    doLayout(opt, &checkRect, &decorationRect, &displayRect, false);

    // draw the item

    drawBackground(painter, opt, index);
    drawCheck(painter, opt, checkRect, checkState);
    if (!icon.isNull())
        icon.paint(painter, decorationRect, option.decorationAlignment, iconMode, iconState);
    else
        drawDecoration(painter, opt, decorationRect, pixmap);
    drawDisplay(painter, opt, displayRect, text);
    drawFocus(painter, opt, text.isEmpty() ? QRect() : displayRect);

    // done
    painter->restore();
}

QSize QItemDelegate::sizeHint(const QStyleOptionViewItem &option,
                              const QModelIndex &index) const
{
    QVariant value = index.data(Qt::SizeHintRole);
    if (value.isValid())
        return qvariant_cast<QSize>(value);
    QRect decorationRect = rect(option, index, Qt::DecorationRole);
    QRect displayRect = rect(option, index, Qt::DisplayRole);
    QRect checkRect = rect(option, index, Qt::CheckStateRole);

    doLayout(option, &checkRect, &decorationRect, &displayRect, true);

    return (decorationRect|displayRect|checkRect).size();
}

QWidget *QItemDelegate::createEditor(QWidget *parent,
                                     const QStyleOptionViewItem &,
                                     const QModelIndex &index) const
{
    Q_D(const QItemDelegate);
    if (!index.isValid())
        return 0;
    QVariant::Type t = static_cast<QVariant::Type>(index.data(Qt::EditRole).userType());
    const QItemEditorFactory *factory = d->f;
    if (factory == 0)
        factory = QItemEditorFactory::defaultFactory();
    return factory->createEditor(t, parent);
}

void QItemDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
#ifdef QT_NO_PROPERTIES
    Q_UNUSED(editor);
    Q_UNUSED(index);
#else
    Q_D(const QItemDelegate);
    QVariant v = index.data(Qt::EditRole);
    QByteArray n = editor->metaObject()->userProperty().name();

    // ### Remove in Qt 5: A work-around for missing "USER true" in
    // qdatetimeedit.h for QTimeEdit's time property and QDateEdit's date
    // property. It only triggers if the default user property "dateTime" is
    // reported for QTimeEdit and QDateEdit.
    if (n == "dateTime") {
        if (editor->inherits("QTimeEdit"))
            n = "time";
        else if (editor->inherits("QDateEdit"))
            n = "date";
    }

    if (n.isEmpty())
        n = d->editorFactory()->valuePropertyName(static_cast<QVariant::Type>(v.userType()));
    if (!n.isEmpty())
        editor->setProperty(n, v);
#endif
}

void QItemDelegate::setModelData(QWidget *editor,
                                 QAbstractItemModel *model,
                                 const QModelIndex &index) const
{
#ifdef QT_NO_PROPERTIES
    Q_UNUSED(model);
    Q_UNUSED(editor);
    Q_UNUSED(index);
#else
    Q_D(const QItemDelegate);
    Q_ASSERT(model);
    Q_ASSERT(editor);
    QByteArray n = editor->metaObject()->userProperty().name();
    if (n.isEmpty())
        n = d->editorFactory()->valuePropertyName(
            static_cast<QVariant::Type>(model->data(index, Qt::EditRole).userType()));
    if (!n.isEmpty())
        model->setData(index, editor->property(n), Qt::EditRole);
#endif
}

void QItemDelegate::updateEditorGeometry(QWidget *editor,
                                         const QStyleOptionViewItem &option,
                                         const QModelIndex &index) const
{
    if (!editor)
        return;
    Q_ASSERT(index.isValid());
    QPixmap pixmap = decoration(option, index.data(Qt::DecorationRole));
    QString text = QItemDelegatePrivate::replaceNewLine(index.data(Qt::DisplayRole).toString());
    QRect pixmapRect = QRect(QPoint(0, 0), option.decorationSize).intersected(pixmap.rect());
    QRect textRect = textRectangle(0, option.rect, option.font, text);
    QRect checkRect = check(option, textRect, index.data(Qt::CheckStateRole));
    QStyleOptionViewItem opt = option;
    opt.showDecorationSelected = true; // let the editor take up all available space
    doLayout(opt, &checkRect, &pixmapRect, &textRect, false);
    editor->setGeometry(textRect);
}

QItemEditorFactory *QItemDelegate::itemEditorFactory() const
{
    Q_D(const QItemDelegate);
    return d->f;
}

void QItemDelegate::setItemEditorFactory(QItemEditorFactory *factory)
{
    Q_D(QItemDelegate);
    d->f = factory;
}

void QItemDelegate::drawDisplay(QPainter *painter, const QStyleOptionViewItem &option,
                                const QRect &rect, const QString &text) const
{
    Q_D(const QItemDelegate);

    if (text.isEmpty())
        return;

    QPen pen = painter->pen();
    QPalette::ColorGroup cg = option.state & QStyle::State_Enabled
                              ? QPalette::Normal : QPalette::Disabled;
    if (cg == QPalette::Normal && !(option.state & QStyle::State_Active))
        cg = QPalette::Inactive;
    if (option.state & QStyle::State_Selected) {
        painter->fillRect(rect, option.palette.brush(cg, QPalette::Highlight));
        painter->setPen(option.palette.color(cg, QPalette::HighlightedText));
    } else {
        painter->setPen(option.palette.color(cg, QPalette::Text));
    }

    if (option.state & QStyle::State_Editing) {
        painter->save();
        painter->setPen(option.palette.color(cg, QPalette::Text));
        painter->drawRect(rect.adjusted(0, 0, -1, -1));
        painter->restore();
    }

    const QStyleOptionViewItemV2 opt = option;
    const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
    QRect textRect = rect.adjusted(textMargin, 0, -textMargin, 0); // remove width padding
    const bool wrapText = opt.features & QStyleOptionViewItemV2::WrapText;
    d->textOption.setWrapMode(wrapText ? QTextOption::WordWrap : QTextOption::ManualWrap);
    d->textOption.setTextDirection(option.direction);
    d->textOption.setAlignment(QStyle::visualAlignment(option.direction, option.displayAlignment));
    d->textLayout.setTextOption(d->textOption);
    d->textLayout.setFont(option.font);
    d->textLayout.setText(QItemDelegatePrivate::replaceNewLine(text));

    QSizeF textLayoutSize = d->doTextLayout(textRect.width());

    if (textRect.width() < textLayoutSize.width()
        || textRect.height() < textLayoutSize.height()) {
        QString elided;
        int start = 0;
        int end = text.indexOf(QChar::LineSeparator, start);
        if (end == -1) {
            elided += option.fontMetrics.elidedText(text, option.textElideMode, textRect.width());
        } else while (end != -1) {
            elided += option.fontMetrics.elidedText(text.mid(start, end - start),
                                                    option.textElideMode, textRect.width());
            start = end + 1;
            end = text.indexOf(QChar::LineSeparator, start);
        }
        d->textLayout.setText(elided);
        textLayoutSize = d->doTextLayout(textRect.width());
    }

    const QSize layoutSize(textRect.width(), int(textLayoutSize.height()));
    const QRect layoutRect = QStyle::alignedRect(option.direction, option.displayAlignment,
                                                  layoutSize, textRect);
    d->textLayout.draw(painter, layoutRect.topLeft(), QVector<QTextLayout::FormatRange>(), layoutRect);
}

void QItemDelegate::drawDecoration(QPainter *painter, const QStyleOptionViewItem &option,
                                   const QRect &rect, const QPixmap &pixmap) const
{
    if (pixmap.isNull() || !rect.isValid())
        return;
    QPoint p = QStyle::alignedRect(option.direction, option.decorationAlignment,
                                   pixmap.size(), rect).topLeft();
    if (option.state & QStyle::State_Selected) {
        QPixmap *pm = selected(pixmap, option.palette, option.state & QStyle::State_Enabled);
        painter->drawPixmap(p, *pm);
    } else {
        painter->drawPixmap(p, pixmap);
    }
}

void QItemDelegate::drawFocus(QPainter *painter,
                              const QStyleOptionViewItem &option,
                              const QRect &rect) const
{
    if ((option.state & QStyle::State_HasFocus) == 0 || !rect.isValid())
        return;
    QStyleOptionFocusRect o;
    o.QStyleOption::operator=(option);
    o.rect = rect;
    o.state |= QStyle::State_KeyboardFocusChange;
    QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled)
                              ? QPalette::Normal : QPalette::Disabled;
    o.backgroundColor = option.palette.color(cg, (option.state & QStyle::State_Selected)
                                             ? QPalette::Highlight : QPalette::Window);
    QApplication::style()->drawPrimitive(QStyle::PE_FrameFocusRect, &o, painter);
}

void QItemDelegate::drawCheck(QPainter *painter,
                              const QStyleOptionViewItem &option,
                              const QRect &rect, Qt::CheckState state) const
{
    if (!rect.isValid())
        return;

    QStyleOptionViewItem opt(option);
    opt.rect = rect;
    opt.state = opt.state & ~QStyle::State_HasFocus;

    switch (state) {
    case Qt::Unchecked:
        opt.state |= QStyle::State_Off;
        break;
    case Qt::PartiallyChecked:
        opt.state |= QStyle::State_NoChange;
        break;
    case Qt::Checked:
        opt.state |= QStyle::State_On;
        break;
    }

    QApplication::style()->drawPrimitive(QStyle::PE_IndicatorViewItemCheck, &opt, painter);
}

void QItemDelegate::drawBackground(QPainter *painter,
                                   const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
{
    if (option.showDecorationSelected && (option.state & QStyle::State_Selected)) {
        QPalette::ColorGroup cg = option.state & QStyle::State_Enabled
                                  ? QPalette::Normal : QPalette::Disabled;
        if (cg == QPalette::Normal && !(option.state & QStyle::State_Active))
            cg = QPalette::Inactive;

        painter->fillRect(option.rect, option.palette.brush(cg, QPalette::Highlight));
    } else {
        QVariant value = index.data(Qt::BackgroundRole);
        if (qVariantCanConvert<QBrush>(value)) {
            QPointF oldBO = painter->brushOrigin();
            painter->setBrushOrigin(option.rect.topLeft());
            painter->fillRect(option.rect, qvariant_cast<QBrush>(value));
            painter->setBrushOrigin(oldBO);
        }
    }
}


void QItemDelegate::doLayout(const QStyleOptionViewItem &option,
                             QRect *checkRect, QRect *pixmapRect, QRect *textRect,
                             bool hint) const
{
    Q_ASSERT(checkRect && pixmapRect && textRect);
    const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
    int x = option.rect.left();
    int y = option.rect.top();
    int w, h;

    textRect->adjust(-textMargin, 0, textMargin, 0); // add width padding
    if (textRect->height() == 0)
        textRect->setHeight(option.fontMetrics.lineSpacing());

    QSize pm(0, 0);
    if (pixmapRect->isValid()) {
        pm = pixmapRect->size();
        pm.rwidth() += 2 * textMargin;
    }
    if (hint) {
        h = qMax(checkRect->height(), qMax(textRect->height(), pm.height()));
        if (option.decorationPosition == QStyleOptionViewItem::Left
            || option.decorationPosition == QStyleOptionViewItem::Right) {
            w = textRect->width() + pm.width();
        } else {
            w = qMax(textRect->width(), pm.width());
        }
    } else {
        w = option.rect.width();
        h = option.rect.height();
    }

    int cw = 0;
    QRect check;
    if (checkRect->isValid()) {
        cw = checkRect->width() + 2 * textMargin;
        if (hint) w += cw;
        if (option.direction == Qt::RightToLeft) {
            check.setRect(x + w - cw, y, cw, h);
        } else {
            check.setRect(x, y, cw, h);
        }
    }

    // at this point w should be the *total* width

    QRect display;
    QRect decoration;
    switch (option.decorationPosition) {
    case QStyleOptionViewItem::Top: {
        if (!pm.isEmpty())
            pm.setHeight(pm.height() + textMargin); // add space
        h = hint ? textRect->height() : h - pm.height();

        if (option.direction == Qt::RightToLeft) {
            decoration.setRect(x, y, w - cw, pm.height());
            display.setRect(x, y + pm.height(), w - cw, h);
        } else {
            decoration.setRect(x + cw, y, w - cw, pm.height());
            display.setRect(x + cw, y + pm.height(), w - cw, h);
        }
        break; }
    case QStyleOptionViewItem::Bottom: {
        if (!textRect->isEmpty())
            textRect->setHeight(textRect->height() + textMargin); // add space
        h = hint ? textRect->height() + pm.height() : h;

        if (option.direction == Qt::RightToLeft) {
            display.setRect(x, y, w - cw, textRect->height());
            decoration.setRect(x, y + textRect->height(), w - cw, h - textRect->height());
        } else {
            display.setRect(x + cw, y, w - cw, textRect->height());
            decoration.setRect(x + cw, y + textRect->height(), w - cw, h - textRect->height());
        }
        break; }
    case QStyleOptionViewItem::Left: {
        if (option.direction == Qt::LeftToRight) {
            decoration.setRect(x + cw, y, pm.width(), h);
            display.setRect(decoration.right() + 1, y, w - pm.width() - cw, h);
        } else {
            display.setRect(x, y, w - pm.width() - cw, h);
            decoration.setRect(display.right() + 1, y, pm.width(), h);
        }
        break; }
    case QStyleOptionViewItem::Right: {
        if (option.direction == Qt::LeftToRight) {
            display.setRect(x + cw, y, w - pm.width() - cw, h);
            decoration.setRect(display.right() + 1, y, pm.width(), h);
        } else {
            decoration.setRect(x, y, pm.width(), h);
            display.setRect(decoration.right() + 1, y, w - pm.width() - cw, h);
        }
        break; }
    default:
        qWarning("doLayout: decoration position is invalid");
        decoration = *pixmapRect;
        break;
    }

    if (!hint) { // we only need to do the internal layout if we are going to paint
        *checkRect = QStyle::alignedRect(option.direction, Qt::AlignCenter,
                                         checkRect->size(), check);
        *pixmapRect = QStyle::alignedRect(option.direction, option.decorationAlignment,
                                          pixmapRect->size(), decoration);
        // the text takes up all awailable space, unless the decoration is not shown as selected
        if (option.showDecorationSelected)
            *textRect = display;
        else
            *textRect = QStyle::alignedRect(option.direction, option.displayAlignment,
                                            textRect->size().boundedTo(display.size()), display);
    } else {
        *checkRect = check;
        *pixmapRect = decoration;
        *textRect = display;
    }
}

QPixmap QItemDelegate::decoration(const QStyleOptionViewItem &option, const QVariant &variant) const
{
    Q_D(const QItemDelegate);
    switch (variant.type()) {
    case QVariant::Icon: {
        QIcon::Mode mode = d->iconMode(option.state);
        QIcon::State state = d->iconState(option.state);
        return qvariant_cast<QIcon>(variant).pixmap(option.decorationSize, mode, state); }
    case QVariant::Color: {
        static QPixmap pixmap(option.decorationSize);
        pixmap.fill(qvariant_cast<QColor>(variant));
        return pixmap; }
    default:
        break;
    }

    return qvariant_cast<QPixmap>(variant);
}

// hacky but faster version of "QString::sprintf("%d-%d", i, enabled)"
static QString qPixmapSerial(quint64 i, bool enabled)
{
    ushort arr[] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, '-', '0' + enabled };
    ushort *ptr = &arr[16];

    while (i > 0) {
        // hey - it's our internal representation, so use the ascii character after '9'
        // instead of 'a' for hex
        *(--ptr) = '0' + i % 16;
        i >>= 4;
    }

    return QString::fromUtf16(ptr, int(&arr[sizeof(arr) / sizeof(ushort)] - ptr));
}

QPixmap *QItemDelegate::selected(const QPixmap &pixmap, const QPalette &palette, bool enabled) const
{
    QString key = qPixmapSerial(qt_pixmap_id(pixmap), enabled);
    QPixmap *pm = QPixmapCache::find(key);
    if (!pm) {
        QImage img = pixmap.toImage().convertToFormat(QImage::Format_ARGB32_Premultiplied);

        QColor color = palette.color(enabled ? QPalette::Normal : QPalette::Disabled,
                                     QPalette::Highlight);
        color.setAlphaF(0.3);

        QPainter painter(&img);
        painter.setCompositionMode(QPainter::CompositionMode_SourceAtop);
        painter.fillRect(0, 0, img.width(), img.height(), color);
        painter.end();

        QPixmap selected = QPixmap(QPixmap::fromImage(img));
        QPixmapCache::insert(key, selected);
        pm = QPixmapCache::find(key);
    }
    return pm;
}

QRect QItemDelegate::rect(const QStyleOptionViewItem &option,
                          const QModelIndex &index, int role) const
{
    Q_D(const QItemDelegate);
    QVariant value = index.data(role);
    if (role == Qt::CheckStateRole)
        return check(option, option.rect, value);
    if (value.isValid()) {
        switch (value.type()) {
        case QVariant::Invalid:
            break;
        case QVariant::Pixmap:
            return QRect(QPoint(0, 0), qvariant_cast<QPixmap>(value).size());
        case QVariant::Image:
            return QRect(QPoint(0, 0), qvariant_cast<QImage>(value).size());
        case QVariant::Icon: {
            QIcon::Mode mode = d->iconMode(option.state);
            QIcon::State state = d->iconState(option.state);
            QIcon icon = qvariant_cast<QIcon>(value);
            QSize size = icon.actualSize(option.decorationSize, mode, state);
            return QRect(QPoint(0, 0), size); }
        case QVariant::Color:
            return QRect(QPoint(0, 0), option.decorationSize);
        case QVariant::String:
        default: {
            QString text = QItemDelegatePrivate::replaceNewLine(value.toString());
            value = index.data(Qt::FontRole);
            QFont fnt = qvariant_cast<QFont>(value).resolve(option.font);
            return textRectangle(0, d->textLayoutBounds(option), fnt, text); }
        }
    }
    return QRect();
}

QRect QItemDelegate::check(const QStyleOptionViewItem &option,
                           const QRect &bounding, const QVariant &value) const
{
    if (value.isValid()) {
        QStyleOptionButton opt;
        opt.QStyleOption::operator=(option);
        opt.rect = bounding;
        return QApplication::style()->subElementRect(QStyle::SE_ViewItemCheckIndicator, &opt);
    }
    return QRect();
}

QRect QItemDelegate::textRectangle(QPainter * /*painter*/, const QRect &rect,
                                   const QFont &font, const QString &text) const
{
    Q_D(const QItemDelegate);
    d->textOption.setWrapMode(QTextOption::WordWrap);
    d->textLayout.setTextOption(d->textOption);
    d->textLayout.setFont(font);
    d->textLayout.setText(QItemDelegatePrivate::replaceNewLine(text));
    const QSize size = d->doTextLayout(rect.width()).toSize();
    const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
    return QRect(0, 0, size.width() + 2 * textMargin, size.height());
}

bool QItemDelegate::eventFilter(QObject *object, QEvent *event)
{
    QWidget *editor = ::qobject_cast<QWidget*>(object);
    if (!editor)
        return false;
    if (event->type() == QEvent::KeyPress) {
        switch (static_cast<QKeyEvent *>(event)->key()) {
        case Qt::Key_Tab:
            emit commitData(editor);
            emit closeEditor(editor, QAbstractItemDelegate::EditNextItem);
            return true;
        case Qt::Key_Backtab:
            emit commitData(editor);
            emit closeEditor(editor, QAbstractItemDelegate::EditPreviousItem);
            return true;
        case Qt::Key_Enter:
        case Qt::Key_Return:
            // We want the editor to be able to process the key press
            // before committing the data (e.g. so it can do
            // validation/fixup of the input).
            QMetaObject::invokeMethod(this, "_q_commitDataAndCloseEditor",
                                      Qt::QueuedConnection, Q_ARG(QWidget*, editor));
            return false;
        case Qt::Key_Escape:
            // don't commit data
            emit closeEditor(editor, QAbstractItemDelegate::RevertModelCache);
            break;
        default:
            return false;
        }
        if (editor->parentWidget())
            editor->parentWidget()->setFocus();
        return true;
    } else if (event->type() == QEvent::FocusOut) {
        if (!editor->isActiveWindow() || (QApplication::focusWidget() != editor)) {
            QWidget *w = QApplication::focusWidget();
            while (w) { // don't worry about focus changes internally in the editor
                if (w == editor)
                    return false;
                w = w->parentWidget();
            }
#ifndef QT_NO_DRAGANDDROP
            // The window may lose focus during an drag operation.
            // i.e when dragging involves the taskbar on Windows.
            if (QDragManager::self() && QDragManager::self()->object != 0)
                return false;
#endif
            // Opening a modal dialog will start a new eventloop
            // that will process the deleteLater event.
            if (QApplication::activeModalWidget() && !QApplication::activeModalWidget()->isAncestorOf(editor))
                return false;
            emit commitData(editor);
            emit closeEditor(editor, NoHint);
        }
    }
    return false;
}

bool QItemDelegate::editorEvent(QEvent *event,
                                QAbstractItemModel *model,
                                const QStyleOptionViewItem &option,
                                const QModelIndex &index)
{
    Q_ASSERT(event);
    Q_ASSERT(model);

    // make sure that the item is checkable
    Qt::ItemFlags flags = model->flags(index);
    if (!(flags & Qt::ItemIsUserCheckable) || !((flags & Qt::ItemIsEnabled)))
        return false;

    // make sure that we have a check state
    QVariant value = index.data(Qt::CheckStateRole);
    if (!value.isValid())
        return false;

    // make sure that we have the right event type
    if ((event->type() == QEvent::MouseButtonRelease)
        || (event->type() == QEvent::MouseButtonDblClick)) {
        const int textMargin = QApplication::style()->pixelMetric(QStyle::PM_FocusFrameHMargin) + 1;
        QRect checkRect = QStyle::alignedRect(option.direction, Qt::AlignLeft | Qt::AlignVCenter,
                                              check(option, option.rect, Qt::Checked).size(),
                                              QRect(option.rect.x() + textMargin, option.rect.y(),
                                                    option.rect.width(), option.rect.height()));
        if (!checkRect.contains(static_cast<QMouseEvent*>(event)->pos()))
            return false;

        // eat the double click events inside the check rect
        if (event->type() == QEvent::MouseButtonDblClick)
            return true;

    } else if (event->type() == QEvent::KeyPress) {
        if (static_cast<QKeyEvent*>(event)->key() != Qt::Key_Space
         && static_cast<QKeyEvent*>(event)->key() != Qt::Key_Select)
            return false;
    } else {
        return false;
    }

    Qt::CheckState state = (static_cast<Qt::CheckState>(value.toInt()) == Qt::Checked
                            ? Qt::Unchecked : Qt::Checked);
    return model->setData(index, state, Qt::CheckStateRole);
}

QStyleOptionViewItem QItemDelegate::setOptions(const QModelIndex &index,
                                               const QStyleOptionViewItem &option) const
{
    QStyleOptionViewItem opt = option;

    // set font
    QVariant value = index.data(Qt::FontRole);
    if (value.isValid()){
        opt.font = qvariant_cast<QFont>(value).resolve(opt.font);
        opt.fontMetrics = QFontMetrics(opt.font);
    }

    // set text alignment
    value = index.data(Qt::TextAlignmentRole);
    if (value.isValid())
        opt.displayAlignment = (Qt::Alignment)value.toInt();

    // set foreground brush
    value = index.data(Qt::ForegroundRole);
    if (qVariantCanConvert<QBrush>(value))
        opt.palette.setBrush(QPalette::Text, qvariant_cast<QBrush>(value));

    return opt;
}

#include "moc_qitemdelegate.cpp"

#endif // QT_NO_ITEMVIEWS

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