qstyleditemdelegate.cpp

Go to the documentation of this file.

// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
 
#include "qstyleditemdelegate.h"
 
#include <qabstractitemmodel.h>
#include <qapplication.h>
#include <qbrush.h>
#if QT_CONFIG(lineedit)
#include <qlineedit.h>
#endif
#if QT_CONFIG(textedit)
#include <qtextedit.h>
#include <qplaintextedit.h>
#endif
#include <qpainter.h>
#include <qpalette.h>
#include <qpoint.h>
#include <qrect.h>
#include <qsize.h>
#include <qstyle.h>
#include <qdatetime.h>
#include <qstyleoption.h>
#include <qevent.h>
#include <qpixmap.h>
#include <qbitmap.h>
#include <qpixmapcache.h>
#include <qitemeditorfactory.h>
#include <private/qitemeditorfactory_p.h>
#include <qmetaobject.h>
#include <qtextlayout.h>
#include <private/qabstractitemdelegate_p.h>
#include <private/qabstractitemmodel_p.h>
#include <private/qtextengine_p.h>
#include <private/qlayoutengine_p.h>
#include <qdebug.h>
#include <qlocale.h>
#if QT_CONFIG(tableview)
#include <qtableview.h>
#endif
 
#include <array>
#include <limits.h>
 
QT_BEGIN_NAMESPACE
 
class QStyledItemDelegatePrivate : public QAbstractItemDelegatePrivate
{
    Q_DECLARE_PUBLIC(QStyledItemDelegate)
 
public:
    QStyledItemDelegatePrivate() : factory(nullptr) { }
 
    static const QWidget *widget(const QStyleOptionViewItem &option)
    {
        return option.widget;
    }
 
    const QItemEditorFactory *editorFactory() const
    {
        return factory ? factory : QItemEditorFactory::defaultFactory();
    }
 
    QItemEditorFactory *factory;
 
    mutable std::array<QModelRoleData, 7> modelRoleData = {
        QModelRoleData(Qt::FontRole),
        QModelRoleData(Qt::TextAlignmentRole),
        QModelRoleData(Qt::ForegroundRole),
        QModelRoleData(Qt::CheckStateRole),
        QModelRoleData(Qt::DecorationRole),
        QModelRoleData(Qt::DisplayRole),
        QModelRoleData(Qt::BackgroundRole)
    };
};
 
QStyledItemDelegate::QStyledItemDelegate(QObject *parent)
    : QAbstractItemDelegate(*new QStyledItemDelegatePrivate(), parent)
{
}
 
QStyledItemDelegate::~QStyledItemDelegate()
{
}
 
QString QStyledItemDelegate::displayText(const QVariant &value, const QLocale& locale) const
{
    return d_func()->textForRole(Qt::DisplayRole, value, locale);
}
 
void QStyledItemDelegate::initStyleOption(QStyleOptionViewItem *option,
                                         const QModelIndex &index) const
{
    option->index = index;
 
    Q_D(const QStyledItemDelegate);
    QModelRoleDataSpan modelRoleDataSpan = d->modelRoleData;
    index.multiData(modelRoleDataSpan);
 
    const QVariant *value;
    value = modelRoleDataSpan.dataForRole(Qt::FontRole);
    if (value->isValid() && !value->isNull()) {
        option->font = qvariant_cast<QFont>(*value).resolve(option->font);
        option->fontMetrics = QFontMetrics(option->font);
    }
 
    value = modelRoleDataSpan.dataForRole(Qt::TextAlignmentRole);
    if (value->isValid() && !value->isNull())
        option->displayAlignment = QtPrivate::legacyFlagValueFromModelData<Qt::Alignment>(*value);
 
    value = modelRoleDataSpan.dataForRole(Qt::ForegroundRole);
    if (value->canConvert<QBrush>())
        option->palette.setBrush(QPalette::Text, qvariant_cast<QBrush>(*value));
 
    value = modelRoleDataSpan.dataForRole(Qt::CheckStateRole);
    if (value->isValid() && !value->isNull()) {
        option->features |= QStyleOptionViewItem::HasCheckIndicator;
        option->checkState = QtPrivate::legacyEnumValueFromModelData<Qt::CheckState>(*value);
    }
 
    value = modelRoleDataSpan.dataForRole(Qt::DecorationRole);
    if (value->isValid() && !value->isNull()) {
        option->features |= QStyleOptionViewItem::HasDecoration;
        switch (value->userType()) {
        case QMetaType::QIcon: {
            option->icon = qvariant_cast<QIcon>(*value);
            if (option->icon.isNull()) {
                option->features &= ~QStyleOptionViewItem::HasDecoration;
                break;
            }
            QIcon::Mode mode;
            if (!(option->state & QStyle::State_Enabled))
                mode = QIcon::Disabled;
            else if (option->state & QStyle::State_Selected)
                mode = QIcon::Selected;
            else
                mode = QIcon::Normal;
            QIcon::State state = option->state & QStyle::State_Open ? QIcon::On : QIcon::Off;
            QSize actualSize = option->icon.actualSize(option->decorationSize, mode, state);
            // For highdpi icons actualSize might be larger than decorationSize, which we don't want. Clamp it to decorationSize.
            option->decorationSize = QSize(qMin(option->decorationSize.width(), actualSize.width()),
                                           qMin(option->decorationSize.height(), actualSize.height()));
            break;
        }
        case QMetaType::QColor: {
            QPixmap pixmap(option->decorationSize);
            pixmap.fill(qvariant_cast<QColor>(*value));
            option->icon = QIcon(pixmap);
            break;
        }
        case QMetaType::QImage: {
            QImage image = qvariant_cast<QImage>(*value);
            option->icon = QIcon(QPixmap::fromImage(image));
            option->decorationSize = image.deviceIndependentSize().toSize();
            break;
        }
        case QMetaType::QPixmap: {
            QPixmap pixmap = qvariant_cast<QPixmap>(*value);
            option->icon = QIcon(pixmap);
            option->decorationSize = pixmap.deviceIndependentSize().toSize();
            break;
        }
        default:
            break;
        }
    }
 
    value = modelRoleDataSpan.dataForRole(Qt::DisplayRole);
    if (value->isValid() && !value->isNull()) {
        option->features |= QStyleOptionViewItem::HasDisplay;
        option->text = displayText(*value, option->locale);
    }
 
    value = modelRoleDataSpan.dataForRole(Qt::BackgroundRole);
    option->backgroundBrush = qvariant_cast<QBrush>(*value);
 
    // disable style animations for checkboxes etc. within itemviews (QTBUG-30146)
    option->styleObject = nullptr;
}
 
void QStyledItemDelegate::paint(QPainter *painter,
        const QStyleOptionViewItem &option, const QModelIndex &index) const
{
    Q_ASSERT(index.isValid());
 
    QStyleOptionViewItem opt = option;
    initStyleOption(&opt, index);
 
    const QWidget *widget = QStyledItemDelegatePrivate::widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    style->drawControl(QStyle::CE_ItemViewItem, &opt, painter, widget);
}
 
QSize QStyledItemDelegate::sizeHint(const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
{
    QVariant value = index.data(Qt::SizeHintRole);
    if (value.isValid())
        return qvariant_cast<QSize>(value);
 
    QStyleOptionViewItem opt = option;
    initStyleOption(&opt, index);
    const QWidget *widget = QStyledItemDelegatePrivate::widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
    return style->sizeFromContents(QStyle::CT_ItemViewItem, &opt, QSize(), widget);
}
 
QWidget *QStyledItemDelegate::createEditor(QWidget *parent,
                                     const QStyleOptionViewItem &option,
                                     const QModelIndex &index) const
{
    Q_UNUSED(option);
    Q_D(const QStyledItemDelegate);
    if (!index.isValid())
        return nullptr;
    return d->editorFactory()->createEditor(index.data(Qt::EditRole).userType(), parent);
}
 
void QStyledItemDelegate::setEditorData(QWidget *editor, const QModelIndex &index) const
{
    QVariant v = index.data(Qt::EditRole);
    QByteArray n = editor->metaObject()->userProperty().name();
 
    if (!n.isEmpty()) {
        if (!v.isValid())
            v = QVariant(editor->property(n).metaType());
        editor->setProperty(n, v);
    }
}
 
void QStyledItemDelegate::setModelData(QWidget *editor,
                                 QAbstractItemModel *model,
                                 const QModelIndex &index) const
{
    Q_D(const QStyledItemDelegate);
    Q_ASSERT(model);
    Q_ASSERT(editor);
    QByteArray n = editor->metaObject()->userProperty().name();
    if (n.isEmpty())
        n = d->editorFactory()->valuePropertyName(
            model->data(index, Qt::EditRole).userType());
    if (!n.isEmpty())
        model->setData(index, editor->property(n), Qt::EditRole);
}
 
void QStyledItemDelegate::updateEditorGeometry(QWidget *editor,
                                         const QStyleOptionViewItem &option,
                                         const QModelIndex &index) const
{
    if (!editor)
        return;
    Q_ASSERT(index.isValid());
    const QWidget *widget = QStyledItemDelegatePrivate::widget(option);
 
    QStyleOptionViewItem opt = option;
    initStyleOption(&opt, index);
    opt.showDecorationSelected = editor->style()->styleHint(QStyle::SH_ItemView_ShowDecorationSelected, nullptr, editor);
 
    QStyle *style = widget ? widget->style() : QApplication::style();
    QRect geom = style->subElementRect(QStyle::SE_ItemViewItemText, &opt, widget);
    editor->setGeometry(geom);
}
 
QItemEditorFactory *QStyledItemDelegate::itemEditorFactory() const
{
    Q_D(const QStyledItemDelegate);
    return d->factory;
}
 
void QStyledItemDelegate::setItemEditorFactory(QItemEditorFactory *factory)
{
    Q_D(QStyledItemDelegate);
    d->factory = factory;
}
 
 
bool QStyledItemDelegate::eventFilter(QObject *object, QEvent *event)
{
    Q_D(QStyledItemDelegate);
    return d->editorEventFilter(object, event);
}
 
bool QStyledItemDelegate::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) || !(option.state & QStyle::State_Enabled)
        || !(flags & Qt::ItemIsEnabled))
        return false;
 
    // make sure that we have a check state
    QVariant value = index.data(Qt::CheckStateRole);
    if (!value.isValid())
        return false;
 
    const QWidget *widget = QStyledItemDelegatePrivate::widget(option);
    QStyle *style = widget ? widget->style() : QApplication::style();
 
    // make sure that we have the right event type
    if ((event->type() == QEvent::MouseButtonRelease)
        || (event->type() == QEvent::MouseButtonDblClick)
        || (event->type() == QEvent::MouseButtonPress)) {
        QStyleOptionViewItem viewOpt(option);
        initStyleOption(&viewOpt, index);
        QRect checkRect = style->subElementRect(QStyle::SE_ItemViewItemCheckIndicator, &viewOpt, widget);
        QMouseEvent *me = static_cast<QMouseEvent*>(event);
        if (me->button() != Qt::LeftButton || !checkRect.contains(me->position().toPoint()))
            return false;
 
        if ((event->type() == QEvent::MouseButtonPress)
            || (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 = QtPrivate::legacyEnumValueFromModelData<Qt::CheckState>(value);
    if (flags & Qt::ItemIsUserTristate)
        state = ((Qt::CheckState)((state + 1) % 3));
    else
        state = (state == Qt::Checked) ? Qt::Unchecked : Qt::Checked;
    return model->setData(index, state, Qt::CheckStateRole);
}
 
QT_END_NAMESPACE
 
#include "moc_qstyleditemdelegate.cpp"