variantdelegate.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** You may use this file under the terms of the BSD license as follows:
 **
 ** "Redistribution and use in source and binary forms, with or without
 ** modification, are permitted provided that the following conditions are
 ** met:
 **   * Redistributions of source code must retain the above copyright
 **     notice, this list of conditions and the following disclaimer.
 **   * Redistributions in binary form must reproduce the above copyright
 **     notice, this list of conditions and the following disclaimer in
 **     the documentation and/or other materials provided with the
 **     distribution.
 **   * Neither the name of Nokia Corporation and its Subsidiary(-ies) nor
 **     the names of its contributors may be used to endorse or promote
 **     products derived from this software without specific prior written
 **     permission.
 **
 ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
 **
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtWidgets>

 #include "variantdelegate.h"

 VariantDelegate::VariantDelegate(QObject *parent)
     : QItemDelegate(parent)
 {
     boolExp.setPattern("true|false");
     boolExp.setCaseSensitivity(Qt::CaseInsensitive);

     byteArrayExp.setPattern("[\\x00-\\xff]*");
     charExp.setPattern(".");
     colorExp.setPattern("\\(([0-9]*),([0-9]*),([0-9]*),([0-9]*)\\)");
     doubleExp.setPattern("");
     pointExp.setPattern("\\((-?[0-9]*),(-?[0-9]*)\\)");
     rectExp.setPattern("\\((-?[0-9]*),(-?[0-9]*),(-?[0-9]*),(-?[0-9]*)\\)");
     signedIntegerExp.setPattern("-?[0-9]*");
     sizeExp = pointExp;
     unsignedIntegerExp.setPattern("[0-9]*");

     dateExp.setPattern("([0-9]{,4})-([0-9]{,2})-([0-9]{,2})");
     timeExp.setPattern("([0-9]{,2}):([0-9]{,2}):([0-9]{,2})");
     dateTimeExp.setPattern(dateExp.pattern() + "T" + timeExp.pattern());
 }

 void VariantDelegate::paint(QPainter *painter,
                             const QStyleOptionViewItem &option,
                             const QModelIndex &index) const
 {
     if (index.column() == 2) {
         QVariant value = index.model()->data(index, Qt::UserRole);
         if (!isSupportedType(value.type())) {
             QStyleOptionViewItem myOption = option;
             myOption.state &= ~QStyle::State_Enabled;
             QItemDelegate::paint(painter, myOption, index);
             return;
         }
     }

     QItemDelegate::paint(painter, option, index);
 }

 QWidget *VariantDelegate::createEditor(QWidget *parent,
         const QStyleOptionViewItem & /* option */,
         const QModelIndex &index) const
 {
     if (index.column() != 2)
         return 0;

     QVariant originalValue = index.model()->data(index, Qt::UserRole);
     if (!isSupportedType(originalValue.type()))
         return 0;

     QLineEdit *lineEdit = new QLineEdit(parent);
     lineEdit->setFrame(false);

     QRegExp regExp;

     switch (originalValue.type()) {
     case QVariant::Bool:
         regExp = boolExp;
         break;
     case QVariant::ByteArray:
         regExp = byteArrayExp;
         break;
     case QVariant::Char:
         regExp = charExp;
         break;
     case QVariant::Color:
         regExp = colorExp;
         break;
     case QVariant::Date:
         regExp = dateExp;
         break;
     case QVariant::DateTime:
         regExp = dateTimeExp;
         break;
     case QVariant::Double:
         regExp = doubleExp;
         break;
     case QVariant::Int:
     case QVariant::LongLong:
         regExp = signedIntegerExp;
         break;
     case QVariant::Point:
         regExp = pointExp;
         break;
     case QVariant::Rect:
         regExp = rectExp;
         break;
     case QVariant::Size:
         regExp = sizeExp;
         break;
     case QVariant::Time:
         regExp = timeExp;
         break;
     case QVariant::UInt:
     case QVariant::ULongLong:
         regExp = unsignedIntegerExp;
         break;
     default:
         ;
     }

     if (!regExp.isEmpty()) {
         QValidator *validator = new QRegExpValidator(regExp, lineEdit);
         lineEdit->setValidator(validator);
     }

     return lineEdit;
 }

 void VariantDelegate::setEditorData(QWidget *editor,
                                     const QModelIndex &index) const
 {
     QVariant value = index.model()->data(index, Qt::UserRole);
     if (QLineEdit *lineEdit = qobject_cast<QLineEdit *>(editor))
         lineEdit->setText(displayText(value));
 }

 void VariantDelegate::setModelData(QWidget *editor, QAbstractItemModel *model,
                                    const QModelIndex &index) const
 {
     QLineEdit *lineEdit = qobject_cast<QLineEdit *>(editor);
     if (!lineEdit->isModified())
         return;

     QString text = lineEdit->text();
     const QValidator *validator = lineEdit->validator();
     if (validator) {
         int pos;
         if (validator->validate(text, pos) != QValidator::Acceptable)
             return;
     }

     QVariant originalValue = index.model()->data(index, Qt::UserRole);
     QVariant value;

     switch (originalValue.type()) {
     case QVariant::Char:
         value = text.at(0);
         break;
     case QVariant::Color:
         colorExp.exactMatch(text);
         value = QColor(qMin(colorExp.cap(1).toInt(), 255),
                        qMin(colorExp.cap(2).toInt(), 255),
                        qMin(colorExp.cap(3).toInt(), 255),
                        qMin(colorExp.cap(4).toInt(), 255));
         break;
     case QVariant::Date:
         {
             QDate date = QDate::fromString(text, Qt::ISODate);
             if (!date.isValid())
                 return;
             value = date;
         }
         break;
     case QVariant::DateTime:
         {
             QDateTime dateTime = QDateTime::fromString(text, Qt::ISODate);
             if (!dateTime.isValid())
                 return;
             value = dateTime;
         }
         break;
     case QVariant::Point:
         pointExp.exactMatch(text);
         value = QPoint(pointExp.cap(1).toInt(), pointExp.cap(2).toInt());
         break;
     case QVariant::Rect:
         rectExp.exactMatch(text);
         value = QRect(rectExp.cap(1).toInt(), rectExp.cap(2).toInt(),
                       rectExp.cap(3).toInt(), rectExp.cap(4).toInt());
         break;
     case QVariant::Size:
         sizeExp.exactMatch(text);
         value = QSize(sizeExp.cap(1).toInt(), sizeExp.cap(2).toInt());
         break;
     case QVariant::StringList:
         value = text.split(",");
         break;
     case QVariant::Time:
         {
             QTime time = QTime::fromString(text, Qt::ISODate);
             if (!time.isValid())
                 return;
             value = time;
         }
         break;
     default:
         value = text;
         value.convert(originalValue.type());
     }

     model->setData(index, displayText(value), Qt::DisplayRole);
     model->setData(index, value, Qt::UserRole);
 }

 bool VariantDelegate::isSupportedType(QVariant::Type type)
 {
     switch (type) {
     case QVariant::Bool:
     case QVariant::ByteArray:
     case QVariant::Char:
     case QVariant::Color:
     case QVariant::Date:
     case QVariant::DateTime:
     case QVariant::Double:
     case QVariant::Int:
     case QVariant::LongLong:
     case QVariant::Point:
     case QVariant::Rect:
     case QVariant::Size:
     case QVariant::String:
     case QVariant::StringList:
     case QVariant::Time:
     case QVariant::UInt:
     case QVariant::ULongLong:
         return true;
     default:
         return false;
     }
 }

 QString VariantDelegate::displayText(const QVariant &value)
 {
     switch (value.type()) {
     case QVariant::Bool:
     case QVariant::ByteArray:
     case QVariant::Char:
     case QVariant::Double:
     case QVariant::Int:
     case QVariant::LongLong:
     case QVariant::String:
     case QVariant::UInt:
     case QVariant::ULongLong:
         return value.toString();
     case QVariant::Color:
         {
             QColor color = qvariant_cast<QColor>(value);
             return QString("(%1,%2,%3,%4)")
                    .arg(color.red()).arg(color.green())
                    .arg(color.blue()).arg(color.alpha());
         }
     case QVariant::Date:
         return value.toDate().toString(Qt::ISODate);
     case QVariant::DateTime:
         return value.toDateTime().toString(Qt::ISODate);
     case QVariant::Invalid:
         return "<Invalid>";
     case QVariant::Point:
         {
             QPoint point = value.toPoint();
             return QString("(%1,%2)").arg(point.x()).arg(point.y());
         }
     case QVariant::Rect:
         {
             QRect rect = value.toRect();
             return QString("(%1,%2,%3,%4)")
                    .arg(rect.x()).arg(rect.y())
                    .arg(rect.width()).arg(rect.height());
         }
     case QVariant::Size:
         {
             QSize size = value.toSize();
             return QString("(%1,%2)").arg(size.width()).arg(size.height());
         }
     case QVariant::StringList:
         return value.toStringList().join(",");
     case QVariant::Time:
         return value.toTime().toString(Qt::ISODate);
     default:
         break;
     }
     return QString("<%1>").arg(value.typeName());
 }