variantdelegate.cpp Example File | Qt Widgets 5.12.5

Qt 5.12 | Qt Widgets | Settings Editor Example | variantdelegate.cpp Example File

Qt 5.12.5 Reference Documentation

# variantdelegate.cpp Example File

tools/settingseditor/variantdelegate.cpp

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      ** This file is part of the examples of the Qt Toolkit.
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      #include <QtWidgets>

      #include "variantdelegate.h"

      VariantDelegate::VariantDelegate(QObject *parent)
          : QItemDelegate(parent)
      {
          boolExp.setPattern("true|false");
          boolExp.setPatternOptions(QRegularExpression::CaseInsensitiveOption);

          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);

          QRegularExpression 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.isValid()) {
              QValidator *validator = new QRegularExpressionValidator(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;
          QRegularExpressionMatch match;

          switch (originalValue.type()) {
          case QVariant::Char:
              value = text.at(0);
              break;
          case QVariant::Color:
              match = colorExp.match(text);
              value = QColor(qMin(match.captured(1).toInt(), 255),
                             qMin(match.captured(2).toInt(), 255),
                             qMin(match.captured(3).toInt(), 255),
                             qMin(match.captured(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:
              match = pointExp.match(text);
              value = QPoint(match.captured(1).toInt(), match.captured(2).toInt());
              break;
          case QVariant::Rect:
              match = rectExp.match(text);
              value = QRect(match.captured(1).toInt(), match.captured(2).toInt(),
                            match.captured(3).toInt(), match.captured(4).toInt());
              break;
          case QVariant::Size:
              match = sizeExp.match(text);
              value = QSize(match.captured(1).toInt(), match.captured(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());
      }