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#include <QComboBox>
#include <QLineEdit>
#include <QDateTime>

#include "qgsvariantdelegate.h"

QgsVariantDelegate::QgsVariantDelegate( QObject *parent )
  : QItemDelegate( parent )
{
  mBoolExp.setPattern( QStringLiteral( "true|false" ) );
  mBoolExp.setCaseSensitivity( Qt::CaseInsensitive );

  mByteArrayExp.setPattern( QStringLiteral( "[\\x00-\\xff]*" ) );
  mCharExp.setPattern( QStringLiteral( "." ) );
  mColorExp.setPattern( QStringLiteral( "\\(([0-9]*),([0-9]*),([0-9]*),([0-9]*)\\)" ) );
  mDoubleExp.setPattern( QString() );
  mPointExp.setPattern( QStringLiteral( "\\((-?[0-9]*),(-?[0-9]*)\\)" ) );
  mRectExp.setPattern( QStringLiteral( "\\((-?[0-9]*),(-?[0-9]*),(-?[0-9]*),(-?[0-9]*)\\)" ) );
  mSignedIntegerExp.setPattern( QStringLiteral( "-?[0-9]*" ) );
  mSizeExp = mPointExp;
  mUnsignedIntegerExp.setPattern( QStringLiteral( "[0-9]*" ) );

  mDateExp.setPattern( QStringLiteral( "([0-9]{,4})-([0-9]{,2})-([0-9]{,2})" ) );
  mTimeExp.setPattern( QStringLiteral( "([0-9]{,2}):([0-9]{,2}):([0-9]{,2})" ) );
  mDateTimeExp.setPattern( mDateExp.pattern() + 'T' + mTimeExp.pattern() );
}

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

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

QWidget *QgsVariantDelegate::createEditor( QWidget *parent,
    const QStyleOptionViewItem &option,
    const QModelIndex &index ) const
{
  Q_UNUSED( option )
  if ( index.column() != 2 )
    return nullptr;

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

  QRegExp regExp;
  switch ( QgsVariantDelegate::type( originalValue ) )
  {
    case QVariant::ByteArray:
      regExp = mByteArrayExp;
      break;
    case QVariant::Char:
      regExp = mCharExp;
      break;
    case QVariant::Color:
      regExp = mColorExp;
      break;
    case QVariant::Date:
      regExp = mDateExp;
      break;
    case QVariant::DateTime:
      regExp = mDateTimeExp;
      break;
    case QVariant::Double:
      regExp = mDoubleExp;
      break;
    case QVariant::Int:
    case QVariant::LongLong:
      regExp = mSignedIntegerExp;
      break;
    case QVariant::Point:
      regExp = mPointExp;
      break;
    case QVariant::Rect:
      regExp = mRectExp;
      break;
    case QVariant::Size:
      regExp = mSizeExp;
      break;
    case QVariant::Time:
      regExp = mTimeExp;
      break;
    case QVariant::UInt:
    case QVariant::ULongLong:
      regExp = mUnsignedIntegerExp;
      break;
    default:
      ;
  }

  if ( QgsVariantDelegate::type( originalValue ) == QVariant::Bool )
  {
    QComboBox *comboBox = new QComboBox( parent );
    comboBox->addItem( QStringLiteral( "false" ) );
    comboBox->addItem( QStringLiteral( "true" ) );
    return comboBox;
  }
  else
  {
    QLineEdit *lineEdit = new QLineEdit( parent );
    lineEdit->setFrame( false );
    if ( !regExp.isEmpty() )
    {
      QValidator *validator = new QRegExpValidator( regExp, lineEdit );
      lineEdit->setValidator( validator );
    }
    return lineEdit;
  }
}

void QgsVariantDelegate::setEditorData( QWidget *editor,
                                        const QModelIndex &index ) const
{
  QVariant value = index.model()->data( index, Qt::UserRole );

  if ( QComboBox *comboBox = qobject_cast<QComboBox * >( editor ) )
  {
    comboBox->setCurrentIndex( value.toBool() ? 1 : 0 );
  }
  else if ( QLineEdit *lineEdit = qobject_cast<QLineEdit * >( editor ) )
  {
    lineEdit->setText( displayText( value ) );
  }
}

void QgsVariantDelegate::setModelData( QWidget *editor, QAbstractItemModel *model,
                                       const QModelIndex &index ) const
{
  QVariant originalValue = index.model()->data( index, Qt::UserRole );
  QVariant value;

  if ( QComboBox *comboBox = qobject_cast<QComboBox * >( editor ) )
  {
    value = comboBox->currentIndex() == 1;
  }
  else if ( 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;
    }

    switch ( QgsVariantDelegate::type( originalValue ) )
    {
      case QVariant::Char:
        value = text.at( 0 );
        break;
      case QVariant::Color:
        ( void )mColorExp.exactMatch( text );
        value = QColor( std::min( mColorExp.cap( 1 ).toInt(), 255 ),
                        std::min( mColorExp.cap( 2 ).toInt(), 255 ),
                        std::min( mColorExp.cap( 3 ).toInt(), 255 ),
                        std::min( mColorExp.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:
        ( void )mPointExp.exactMatch( text );
        value = QPoint( mPointExp.cap( 1 ).toInt(), mPointExp.cap( 2 ).toInt() );
        break;
      case QVariant::Rect:
        ( void )mRectExp.exactMatch( text );
        value = QRect( mRectExp.cap( 1 ).toInt(), mRectExp.cap( 2 ).toInt(),
                       mRectExp.cap( 3 ).toInt(), mRectExp.cap( 4 ).toInt() );
        break;
      case QVariant::Size:
        ( void )mSizeExp.exactMatch( text );
        value = QSize( mSizeExp.cap( 1 ).toInt(), mSizeExp.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( QgsVariantDelegate::type( originalValue ) );
    }
  }

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

bool QgsVariantDelegate::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 QgsVariantDelegate::displayText( const QVariant &value )
{
  switch ( QgsVariantDelegate::type( value ) )
  {
    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 QStringLiteral( "(%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 QStringLiteral( "<Invalid>" );
    case QVariant::Point:
    {
      QPoint point = value.toPoint();
      return QStringLiteral( "(%1,%2)" ).arg( point.x() ).arg( point.y() );
    }
    case QVariant::Rect:
    {
      QRect rect = value.toRect();
      return QStringLiteral( "(%1,%2,%3,%4)" )
             .arg( rect.x() ).arg( rect.y() )
             .arg( rect.width() ).arg( rect.height() );
    }
    case QVariant::Size:
    {
      QSize size = value.toSize();
      return QStringLiteral( "(%1,%2)" ).arg( size.width() ).arg( size.height() );
    }
    case QVariant::StringList:
      return value.toStringList().join( QStringLiteral( "," ) );
    case QVariant::Time:
      return value.toTime().toString( Qt::ISODate );
    default:
      break;
  }
  return QStringLiteral( "<%1>" ).arg( value.toString() );

}

/* hack to get "real" type of a variant, because QVariant::type() almost always returns QString */
QVariant::Type QgsVariantDelegate::type( const QVariant &value )
{
  if ( value.type() == QVariant::String )
  {
    QString str = value.toString();
    QRegExp regExp;
    bool ok;

    // is this a bool (true,false)
    regExp.setPattern( QStringLiteral( "true|false" ) );
    regExp.setCaseSensitivity( Qt::CaseInsensitive );
    if ( regExp.indexIn( str ) != -1 )
      return QVariant::Bool;

    // is this an int?
    // perhaps we should treat as double for more flexibility
    str.toInt( &ok );
    if ( ok )
      return QVariant::Int;

    // is this a double?
    str.toDouble( &ok );
    if ( ok )
      return QVariant::Double;

  }

  // fallback to QVariant::type()
  return value.type();
}