QItemSelectionModel::currentChanged and revert change

[Lykurg]

Hi,

I have a QListView and connect the signal from its selection model ItemSelectionModel::currentChanged(const QModelIndex &current, const QModelIndex &previous) to my slot. In that slot I want to revert the change. But I fail. How to revert an selection?

Example:

#include <QtGui>
#include "test.h"
 
int main(int argc, char **argv)
{
  QApplication app(argc, argv);
 
  Test w;
  w.show();
 
  return app.exec();
}

#include <QtGui>
#include "test.h"

int main(int argc, char **argv)
{
  QApplication app(argc, argv);
   
  Test w;
  w.show();

  return app.exec();
}

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#ifndef TEST_H
#define TEST_H
 
#include <QtGui>
 
class Test : public QWidget
{
  Q_OBJECT
  public:
    Test(QWidget *parent = 0);
    QListView *v;
    bool canceled;
 
  public slots:
    void changed( const QModelIndex & current, const QModelIndex & previous );
};
#endif

#ifndef TEST_H
#define TEST_H

#include <QtGui>

class Test : public QWidget
{
  Q_OBJECT
  public:
    Test(QWidget *parent = 0);
    QListView *v;
    bool canceled;

  public slots:
    void changed( const QModelIndex & current, const QModelIndex & previous );
};
#endif

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#include "test.h"
#include <QtGui>
 
Test::Test(QWidget *parent) 
  : QWidget(parent)
{
  QLayout *l = new QHBoxLayout(this);
  v = new QListView(this);
  v->setSelectionMode(QAbstractItemView::SingleSelection);
  QStringListModel *model = new QStringListModel();
  QStringList list;
  list << "a" << "b" << "c" << "d" << "e" << "f";
  model->setStringList(list);
  v->setModel(model);
  l->addWidget(v);
  setLayout(l);
  v->setCurrentIndex(model->index(0,0));
  connect(v->selectionModel(), SIGNAL(currentChanged(const QModelIndex& , const QModelIndex&)), this, SLOT(changed(const QModelIndex& , const QModelIndex&)));
  canceled = false;
}
 
void Test::changed( const QModelIndex & current, const QModelIndex & previous )
{
  qWarning() << current << previous;
  if (canceled)
  {
    canceled = false;
    return;
  }
 
  QMessageBox msgBox;
  msgBox.setStandardButtons(QMessageBox::Discard | QMessageBox::Cancel);
  int ret = msgBox.exec();
  switch (ret)
  {
    case QMessageBox::Discard:
      break;
    case QMessageBox::Cancel:
      canceled = true;
      v->selectionModel()->setCurrentIndex(previous, QItemSelectionModel::ClearAndSelect); // no "back change"
      //v->setCurrentIndex(previous); // all lines between current and previous are selected
      return;
      break;
  }
}

#include "test.h"
#include <QtGui>

Test::Test(QWidget *parent) 
  : QWidget(parent)
{
  QLayout *l = new QHBoxLayout(this);
  v = new QListView(this);
  v->setSelectionMode(QAbstractItemView::SingleSelection);
  QStringListModel *model = new QStringListModel();
  QStringList list;
  list << "a" << "b" << "c" << "d" << "e" << "f";
  model->setStringList(list);
  v->setModel(model);
  l->addWidget(v);
  setLayout(l);
  v->setCurrentIndex(model->index(0,0));
  connect(v->selectionModel(), SIGNAL(currentChanged(const QModelIndex& , const QModelIndex&)), this, SLOT(changed(const QModelIndex& , const QModelIndex&)));
  canceled = false;
}

void Test::changed( const QModelIndex & current, const QModelIndex & previous )
{
  qWarning() << current << previous;
  if (canceled)
  {
    canceled = false;
    return;
  }

  QMessageBox msgBox;
  msgBox.setStandardButtons(QMessageBox::Discard | QMessageBox::Cancel);
  int ret = msgBox.exec();
  switch (ret)
  {
    case QMessageBox::Discard:
      break;
    case QMessageBox::Cancel:
      canceled = true;
      v->selectionModel()->setCurrentIndex(previous, QItemSelectionModel::ClearAndSelect); // no "back change"
      //v->setCurrentIndex(previous); // all lines between current and previous are selected
      return;
      break;
  }
}

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Thanks for any help.