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QListWidget deselection and multiple selection

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kuhtee

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1

Friday, June 8th 2007, 10:11am

QListWidget deselection and multiple selection

Hi,

i'm just searching for more than a hour in the docu and can not find the solution for the following two problems with QListWidget:

a) i would like to deselect (deactivate) items in the QListWidget from the software

b) i use multiple selection: setSelectionMode(QAbstractItemView::MultiSelection)
I would like to pre-select more than one item from the software. If i use
setCurrentRow() i can only select on item (it toggles the selected item). How can i do multiple selections?

Your help is very welcome, i have already been gone throw the complete Members List of QListWidget but without finding a suitable method....

lifthrasir

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2

Friday, June 8th 2007, 11:06am

you must use QItemSelectionModel

Source code

 
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QItemSelectionModel * selectionModel = myListWidget->selectionModel();

// clear the selection
selectionModel->clearSelection();    // or QItemSelectionModel::clear()

// make a multiple selection (i'm not sure, maybe you need to use QItemSelection)
selectionModel->select(index1, QItemSelectionModel::SelectCurrent);
selectionModel->select(index2, QItemSelectionModel::SelectCurrent);
selectionModel->select(index3, QItemSelectionModel::SelectCurrent);

This post has been edited 1 times, last edit by "lifthrasir" (Jun 8th 2007, 11:07am)

kuhtee

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3

Friday, June 8th 2007, 12:06pm

lifthrasir, many thanksfor the hint,

i tried your proposal, using the following code:

Source code

 
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  QItemSelectionModel *selectionModel=listWidgetRunName->selectionModel();
  int row=get_the_row(i);
  QListWidgetItem *myItem=listWidgetRunName->item(row);
  QModelIndex myIndex=listWidgetRunName->indexFromItem(myItem);
  selectionModel->select(myIndex, QItemSelectionModel::Select);

Unfortunately the indexFromItem function is protected -> i can not use it. But i need to access the entries by the row index, because the row index is the data i am interested in.

The problem is now reduced to: How to get the QModelIndex for a given row in the QListWidget :-(

kuhtee

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4

Thursday, July 12th 2007, 5:44pm

If somebody is interested in a solution, i did the following:

I inherited a class from QListWidget that only made the protected function visible to the public.

Source code

 
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class ListWidgetMulti : public QListWidget
{
  Q_OBJECT

  public:
    ListWidgetMulti(QListWidget *parent = 0);
    QModelIndex indexFromItem ( QListWidgetItem * item ) const;
};

Source code

 
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ListWidgetMulti::ListWidgetMulti(QListWidget *parent)
   : QListWidget(parent)
{
}

QModelIndex ListWidgetMulti::indexFromItem ( QListWidgetItem * item ) const
{
  return QListWidget::indexFromItem(item);
}

Use this class instead of the standard QListWidget in the code above and it is possible to select multiple lines in a QListWidget from the code.

csw199

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5

Monday, March 10th 2008, 8:58am

lifthrasir's solution works fine, but is there a way to stop the signal selectionChanged() being emitted on every call to selectionModel->select(..).?

This really kills the application when you have a large number of items in the list that you wish to select.