QTreeView focus events and losing selection

Dariusz

Hello

Say I have a programatic function that selects tree items in my view. However when I click back on view, it auto deselects all items and select the one I clicked on to...

How can I combat this behavior? I tried focusInEvent/set flag to ignore next selection change but I had no luck...

I'd like to control when click on tree view will cause selection "action" vs when to ignore it as I just want to bring the view to focus so I can execute say... short cut that would scroll to selected items...

TIA

mpergand

Hi,
Installing an EventFilter seems to be a solution.
This is what I'm using to prevent a right click to operate on inactive windows:

bool Application::eventFilter(QObject *obj, QEvent *event)
{
	if(event->type() EQ QEvent::MouseButtonPress)
		{
		QMouseEvent* mouseEvent=static_cast<QMouseEvent*>(event);
		QWidget* win=topLevelAt(mouseEvent->globalPos());

		if(mouseEvent->button() EQ Qt::RightButton)
			{
			if( win AND win!=activeWindow())
				{
				// empêche de faire un clic droit sur une fenetre non active
// prevent a right click on non active windows
                win->activateWindow();
                win->raise();
				return true;
				}
			}
....

In your case, replace Qt::RightButton by Qt::LeftButton
I'm installing this filter at app level (all top level widgets are concerned)
I think you can install this filter only for the widgets your treeview is in.

Dariusz

@mpergand Interesting thanks! It sounds like a solution. I will give it a go in a few.

TIA

CKurdu

You can subclass QTreeView and override setSelection. Firstly don't forget to set the multiselection mode.

view->setSelectionMode(QAbstractItemView::MultiSelection);

Override the setSelection method.

#define MAX_SELECT 3
void TreeView::setSelection(const QRect &rect, QItemSelectionModel::SelectionFlags command)
{
    if(command & QItemSelectionModel::Deselect)
    {
        QTreeView::setSelection(rect,command);
        return;
    }
    if(command & QItemSelectionModel::Clear)
    {
        //Actually purpose this "if branch" to disable clear
        //but MultiSelection mode already do that so execute below command is normal.
        QTreeView::setSelection(rect,command);
        return;
    }
    QModelIndexList  ls = this->selectedIndexes();
    int total = 0;
    for(int i=0; i< ls.size();i++)
    {
        if(ls[i].column() != 0) continue;
        QModelIndex p = ls[i].child(0,0);
        if(!p.isValid())
        {
            //I think when p is invalid ls[i] doesn't have any child. Maybe there is an another way to find this.
            total++;
        }else{
            QString child_data =  p.data().toString();
        }
    }
    if(total < MAX_SELECT )
    {
        QTreeView::setSelection(rect,command);
    }else{
        //You can scroll here.
    }
    return;
}