use QModelIndex to set background of a QTreeWidgetItem - c++

Question

I have MainWindow with a qTreeWidget. To add elements to this widget I've implemented this functions:
QTreeWidgetItem *MainWindow::prepareIt(QTreeWidgetItem *it, const QString &name, const QString &descr)
{
it->setText(0, name);
it->setText(1, descr);
return it;
}
QTreeWidgetItem *MainWindow::addRoot(const QString &name, const QString &descr)
{
QTreeWidgetItem *it = prepareIt(new QTreeWidgetItem(ui->treeWidget), name, descr);
it->setBackground( 0, QColor{112, 77, 75} );
it->setBackground( 1, QColor{78, 90, 110} );
return it;
}
QTreeWidgetItem *MainWindow::addChild(QTreeWidgetItem *parent, const QString &name, const QString &descr)
{
auto child = new QTreeWidgetItem(parent);
child->setBackground( 0, QColor{102, 67, 65} );
child->setBackground( 1, QColor{68, 80, 99} );
parent->addChild(prepareIt(child, name, descr));
return child;
}
...
addRoot(...);
addChild(parent,...);
...
It works as expected. Now I want to highlight some entrys in this qTreeWidget with a right mouse click. In the C-Tor of my MainWindow I implemented:
MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
...
ui->treeWidget->setContextMenuPolicy(Qt::CustomContextMenu);
connect(ui->treeWidget, SIGNAL (customContextMenuRequested(const QPoint &)), this, SLOT (rightClick(const QPoint &)));
...
}
and the slot is
void MainWindow::rightClick(const QPoint &pt)
{
QModelIndex idx = ui->treeWidget->indexAt(pt);
if (idx.isValid())
{
qDebug() << idx.data().toString();
qDebug() << idx << "index.row()" << idx.row() << " index.column()" << idx.column();
}
}
The slot is called as expected (the qDebug works), but how can I get from the QModelIndex idx to the corresponding QTreeWidgetItem for the highlighting? Or is there another way to make the highligt / change the color of the element?
Thanks in advance!!

Answer 1

Change the color of the cell:
A possible solution is to use the setData() method:
void MainWindow::rightClick(const QPoint &pt)
{
QModelIndex idx = ui->treeWidget->indexAt(pt);
if (idx.isValid())
{
ui->treeWidget->model()->setData(idx, QColor("red"), Qt::BackgroundRole);
}
}
But that will only change one cell, if you want to change the color then the entire row will have to be traversed:
Change the row color:
void MainWindow::rightClick(const QPoint &pt)
{
QModelIndex idx = ui->treeWidget->indexAt(pt);
if (idx.isValid())
{
for(int c=0; c < ui->treeWidget->columnCount(); ++c){
QModelIndex ix = idx.sibling(idx.row(), c);
ui->treeWidget->model()->setData(ix, QColor("red"), Qt::BackgroundRole);
}
}
}
Or:
void MainWindow::rightClick(const QPoint &pt)
{
QTreeWidgetItem *it = ui->treeWidget->itemAt(pt);
if (it)
{
for(int c=0; c < ui->treeWidget->columnCount(); ++c){
it->setBackground(c, QColor("red"));
}
}
}