How to add a QAction to a QListWidget - qt

Question

I have the following code:
roslaserscandoialog.h
public:
explicit ROSLaserScanDialog(QWidget *parent = nullptr);
~ROSLaserScanDialog();
QListWidgetItem *createItemFromAction(const QAction* action);
private slots:
void on_listWidget_itemClicked(QListWidgetItem *item);
private:
Ui::ROSLaserScanDialog *ui;
QAction *mAddMsgs;
QAction *mDeleteMsgs;
roslaserscandoialog.cpp
ROSLaserScanDialog::ROSLaserScanDialog(QWidget *parent) :
QDialog(parent),
ui(new Ui::ROSLaserScanDialog)
{
ui->setupUi(this);
connect(ui->listWidget,SIGNAL(on_listWidget_itemClicked(QListWidgetItem*)),this,SLOT(createItemFromAction(QListWidgetItem*)));
}
QListWidgetItem *ROSLaserScanDialog::createItemFromAction(const QAction *action)
{
Q_ASSERT( action );
QListWidgetItem *mAddMsgs = new QListWidgetItem();
mAddMsgs->setText( action->text() );
mAddMsgs->setToolTip( action->toolTip() );
mAddMsgs->setIcon( action->icon() );
// ...
return mAddMsgs;
}
void ROSLaserScanDialog::on_listWidget_itemClicked(QListWidgetItem *item)
{
mAddMsgs = new QAction(QIcon(":ros.png"), tr("Add New Message"), this);
mDeleteMsgs = new QAction(QIcon(":remove_item.png"), tr("Remove Message"), this);
}
What I have done so far:
I came across this post and also this one. Very useful as I set up my project in a very similar way, but nothing happens when I try to click on the QListWidget.
I know that in order to trigger the action I have to go to the slot called itemClicked as I did on the above code provided.
On the official documentation I was trying to apply what is advised but I don't know why nothing happens.
Please point to the right direction for solving this problem.

Answer 1

Look at console output, there should a warning about connect failing. If you look at your code, the reason should be pretty obvious. Consider
SLOT(createItemFromAction(QListWidgetItem*))
versus your method which isn't even a slot
QListWidgetItem *createItemFromAction(const QAction* action);
See the difference?
And then you have this slot:
void on_listWidget_itemClicked(QListWidgetItem *item);
which you are trying to use as a signal
SIGNAL(on_listWidget_itemClicked(QListWidgetItem*))
That obviously won't work.
It's a bit unclear what you want to happen when an item is clicked, but maybe you just should call createItemFromAction directly from the on_listWidget_itemClicked.
Additionally, add debug print or use breakpoint to verify that the on_listWidget_itemClicked is actually called when you click an item. If not, then you are missing connecting the relevant signal from your list view, ie. ui->setupUi(this); does not have that connect (in other words you did not do the connection in the GUI Designer).