QListWidget, prompt before currentItemChanged signal

[SPlatten]

I thought I had this working...I add the following to QListWidget:

    QString strFunc(slstScript[SSF_FUNCTION_IDX]
                  + QString(clsDebugService::msccBrktOpen)
                  + QString(clsDebugService::msccBrktClose));
    QByteArray baScriptWithCall(clsMainWnd::baGetScriptWithCall(itr->second, strFunc));
    QJSEngine* pobjScriptEng(clsJSON::pobjGetScriptEng());
    //Use "clsQtAskBeforeChange" to prompt user for confirmation if
    //changes in child nodes before allowing change
    clsQtAskBeforeChange* pobjABC(new clsQtAskBeforeChange(model(), this));
    setSelectionMode(QAbstractItemView::ExtendedSelection);
    setSelectionModel(pobjABC);
    //Now the widget should be set-up, finalise set-up
    clsXMLinterface::setup();
    //Connect signal
    QObject::connect(pobjABC, &clsQtAskBeforeChange::pendingSelect
            ,this, [this, pobjABC, pobjScriptEng, strFile, strFunc, baScriptWithCall]
                    (const QItemSelection& crobjSelection
                    ,QItemSelectionModel::SelectionFlags cmdFlags) {
        bool blnBlock(this->blockSignals(true));
        QJSValue objResult(pobjScriptEng->evaluate(baScriptWithCall));
        this->blockSignals(blnBlock);
        if ( objResult.isError() == true ) {
            qcrt() << "\n*****************************************************************"
                   << "\n" << strFile << strFunc
                   << "\n" << objResult.toString()
                   << "\n*****************************************************************";
        } else {
            QString strResult(objResult.toString());
            if ( strResult.compare(clsXMLnode::mscszTrue) == 0 ) {
                pobjABC->actuallySelect(crobjSelection, cmdFlags);
            } else if ( strResult.compare("undefined") != 0 ) {
                qdbg() << "9" << clsDebugService::msccDebugLevelDelimiter
                              << strResult.toLocal8Bit().data();//HACK
            }
        }
    });

I have a breakpoint on the first line of the lambda slot:

bool blnBlock(this->blockSignals(true));

I have connections to all the signals and I see that when I make a selection from the list, it jumps directly into:

void clsQtListWidget::rptrCurrentItemChanged(QListWidgetItem* pobjCurrent
                                            ,QListWidgetItem* pobjPrevious) {

Which is connected to the signal currentItemChanged.

Can anyone see why the pendingSelect select signal isn't occurring?

[SPlatten]

@Christian-Ehrlicher , @jsulm , I think I've been going down a rabbit hole in trying to implement this model, when all I actually need to do is move the test for change into the slot and then if I don't want to allow the selection change assign QListWidgetItem* pobjCurrent to QListWidgetItem* pobjPrevious.

[jsulm]

@SPlatten said in QListWidget, prompt before currentItemChanged signal:

Can anyone see why the pendingSelect select signal isn't occurring?

How should anyone know?
What is clsQtAskBeforeChange and when does it emit pendingSelect signal?

[SPlatten]

@jsulm

    class clsQtAskBeforeChange : public QItemSelectionModel {
    Q_OBJECT
    Q_DISABLE_COPY_MOVE(clsQtAskBeforeChange)
    public:
        using QItemSelectionModel::QItemSelectionModel;        
        QModelIndexList mobjLastIdxList;

    public slots:
        void select(const QItemSelection& crobjSelection
                   ,QItemSelectionModel::SelectionFlags flgsCmd) override {
            QModelIndexList objIdxList(crobjSelection.indexes());
            if ( mobjLastIdxList == objIdxList ) {
                return;
            }
            mobjLastIdxList = objIdxList;
            emit pendingSelect(crobjSelection, flgsCmd);
        }
        virtual void actuallySelect(const QItemSelection& crobjSelection
                                   ,QItemSelectionModel::SelectionFlags flgsCmd) {
            QItemSelectionModel::select(crobjSelection, flgsCmd);
        }

    signals:
        void pendingSelect(const QItemSelection& crobjSelection
                          ,QItemSelectionModel::SelectionFlags flgsCmd);
    };

After posting this I though it might be the check:

if ( mobjLastIdxList == objIdxList ) {
    return;
}

Causing it to return, but it isn't.

[jsulm]

@SPlatten Is the select() slot called?

[SPlatten]

@jsulm, as far as I can see with a breakpoint on the first line in the select function, no it isn't.

[jsulm]

@SPlatten Well, then find out why not.

[SPlatten]

@jsulm , that's exactly why I posted here, how ?

[jsulm]

@SPlatten How should I know?!
You did not even tell us to what signal select() is connected!

[Christian Ehrlicher]

There are two select functions, the second is mostly called from QAbstractItemView

[SPlatten]

@jsulm , I'm not asking out specifically....looking at the class, its derived from QItemSelectionModel:
https://doc.qt.io/qt-5/qitemselectionmodel.html#signals

[jsulm]

@SPlatten said in QListWidget, prompt before currentItemChanged signal:

QItemSelectionModel

OK, did not notice this

[SPlatten]

@Christian-Ehrlicher , thank you, I can see that the select slot is getting called, but it appears that it is being called after the currentItemChanged signal, which is wrong isn't it?

[Christian Ehrlicher]

@SPlatten said in QListWidget, prompt before currentItemChanged signal:

which is wrong isn't it?

Why? Is it written down somewhere? And from my pov a cell has to be the current one until the selection can change.

[SPlatten]

@Christian-Ehrlicher , the intention is that when the user tries to make a new selection, an interim step checks that its ok to allow the change, by checking other content using the slot...it can then allow or disallow the selection.

[SPlatten]

@Christian-Ehrlicher , @jsulm , I think I've been going down a rabbit hole in trying to implement this model, when all I actually need to do is move the test for change into the slot and then if I don't want to allow the selection change assign QListWidgetItem* pobjCurrent to QListWidgetItem* pobjPrevious.