Need help from QT Experts ( Model / View for QDateTimeEdit widget)

[tajny_agent]

You can use QDataWidgetMapper with custom delegate.

void MyDelegate::setEditorData(QWidget* parent, const QModelIndex& index) const
{
  if (auto dte = qobject_cast<QDateTimeEdit*>(editor); dte) {
    auto* model = index.model();
    const auto& year = model->index(0, 0, index.parent()).data().toString();
    const auto& month = model->index(1, 0, index.parent()).data().toString();
    // ...
    QDateTime dt = QDateTime::fromString(/*combine above to QDateTime*/);
    dte->setDateTime(dt);
  }
}

Then map your QDateTimeEdit with QDataWidgetMapper, set delegate. and voila

[VRonin]

Something like this minimal example is what you want or did I miss something?

#include <QApplication>
#include <QTreeWidget>
#include <QVBoxLayout>
#include <QDateTimeEdit>
#include <QStandardItemModel>
class ExampleWid : public QWidget{
    //Q_OBJECT
    Q_DISABLE_COPY(ExampleWid)
public:
    explicit ExampleWid(QWidget *parent = Q_NULLPTR)
        :QWidget(parent)
        ,view(new QTreeView(this))
        ,editor(new QDateTimeEdit(this))
    {
        QAbstractItemModel* model = new QStandardItemModel(this);
        model->insertColumn(0);
        model->insertRows(0,2);
        QModelIndex parIdx= model->index(0,0);
        model->setData(parIdx,QStringLiteral("Parent A"));
        model->insertColumn(0,parIdx);
        model->insertRows(0,7,parIdx);
        model->setData(model->index(0,0,parIdx),2019);
        model->setData(model->index(1,0,parIdx),12);
        model->setData(model->index(2,0,parIdx),25);
        model->setData(model->index(3,0,parIdx),13);
        model->setData(model->index(4,0,parIdx),58);
        model->setData(model->index(5,0,parIdx),15);
        model->setData(model->index(6,0,parIdx),QStringLiteral("Wednesday"));
        parIdx= model->index(1,0);
        model->setData(parIdx,QStringLiteral("Parent B"));
        model->insertColumn(0,parIdx);
        model->insertRows(0,7,parIdx);
        model->setData(model->index(0,0,parIdx),2019);
        model->setData(model->index(1,0,parIdx),5);
        model->setData(model->index(2,0,parIdx),30);
        model->setData(model->index(3,0,parIdx),20);
        model->setData(model->index(4,0,parIdx),30);
        model->setData(model->index(5,0,parIdx),55);
        model->setData(model->index(6,0,parIdx),QStringLiteral("Thursday"));

        view->setModel(model);
        QVBoxLayout* minLay = new QVBoxLayout(this);
        minLay->addWidget(editor);
        minLay->addWidget(view);
        QObject::connect(view->selectionModel(),&QItemSelectionModel::currentChanged,this,[this](QModelIndex idx)->void{
            if(!idx.isValid())
                return;
            while(idx.parent().isValid())
                idx =idx.parent();
            lastIdx = QPersistentModelIndex();
            editor->setDateTime(QDateTime(
                QDate(
                    idx.model()->index(0,0,idx).data().toInt()
                    ,idx.model()->index(1,0,idx).data().toInt()
                    ,idx.model()->index(2,0,idx).data().toInt()
                )
                , QTime(
                    idx.model()->index(3,0,idx).data().toInt()
                    ,idx.model()->index(4,0,idx).data().toInt()
                    ,idx.model()->index(5,0,idx).data().toInt()
                )
            ));
            lastIdx = idx;
        });
        QObject::connect(editor,&QDateTimeEdit::dateTimeChanged,this,[this](const QDateTime &datetime)->void {
            if(!lastIdx.isValid())
                return;
            QAbstractItemModel * model = view->model();
            model->setData(model->index(0,0,lastIdx),datetime.date().year());
            model->setData(model->index(1,0,lastIdx),datetime.date().month());
            model->setData(model->index(2,0,lastIdx),datetime.date().day());
            model->setData(model->index(3,0,lastIdx),datetime.time().hour());
            model->setData(model->index(4,0,lastIdx),datetime.time().minute());
            model->setData(model->index(5,0,lastIdx),datetime.time().second());
            model->setData(model->index(6,0,lastIdx),view->locale().toString(datetime.date(),QStringLiteral("dddd")));
        });
    }
private:
    QTreeView* view;
    QDateTimeEdit *editor;
    QPersistentModelIndex lastIdx;
};

int main(int argc, char **argv)
{
    QApplication app(argc,argv);
    ExampleWid wid;
    wid.show();
    return app.exec();
}

[chakry]

@VRonin said in Need help from QT Experts ( Model / View for QDateTimeEdit widget):

view

HI VRonin,

Thank you for your reply. This would work but my model is not a local one , it is set from a different class using a set-model function(example). I need it because the model might change during run time. in this case i need dynamic signal slot right ?. I have a requirement of sessions in my program if a session is changed then the model changes which i have to set it externally.

Thanks and regards

[VRonin]

Nothing difficult, mine was just an example, just remove everything in the constructor before QVBoxLayout* minLay = new QVBoxLayout(this); and add a public void setModel(QAbstractItemModel* model){view->setModel(model);} that you can use to set a new model from outside this class. Everything else is all the same

[chakry]

Yes i tried that but when the model data is changed then the signal is not fired , it never comes to this function . why is that ?

QObject::connect(lView->selectionModel(), &QItemSelectionModel::currentChanged, this, [this](QModelIndex idx) -> void {
	qDebug() << "modelchanged " << idx;
    }

[JonB]

@chakry

I need it because the model might change during run time

Do you mean the whole model is changed, or just one item? If it's the former:
https://doc.qt.io/qt-5/qitemselectionmodel.html#currentChanged

Note that this signal will not be emitted when the item model is reset.

and you might mean:
https://doc.qt.io/qt-5/qitemselectionmodel.html#modelChanged

This signal is emitted when the model is successfully set with setModel().

or am I grasping the wrong end of the stick for what you are saying?

[chakry]

@JonB Thank you .
sorry i want to correct few things . Your code is working fine with view and set model i have just verified that. The reason it didnt work was i was not displaying my view.
I must not show view to user . i just have to map the model to widget(QDateTimeEdit) and show that widget to user. I thought with view it might work if i dont show this to user. just set everything but not showing. This dont work right? please correct me.

I meant both cases. in one case , one child value will be changed in another case a new model is set.I can connect these signals as you mentioned but they work with TreeView when visible right?

[VRonin]

@chakry said in Need help from QT Experts ( Model / View for QDateTimeEdit widget):

The reason it didnt work was i was not displaying my view.
I must not show view to user . i just have to map the model to widget

So how do you decide what parent item of the model should be edited in the widget?

[chakry]

@VRonin parent has a name , which is fixed. I will find it based on the name. The respective Model index is used unless a new model is updated.

just a bit more explanation to be clear. I have a tree model and all these elements/children in tree model should be shown in view as a widget easily editable( ex: text box, checkbox, combobox, spinbox ..etc) . These standard items are working using widget mapper. I search for a parent and map its model index to one of the these standard widgets. In this model i also have 6 children's having date ,time info. I wanted to map these 6 children's to a single widget datetimeedit. This was my main issue . This is not possible with restriction on datawidgetmapper ( only one property can be mapped ).

thanks and regards.

[VRonin]

@chakry said in Need help from QT Experts ( Model / View for QDateTimeEdit widget):

I wanted to map these 6 children's to a single widget datetimeedit. This was my main issue . This is not possible with restriction on datawidgetmapper ( only one property can be mapped ).

This is what the code in my 2 connect do:
This puts an index inside the QDatetimeEdit

if(!idx.isValid())
                return;
            while(idx.parent().isValid())
                idx =idx.parent();
            lastIdx = QPersistentModelIndex();
            editor->setDateTime(QDateTime(
                QDate(
                    idx.model()->index(0,0,idx).data().toInt()
                    ,idx.model()->index(1,0,idx).data().toInt()
                    ,idx.model()->index(2,0,idx).data().toInt()
                )
                , QTime(
                    idx.model()->index(3,0,idx).data().toInt()
                    ,idx.model()->index(4,0,idx).data().toInt()
                    ,idx.model()->index(5,0,idx).data().toInt()
                )
            ));
            lastIdx = idx;

This puts the data from the QDatetimeEdit back into the model

if(!lastIdx.isValid())
                return;
            model->setData(model->index(0,0,lastIdx),datetime.date().year());
            model->setData(model->index(1,0,lastIdx),datetime.date().month());
            model->setData(model->index(2,0,lastIdx),datetime.date().day());
            model->setData(model->index(3,0,lastIdx),datetime.time().hour());
            model->setData(model->index(4,0,lastIdx),datetime.time().minute());
            model->setData(model->index(5,0,lastIdx),datetime.time().second());
            model->setData(model->index(6,0,lastIdx),view->locale().toString(datetime.date(),QStringLiteral("dddd")));

[chakry]

@VRonin said in Need help from QT Experts ( Model / View for QDateTimeEdit widget):

@chakry said in Need help from QT Experts ( Model / View for QDateTimeEdit widget):

I wanted to map these 6 children's to a single widget datetimeedit. This was my main issue . This is not possible with restriction on datawidgetmapper ( only one property can be mapped ).

Thank you VRonin for helping
This is what the code in my 2 connect do:
This puts an index inside the QDatetimeEdit ```
( Its true but where should i add this code , view and selectionmodel as you mentioned before doesnot work as there is no view in my case , any suggestion where to keep this )

> ```cpp
> if(!idx.isValid())
>                 return;
>             while(idx.parent().isValid())
>                 idx =idx.parent();
>             lastIdx = QPersistentModelIndex();
>             editor->setDateTime(QDateTime(
>                 QDate(
>                     idx.model()->index(0,0,idx).data().toInt()
>                     ,idx.model()->index(1,0,idx).data().toInt()
>                     ,idx.model()->index(2,0,idx).data().toInt()
>                 )
>                 , QTime(
>                     idx.model()->index(3,0,idx).data().toInt()
>                     ,idx.model()->index(4,0,idx).data().toInt()
>                     ,idx.model()->index(5,0,idx).data().toInt()
>                 )
>             ));
>             lastIdx = idx;
> ```
> 
> This puts the data from the `QDatetimeEdit` back into the model  ```
**( This works as in this case i use dateTimechanged from QDateTimeEditsignal and set the passed model data)**

if(!lastIdx.isValid())
                return;
            model->setData(model->index(0,0,lastIdx),datetime.date().year());
            model->setData(model->index(1,0,lastIdx),datetime.date().month());
            model->setData(model->index(2,0,lastIdx),datetime.date().day());
            model->setData(model->index(3,0,lastIdx),datetime.time().hour());
            model->setData(model->index(4,0,lastIdx),datetime.time().minute());
            model->setData(model->index(5,0,lastIdx),datetime.time().second());
            model->setData(model->index(6,0,lastIdx),view->locale().toString(datetime.date(),QStringLiteral("dddd")));

[VRonin]

Can you reformat the answer? it's difficult to follow...