[SOLVED] receiving list from c++ to qml listview

kkrzewniak

Please add some new lines to your code.

Expose a QAbstractListModel subclass as a context property or by using a Q_INVOAKABLE method.
Other options are using a QStringList or a QList<QObject> as the model.

Remember to register your QAbstractListModel subclass if you'll not be exposing it via context property.
qmlRegisterUncreatableType/qmlRegisterType

spode

i will use "Other options are using a QStringList or a QList<QObject> as the model.", but the problem is: how to pass this qlist to this QML file?
main.qml
@
Rectangle {
width: 500; height: 500; signal emitsignal();
Component { id: delegate_grafica; Rectangle { width: 300; height: 30; color: "orange"; border.width: 1; border.color: "yellow"; Text { color: "black"; text: deutschesWort; font.pixelSize: 15; anchors.centerIn: parent } } }
ListView { id: list_parolaSalvate; x: 0; y: 0; width: 300; height: 300; delegate: delegate_grafica; model: emitsignal() }
}
@
here i need a model, that i want to obtain from emitsignal, by which i would to obtain a qlist that is then the container of the model of my listview {}. my qlist will contain qlist<biglietto>
where biglietto is:
@
biglietto::biglietto(QString newcolor, int newnumberm, bool important){
QString color = newcolor;
int number = newnumber;
bool isImportant = important;
etc.
}
@
however, thank yoU!

srikanth_trulyit

@ QDeclarativeContext* context = declarativeView.rootContext();
context->setContextProperty("mymodel",(QObject*)&myModel); // here myModel is the QObject that exposes your model
@

@
MyModel: public QObject {
...
Q_INVOKABLE QStringList dataModel();
}
@

In Qml
@
ListView {
...
model: myModel.dataModel();
}
@

raja26

But still how can I access the model data in delegate?

spode

You need to write in the delegate the name of a public variable contained in the model, which you associate with QDeclarativeView.contextProperty.setContextProperty(nameOfTheModel, listThatyouhavemade). Note the you have to use first that I have just written and then set the source of the qml file where the model is needed.

raja26

I found that a simple @modelData@ in the delegate does it for QStringList.
[quote author="spode" date="1345319889"]You need to write in the delegate the name of a public variable contained in the model, which you associate with QDeclarativeView.contextProperty.setContextProperty(nameOfTheModel, listThatyouhavemade). Note the you have to use first that I have just written and then set the source of the qml file where the model is needed.[/quote]

spode

I have not understood. could you please explain youself better?

raja26

To access the list of @QString@ in that QStringList I have used @modelData.

Like this:

ListView {
model: stringListPassedFromCpp
delegate: Text {
text: modelData
}
}@

spode

I do not understand..

raja26

Look at my above code. The 'modelData' gives the QString stored in QStringList. So that I can use 'modelData' to access the QString stored inside the QStrlingList.

I have used QStringList as the model for QML ListView. Have you understood now?

spode

Ok. Now i have understood! :)

raja26

@spode: My pleasure.. :-)

joonne

Hi, I am trying to do almost same thing as mentioned here but I don't understand what modelData means here:

@ListView {
model: stringListPassedFromCpp
delegate: Text {
text: modelData
}
}@

How and where should I declare this modelData ? Thanks in advance. :)

I could ask something more and accurate about this too:

I have now QStringList for testing purposes which has 3 strings and I would like to get this QStringList to qml. I would like to use TextSwitch as delegate. This is what I have at the moment:

@SilicaListView {

        anchors.fill: parent
        model: model_.excerciseNames()

        delegate: TextSwitch {

            text: 
            onClicked: {}
        }
    }

}@

The function excerciseNames() is defined as

@Q_INVOKABLE QStringList excerciseNames();@

I think I am yet very far from the solution so any help would be great :D

raja26

joone
Read about modelData in this link "QStringList to QML":https://qt-project.org/doc/qt-5.0/qtquick/qtquick-modelviewsdata-cppmodels.html#qstringlist-based-model

So all the QString within the QStringList will can be accessed as modelData

So you can access the QString data in the TextSwitch delegate as

@SilicaListView {
anchors.fill: parent
model: model_.excerciseNames()

delegate: TextSwitch {
text: modelData
onClicked: {}
}
}@

joonne

The examples in that page you pointed me are invisible for me, can someone see whats in there? I tried to solve this from the Qt-Creator examples also but didn't get it to work yet. When I use the Q_INVOKABLE method with QStringList I get one of the Strings from the list but when I try to do as the example refered and use this :

@context>setContextProperty("excerciseNamesModel",QVariant::fromValue(model->excerciseNames()));

SilicaListView {
anchors.fill: parent
model: excerciseNamesModel

delegate: TextSwitch {
text: modelData
onClicked: {}
}
}
@

then I don't get anything. The registered excerciseNamesModel is coloured in the editor so it apparently recognizes the model but it is not working for some reason.

raja26

@Q_INVOKABLE@

means the the method can be called from the QML side. So you have to set your cpp model object as
@
ExcerciseNamesModel namesModel;
auto context = viewer.rootContext();
context->setContextProperty("excerciseNamesModel", namesModel)@

and then set the model in QML file as
@
SilicaListView {
anchors.fill: parent
model: excerciseNamesModel.excerciseNames()

delegate: TextSwitch {
text: modelData
onClicked: {}
}
}@

Note: This code is just like pseudocode and I didn't compile it or test it.

raja26

You can read more about Exposing CPP models to QML in this link "Link":http://qt-project.org/doc/qt-4.8/qdeclarativemodels.html#qstringlist-based-model

joonne

Okay thanks, I will try to figure this out. :)

joonne

Would you happen to know a solution for my other problem also ? After updating this Sailfish SDK to a newer version, I lost qDebug() prints and I haven't found where they would come back. I can't see them at the application output view anymore and this makes it a lot harder to track down the behaviour of my program. :D

joonne

Ok I realised something, I had to use setContextProperty function again to update the excerciseNamesModel and I passed the variable context to my actual model class and now everything works. Thank you for the help! :)