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

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! :)

raja26

Hi joonne, I am afraid that the moderators will not allow us to discuss about 'qDebug()' problem in this thread, so you have to search in the forums, to see if this question ahs been answered already, else you have to create a new thread for this. :-)