QML ListView inside Repeater - c++

Question

How can I assign different models to a ListView, which is inside a Repeater?
I did a sketch (my actual project is much larger):
Column {
Repeater {
model: ["Line1","Line2","Line3","Line4"]
Rectangle {
ListView {
model: ???
delegate: Rectangle {
Text {
text: somemodelproperty
}
}
}
}
}
}
Currently, I am solving the idea by copy-pasting 10 Rectangles, each containing a ListView. In C++, I have implemented 10 QList<QObject*>, and each list is "bounded" to a ListView by doing
QQmlContext * example = engine.rootContext();
example->setContextProperty(modelname,QVariant::fromValue(listobject));
I am pretty sure there is a more intelligent way to do this, but I have just started working with QML a few days ago, and can't figure out a solution.

Answer 1

There is the catch, you can't use an id as a value for a list element, nor can you nest a list model inside a list element, at least not directly.
You can however populate it like this:
Item {
id: models
ListModel {/*...*/}
ListModel {/*...*/}
//...
}
ListModel {
id: outerModel
}
function set() {
for (var i = 0; i < models.data.length; ++i) {
outerModel.append({"model": models.data[i] /* and other stuff */})
}
}
Or if you prefer using your C++ data, you can add a QObject* "model" property to each of the elements in the list and set it with a function, either as in the example above or with the ids for the inner models you specify.
On a second thought, you might want to use another name instead of "model" because I can't imagine QML will be happy about something like model: model
Update: You could try doing something like this (assuming your 10 models are exposed as m1 - m10 in QML)
property var subModels: [m1, m2, ... m10]
Then for the ListView inside the repeater delegate you can:
ListView {
model: subModels[index]
// ...
}
Then assuming you have 10 elements in the repeater, the model for each list view will be selected from the array with the appropriate element index.

Answer 2

Declare model for repeater instead of using array of strings. You can use ListModel for that purposes. You can also add to ListModels element, ListElement, any properties you want. Declare something like following:
ListModel {
id: repeaterModel
ListElement { title: "Line1"; model: modelForFirstElement; }
ListElement { title: "Line2"; model: modelForSecondElement; }
// ...
}
Then assign it to your Repeater's model property
Repeater {
id: repeater
model: repeaterModel
// ...
Then you will be able to access to model for your ListView by just calling model's model property, like this (assuming that you have assigned id "repeater" for your Repeater element):
ListView {
model: repeater.model.model
// ...

Answer 3

For the model, consider an array that has a sub-array nested within. To differentiate since both the outer Repeater and the inner ListView have a different instance of modelData consider copying the outer modelData to a property named outerModelData.
In the following example, I refactor out Column-Repeater-ListView and replaced it with ListView-ListView. Both patterns achieve the same thing but the latter does it shorter.
import QtQuick
import QtQuick.Controls
Page {
ListView {
anchors.fill: parent
model: [
{la:"English",v:["one","two","three"]},
{la:"Mandarin",v:["yi","er","san"]},
{la:"French",v:["un","duex","trois"]},
{la:"German",v:["eins","zwei","drei"]},
{la:"Indonesian",v:["satu","dua","tiga"]},
]
delegate: ListView {
property var outerModelData: modelData
width: 120
height: childrenRect.height
header: Text { text: outerModelData.la }
model: outerModelData.v
delegate: Frame {
width: 100
Text { text: modelData }
}
}
}
}
You can Try it Online!