Dynamically get QML model of selected TreeView item

[PavloPonomarov]

Hello. I'm creating a dynamic UI, where the user could choose which model item to display. To list model items I use Qt1.4 TreeView. I've created a working example of my code:
main.qml

import QtQuick 2.12
import QtQuick.Window 2.12
import QtQuick.Dialogs 1.2
import QtQuick.Controls 2.12
import QtQuick.Controls 1.4
import QtQml.Models 2.11
import QtQuick.Layouts 1.12

import test.io.myModel 1.0

Window {
    width: 240
    height: 280
    visible: true

    MyModel{
        id: myModel
    }

    RowLayout{
        TextField{
            id: textField
            property var modelIndex: undefined
            property var qmlModel: undefined
            text: qmlModel? qmlModel.value : "Item not chosen"
            onAccepted: {
                if(modelIndex)
                    myModel.setValue(modelIndex, Number(textField.text));
                else
                    text = "Item not chosen";
                focus = false;
            }
        }

        Button{
            text: "Set param1"
            onClicked: {
                textField.modelIndex = myModel.getIndex(0);
                //How do I get QML model from TreeView?
            }
        }
    }

    TreeView{
        id: treeView
        y: 50
        model: myModel
        selection: ItemSelectionModel{
            id:mySelectionModel
            model: myModel
            onCurrentIndexChanged:{ }
        }
        itemDelegate: ItemDelegate{
            MouseArea{
                anchors.fill: parent
                onClicked: {
                    treeView.selection.setCurrentIndex(styleData.index, ItemSelectionModel.NoUpdate);
                    treeView.selection.select(styleData.index, ItemSelectionModel.ClearAndSelect);
                    treeView.selection.setCurrentIndex(styleData.index,ItemSelectionModel.SelectCurrent);
                }
                onDoubleClicked: {
                    textField.modelIndex = styleData.index
                    textField.qmlModel = model
                }
            }
            Text{
                text: styleData.value !== undefined ? styleData.value : ""
                anchors.centerIn: parent
            }
        }
        TableViewColumn{
            title:"Name"
            role: "name"
            width: 100
        }
        TableViewColumn{
            title:"Value"
            role: "value"
            width: 100
            delegate: TextInput{
                text: styleData.value !== undefined ? styleData.value :""
                selectByMouse: true
                onAccepted: {
                    myModel.setValue(styleData.index, Number(text));
                    focus = false;
                }
            }
        }
    }
}

mymodel.h

#ifndef MYMODEL_H
#define MYMODEL_H

#include <QObject>
#include <QStandardItemModel>
#include <QStandardItem>

class MyModel : public QStandardItemModel
{
    Q_OBJECT
public:
    explicit MyModel(QObject *parent = nullptr);
    enum{
       Name =Qt::UserRole,
       Value
    };
    Q_INVOKABLE void setValue(const QModelIndex &index, double value);
    Q_INVOKABLE double getValue(const QModelIndex &index);
    Q_INVOKABLE QModelIndex getIndex(int row);

    QHash<int, QByteArray> roleNames() const override;
    QVector<MyModel> mItems;


signals:

};

#endif // MYMODEL_H

mymodel.cpp

#include "mymodel.h"

MyModel::MyModel(QObject *parent) : QStandardItemModel(parent)
{
    for(int i = 0; i < 5; i++){
        QStandardItem *item = new QStandardItem;
        item->setData("Param"+QString::number(i+1), Name);
        item->setData(i, Value);
        appendRow(item);
    }

}

void MyModel::setValue(const QModelIndex &index, double value)
{
    itemFromIndex(index)->setData(value, Value);
}

double MyModel::getValue(const QModelIndex &index)
{
    return itemFromIndex(index)->data(Value).toDouble();
}

QModelIndex MyModel::getIndex(int row)
{
    return index(row, 0);
}

QHash<int, QByteArray> MyModel::roleNames() const
{
    QHash<int, QByteArray> names;
    names[Name] = "name";
    names[Value] = "value";
    return names;
}

What this code does: When I doubleclick an item in the TreeView I bind it to TextField, the value that the user chose is then interconnected between TreeView and TextField, I can change it on one component and it will be automatically updated in another through the property binding to my model. Now what each dynamic UI needs is save/load feature, so for this example I've added a Button, that should bind Parameter1 to TextField (as if it was done during the loading process). I can take QModelIndex directly from the C++ model, but can I get the QML model?