StackView and ObjectModel width problem

[Luno]

Hi!
I'm working on my project in QML and I've meet a problem. I need to make a ListView (menu), where I can select the element, click on it and see the details on the separate view. I've used the stocqt example as a solution for this issue, but I've meet a problem with width of StackView element: if width of the RForm (id:RView) is set, the application isn't running (it's trying to start without any success). So, now I have:
main.qml

ApplicationWindow {
    id:mainWindow
width:1280
height:720
StackView {
    id:homeView
    anchors.fill: parent
    initialItem: DataList {
    }
    }

DataList.qml:

import QtQuick 2.4
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.0
import QtQuick.Controls.Material 2.0
import QtQml.Models 2.1
import "."

Rectangle {
    id:mainView
    width:mainWindows.width
    height:parent.height
    property alias currentIndex: root.currentIndex
    ListView {
        id:root
        width:mainWindow.width
        height:parent.height
        anchors.fill: parent
        snapMode: ListView.SnapOneItem
        highlightRangeMode: ListView.StrictlyEnforceRange
        highlightMoveDuration: 250
        focus: false
        orientation: ListView.Horizontal
        boundsBehavior: Flickable.StopAtBounds
        FormModelForm {
            id: dataModel
            dataId: listView.currentDataId
        }
        model: ObjectModel {
            DListView {
                id:listView
                anchors.fill: parent
                width:root.width
                height:root.height
            }
            RForm {
                id:RView
                dataSet:RDataModel
                width:root.width
                height:root.height

            }
        }
    }
}

I really need to use StackView, because I have a MasterFlow menu. Could you help me how to set the width property of this element? May be there is an another idea how to realise such ListView?

[Eeli K]

@Luno First,

id:mainView
width:mainWindows.width

mainWindows doesn't exist (should be mainWindow?)
Second,

id:RView
dataSet:RDataModel

Only type names should begin with upper case letter.
Third, the implicit/explicit sizing system of Quick is annoying. In most cases you have to find a working combination of implicitWidth and width properties for your components.

[Luno]

Thank you for your reply. I'm sorry, I've changed some ids, but it's ok in the code. Originally (in stocqt), all components of ObjectModel are in the Rectangle (but I have to you StackView because of MasterFlow menu). So, I think that all problems are in differences between these objects.. I'll try to work with implicitWidth, may be it's a solution

[ekkescorner]

@Luno you're using QtQuickControls2 StackView - please try QQC2 Page instead of a Rectangle

[Luno]

Unfortunately, it'n't a solution:(
But I'm stupid...the "root" element should has the following properties

        Layout.fillHeight: true
        Layout.fillWidth: true

Thank you everyone, who tried to help with it :)