I am trying to create tabview with tabs like browser in qml.I have written below code

import QtQuick 2.0
import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Layouts 1.1
import QtQuick.Controls 2.2
import QtQuick.Controls 2.15
import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Dialogs 1.3
import QtQuick.Controls.Styles 1.1
import QtQuick.Controls 1.2

Rectangle
{
id:tabViewgui
color: "gray"
border.color: "black"
border.width: 5
radius: 8
visible: true

Dialog
{
    id: errorDialog
    title: "Yazmi"
    width: 300

    ColumnLayout
    {
        Label
        {
            text: qsTr("More than 10 tabs cannot be created.")
            font.pixelSize: 15
        }

    }
    standardButtons: StandardButton.Ok
}


TabView
{
    id: tabView
    anchors.margins: 2
    visible: false
    anchors.fill: parent
    style: TabViewStyle
    {
        property color frameColor: "#484848"
        property color fillColor: "#484848"

        tab: Rectangle
        {
            color: styleData.selected ? fillColor : frameColor
            implicitWidth: Math.max(text.width + 45, 80)
            implicitHeight: 35
            border.color: "black"
            border.width:1.5
            radius: 8

            Text
            {
                id: text
                anchors.left: parent.left
                anchors.verticalCenter: parent.verticalCenter
                anchors.leftMargin: 6
                text: styleData.title
                color: styleData.selected ? "white" : "white"
                font.pixelSize: 15

            }
            ToolButton
            {
                anchors.right: parent.right
                anchors.verticalCenter: parent.verticalCenter
                anchors.rightMargin: 4
                implicitWidth: 30
                implicitHeight: 30
                iconSource: "qrc:/images/close2.png"

                onClicked:
                {
                    onClicked: tabView.removeTab(styleData.index)
                    addbutn.x = (addbutn.x - tabView.implicitWidth/2)
                }
            }


        }

    }
}
ToolButton
{
    id:addbutn
    iconSource: "qrc:/images/Add2.png"
    antialiasing: true
    x:0
    y:0
    //anchors.fill:parent
    onClicked:
    {
        console.log("addbutn clicked")

        tabView.visible = true
        if(tabView.count < 10)
        {
            var c = Qt.createComponent("Paintview.qml");
            tabView.addTab("WhiteBoard",c);
            var last = tabView.count-1;
            tabView.getTab(last).active = true; // Now the content will be loaded
            addbutn.x = tabView.count*(tabView.implicitWidth/2)
            console.log("addbutn X Position :",addbutn.x,anchors.leftMargin,tabView.count)
        }
        else
        {
            errorDialog.open()
        }

    }
}

}

In this when in click on ToolButton it is not working.
when i enable this line in code //anchors.fill:parent
it is working but I cannot put x and y pos to zero.
Can anybody tell problem and how to solve.