Qt Quick item visibility not changed when virtual keyboard is open

import QtQuick 2.2
import QtQuick.Controls 1.1
import QtQuick.Layouts 1.1

ApplicationWindow {
    visible: true
    width: 300
    height: 640
    title: qsTr("Hello World")

    menuBar: MenuBar {
        Menu {
            title: qsTr("File")
            MenuItem {
                text: qsTr("Exit")
                onTriggered: Qt.quit();
            }
        }
    }
    RowLayout{
        id: rowLayout
        spacing: 0
        TextField{
            id: txtSearch
            placeholderText: "Type the URL"
            Layout.fillWidth: true
            Layout.fillHeight: true
            onTextChanged: onTextFieldTextChanged();
        }
        Image{
            id: img
            visible:false
            source: "qrc:///Images/stop.png"
            Layout.maximumHeight: rowLayout.height
            Layout.maximumWidth: rowLayout.height
            Layout.minimumWidth: rowLayout.height
            Layout.minimumHeight: rowLayout.height
            MouseArea{
                id: mouseArea
                anchors.fill: parent
            }
        }
    }
    function onTextFieldTextChanged(){
        if(txtSearch.text.length>0){
            img.visible=true;
        }else img.visible=false;
    }
}