Qt Quick borderless window not redrawn

[Fabian Sturm]

Hi,

I try to create a simple application where the user needs to enter a date. For this I want to connect a button with a calendar popup. This works fine as long as the popup is its own window and has a border. But the moment I make the window borderless it seems to be not drawn anymore. Actually if you move the underlaying window around you see that the area with the calendar widget stays undrawn.

import QtQuick 2.2
import QtQuick.Controls 1.2
import QtQuick.Layouts 1.1
import QtQuick.Window 2.1

ApplicationWindow {
    width: 800
    height: 600
    property var pos : getOffset(dateField)

    Button {
        id: dateField
        width: 100
        height: 50
        anchors.centerIn: parent
        text: "show widget"
        onClicked:{ toggleModal() }
    }

    function getOffset(item) {
        var offset = {
            "x": item.x,
            "y": item.y + item.height
        };
        while(item.parent) {
            item = item.parent;
            offset.x += item.x;
            offset.y += item.y;
        }
        console.debug("total", "x", offset.x, "y", offset.y)

        return offset;
    }

    function toggleModal() {
        if(modal.active) {
            console.log("hide calendar")
            loseFocus();
        }
        else {
            console.log("show calendar")
            modal.show()
            modal.requestActivate()
        }
    }

    function loseFocus(newDate) {
        modal.close();
    }

    Window {
        id: modal
        flags: Qt.Window | Qt.FramelessWindowHint
        //flags: Qt.Window
        //modality: Qt.ApplicationModal
        minimumHeight: calendar.height; minimumWidth: calendar.width
        maximumHeight: calendar.height; maximumWidth: calendar.width
        x: pos.x
        y: pos.y

        Calendar {
            id: calendar
            width: 200
            height: 300
        }
    }
}