Qt Quick very slow painting

[Vusa360]

I have just started to look at Qt Quick and I have a very basic program, essentially the same as when you start a Qt Quick Controls application project.

The problem is when I try to resize the window it takes a very long time to do so. This can be seen in the .gif below.

The only information I could find on the web about people having a similar problem was that you could use the QML Profiler to find where the lag is being generated and sometimes it is due to the debugger. So below you can see the QML profiler and the gif was recorded in release mode.

As far as I can tell the animation is locking the GUI thread up which is causing the render or repainting to be slow but I am not sure what is causing it.

I would appreciate any help in solving the problem.

And there is not much code to it.

CD_Burner.pro

QT += qml quick
CONFIG += c++11
SOURCES += main.cpp
RESOURCES += qml.qrc
QML_IMPORT_PATH =
QML_DESIGNER_IMPORT_PATH =
DEFINES += QT_DEPRECATED_WARNINGS
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

main.cpp

#include <QGuiApplication>
#include <QQmlApplicationEngine>

int main(int argc, char *argv[])
{
    QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
    QGuiApplication app(argc, argv);

    QQmlApplicationEngine engine;
    engine.load(QUrl(QLatin1String("qrc:/main.qml")));
    if (engine.rootObjects().isEmpty())
        return -1;

    return app.exec();
}

main.qml

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3

ApplicationWindow {
    visible: true
    width: 640
    height: 480
    title: qsTr("Hello World")

    SwipeView {
        id: swipeView
        anchors.fill: parent
        currentIndex: tabBar.currentIndex

        Page1 {
            Label {
                text: qsTr("First page")
                anchors.centerIn: parent
            }
        }

        Page {
            Label {
                text: qsTr("Second page")
                anchors.centerIn: parent
            }
        }

        Page {
            Label {
                text: qsTr("Third page")
                anchors.centerIn: parent
            }
        }
    }

    footer: TabBar {
        id: tabBar
        currentIndex: swipeView.currentIndex
        TabButton {
            text: qsTr("First")
        }
        TabButton {
            text: qsTr("Second")
        }
        TabButton {
            text: qsTr("Third")
        }
    }
}

Page1.qml

import QtQuick 2.7

Page1Form {
    button1.onClicked: {
        console.log("Button Pressed. Entered text: " + textField1.text);
    }
}

Page1Form.ui.qml

import QtQuick 2.7
import QtQuick.Controls 2.0
import QtQuick.Layouts 1.3

Item {
    property alias textField1: textField1
    property alias button1: button1

    RowLayout {
        anchors.horizontalCenter: parent.horizontalCenter
        anchors.topMargin: 20
        anchors.top: parent.top

        TextField {
            id: textField1
            placeholderText: qsTr("Text")
        }

        Button {
            id: button1
            text: qsTr("Press Me")
        }
    }
}

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Specs: Windows 10, Qt 5.9, MSVC 2017

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