QML Multitouch on Ubuntu 16.04 not working?

[Axorn]

I would like to use the PinchArea on Ubuntu 16.04 and it doesn't seem to work. What I did so far:

• Tried PinchArea and Multitouch example from Qt, both not working on Ubuntu 16.04 (Qt 5.6, gcc5.4)
• Same applications work on Windows 7 (Qt5.6, mingw)
• Pinch zoom works on Ubuntu 16.04 for image viewer
• Geisview shows gesture events when I am touching in the qml application, however no pinch event arises in qml
• Flickable from qml does work (single touch)
• tried different touch screens from different manufacturers, all do not trigger the pinch/multitouch event
• installed recommended driver from manufacturer, but no effect

Here is the example PinchArea code from Qt, which I am using:

import QtQuick 2.6
import QtQuick.Window 2.2

Window {
    visible: true
    width: 640
    height: 360
    title: qsTr("Hello World")

    Rectangle {
        id: test
        width: 640
        height: 360
        color: "gray"

        Flickable {
            id: flick
            anchors.fill: parent
            contentWidth: 500
            contentHeight: 500

            PinchArea {
                width: Math.max(flick.contentWidth, flick.width)
                height: Math.max(flick.contentHeight, flick.height)

                property real initialWidth
                property real initialHeight

                onPinchStarted: {
                    console.log("pinched!")
                    test.color = "red"
                    flick.interactive = false
                    initialWidth = flick.contentWidth
                    initialHeight = flick.contentHeight
                }

                onPinchUpdated: {
                    console.log("pinched2!")
                    test.color = "red"
                    // adjust content pos due to drag
                    flick.contentX += pinch.previousCenter.x - pinch.center.x
                    flick.contentY += pinch.previousCenter.y - pinch.center.y

                    // resize content
                    flick.resizeContent(initialWidth * pinch.scale, initialHeight * pinch.scale, pinch.center)
                }

                onPinchFinished: {
                    console.log("pinched3!")
                    // Move its content within bounds.
                    flick.returnToBounds()
                    flick.interactive = true
                    test.color = "red"

                }

                Rectangle {
                    width: flick.contentWidth
                    height: flick.contentHeight
                    color: "white"
                    Image {
                        anchors.fill: parent
                        source: "image.png"
                        MouseArea {
                            anchors.fill: parent
                            onDoubleClicked: {
                                console.log("teeest")
                                test.color = "red"
                                flick.contentWidth = 500
                                flick.contentHeight = 500
                            }
                        }
                    }
                }
            }
        }
    }
}

Am I missing something or do you have any ideas how to fix this issue? Any help would be highly appreciated.

[Axorn]

Works with pre-built Qt version. Has to be build parameter dependant.