MouseEvent jumps in custom window

[Nilres]

Hi Guys,

I have a rather strange problem: I created a custom window like this:

Window {
    id: root

    flags: Qt.FramelessWindowHint

    default property list<Item> items

    property Component style: DockSettings.fromRessource("Styles/MyWindowStyle", root)

    readonly property Loader __styleComponent: Loader {
        id: styleComponentLoader
        sourceComponent: style

        property QtObject styleData: QtObject {
            readonly property alias windowX: root.x
            readonly property alias windowY: root.y

            readonly property var setPosition: root.setPosition
        }
    }


    readonly property Item header: Loader {
        id: headerLoader
        sourceComponent: __styleComponent.item.header
        parent: renderTarget
    }

    signal creationCompleted()

    function setPosition(x, y) {
        root.x = x
        root.y = y
        show()
    }

    Rectangle {
        id: renderTarget
        anchors.fill: parent
    }
}

And then I created a Style that is attached to it:

DockStyle {
    property Component header: Item {
        width: styleData.contentWidth
        height: 25

        Rectangle {
            height: parent.height
            width: parent.width

            color: "lavender"

            MouseArea {
                anchors.fill: parent

                property bool dragging: false
                property point startPosition: Qt.point(0, 0)

                function startDragging(x, y) {
                    dragging = true
                    startPosition = Qt.point(x, y)
                }

                function stopDragging() {
                    dragging = true
                    startPosition = Qt.point(0, 0)
                }

                onPressed: {
                    if(mouse.button === Qt.LeftButton) {
                        startDragging(mouse.x, mouse.y)
                    }
                }

                onReleased: {
                    stopDragging()
                }

                onPositionChanged: {
                    if(dragging) {
                        styleData.setPosition(styleData.windowX + mouse.x - startPosition.x, styleData.windowY + mouse.y - startPosition.y)
                        console.log(mouse.x, styleData.windowX)
                    }
                }
            }
        }
    }
}

As you can see I created my own header for the window and want to make it moveable over the screen. Which in general works but I always get some random mouse positions in between. Log output looks like this (just dragging it slowly left to right):

qml: 92 2352
qml: -5 2281
qml: -21 2194
qml: -22 2106
qml: -22 2018
qml: 309 2437
qml: 307 2678
qml: -355 2257
qml: -356 1835
qml: 487 2256
qml: 66 2256

Where are those random values come from and how do I get rid of them?

Thanks a lot
Nils

[raven-worx]

@Nilres

1. in your stopDragging() you should set dragging = false
2. in the onPressed / onReleased / onPositionChanged add a mouse.accepted = true to prevent event propagation

[Nilres]

Good spots but neither of those two things fixed it.
But I think I found the answer. I realized that this just happens in one of my setups where I use Windows Subsystem for Linux and xming. It does not happen on my Mac OS X or my Linux system. I then recactivated my old mingw setup on the Window system and it also not happen. So my best guess is that it is a bug in xming or the integration layer.
I tested with exactly the same qt versions on all systems so yeah it is not a Qt thing so I mark this as solved.