In addition to MouseArea's onPositionChanged, QtCreator's word completion
also suggests onMousePositionChanged, which apparently does exist but doesn't
work correctly when one expects onPositionChanged (e.g. it's called even
though "mouse.accepted = false" is called in onPressed). If it's an internal
signal it ought to be better hidden, as it is too easy to confuse it with
onPositionChanged.

Run the code below. Press down and drag in the window. because "mouse.accepted = false" is called in onPressed, no printout is expected to the console if the onPositionChanged was used correctly. But because the onMousePositionChanged was used "by mistake" the signal is triggered unexpectedly.

import QtQuick 1.1

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

    MouseArea {
        anchors.fill: parent
        onPressed: mouse.accepted = false
        onMousePositionChanged: print("onMousePositionChanged")
    }
}