MouseArea.pressed is a boolean property instead of function

Item {
    signal clicked()
    signal pressed()
    MouseArea {
        id: mouse
    }
    Component.onCompleted: {
        console.log(typeof(mouse.clicked)) // OK - function
        mouse.clicked.connect(clicked) // OK
        console.log(typeof(mouse.pressed)) // NOT OK - boolean
        mouse.pressed.connect(pressed) // NOT OK - TypeError: Result of expression 'mouse.pressed.connect' [undefined] is not a function.
    }
}