SwipeDelegate: add swipe.pressed, close(), and completed()

import QtQuick 2.5
import QtQuick.Window 2.2
import QtQuick.Controls 2.0

ApplicationWindow {
    id: window

    width: 360
    height: 360
    visible: true

    ListView {
        anchors.fill: parent

        model: 100

        delegate: SwipeDelegate {
            id: delegate
            width: parent.width
            text: "SwipeDelegate" + index
            down: pressed || swipe.complete

            onClicked: {
                if (swipe.complete)
                    swipe.close() // <==
            }

            swipe.right: Label {
                x: parent.width - width
                height: parent.height
                text: "Action"
                color: "white"
                padding: 12
                background: Rectangle {
                    color: delegate.swipe.pressed ? "darkred" : "red" // <==
                }
            }
        }
    }
}