Simple example to show how to move an object with a drag target on a MouseArea without breaking the model link for (x, y) values. The solution is States. I use StateGroups because it's a good pratice to use StateGroups instead of the default state when creating a reusable component. There is no specific reason for this example.

test_qmlStateBindingWithDrag.qml

import QtQuick 1.1

Rectangle {
    id: mainWindowId

    implicitWidth: 500
    implicitHeight: 500
    anchors.fill: parent

    color: "black"
    
    QtObject {
        id: m
        property real modelPosX: 50
        property real modelPosY: 20
    }

    MouseArea {
        anchors.fill: parent
        onReleased: {
            console.log("mainWindowId onReleased")
            // some external changes modify the model pos value
            m.modelPosX = m.modelPosX + 10
        }
    }

    Rectangle {
        id: nodeId
        width: 50
        height: 50
        color: "blue"

        StateGroup {
            id: stateMoving
            state: "normal"
            states: [
                State {
                    name: "normal"
                    PropertyChanges { target: nodeId; x: m.modelPosX; y: m.modelPosY }
                },
                State {
                    name: "moving"
                    PropertyChanges { target: nodeId; x: m.modelPosX; y: m.modelPosY }
                }
            ]
        }

        StateGroup {
            id: statePressed
            states: [
                State {
                    name: "pressed"
                    when: nodeMouseArea.pressed
                    PropertyChanges { target: nodeId; opacity: .5 }
                }
            ]
        }

        MouseArea {
            id: nodeMouseArea
            anchors.fill: parent

            drag.target: parent
            drag.axis: Drag.XandYAxis

            onPressed: {
                console.log("nodeId onPressed")
                stateMoving.state = "moving"
            }
            onReleased: {
                console.log("nodeId onReleased")
                stateMoving.state = "normal"
            }
        }
    }
}

Je suis en train de regarder l'exemple mais je ne comprends pas comment il fonctionne. Dans les states moving et normal, on applique les même changements. Lorsqu'on relâche le carré bleu, il revient à sa position initiale.