Проверка границ свойства

import QtQuick 2.0

Rectangle {
    id: containing_rect
    property string text

    text: "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat"
    //text: "a short string"

    Text {
        id: text_field
        anchors.top: parent.top
        anchors.left: parent.left

        height: parent.height
        width: parent.width
        text: parent.text
        wrapMode: Text.WordWrap

    }

    Text {
        id: dummy_text
        text: parent.text
        visible: false
    }

    states: [
            State {
                name: "wide text"
                when: containing_rect.text.length > 20
                PropertyChanges {
                    target: containing_rect
                    width: 200
                    height: text_field.paintedHeight
                }
            },
            State {
                name: "not wide text"
                when: containing_rect.text.length <= 20
                PropertyChanges {
                    target: containing_rect
                    width: dummy_text.paintedWidth
                    height: text_field.paintedHeight
                }
            }
        ]
}

Text {
        id: dummy_text
        text: parent.text
        visible: false

        onWidthChanged: {
            if (width > 200){
                parent.width = 200
            }else{
                parent.width = width
            }
        }
    }