Qml text wrap (max width)

I would like to put text inside a bubble, and I want that my bubble be equal to the text width, but if the text length is too long, I would like the text to wrap automatically and be equal to the parent width.

This code works but the text is not wrapping if text is too long:

Rectangle {
    id:messageBoxCadre
    width: (modelData.messageLength>25)? (wrapper.width - 20): messageBox.width+10
    height: messageBox.height+5
    color: modelData.myMessage ? "#aa84b2":"#380c47"
    radius: 10

    Text {
        id:messageBox
        text: '<b><font color=purple>'+modelData.message+'</font></b> '
        wrapMode: "WordWrap"
    }
}

and I tried this, text wrap, but if the text is too small the bubble width is not equal to the text size:

Rectangle {
    id:messageBoxCadre
    width: (modelData.messageLength>25)? (wrapper.width - 20): messageBox.width+10
    height: messageBox.height+5
    color: modelData.myMessage ? "#aa84b2":"#380c47"
    radius: 10

    Text {
        id:messageBox
        width: (modelData.messageLength>25)? (wrapper.width - 20): messageBox.width
        text: '<b><font color=purple>'+modelData.message+'</font></b> '
        wrapMode: "WordWrap"
    }
}

You can almost do this neatly with states. The problem is that attempting to set the width of the parent by assigning it to the paintedWidth of the text box means it then sets the width of the text box, which QML detects as influencing paintedWidth. It wouldn't recurse further than this, but QML still kicks out warnings. One way around the problem is to do as follows, and have a dummy invisible text box that just works out how wide the text is/should be. Its a bit of a hack, but it works nicely.

You could change the "when" property of the state to be dependent on the size of the dummy text box (rather than the length of the string) if you preferred a pixel limit on the width of the box.

import QtQuick 1.0

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
                }
            }
        ]
}