void QmlAnchorBindingProxy::setBottomTarget(const QVariant &target)
{
    QmlItemNode newTarget(target.value<ModelNode>());

    if (newTarget == m_bottomTarget)
        return;

    RewriterTransaction transaction = m_fxItemNode.modelNode().view()->beginRewriterTransaction();

    m_bottomTarget = newTarget;
    calcBottomMargin();

    emit bottomTargetChanged();
}
void QmlAnchorBindingProxy::setBottomAnchor(bool anchor)
{
    if (!m_qmlItemNode.hasNodeParent())
        return;

    if (bottomAnchored() == anchor)
        return;

    RewriterTransaction transaction = m_qmlItemNode.modelNode().view()->beginRewriterTransaction(QByteArrayLiteral("QmlAnchorBindingProxy::setBottomAnchor"));

    if (!anchor) {
        removeBottomAnchor();
    } else {
        calcBottomMargin();
        if (topAnchored())
            backupPropertyAndRemove(modelNode(), "height");
    }
    emit bottomAnchorChanged();

    if (hasAnchors() != anchor)
        emit anchorsChanged();
}