Flickable doesn't position below header on start

[Didier Roche-Tolomelli]

with Ubuntu Components 1.2, instantiating a MainView should adjust on start contentY of the flickable component to header.height.
In the following example, this isn't recalculated properly before an user's drag.

import QtQuick 2.4
import Ubuntu.Components 1.2

MainView {
    id: mainview
    objectName: "mainView"
    applicationName: "foo.bar"

    width: units.gu(40)
    height: units.gu(75)

    Page {
        title: "Settings"
        Flickable {
            anchors.fill: parent
            contentHeight: childrenRect.height

            Column {
                anchors.left: parent.left
                anchors.right: parent.right

                OptionSelector {
                    text: i18n.tr("Label")
                    model: [i18n.tr("Value 1"),
                            i18n.tr("Value 2"),
                            i18n.tr("Value 3"),
                            i18n.tr("Value 4")]
                }
            }
        }
    }
}

This is due to Flickable width to be 0, (Column's parent is the Flickable.contentItem, not the flickable)

Solution is to give an ID to your flickable (i.e. id: flickable), and set the width of the column using that (width:
flickable.width). Then, give an id to Column and set flickable.contentHeight: column.height

[Tim Peeters (tpeeters)]

This should not be a problem any more with the new PageHeader, you set the flickable property there explicitly. See https://developer.ubuntu.com/en/blog/2016/02/24/pageheader-tutorial/