Locked header does not work with conditional loading components

I added some prints in our Page code. In Page10.qml (also valid for Page 1.1), I have this now:

    // avoid using parent.height because parent may be a Loader which does not have its height set.
    height: parentNode ? page.flickable ? parentNode.height : parentNode.height - internal.headerHeight : undefined
    onHeightChanged: print("height of "+page+" changed to "+parentNode.height+" - "+internal.headerHeight+" = "+height)

and this is being printed for the incorrect page:

qml: parent node of Page11_QMLTYPE_35(0x2779620) = Tab_QMLTYPE_26(0x217f4f0)
qml: parent height = 400
qml: height of Page11_QMLTYPE_35(0x2779620) changed to 400 - 72 = 328
qml: parent node of Page11_QMLTYPE_35(0x2779620) = Tab_QMLTYPE_26(0x217f4f0)
qml: parent height = 400
qml: height of Page11_QMLTYPE_35(0x2779620) changed to 400 - 72 = 400

so it seems that height is not updated, even though internal.headerHeight is correct here.

It is a problem here that the Loader has anchors, and thus width and height, and will set the width and height of its loaded item accordingly, overriding the logic we have in the Page.

I modified the example code like this: http://paste.ubuntu.com/10372933/ and now it works fine. It is not really a bug in UITK, but a result of how the UITK works and how the Loader changes the size of its children, see Loader sizing behavior on http://doc-snapshot.qt-project.org/qt5-5.4/qml-qtquick-loader.html

I linked an MR that fixes the issues and adds documentation to Tab.page.

With the fix from the MR, the test program works like this: http://paste.ubuntu.com/10388468/

This bug was fixed in the package ubuntu-ui-toolkit - 1.2.1433+15.04.20150306-0ubuntu1

---------------
ubuntu-ui-toolkit (1.2.1433+15.04.20150306-0ubuntu1) vivid; urgency=medium

  [ Albert Astals Cid ]
  * Fix infinite icon size grow when asked for a non square icon
    Fixes: LP: #1422835
  * IconProvider: Make sure icons fit in the given size
  [ Christian Dywan ]
  * Skip select_text_longtap_when_active under opengles2.
    Fixes: LP: #1401140
  * Support for multiple devices with push_to_phone.sh.
  * Take OrientationHelper y coordinate from real parent height.
    Fixes: LP: #1413194
  * Update popover position upon pointer movement.
    Fixes: LP: #1199502, LP: #1415532
  * Change <code> to be inline-block. Fixes LP: #1427534
  * Set right anchor on tab overflow buttons. Fixes LP: #1425433
  * Add tst_listitems_itemselector.qml to EXCEPTIONS. So warnings are
    no longer fatal for unit test.
  [ Sebastien Bacher ]
  * document that MainView's applicationName is used to set the gettext
    domain. Fixes: LP: #1421661.
  [ Tiago Salem Herrmann ]
  * Drop cache once properties are successfully restored.
  [ Timo Jyrinki ]
  * Add dist-upgrade option to the UITK Test Plan script. Output the
    selected parameters in the beginning.
  [ Tim Peeters ]
  * Add MainView 1.2 which removes the deprecated toolbar support.
  * Enable PageStack header animations for MainView 1.2.
  * Fix the size and anchors of a Page that is loaded inside a Loader.
    This is useful when a Page is Loaded by a Tab. Fixes: LP: #1424635
  * Fix UITK gallery content page width.
    Fixes: LP: #1424635, LP: #1425470
  * Set objectName for MainView int est_textinput.header.qml and fix
    scenarios in test_textinput.py
  [ Zsombor Egri ]
  * Alarm services regression fix. Fixes: LP: #1401883
  * Implement ListItem dragging support in ListView.
    Fixes: LP: #119535
  * Introducing select/multiselect mode in ListItem.
  * Moving the tst_focus.qml under exceptions till we fix DatePicker
    binding loops.
  * RTL (Right To Left) support in ListItem.
  * RTM branch diff merge. Fixes: LP: #1358610.
  * Second stage of simplification - divider group property is an item,
    simplifying the anchoring of the contentItem. PropertyChange does
    not backup the property binding, uses QQmlPropertyPrivate::write()
    with parameter to keep bindings. ListItemAnimator uses behavior to
    animate snapping. Styling got "styledItem" context property to obey
    general styling rules. clicked() and pressAndHold() emission fix
    when content is swiped.
  * Transferring the ListItem attached properties to ListItemStyle API.
    Most of the style API became redundant, and removed. Few API from
    ListItem were also removed as not needed. ListItemAnimator,
    UCListItemAttached and UCActionPanel classes removed.
    Panel swiping overshoot made elastic. Snapping animation transformed
    into SmoothedAnimation, uses velocity of 60GU/second. Turning
    warnings to be reported in the error property.
    SHOW_SERVICEPROPERTIES_WARNINGS environment variable set will
    display them in the console. Fixes: LP: #1423203.
  * Updating documentation and imports for 1.2 & Vivid (Qt 5.4).
...

Status changed to 'Confirmed' because the bug affects multiple users.