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Changing the order MapQuickItems are drawn on a Map

  • Hi,

    I'm trying to change the order MapQuickItems are drawn, so I can control which item is on top, when two items overlap.

    My map items are created in a C++ model that inherits from QAbstractListModel. It seems the items are normally drawn in the order they are in the model's list. So, I thought I could try reordering the items in the list, in order to control the order they are drawn. Is there a better/alternative way?

    The results seem to vary on the way in which I reorder the items in the model.

    If I call beginResetModel() before the move, it works, but it seems to be very slow (and seems a bit suboptimal to reset the entire model if only changing a few rows):

                m_items.move(oldRow, newRow);

    If I call beginMoveRows() instead,

                beginMoveRows(parent, oldRow, oldRow, parent, newRow);
                m_items.move(oldRow, newRow);

    I get messages in the console of the form:

    item  QDeclarativeGeoMapQuickItem(0x1fe48ca0640, parent=0x0, geometry=449.254,281 66x18)  still referenced declarativemaps\qdeclarativegeomapitemview.cpp: 475

    If I try beginRemoveRows() followed by beginInsertRows()

    beginRemoveRows(QModelIndex(), oldRow, oldRow);
    beginInsertRows(QModelIndex(), newRow, newRow);

    Then this works if the item is moved to a latter index in the list, but not if moved to an earlier index.


    emit dataChanged(index(oldRow), index(newRow));

    afterwards doesn't seem to make any difference.

    Perhaps it's an issue in my .qml, so I've put a simplified example here: Example project

    Any ideas? Thanks.

  • Err... just use Z index? That's all I do anyway.

  • Hmm - I had tried that, but couldn't get it working, but it seems to work in the cut down example I've created - so I guess I had another problem that was stopping it from working. Thanks.

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