Changing the order MapQuickItems are drawn on a Map

srce

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):

            beginResetModel();
            m_items.move(oldRow, newRow);
            endResetModel();

If I call beginMoveRows() instead,

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

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);
m_items.removeAt(oldRow);
endRemoveRows();
beginInsertRows(QModelIndex(), newRow, newRow);
m_items.append(text);
endInsertRows();

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

Calling

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.

6thC

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

srce

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.