Preprocessing the dirty item list

[uwerat]

Qt/Quick puts a transform and a couple of optional nodes ( clip/opacity .. ) on top of the paint node, that can be manipulated by QQuickItem::updatePaintNode(). This is an quite unfortunate design, when manipulation of those heading nodes is required.

F.e the implementation in QQuickWindowPrivate::updateDirtyNode limits the clip node to the bounding rectangle of the item, what is not what we need, when trying to put an item on a QskScrollArea ( currently solved by inserting an invisible item between scrollarea and its child with a manipulated clip node ). Also it would be nice to be able to manipulate those parameters using the Qskinny animatior system, so that transitions for opacity/geometry/size/clips etc. of the controls can be defined/customized in the same way as it can be done for their sub controls,

Thus it makes sense to investigate in playing with preprocessing the dirty item list and doing the updates by forwarding the node updates to virtual methods of the items - like updatePaintNode, but for all nodes.