I've wrote 1 treeView/model system last year that had it all re-implemented from scratch, a few days ago I decided to rewrite it to increase performance and relay more on native functions of QT. Which I did and works great but the margin thing is a sticking point. I remember how much work it was before to get it to work properly... took a while as I had to write quite a few functions before I got to the point of margin detection. I'm very surprised there is no margin = (qt code ) + userMarginOverrideVal in the canDrop() function... this would have allowed us to just say, hey add +5 pixels to detection or something like that... Perhaps I should add it to feature request, would posting it in a bug report tracker be a good place? I don't see feature requests and I have no idea how to get the source to compile (Just didn't spend enough time on it) and add it myself & post to qt as commit... As far as I can tell we need like 2 functions, setOverrideMargin(int val) and getOverrideMargin(), skipping setting flag true/false if we want to use it as defaultVal should just be 0... TIA

@raven-worx said in QTreeView/Model drop action - no expand sign ?: Also did you emit the dataChanged() signal on the parent index? I've just read the post. I forgot to correct it. This is what I edit: bool testModel::dropMimeData(const QMimeData *data, Qt::DropAction action, int row, int column, const QModelIndex &parent) { ... Q_EMIT dataChanged(itemFirst.index(),itemLast.index()) } Hmmmm so I tried this, the parent is the object that is in function above. Q_EMIT dataChanged(parent, parent) Now this now "magically" works, I get extra ">" when I drop item on another item... I also learned that I also need to call Q_EMIT layoutChanged({parent}/flag) to update view if I drop items on expanded parent... Ok all good then, thanks! Weird issue o.o