[Interest] QTreeView expand/expandAll performance

[Paul Miller]

On 9/26/2014 8:33 AM, William Hallatt wrote:
> Hi everyone,
>
> I have just started playing with Qt’s MVC classes and have created a
> hierarchical model to display in a QTreeView. Some of the nodes,
> however, have a fair amount of children and when I expand these nodes
> (or, heaven forbid, expandAll), the app hangs for a remarkably long time.

I encountered a serious performance problem with a QTreeView when using 
a custom style that had dotted lines for the connecting lines, but on 
Mac OS X only.

Otherwise, I haven't had any performance issues with deep graphs at all. 
Make sure your model is as efficient as possible though.