<![CDATA[How to get the effective icon size used in a QTreeView?]]>This seems like a really basic question, but I have been unable to find out how to do this: How do I retrieve the actual icon size that is used in a QTreeView? When I create a QTreeView and call iconSize() I get the default value of (-1, -1), which apparently indicates that the size will be based on the font metrics. However, it is unclear in what way. For instance, the actual size does not correspond to tree_view->fontMetrics().height(). Is there a reliable way to retrieve the icon size? All items are just icon+text and I call setUniformRowHeights(true) in case that makes any difference.
The background ist that I want to dynamically generate bitmap icons at the right size, so they are not scaled when being used in the tree view.

]]>https://forum.qt.io/topic/145924/how-to-get-the-effective-icon-size-used-in-a-qtreeviewRSS for NodeThu, 30 Apr 2026 05:07:45 GMTWed, 21 Jun 2023 11:03:51 GMT60<![CDATA[Reply to How to get the effective icon size used in a QTreeView? on Wed, 21 Jun 2023 13:42:04 GMT]]>@tempus_fugit
There's a protected method:
[protected] int QTreeView::rowHeight(const QModelIndex &index) const

]]>https://forum.qt.io/post/762208https://forum.qt.io/post/762208Wed, 21 Jun 2023 13:42:04 GMT<![CDATA[Reply to How to get the effective icon size used in a QTreeView? on Wed, 21 Jun 2023 13:25:25 GMT]]>@mpergand said in How to get the effective icon size used in a QTreeView?:

@tempus_fugit said in How to get the effective icon size used in a QTreeView?:

The background ist that I want to dynamically generate bitmap icons at the right size, so they are not scaled when being used in the tree view.

You can return the height of a row according to the icon size you want in Qt::SizeHintRole in your item model.

Thanks. Yes, that would work but that only shifts the problem. I do not really want the burden of controlling the row height, because that would mean that I would have to compute a suitable value for the row height. I would really prefer letting QTreeView work out the row height for me based on the natural height of the items.

]]>https://forum.qt.io/post/762206https://forum.qt.io/post/762206Wed, 21 Jun 2023 13:25:25 GMT<![CDATA[Reply to How to get the effective icon size used in a QTreeView? on Wed, 21 Jun 2023 12:39:23 GMT]]>@tempus_fugit said in How to get the effective icon size used in a QTreeView?:

The background ist that I want to dynamically generate bitmap icons at the right size, so they are not scaled when being used in the tree view.

You can return the height of a row according to the icon size you want in Qt::SizeHintRole in your item model.

]]>https://forum.qt.io/post/762204https://forum.qt.io/post/762204Wed, 21 Jun 2023 12:39:23 GMT