I am writing an extension for LibreOffifce. A tree with columns on my sidebar is needed. (example - https://doc.qt.io/qt-5/qtwidgets-itemviews-simpletreemodel-example.html)
I found information about Tree Control and module "tree", e.g. here https://wiki.openoffice.org/wiki/Treecontrol https://www.openoffice.org/api/docs/common/ref/com/sun/star/awt/tree/module-ix.html
But I couldn't find anything about writing a tree with columns.
There is a quote "You can provide your own model which must at least support the interface com.sun.star.awt.XTreeModel." in the article "Tree control", but I also couldn't find any information about providing of my own models...
Please, help me find information and examples, if it is possible to provide tree with columns for LibreOffice extension.
Here is some Python-UNO code (as tagged in your question) that shows how to implement the
XTreeDataModelUNO interface. You'll have to write a lot more code in order to render the nodes in multiple columns and do everything else you want. It may be required to create another class that implementsXTreeNode.More information for working with trees is at https://wiki.openoffice.org/wiki/Going_further_with_Dialog_and_Component#The_New_Tree_Control.
If it turns out that there is no convenient way to do this directly with UNO, I once did this with a JTreeTable in Java. LibreOffice extensions can be written in Java, so perhaps that would solve your needs instead.