Thanks for the PR! I've left some initial comments. We will still need to go through the API review process, but I think exposing a way to get the active tree item is a useful change.

This is looking good! I will bring it to our API discussion next week and then merge it assuming that there are no concerns.

@EhabY thank you for the ping. One output from API discussion that needs to be addressed is making sure that the selection is already updated with the active event fires and the active item is already updated with the selection event fires. For example, if you create a tree view and do the following:

		view.onDidChangeActiveItem(e => {
			console.log('selection');
			console.log(view.selection);
			console.log('active');
			console.log(view.activeItem);
	});
		view.onDidChangeSelection(e => {
			console.log('selection');
			console.log(view.selection);
			console.log('active');
			console.log(view.activeItem);
	});

The console logs from the two event listners should print the same thing each time they both fire. To that end $setSelection and $setFocus should be merged into one $setSelectionAndFocus so that both values are set in the same RPC call.

https://github.com/ehaby/vscodetreeviewfocus/blob/b72b9c0ea0a984ae11b3bcd81b9e01dddcc0ab6f/src/vs/workbench/api/common/extHostTreeViews.ts#L235-L249

Thank you for the PR! We do not need to wait to address #185563 to merge as this is still proposed API. I will follow up on #185563.

Looks good, I've resolved the conflicts!