RFR: 8196065: ListChangeListener getRemoved() returns items that were not removed. [v6]

[Jeanette Winzenburg]

On Sun, 23 May 2021 15:03:21 GMT, Michael Strauß <mstrauss at openjdk.org> wrote:

> This was my first thought, too. However, it doesn't work because `SelectedItemsReadOnlyObservableList` doesn't truthfully report its changes, so we can't simply replay its reported changes onto our copy of the items list. 

You mean `selectedIndices` not reporting truthfully? That's true, but no excuse for selectedItems to misbehave on its own :) The one and only task of selectedItems is to transform the notifications received from the indices into items' value space and that's what it must do correctly.

And yes, MultipleSelectionModelBase is a very deep and very dark pit. Some corners where smoothed over the years which generally improved the overall behaviour. The path chosen has hacky elements, though: f.i. exposing internal api (like the nextXX methods) as public is .. extremely suboptimal and introduced the smear of who-does-what without caring overly much about contracts. Now we have to deal with a multi-headed monster that grows new heads whenever one is cut .. /rant-end

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PR: https://git.openjdk.java.net/jfx/pull/478