On Wed, 15 Oct 2025 03:40:24 GMT, John Hendrikx <[email protected]> wrote:

> This PR implements a new default method on `ObservableList` to be able to 
> replace elements within a specified range.
> 
> Justification for this change is to allow an `ObservableList` to be bulk 
> modified resulting in a single `ListChangeListener` call back.  In this way 
> the callbacks don't observe the list changing its size from S to S-X back to 
> S again(*). Currently the only way to bulk replace a range of items is to 
> remove X items then add X items, resulting in two listener callbacks in 
> between which the size of the list can be observed to change.
> 
> The other alternative is to call `set` individually for each item, which 
> results in many change notifications.
> 
> With the addition of this PR, and the changes in 
> `ModifiableObservableListBase`, replacing a range of items becomes a single 
> change callback.
> 
> (*) The list may indeed change size still as plain `List` does not have 
> `setAll` operations; size listeners may observe this, but it will no longer 
> be observable from a `ListChangeListener` due to multiple separate callbacks.

This pull request has now been integrated.

Changeset: b76090df
Author:    John Hendrikx <[email protected]>
URL:       
https://git.openjdk.org/jfx/commit/b76090dfe6821efcbd86230e1b24ad7f455c7a41
Stats:     135 lines in 3 files changed: 134 ins; 1 del; 0 mod

8091429: ObservableList<E>#replaceRange(int from, int to, Collection<? extends 
E> col)

Reviewed-by: mstrauss, kcr

-------------

PR: https://git.openjdk.org/jfx/pull/1937

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