RFR: 8091429: ObservableList<E>#replaceRange(int from, int to, Collection<? extends E> col) [v3]

John Hendrikx jhendrikx at openjdk.org
Wed Nov 5 16:19:36 UTC 2025


> 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.

John Hendrikx has updated the pull request incrementally with one additional commit since the last revision:

  Add additional tests

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

Changes:
  - all: https://git.openjdk.org/jfx/pull/1937/files
  - new: https://git.openjdk.org/jfx/pull/1937/files/0b42426b..730ea77f

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jfx&pr=1937&range=02
 - incr: https://webrevs.openjdk.org/?repo=jfx&pr=1937&range=01-02

  Stats: 29 lines in 1 file changed: 28 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1937.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1937/head:pull/1937

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


More information about the openjfx-dev mailing list