ProxyBuilder is used by the FXML loader to instantiate classes whose constructors are annotated with `@NamedArg`. When such a class also exposes a read-only `Map` property (e.g. getProperties() — the same pattern used by `javafx.scene.Node`), setting child elements under that property in FXML caused incorrect behaviour or a runtime error.
**Root cause:** _getReadOnlyProperty()_ always returned an `ArrayListWrapper` regardless of the actual **getter** return type. When the getter returns a `Map`, an `ArrayListWrapper` is the wrong container and the entries are never transferred to the real map on the object. - [x] I confirm that I make this contribution in accordance with the [OpenJDK Interim AI Policy](https://openjdk.org/legal/ai). ------------- Commit messages: - Fix ProxyBuilder to correctly handle read-only Observable Map/List with @NamedArg - Fix ProxyBuilder to correctly handle read-only Map properties with @NamedArg Changes: https://git.openjdk.org/jfx/pull/2167/files Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=2167&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8203870 Stats: 162 lines in 3 files changed: 157 ins; 0 del; 5 mod Patch: https://git.openjdk.org/jfx/pull/2167.diff Fetch: git fetch https://git.openjdk.org/jfx.git pull/2167/head:pull/2167 PR: https://git.openjdk.org/jfx/pull/2167
