It is currently blocked with an artificial check:
if (panelCreator != null) {
if (splitUI && (testWindows != null || windowListCreator != null)) {
// TODO Is it required? We can support both
throw new IllegalStateException("Split UI is not allowed "
+ "with additional windows");
}
}
We have a number of manual tests, which has some text area in the instruction window to print a feedback from the test to be evaluated by a tester.
Removing this check allows us to implement this.
We can consider making a special methods for this later.
This is required for the https://github.com/openjdk/jdk/pull/18250.