setHidden doesn't work correctly when scrollableX enable

[JrmyDev]

After 2 hours of debugging, I finally found what cause wrong behavior when hidding a component in my application.

Platform : Simulator
Codename One revisions: 1b2a6d1
Windows 7
Eclipse Neon 4.6.3

I've extract a simple test case. It show a form with two container. The container cnt1 (with label 1) should be hidden, but it's the container cnt2 that is hidden. If you comment cnt1.setScrollableX(true), no problem !

Test case :

Form f = new Form();
Label lbl1 = new Label("Label1");
Label lbl2 = new Label("Label2");
Container cnt1 = FlowLayout.encloseCenter(lbl1);
cnt1.setScrollableX(true);
Container cnt2 = FlowLayout.encloseCenter(lbl2);
f.add(BorderLayout.center(cnt2).add(BorderLayout.SOUTH, cnt1));
cnt1.setHidden(true);
f.show();

I'm not sure this is a bug. setHidden on a scrollable container is conceptually tricky as scrollability manipulates preferred size just like setHidden does.. There is a simple workaround of setScrollableX(false) then restoring scrollability when needed.

[JrmyDev]

Read again my issue please!!
First, I tried to hide cnt1 and cnt2 is hidden.
Second, don't you think you should put your workaround in your implementation ?
Finally, I think you must at least mentionned in your doc that setHidden doesn't work in case of BorderLayout/Scrollable container, even if I don't understand why you don't manage it in your implem.
I'm aware that you manage issues to avoid backward compatibility problems, but sometimes, I think you should be a bit more careful about reported problems.

I ran the code and saw that before posting. setVisible is more consistent but setHidden relies on nuanced behavior that's sometimes hard to quantify. I looked at the current JavaDocs and they explain what setHidden does correctly. I've added "Notice that this might not behave as expected with scrollable containers or layouts that ignore preferred size."

I don't think that will help clarify this by much but as I said it's a nuanced behavior. Coding this workaround into our implementation doesn't make sense as it would break scrollability when you restore. If you need this behavior you need to know that you disabled scrolling so you can restore it later on. Just to be clear, this isn't about backward compatibility. It's a conceptual issue with the way preferred size works.