Hello World Hiding a `ComposePanel` with `isVisible = false`

Question

Hello World Hiding a `ComposePanel` with `isVisible = false` doesn t seem to work the UI stays visible but is no longer interactive This looks like a bug but just wanted to check here first Anyone has seen this before Reproducer in thread

bod · Answer

```fun main = SwingUtilities invokeLater val composePanel = ComposePanel apply setContent Button onClick = isVisible = false lt this should hide the ComposePanel but doesn t Text Hello World JFrame apply setSize 800 600 contentPane add composePanel isVisible = true ```

Alexander Maryanovsky · Answer

It s kind of on the boundary between Swing and Compose so I m not sure it d be classed as a bug although it does make sense we d check whether the `ComposePanel` is visible before rendering it Judging by the animation though maybe we aren t rendering it when invisible but also not clearing the last rendered frame Any way you can use something like this as a workaround ```fun main = SwingUtilities invokeLater val composePanel = ComposePanel apply setContent var visible by remember mutableStateOf true if visible Button onClick = visible = false Text Hello World JFrame apply setSize 800 600 contentPane add composePanel isVisible = true ```

Alexander Maryanovsky · Answer

Does sound like a bug actually If you wanted to make the panel invisible from Swing code you wouldn t be able to

Alexander Maryanovsky · Answer

Not easily anyway

bod · Answer

Thanks a lot Yeah I was gonna say in my case I m actually trying to produce the settings UI for an IntelliJ plugin I know this is probably unorthodox and so I don t really have access to the code showing hiding the panel It s called by the host

Alexander Maryanovsky · Answer

As a workaround you can override setVisible of the panel and set a compose state variable accordingly

bod · Answer

Ah cool idea bulb I ll try that

bod · Answer

well that doesn t really work because setVisible is actually never called The way the plugin SDK works is that you implement an interface that returns a JPanel I add the ContentPanel inside this JPanel and then it will show it hide it but I think it does that by changing the visibility of one of its parents I m guessing a LayoutManager is managing the visibility of a parent several layers above my JPanel and I m no sure how to get called when that happens

bod · Answer

also I guess I d need an event sent before the component is hidden so I can update the compose UI first

bod · Answer

anyway I opened this issue <https github com JetBrains compose jb issues 2656>

Alexander Maryanovsky · Answer

Thanks for opening the ticket Maybe overriding removeNotify instead will help

bod · Answer

no unfortunately it appears this is not called when switching to a different tab but only when closing the whole window I guess switching to a different tab doesn t remove the component but only hides it

Alexander Maryanovsky · Answer

Maybe `addHierarchyListener` <https docs oracle com javase 7 docs api java awt event HierarchyEvent html>

bod · Answer

Alas It appears the event is received after the panel is already hidden so my hiding the compose UI is too late and not reflected