Description

fsamanos-boop

opened on Feb 5, 2026

Issue body actions

Most appropriate sub-area of Processing 4?

I'm not sure

Processing version

4.5.2

Operating system

Linux mint 22.1 Xia

Bug description

I get the following error: "java.awt.IllegalComponentStateException: The frame is displayable".
​This happens on both my desktop and my laptop. It seems to be related to java.awt.Frame.setUndecorated being called while the frame is already visible.
​Steps to reproduce:
​Open Processing.
​Click on the "Java" mode button to switch to "Android".
​The error window pops up immediately.

Steps to reproduce this

snippet

// Paste your code below :)

void setup() {

}

void draw() {

}

Additional context

No response

Would you like to work on the issue?

No, I’m just reporting the issue

Reacted by Alexandre B A Villares

Activity

1. fsamanos-boop

   added

   bugSomething isn't workingSomething isn't working

   on Feb 5, 2026
2. SalmaneKhalili commented on Feb 23, 2026

   

   SalmaneKhalili

   on Feb 23, 2026

   Contributor

   More actions

   Debugging

   Hello, looking at the documentation, it seems frames cannot be set to undecorated while being displayed.

   

   Solution

   A simple solution is to encompass the setUndecorated(true) method in Editor.java with a isDisplayable() conditional.

         if (Platform.isLinux()) {
           if (!isDisplayable()) {
             setUndecorated(true);
           }
             getRootPane().setWindowDecorationStyle(JRootPane.FRAME);
         }

   TRADEOFF

   EDIT - It is no longer being decorated, this PR is ready for user testing! @catilac

   Reacted by Alexandre B A Villares

   Reacted by Alexandre B A Villares

   Reacted by Alexandre B A Villares
3. fsamanos-boop commented on Mar 28, 2026

   

   fsamanos-boop

   on Mar 28, 2026 via email

   Author

   More actions

   Thank you very much, I will try it

Issue actions