Rather than setting the decorations app wide, just modify the editor screen

Author: Stefterv

app/src/processing/app/platform/LinuxPlatform.java

@@ -22,16 +22,13 @@
 
 package processing.app.platform;
 
-import java.io.File;
-import java.awt.Desktop;
-import java.awt.Toolkit;
-
 import processing.app.Base;
 import processing.app.Messages;
 import processing.app.Preferences;
 import processing.core.PApplet;
 
-import javax.swing.*;
+import java.awt.*;
+import java.io.File;
 
 
 public class LinuxPlatform extends DefaultPlatform {
@@ -40,8 +37,6 @@ public class LinuxPlatform extends DefaultPlatform {
 
   public void initBase(Base base) {
     super.initBase(base);
-
-    JFrame.setDefaultLookAndFeelDecorated(true);
     System.setProperty("flatlaf.menuBarEmbedded", "true");
 
     // Set X11 WM_CLASS property which is used as the application

app/src/processing/app/ui/Editor.java

@@ -23,38 +23,42 @@
 
 package processing.app.ui;
 
-import java.awt.*;
-import java.awt.datatransfer.*;
-import java.awt.event.*;
-import java.awt.print.*;
-import java.io.*;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.HashSet;
-import java.util.List;
-import java.util.Map;
-import java.util.Set;
-import java.util.Stack;
-import java.util.Timer;
-import java.util.TimerTask;
-import java.util.stream.Collectors;
-
-import javax.swing.*;
-import javax.swing.border.EmptyBorder;
-import javax.swing.event.*;
-import javax.swing.plaf.basic.*;
-import javax.swing.text.*;
-import javax.swing.text.html.*;
-import javax.swing.undo.*;
-
 import com.formdev.flatlaf.util.SystemInfo;
 import processing.app.*;
-import processing.utils.SketchException;
+import processing.app.Formatter;
 import processing.app.contrib.ContributionManager;
 import processing.app.laf.PdeMenuItemUI;
 import processing.app.syntax.*;
-import processing.core.*;
+import processing.core.PApplet;
+import processing.utils.SketchException;
+
+import javax.swing.*;
+import javax.swing.border.EmptyBorder;
+import javax.swing.event.*;
+import javax.swing.plaf.basic.BasicSplitPaneDivider;
+import javax.swing.plaf.basic.BasicSplitPaneUI;
+import javax.swing.text.BadLocationException;
+import javax.swing.text.Element;
+import javax.swing.text.View;
+import javax.swing.text.ViewFactory;
+import javax.swing.text.html.HTMLEditorKit;
+import javax.swing.undo.CannotRedoException;
+import javax.swing.undo.CannotUndoException;
+import javax.swing.undo.CompoundEdit;
+import javax.swing.undo.UndoManager;
+import java.awt.*;
+import java.awt.datatransfer.DataFlavor;
+import java.awt.datatransfer.Transferable;
+import java.awt.event.*;
+import java.awt.print.PageFormat;
+import java.awt.print.PrinterException;
+import java.awt.print.PrinterJob;
+import java.io.File;
+import java.io.IOException;
+import java.util.*;
+import java.util.List;
+import java.util.Timer;
+import java.util.stream.Collectors;
 
 
 /**
@@ -207,6 +211,10 @@ public void windowDeactivated(WindowEvent e) {
       spacer.setAlignmentX(Component.LEFT_ALIGNMENT);
       box.add(spacer);
     }
+      if (Platform.isLinux()) {
+          setUndecorated(true);
+          getRootPane().setWindowDecorationStyle(JRootPane.FRAME);
+      }
 
     rebuildModePopup();
     toolbar = createToolbar();