@Override
	public boolean getSupportsWindowDecorations() {
		if( SystemInfo.isProjector || SystemInfo.isWebswing || SystemInfo.isWinPE )
			return false;

		if( SystemInfo.isWindows_10_orLater &&
			FlatNativeWindowBorder.isSupported() )
		  return false;

		return SystemInfo.isWindows_10_orLater || SystemInfo.isLinux;
	}
Returns whether FlatLaf supports custom window decorations.
This depends on the operating system and on the used Java runtime.
<p>
This method returns {@code true} on Windows 10/11 (see exception below)
and on Linux, otherwise returns {@code false}.
<p>
Returns also {@code false} on Windows 10/11 if
FlatLaf native window border support is available (requires Windows 10/11).
<p>
In these cases, custom decorations are enabled by the root pane.
Usage of {@link JFrame#setDefaultLookAndFeelDecorated(boolean)} or
{@link JDialog#setDefaultLookAndFeelDecorated(boolean)} is not necessary.
flatlaf-core/src/main/java/com/formdev/flatlaf/FlatLaf.java