Prevent Options dialog from closing when click Apply button

Author: demitriusbelai

platform/o.n.swing.laf.flatlaf/src/org/netbeans/swing/laf/flatlaf/FlatLafOptionsPanelController.java

@@ -22,6 +22,9 @@
 import java.awt.Window;
 import java.beans.PropertyChangeListener;
 import java.beans.PropertyChangeSupport;
+import java.util.Arrays;
+import java.util.List;
+import java.util.stream.Collectors;
 import javax.swing.JComponent;
 import javax.swing.JDialog;
 import javax.swing.JFrame;
@@ -87,6 +90,8 @@ public void applyChanges() {
                     JDialog.setDefaultLookAndFeelDecorated(isUseWindowDecorations);
                     for (Window w : Window.getWindows()) {
                         if (w.isDisplayable() && (w instanceof JFrame || w instanceof JDialog)) {
+                            List<Window> childs = Arrays.stream(w.getOwnedWindows())
+                                    .filter(Window::isVisible).collect(Collectors.toList());
                             w.dispose();
                             if (w instanceof JFrame) {
                                 ((JFrame) w).setUndecorated(isUseWindowDecorations);
@@ -98,6 +103,7 @@ public void applyChanges() {
                                     isUseWindowDecorations ? JRootPane.FRAME : JRootPane.NONE);
                             }
                             w.setVisible(true);
+                            childs.forEach(child -> child.setVisible(true));
                         }
                     }
                 }