Focus: Make focus parent mechanism available without having access to the FocusParentHelper class.

core/src/main/java/com/github/weisj/darklaf/focus/FocusParentHelper.java

@@ -44,7 +44,7 @@ public final class FocusParentHelper {
             if (e.getID() != FocusEvent.FOCUS_GAINED && e.getID() != FocusEvent.FOCUS_LOST) return;
             Component comp = e.getComponent();
             listeners.forEach((c, focusParent) -> {
-                if (SwingUtilities.isDescendingFrom(comp, focusParent)) {
+                if (c instanceof JComponent && SwingUtilities.isDescendingFrom(comp, focusParent)) {
                     RepaintAction repaintAction = PropertyUtil.getObject(c, KEY_FOCUS_ACTION, RepaintAction.class);
                     if (repaintAction != null) {
                         repaintAction.accept(c);
@@ -54,6 +54,15 @@ public final class FocusParentHelper {
         }, AWTEvent.FOCUS_EVENT_MASK);
     }
 
+    public static void updateFocusParentRegistry(final JComponent c, final Component parent) {
+        if (parent == null) {
+            c.putClientProperty(KEY_FOCUS_ACTION, null);
+            listeners.remove(c);
+        } else {
+            listeners.put(c, parent);
+        }
+    }
+
     public static void setFocusParent(final JComponent c, final JComponent focusParent) {
         setFocusParent(c, focusParent, Component::repaint);
     }
@@ -62,12 +71,9 @@ public final class FocusParentHelper {
             final RepaintAction focusChangedAction) {
         if (c == null) return;
         c.putClientProperty(KEY_FOCUS_PARENT, focusParent);
-        if (focusParent == null) {
+        updateFocusParentRegistry(c, focusParent);
-            c.putClientProperty(KEY_FOCUS_ACTION, null);
+        if (focusParent != null) {
-            listeners.remove(c);
-        } else {
             c.putClientProperty(KEY_FOCUS_ACTION, focusChangedAction);
-            listeners.put(c, focusParent);
         }
     }
 

core/src/main/java/com/github/weisj/darklaf/util/DarkUIUtil.java

@@ -192,6 +192,9 @@ public final class DarkUIUtil {
      */
     public static boolean hasFocus(final Component c, final FocusEvent e) {
         Component focusParent = PropertyUtil.getObject(c, FocusParentHelper.KEY_FOCUS_PARENT, Component.class);
+        if (c instanceof JComponent) {
+            FocusParentHelper.updateFocusParentRegistry((JComponent) c, focusParent);
+        }
         return hasFocusImpl(c, focusParent, e);
     }