From 92edb52b41940ca443fe10fbd4dae71184d764ba Mon Sep 17 00:00:00 2001
From: weisj <weisj@arcor.de>
Date: Sat, 27 Jun 2020 23:19:31 +0200
Subject: [PATCH] Delay scroll popup menu container initialisation.

---
 .../darklaf/ui/popupmenu/DarkPopupMenuUI.java |  15 ++-
 .../ui/popupmenu/PopupMenuContainer.java      | 119 ++++++++++--------
 2 files changed, 80 insertions(+), 54 deletions(-)

diff --git a/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/DarkPopupMenuUI.java b/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/DarkPopupMenuUI.java
index c637ba60..391e3394 100644
--- a/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/DarkPopupMenuUI.java
+++ b/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/DarkPopupMenuUI.java
@@ -80,13 +80,17 @@ public class DarkPopupMenuUI extends BasicPopupMenuUI {
 
     @Override
     public void installDefaults() {
-        if (!(popupMenu instanceof ScrollPopupMenu)) {
-            popupMenuContainer = new PopupMenuContainer();
-        }
         super.installDefaults();
         popupMenu.putClientProperty(DarkPopupFactory.KEY_START_HIDDEN, true);
     }
 
+    private PopupMenuContainer getPopupMenuContainer() {
+        if (popupMenuContainer == null && !(popupMenu instanceof ScrollPopupMenu)) {
+            popupMenuContainer = new PopupMenuContainer();
+        }
+        return popupMenuContainer;
+    }
+
     @Override
     protected void installListeners() {
         super.installListeners();
@@ -95,8 +99,9 @@ public class DarkPopupMenuUI extends BasicPopupMenuUI {
 
     @Override
     public Popup getPopup(final JPopupMenu popup, final int x, final int y) {
-        if (popupMenuContainer == null) return super.getPopup(popup, x, y);
+        PopupMenuContainer container = getPopupMenuContainer();
+        if (container == null) return super.getPopup(popup, x, y);
         int maxHeight = DarkUIUtil.getScreenBounds(popup, x, y, false).height;
-        return popupMenuContainer.createPopup(popup, x, y, maxHeight);
+        return container.createPopup(popup, x, y, maxHeight);
     }
 }
diff --git a/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/PopupMenuContainer.java b/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/PopupMenuContainer.java
index a0d360ff..c4a24b2e 100644
--- a/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/PopupMenuContainer.java
+++ b/core/src/main/java/com/github/weisj/darklaf/ui/popupmenu/PopupMenuContainer.java
@@ -39,69 +39,89 @@ import com.github.weisj.darklaf.util.DarkUIUtil;
 
 public class PopupMenuContainer extends JPanel {
 
-    private final JScrollPane scrollPane;
-    private final MenuKeyListener menuKeyListener;
-    private final PopupMenuListener menuListener;
-    private final JPanel view;
+    private JScrollPane scrollPane;
+    private JPanel view;
+
+    private MenuKeyListener menuKeyListener;
+    private PopupMenuListener menuListener;
     private JPopupMenu popupMenu;
 
     public PopupMenuContainer() {
         super(new BorderLayout());
-        view = new JPanel(new BorderLayout());
-        OverlayScrollPane overlayScrollPane = createScrollPane(view);
-        scrollPane = overlayScrollPane.getScrollPane();
-        add(overlayScrollPane, BorderLayout.CENTER);
-        menuKeyListener = new MenuKeyListener() {
-            @Override
-            public void menuKeyTyped(final MenuKeyEvent e) {}
-
-            @Override
-            public void menuKeyPressed(final MenuKeyEvent e) {
-                SwingUtilities.invokeLater(() -> {
-                    if (popupMenu == null) return;
-                    MenuElement[] path = e.getMenuSelectionManager().getSelectedPath();
-                    if (path.length == 0) {
-                        return;
-                    }
-                    Rectangle bounds = path[path.length - 1].getComponent().getBounds();
-                    Rectangle r = SwingUtilities.convertRectangle(popupMenu, bounds, scrollPane);
-                    scrollPane.getViewport().scrollRectToVisible(r);
-                });
-            }
+    }
 
-            @Override
-            public void menuKeyReleased(final MenuKeyEvent e) {}
-        };
-        menuListener = new PopupMenuAdapter() {
-            @Override
-            public void popupMenuWillBecomeInvisible(final PopupMenuEvent e) {
-                onHide();
-            }
+    private void initComponents() {
+        if (view == null) {
+            view = new JPanel(new BorderLayout());
+            OverlayScrollPane overlayScrollPane = createScrollPane(view);
+            scrollPane = overlayScrollPane.getScrollPane();
+            add(overlayScrollPane, BorderLayout.CENTER);
+        }
+    }
 
-            @Override
-            public void popupMenuCanceled(final PopupMenuEvent e) {
-                onHide();
-            }
+    protected MenuKeyListener getMenuKeyListener() {
+        if (menuKeyListener == null) {
+            menuKeyListener = new MenuKeyListener() {
+                @Override
+                public void menuKeyTyped(final MenuKeyEvent e) {}
 
-            private void onHide() {
-                if (popupMenu == null) return;
-                popupMenu.removePopupMenuListener(this);
-                popupMenu.removeMenuKeyListener(menuKeyListener);
-            }
-        };
+                @Override
+                public void menuKeyPressed(final MenuKeyEvent e) {
+                    SwingUtilities.invokeLater(() -> {
+                        if (popupMenu == null) return;
+                        MenuElement[] path = e.getMenuSelectionManager().getSelectedPath();
+                        if (path.length == 0) {
+                            return;
+                        }
+                        Rectangle bounds = path[path.length - 1].getComponent().getBounds();
+                        Rectangle r = SwingUtilities.convertRectangle(popupMenu, bounds, scrollPane);
+                        scrollPane.getViewport().scrollRectToVisible(r);
+                    });
+                }
+
+                @Override
+                public void menuKeyReleased(final MenuKeyEvent e) {}
+            };
+        }
+        return menuKeyListener;
+    }
+
+    protected PopupMenuListener getMenuListener() {
+        if (menuListener == null) {
+            menuListener = new PopupMenuAdapter() {
+                @Override
+                public void popupMenuWillBecomeInvisible(final PopupMenuEvent e) {
+                    onHide();
+                }
+
+                @Override
+                public void popupMenuCanceled(final PopupMenuEvent e) {
+                    onHide();
+                }
+
+                private void onHide() {
+                    if (popupMenu == null) return;
+                    popupMenu.removePopupMenuListener(this);
+                    popupMenu.removeMenuKeyListener(menuKeyListener);
+                }
+            };
+        }
+        return menuListener;
     }
 
     public void setPopupMenu(final JPopupMenu popupMenu) {
+        MenuKeyListener keyListener = getMenuKeyListener();
+        PopupMenuListener popupMenuListener = getMenuListener();
         if (this.popupMenu != null) {
-            this.popupMenu.removeMenuKeyListener(menuKeyListener);
-            this.popupMenu.removePopupMenuListener(menuListener);
+            this.popupMenu.removeMenuKeyListener(keyListener);
+            this.popupMenu.removePopupMenuListener(popupMenuListener);
         }
         this.popupMenu = popupMenu;
         if (popupMenu != null) {
-            popupMenu.removeMenuKeyListener(menuKeyListener);
-            popupMenu.removePopupMenuListener(menuListener);
-            popupMenu.addMenuKeyListener(menuKeyListener);
-            popupMenu.addPopupMenuListener(menuListener);
+            popupMenu.removeMenuKeyListener(keyListener);
+            popupMenu.removePopupMenuListener(popupMenuListener);
+            popupMenu.addMenuKeyListener(keyListener);
+            popupMenu.addPopupMenuListener(popupMenuListener);
         }
     }
 
@@ -113,6 +133,7 @@ public class PopupMenuContainer extends JPanel {
             popupMenu.setBorderPainted(true);
             return PopupFactory.getSharedInstance().getPopup(popupMenu.getInvoker(), popupMenu, posX, posY);
         } else {
+            initComponents();
             int increment = 1;
             if (popupMenu.getComponentCount() > 0) {
                 increment = Math.max(1, popupMenu.getComponent(0).getPreferredSize().height / 2);