Fix too large combobox popup.

core/src/main/java/com/github/weisj/darklaf/ui/WidgetPopupHelper.java

@@ -29,28 +29,29 @@ import com.github.weisj.darklaf.util.DarkUIUtil;
 
 public class WidgetPopupHelper {
 
-    public static Rectangle getPopupBounds(final JComponent parent, final JComponent popup, final Dimension popupSize) {
-        return getPopupBounds(parent, popup, popupSize, true, false);
+    public static Rectangle getPopupBounds(final JComponent parent, final Dimension popupSize,
+            final Dimension parentSize) {
+        return getPopupBounds(parent, popupSize, parentSize, true, false);
     }
 
-    public static Rectangle getPopupBounds(final JComponent parent, final JComponent popup, final Dimension popupSize,
+    public static Rectangle getPopupBounds(final JComponent parent, final Dimension popupSize,
+            final Dimension parentSize,
             final boolean useParentSizeAsMinimum, final boolean alignOpposite) {
         Insets parentIns = parent.getInsets();
-        Insets popupIns = popup.getInsets();
 
         // reduce the width of the popup by the insets so that the popup
         // is the same width as the parent.
         if (useParentSizeAsMinimum) {
-            popupSize.width = Math.max(popupSize.width, parent.getWidth() - parentIns.left - parentIns.right);
+            popupSize.width = Math.max(popupSize.width, parentSize.width - parentIns.left - parentIns.right);
         }
         // popupSize.width -= popupIns.left + popupIns.right;
 
         boolean ltr = parent.getComponentOrientation().isLeftToRight();
         if (alignOpposite) ltr = !ltr;
 
-        int x = ltr ? parentIns.left : parent.getWidth() - parentIns.right - popupSize.width;
+        int x = ltr ? parentIns.left : parentSize.width - parentIns.right - popupSize.width;
 
-        return computePopupBounds(parent, x, parent.getHeight() - parentIns.bottom, popupSize.width, popupSize.height);
+        return computePopupBounds(parent, x, parentSize.height - parentIns.bottom, popupSize.width, popupSize.height);
     }
 
     protected static Rectangle computePopupBounds(final JComponent parent, final int px, final int py, final int pw,

core/src/main/java/com/github/weisj/darklaf/ui/combobox/DarkComboPopup.java

@@ -133,9 +133,17 @@ public class DarkComboPopup extends BasicComboPopup {
     }
 
     protected Point getPopupLocation() {
+        scroller.setPreferredSize(null);
         Dimension dim = getPreferredSize();
         dim.height = getPopupHeightForRowCount(comboBox.getMaximumRowCount());
-        Rectangle popupBounds = WidgetPopupHelper.getPopupBounds(comboBox, this, dim);
+
+        Dimension parentSize = comboBox.getSize();
+        Insets ins = getInsets();
+        parentSize.width -= ins.left + ins.right;
+        dim.width -= ins.left + ins.right;
+
+        Rectangle popupBounds = WidgetPopupHelper.getPopupBounds(comboBox, dim, parentSize);
+
         Dimension scrollSize = popupBounds.getSize();
         Point popupLocation = popupBounds.getLocation();
 

core/src/main/java/com/github/weisj/darklaf/ui/splitbutton/DarkSplitButtonListener.java

@@ -55,7 +55,8 @@ public class DarkSplitButtonListener implements ActionListener, PropertyChangeLi
             actionMenu.setPreferredSize(null);
             Dimension size = actionMenu.getPreferredSize();
             Rectangle popupBounds =
-                    WidgetPopupHelper.getPopupBounds(ui.splitButton, actionMenu, size, splitButton, !splitButton);
+                    WidgetPopupHelper.getPopupBounds(ui.splitButton, size, ui.splitButton.getSize(), splitButton,
+                            !splitButton);
             if (splitButton) {
                 actionMenu.setPreferredSize(popupBounds.getSize());
             }