From 5ebdf64d300354c8ce4795ce60a85b8c2596f5ea Mon Sep 17 00:00:00 2001
From: Karl Tauber <karl@jformdesigner.com>
Date: Thu, 30 Jul 2020 13:30:50 +0200
Subject: [PATCH] ComboBox: fixed width of popup, which was too small if popup
 is wider than combo box and vertical scroll bar is visible (issue #137)

---
 CHANGELOG.md                                  |  2 ++
 .../formdev/flatlaf/ui/FlatComboBoxUI.java    | 24 +++++++++++++++----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 61590d3d..17f148e4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -15,6 +15,8 @@ FlatLaf Change Log
 - ToolTip: Do not show empty tooltip component if tooltip text is an empty
   string. (issue #134)
 - Button: Support specifying button border width.
+- ComboBox: Fixed width of popup, which was too small if popup is wider than
+  combo box and vertical scroll bar is visible. (issue #137)
 - ComboBox: Changed maximum row count of popup list to 15 (was 20). Set UI value
   `ComboBox.maximumRowCount` to any integer to use a different value.
 
diff --git a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java
index cb42c5b6..471cc905 100644
--- a/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java
+++ b/flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatComboBoxUI.java
@@ -47,6 +47,7 @@ import javax.swing.JComboBox;
 import javax.swing.JComponent;
 import javax.swing.JList;
 import javax.swing.JPanel;
+import javax.swing.JScrollBar;
 import javax.swing.JTextField;
 import javax.swing.KeyStroke;
 import javax.swing.ListCellRenderer;
@@ -544,13 +545,26 @@ public class FlatComboBoxUI
 
 		@Override
 		protected Rectangle computePopupBounds( int px, int py, int pw, int ph ) {
-			// get maximum display size of all items
-			Dimension displaySize = getDisplaySize();
+			// get maximum display width of all items
+			int displayWidth = getDisplaySize().width;
+
+			// add border insets
+			for( Border border : new Border[] { scroller.getViewportBorder(), scroller.getBorder() } ) {
+				if( border != null ) {
+					Insets borderInsets = border.getBorderInsets( null );
+					displayWidth += borderInsets.left + borderInsets.right;
+				}
+			}
+
+			// add width of vertical scroll bar
+			JScrollBar verticalScrollBar = scroller.getVerticalScrollBar();
+			if( verticalScrollBar != null )
+				displayWidth += verticalScrollBar.getPreferredSize().width;
 
 			// make popup wider if necessary
-			if( displaySize.width > pw ) {
-				int diff = displaySize.width - pw;
-				pw = displaySize.width;
+			if( displayWidth > pw ) {
+				int diff = displayWidth - pw;
+				pw = displayWidth;
 
 				if( !comboBox.getComponentOrientation().isLeftToRight() )
 					px -= diff;