Windows 11: made rounded popup border configurable via UI properties and client property

CHANGELOG.md

@@ -5,6 +5,8 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- Windows 11: Popups (`JPopupMenu`, `JComboBox`, `JToolTip`, etc.) now use
+  native Windows 11 rounded borders and drop shadows.
 - Fonts:
   - Added **Roboto Mono** (https://fonts.google.com/specimen/Roboto+Mono). (PR
     #639, issue #638)

flatlaf-core/src/main/java/com/formdev/flatlaf/FlatClientProperties.java

@@ -268,6 +268,25 @@ public interface FlatClientProperties
 
 	//---- Popup --------------------------------------------------------------
 
+	/**
+	 * Specifies the popup border corner radius if the component is shown in a popup
+	 * or if the component is the owner of another component that is shown in a popup.
+	 * <p>
+	 * Note that this is not available on all platforms since it requires special support.
+	 * Supported platforms:
+	 * <p>
+	 * <strong>Windows 11</strong> (x86 or x86_64): Only two corner radiuses are supported
+	 * by the OS: {@code DWMWCP_ROUND} is 8px and {@code DWMWCP_ROUNDSMALL} is 4px.
+	 * If this value is {@code 1 - 4}, then {@code DWMWCP_ROUNDSMALL} is used.
+	 * If it is {@code >= 5}, then {@code DWMWCP_ROUND} is used.
+	 * <p>
+	 * <strong>Component</strong> {@link javax.swing.JComponent}<br>
+	 * <strong>Value type</strong> {@link java.lang.Integer}<br>
+	 *
+	 * @since 3.1
+	 */
+	String POPUP_BORDER_CORNER_RADIUS = "Popup.borderCornerRadius";
+
 	/**
 	 * Specifies whether a drop shadow is painted if the component is shown in a popup
 	 * or if the component is the owner of another component that is shown in a popup.

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupFactory.java

@@ -43,6 +43,7 @@ import java.lang.reflect.Method;
 import javax.swing.JComponent;
 import javax.swing.JLayeredPane;
 import javax.swing.JPanel;
+import javax.swing.JPopupMenu;
 import javax.swing.JToolTip;
 import javax.swing.JWindow;
 import javax.swing.Popup;
@@ -54,6 +55,7 @@ import javax.swing.UIManager;
 import javax.swing.border.Border;
 import javax.swing.border.EmptyBorder;
 import javax.swing.border.LineBorder;
+import javax.swing.plaf.basic.BasicComboPopup;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.util.SystemInfo;
 import com.formdev.flatlaf.util.UIScale;
@@ -91,10 +93,13 @@ public class FlatPopupFactory
 			return new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), contents );
 
 		// Windows 11 with FlatLaf native library can use rounded corners and shows drop shadow for heavy weight popups
-		if( SystemInfo.isWindows_11_orLater && FlatNativeWindowsLibrary.isLoaded() ) {
+		int borderCornerRadius;
+		if( isWindows11BorderSupported() &&
+			(borderCornerRadius = getBorderCornerRadius( owner, contents )) > 0 )
+		{
 			NonFlashingPopup popup = new NonFlashingPopup( getPopupForScreenOfOwner( owner, contents, x, y, true ), contents );
 			if( popup.popupWindow != null )
-				setupWindows11Border( popup.popupWindow, contents );
+				setupWindows11Border( popup.popupWindow, contents, borderCornerRadius );
 			return popup;
 		}
 
@@ -176,19 +181,39 @@ public class FlatPopupFactory
 	}
 
 	private boolean isOptionEnabled( Component owner, Component contents, String clientKey, String uiKey ) {
-		if( owner instanceof JComponent ) {
+		Object value = getOption( owner, contents, clientKey, uiKey );
-			Boolean b = FlatClientProperties.clientPropertyBooleanStrict( (JComponent) owner, clientKey, null );
+		return (value instanceof Boolean) ? (Boolean) value : false;
-			if( b != null )
+	}
-				return b;
+
+	private int getBorderCornerRadius( Component owner, Component contents ) {
+		String uiKey =
+			(contents instanceof BasicComboPopup) ? "ComboBox.borderCornerRadius" :
+			(contents instanceof JPopupMenu) ? "PopupMenu.borderCornerRadius" :
+			(contents instanceof JToolTip) ? "ToolTip.borderCornerRadius" :
+			"Popup.borderCornerRadius";
+
+		Object value = getOption( owner, contents, FlatClientProperties.POPUP_BORDER_CORNER_RADIUS, uiKey );
+		return (value instanceof Integer) ? (Integer) value : 0;
+	}
+
+	/**
+	 * Get option from:
+	 * <ol>
+	 * <li>client property {@code clientKey} of {@code owner}
+	 * <li>client property {@code clientKey} of {@code contents}
+	 * <li>UI property {@code uiKey}
+	 * </ol>
+	 */
+	private Object getOption( Component owner, Component contents, String clientKey, String uiKey ) {
+		for( Component c : new Component[] { owner, contents } ) {
+			if( c instanceof JComponent ) {
+				Object value = ((JComponent)c).getClientProperty( clientKey );
+				if( value != null )
+					return value;
+			}
 		}
 
-		if( contents instanceof JComponent ) {
+		return UIManager.get( uiKey );
-			Boolean b = FlatClientProperties.clientPropertyBooleanStrict( (JComponent) contents, clientKey, null );
-			if( b != null )
-				return b;
-		}
-
-		return UIManager.getBoolean( uiKey );
 	}
 
 	/**
@@ -310,7 +335,11 @@ public class FlatPopupFactory
 			((JComponent)owner).getToolTipLocation( me ) != null;
 	}
 
-	private static void setupWindows11Border( Window popupWindow, Component contents ) {
+	private static boolean isWindows11BorderSupported() {
+		return SystemInfo.isWindows_11_orLater && FlatNativeWindowsLibrary.isLoaded();
+	}
+
+	private static void setupWindows11Border( Window popupWindow, Component contents, int borderCornerRadius ) {
 		// make sure that the Windows 11 window is created
 		if( !popupWindow.isDisplayable() )
 			popupWindow.addNotify();
@@ -319,7 +348,10 @@ public class FlatPopupFactory
 		long hwnd = FlatNativeWindowsLibrary.getHWND( popupWindow );
 
 		// set corner preference
-		FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, FlatNativeWindowsLibrary.DWMWCP_ROUNDSMALL );
+		int cornerPreference = (borderCornerRadius <= 4)
+			? FlatNativeWindowsLibrary.DWMWCP_ROUNDSMALL  // 4px
+			: FlatNativeWindowsLibrary.DWMWCP_ROUND;      // 8px
+		FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, cornerPreference );
 
 		// set border color
 		int red = -1; // use system default color
@@ -347,6 +379,16 @@ public class FlatPopupFactory
 		FlatNativeWindowsLibrary.setWindowBorderColor( hwnd, red, green, blue );
 	}
 
+	private static void resetWindows11Border( Window popupWindow ) {
+		// get window handle
+		long hwnd = FlatNativeWindowsLibrary.getHWND( popupWindow );
+		if( hwnd == 0 )
+			return;
+
+		// reset corner preference
+		FlatNativeWindowsLibrary.setWindowCornerPreference( hwnd, FlatNativeWindowsLibrary.DWMWCP_DONOTROUND );
+	}
+
 	//---- class NonFlashingPopup ---------------------------------------------
 
 	private class NonFlashingPopup
@@ -478,6 +520,14 @@ public class FlatPopupFactory
 					oldDropShadowWindowBackground = dropShadowWindow.getBackground();
 					dropShadowWindow.setBackground( new Color( 0, true ) );
 				}
+
+				// Windows 11: reset corner preference on reused heavy weight popups
+				if( isWindows11BorderSupported() ) {
+					resetWindows11Border( popupWindow );
+					if( dropShadowWindow != null )
+						resetWindows11Border( dropShadowWindow );
+				}
+
 			} else {
 				mediumWeightPanel = (Panel) SwingUtilities.getAncestorOfClass( Panel.class, contents );
 				if( mediumWeightPanel != null ) {

flatlaf-core/src/main/java/com/formdev/flatlaf/ui/FlatPopupMenuUI.java

@@ -67,6 +67,7 @@ import javax.swing.plaf.basic.BasicComboPopup;
 import javax.swing.plaf.basic.BasicMenuItemUI;
 import javax.swing.plaf.basic.BasicPopupMenuUI;
 import javax.swing.plaf.basic.DefaultMenuLayout;
+import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.ui.FlatStylingSupport.Styleable;
 import com.formdev.flatlaf.ui.FlatStylingSupport.StyleableUI;
 import com.formdev.flatlaf.util.LoggingFacade;
@@ -297,6 +298,9 @@ public class FlatPopupMenuUI
 			popup.addMenuKeyListener( this );
 
 			updateArrowButtons();
+
+			putClientProperty( FlatClientProperties.POPUP_BORDER_CORNER_RADIUS,
+				UIManager.getInt( "PopupMenu.borderCornerRadius" ) );
 		}
 
 		void scroll( int unitsToScroll ) {

flatlaf-core/src/main/resources/com/formdev/flatlaf/FlatLaf.properties

@@ -288,6 +288,7 @@ ComboBox.buttonPressedArrowColor = @buttonPressedArrowColor
 ComboBox.popupInsets = 0,0,0,0
 ComboBox.selectionInsets = 0,0,0,0
 ComboBox.selectionArc = 0
+ComboBox.borderCornerRadius = $Popup.borderCornerRadius
 
 
 #---- Component ----
@@ -503,6 +504,7 @@ PasswordField.revealIcon = com.formdev.flatlaf.icons.FlatRevealIcon
 
 #---- Popup ----
 
+Popup.borderCornerRadius = 4
 Popup.dropShadowPainted = true
 Popup.dropShadowInsets = -4,-4,4,4
 
@@ -511,6 +513,7 @@ Popup.dropShadowInsets = -4,-4,4,4
 
 PopupMenu.border = com.formdev.flatlaf.ui.FlatPopupMenuBorder
 PopupMenu.borderInsets = 4,1,4,1
+PopupMenu.borderCornerRadius = $Popup.borderCornerRadius
 PopupMenu.background = @menuBackground
 PopupMenu.scrollArrowColor = @buttonArrowColor
 
@@ -880,6 +883,11 @@ ToolBar.spacingBorder = $Button.toolbar.spacingInsets
 ToolTipManager.enableToolTipMode = activeApplication
 
 
+#---- ToolTip ----
+
+ToolTip.borderCornerRadius = $Popup.borderCornerRadius
+
+
 #---- Tree ----
 
 Tree.border = 1,1,1,1

flatlaf-core/src/main/resources/com/formdev/flatlaf/themes/FlatMacDarkLaf.properties

@@ -149,6 +149,7 @@ ComboBox.selectionBackground = @menuSelectionBackground
 ComboBox.popupInsets = 5,0,5,0
 ComboBox.selectionInsets = 0,5,0,5
 ComboBox.selectionArc = 8
+ComboBox.borderCornerRadius = 8
 
 
 #---- Component ----
@@ -205,6 +206,7 @@ PasswordField.selectionForeground = @textSelectionForeground
 #---- PopupMenu ----
 
 PopupMenu.borderInsets = 6,1,6,1
+PopupMenu.borderCornerRadius = 8
 
 
 #---- ProgressBar ----

flatlaf-core/src/main/resources/com/formdev/flatlaf/themes/FlatMacLightLaf.properties

@@ -150,6 +150,7 @@ ComboBox.selectionBackground = @menuSelectionBackground
 ComboBox.popupInsets = 5,0,5,0
 ComboBox.selectionInsets = 0,5,0,5
 ComboBox.selectionArc = 8
+ComboBox.borderCornerRadius = 8
 
 
 #---- Component ----
@@ -206,6 +207,7 @@ PasswordField.selectionForeground = @textSelectionForeground
 #---- PopupMenu ----
 
 PopupMenu.borderInsets = 6,1,6,1
+PopupMenu.borderCornerRadius = 8
 
 
 #---- ProgressBar ----

flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0.txt

@@ -198,6 +198,7 @@ ColumnControlButton.iconColor  #a8a8a8  HSL   0   0  66    javax.swing.plaf.Colo
 
 ComboBox.background            #46494b  HSL 204   3  28    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.border                [lazy] 1,1,1,1  false    com.formdev.flatlaf.ui.FlatRoundBorder [UI]
+ComboBox.borderCornerRadius    4
 ComboBox.buttonArrowColor      #9b9b9b  HSL   0   0  61    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonBackground      #46494b  HSL 204   3  28    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonDarkShadow      #7a7d7f  HSL 204   2  49    javax.swing.plaf.ColorUIResource [UI]
@@ -734,6 +735,7 @@ PasswordFieldUI                com.formdev.flatlaf.ui.FlatPasswordFieldUI
 
 #---- Popup ----
 
+Popup.borderCornerRadius       4
 Popup.dropShadowColor          #000000  HSL   0   0   0    javax.swing.plaf.ColorUIResource [UI]
 Popup.dropShadowInsets         -4,-4,4,4    javax.swing.plaf.InsetsUIResource [UI]
 Popup.dropShadowOpacity        0.25
@@ -745,6 +747,7 @@ Popup.dropShadowPainted        true
 PopupMenu.background           #303234  HSL 210   4  20    javax.swing.plaf.ColorUIResource [UI]
 PopupMenu.border               [lazy] 4,1,4,1  false    com.formdev.flatlaf.ui.FlatPopupMenuBorder [UI]    lineColor=#5d6061  HSL 195   2  37    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
 PopupMenu.borderColor          #5d6061  HSL 195   2  37    javax.swing.plaf.ColorUIResource [UI]
+PopupMenu.borderCornerRadius   4
 PopupMenu.borderInsets         4,1,4,1    javax.swing.plaf.InsetsUIResource [UI]
 PopupMenu.consumeEventOnClose  false
 PopupMenu.font                 [active] $defaultFont [UI]
@@ -1345,6 +1348,7 @@ ToolBarUI                      com.formdev.flatlaf.ui.FlatToolBarUI
 
 ToolTip.background             #1e2021  HSL 200   5  12    javax.swing.plaf.ColorUIResource [UI]
 ToolTip.border                 [lazy] 4,6,4,6  false    com.formdev.flatlaf.ui.FlatEmptyBorder [UI]
+ToolTip.borderCornerRadius     4
 ToolTip.font                   [active] $defaultFont [UI]
 ToolTip.foreground             #bbbbbb  HSL   0   0  73    javax.swing.plaf.ColorUIResource [UI]
 

flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0.txt

@@ -202,6 +202,7 @@ ColumnControlButton.iconColor  #737373  HSL   0   0  45    javax.swing.plaf.Colo
 
 ComboBox.background            #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.border                [lazy] 1,1,1,1  false    com.formdev.flatlaf.ui.FlatRoundBorder [UI]
+ComboBox.borderCornerRadius    4
 ComboBox.buttonArrowColor      #666666  HSL   0   0  40    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonBackground      #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonDarkShadow      #9c9c9c  HSL   0   0  61    javax.swing.plaf.ColorUIResource [UI]
@@ -739,6 +740,7 @@ PasswordFieldUI                com.formdev.flatlaf.ui.FlatPasswordFieldUI
 
 #---- Popup ----
 
+Popup.borderCornerRadius       4
 Popup.dropShadowColor          #000000  HSL   0   0   0    javax.swing.plaf.ColorUIResource [UI]
 Popup.dropShadowInsets         -4,-4,4,4    javax.swing.plaf.InsetsUIResource [UI]
 Popup.dropShadowOpacity        0.15
@@ -750,6 +752,7 @@ Popup.dropShadowPainted        true
 PopupMenu.background           #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 PopupMenu.border               [lazy] 4,1,4,1  false    com.formdev.flatlaf.ui.FlatPopupMenuBorder [UI]    lineColor=#aeaeae  HSL   0   0  68    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
 PopupMenu.borderColor          #aeaeae  HSL   0   0  68    javax.swing.plaf.ColorUIResource [UI]
+PopupMenu.borderCornerRadius   4
 PopupMenu.borderInsets         4,1,4,1    javax.swing.plaf.InsetsUIResource [UI]
 PopupMenu.consumeEventOnClose  false
 PopupMenu.font                 [active] $defaultFont [UI]
@@ -1350,6 +1353,7 @@ ToolBarUI                      com.formdev.flatlaf.ui.FlatToolBarUI
 
 ToolTip.background             #fafafa  HSL   0   0  98    javax.swing.plaf.ColorUIResource [UI]
 ToolTip.border                 [lazy] 4,6,4,6  false    com.formdev.flatlaf.ui.FlatLineBorder [UI]    lineColor=#919191  HSL   0   0  57    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
+ToolTip.borderCornerRadius     4
 ToolTip.font                   [active] $defaultFont [UI]
 ToolTip.foreground             #000000  HSL   0   0   0    javax.swing.plaf.ColorUIResource [UI]
 

flatlaf-testing/dumps/uidefaults/FlatMacDarkLaf_1.8.0.txt

@@ -202,6 +202,7 @@ ColumnControlButton.iconColor  #c7c7c7  HSL   0   0  78    javax.swing.plaf.Colo
 
 ComboBox.background            #565656  HSL   0   0  34    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.border                [lazy] 3,3,3,3  false    com.formdev.flatlaf.ui.FlatRoundBorder [UI]
+ComboBox.borderCornerRadius    8
 ComboBox.buttonArrowColor      #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonBackground      #007aff  HSL 211 100  50    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonDarkShadow      #ffffff19  10%  HSLA   0   0 100 10    javax.swing.plaf.ColorUIResource [UI]
@@ -742,6 +743,7 @@ PasswordFieldUI                com.formdev.flatlaf.ui.FlatPasswordFieldUI
 
 #---- Popup ----
 
+Popup.borderCornerRadius       4
 Popup.dropShadowColor          #000000  HSL   0   0   0    javax.swing.plaf.ColorUIResource [UI]
 Popup.dropShadowInsets         -4,-4,4,4    javax.swing.plaf.InsetsUIResource [UI]
 Popup.dropShadowOpacity        0.25
@@ -753,6 +755,7 @@ Popup.dropShadowPainted        true
 PopupMenu.background           #323232  HSL   0   0  20    javax.swing.plaf.ColorUIResource [UI]
 PopupMenu.border               [lazy] 6,1,6,1  false    com.formdev.flatlaf.ui.FlatPopupMenuBorder [UI]    lineColor=#444444  HSL   0   0  27    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
 PopupMenu.borderColor          #444444  HSL   0   0  27    javax.swing.plaf.ColorUIResource [UI]
+PopupMenu.borderCornerRadius   8
 PopupMenu.borderInsets         6,1,6,1    javax.swing.plaf.InsetsUIResource [UI]
 PopupMenu.consumeEventOnClose  false
 PopupMenu.font                 [active] $defaultFont [UI]
@@ -1355,6 +1358,7 @@ ToolBarUI                      com.formdev.flatlaf.ui.FlatToolBarUI
 
 ToolTip.background             #0f0f0f  HSL   0   0   6    javax.swing.plaf.ColorUIResource [UI]
 ToolTip.border                 [lazy] 4,6,4,6  false    com.formdev.flatlaf.ui.FlatEmptyBorder [UI]
+ToolTip.borderCornerRadius     4
 ToolTip.font                   [active] $defaultFont [UI]
 ToolTip.foreground             #dddddd  HSL   0   0  87    javax.swing.plaf.ColorUIResource [UI]
 

flatlaf-testing/dumps/uidefaults/FlatMacLightLaf_1.8.0.txt

@@ -207,6 +207,7 @@ ColumnControlButton.iconColor  #888888  HSL   0   0  53    javax.swing.plaf.Colo
 
 ComboBox.background            #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.border                [lazy] 3,3,3,3  false    com.formdev.flatlaf.ui.FlatRoundBorder [UI]
+ComboBox.borderCornerRadius    8
 ComboBox.buttonArrowColor      #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonBackground      #007aff  HSL 211 100  50    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonDarkShadow      #00000026  15%  HSLA   0   0   0 15    javax.swing.plaf.ColorUIResource [UI]
@@ -746,6 +747,7 @@ PasswordFieldUI                com.formdev.flatlaf.ui.FlatPasswordFieldUI
 
 #---- Popup ----
 
+Popup.borderCornerRadius       4
 Popup.dropShadowColor          #000000  HSL   0   0   0    javax.swing.plaf.ColorUIResource [UI]
 Popup.dropShadowInsets         -4,-4,4,4    javax.swing.plaf.InsetsUIResource [UI]
 Popup.dropShadowOpacity        0.15
@@ -757,6 +759,7 @@ Popup.dropShadowPainted        true
 PopupMenu.background           #ececec  HSL   0   0  93    javax.swing.plaf.ColorUIResource [UI]
 PopupMenu.border               [lazy] 6,1,6,1  false    com.formdev.flatlaf.ui.FlatPopupMenuBorder [UI]    lineColor=#b1b1b1  HSL   0   0  69    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
 PopupMenu.borderColor          #b1b1b1  HSL   0   0  69    javax.swing.plaf.ColorUIResource [UI]
+PopupMenu.borderCornerRadius   8
 PopupMenu.borderInsets         6,1,6,1    javax.swing.plaf.InsetsUIResource [UI]
 PopupMenu.consumeEventOnClose  false
 PopupMenu.font                 [active] $defaultFont [UI]
@@ -1359,6 +1362,7 @@ ToolBarUI                      com.formdev.flatlaf.ui.FlatToolBarUI
 
 ToolTip.background             #fefefe  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ToolTip.border                 [lazy] 4,6,4,6  false    com.formdev.flatlaf.ui.FlatLineBorder [UI]    lineColor=#949494  HSL   0   0  58    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
+ToolTip.borderCornerRadius     4
 ToolTip.font                   [active] $defaultFont [UI]
 ToolTip.foreground             #262626  HSL   0   0  15    javax.swing.plaf.ColorUIResource [UI]
 

flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0.txt

@@ -220,6 +220,7 @@ ColumnControlButton.actionIcon [lazy] 10,10    com.formdev.flatlaf.swingx.icons.
 
 ComboBox.background            #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.border                [lazy] 1,1,1,1  false    com.formdev.flatlaf.ui.FlatRoundBorder [UI]
+ComboBox.borderCornerRadius    4
 ComboBox.buttonArrowColor      #666666  HSL   0   0  40    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonBackground      #f0f0f0  HSL   0   0  94    javax.swing.plaf.ColorUIResource [UI]
 ComboBox.buttonDarkShadow      #696969  HSL   0   0  41    javax.swing.plaf.ColorUIResource [UI]
@@ -765,6 +766,7 @@ PasswordFieldUI                com.formdev.flatlaf.ui.FlatPasswordFieldUI
 
 #---- Popup ----
 
+Popup.borderCornerRadius       4
 Popup.dropShadowColor          #00ff00  HSL 120 100  50    javax.swing.plaf.ColorUIResource [UI]
 Popup.dropShadowInsets         -6,6,6,6    javax.swing.plaf.InsetsUIResource [UI]
 Popup.dropShadowOpacity        0.5
@@ -776,6 +778,7 @@ Popup.dropShadowPainted        true
 PopupMenu.background           #ffffff  HSL   0   0 100    javax.swing.plaf.ColorUIResource [UI]
 PopupMenu.border               [lazy] 4,1,4,1  false    com.formdev.flatlaf.ui.FlatPopupMenuBorder [UI]    lineColor=#0000ff  HSL 240 100  50    javax.swing.plaf.ColorUIResource [UI]    lineThickness=1.000000
 PopupMenu.borderColor          #0000ff  HSL 240 100  50    javax.swing.plaf.ColorUIResource [UI]
+PopupMenu.borderCornerRadius   4
 PopupMenu.borderInsets         4,1,4,1    javax.swing.plaf.InsetsUIResource [UI]
 PopupMenu.consumeEventOnClose  false
 PopupMenu.font                 [active] $defaultFont [UI]
@@ -1395,6 +1398,7 @@ ToolBarUI                      com.formdev.flatlaf.ui.FlatToolBarUI
 
 ToolTip.background             #eeeeff  HSL 240 100  97    javax.swing.plaf.ColorUIResource [UI]
 ToolTip.border                 [lazy] line: #000000  HSL   0   0   0    java.awt.Color 1 false    1,1,1,1  true    javax.swing.plaf.BorderUIResource$LineBorderUIResource [UI]
+ToolTip.borderCornerRadius     4
 ToolTip.font                   [active] $defaultFont [UI]
 ToolTip.foreground             #ff0000  HSL   0 100  50    javax.swing.plaf.ColorUIResource [UI]
 

flatlaf-theme-editor/src/main/resources/com/formdev/flatlaf/themeeditor/FlatLafUIKeys.txt

@@ -181,6 +181,7 @@ ColumnControlButton.iconColor
 ComboBox.ancestorInputMap
 ComboBox.background
 ComboBox.border
+ComboBox.borderCornerRadius
 ComboBox.buttonArrowColor
 ComboBox.buttonBackground
 ComboBox.buttonDarkShadow
@@ -594,6 +595,7 @@ PasswordField.selectionForeground
 PasswordField.showCapsLock
 PasswordField.showRevealButton
 PasswordFieldUI
+Popup.borderCornerRadius
 Popup.dropShadowColor
 Popup.dropShadowInsets
 Popup.dropShadowOpacity
@@ -601,6 +603,7 @@ Popup.dropShadowPainted
 PopupMenu.background
 PopupMenu.border
 PopupMenu.borderColor
+PopupMenu.borderCornerRadius
 PopupMenu.borderInsets
 PopupMenu.consumeEventOnClose
 PopupMenu.font
@@ -1104,6 +1107,7 @@ ToolBarSeparatorUI
 ToolBarUI
 ToolTip.background
 ToolTip.border
+ToolTip.borderCornerRadius
 ToolTip.font
 ToolTip.foreground
 ToolTipManager.enableToolTipMode