TableHeader: Moved table header column border painting from FlatTableHeaderUI to new border FlatTableHeaderBorder to improve compatibility with custom table header implementations (issue #228)

CHANGELOG.md

@@ -13,6 +13,9 @@ FlatLaf Change Log
   - If frame is deiconified, dock is compacted (icons move to the left).
   - If dock is wider than desktop width, additional rows are used.
   - If desktop pane is resized, layout of dock is updated.
+- TableHeader: Moved table header column border painting from
+  `FlatTableHeaderUI` to new border `FlatTableHeaderBorder` to improve
+  compatibility with custom table header implementations. (issue #228)
 - IntelliJ Themes: Added "Material Theme UI Lite / GitHub Dark" theme.
 - JIDE Common Layer: Improved support for `JideTabbedPane`. (PR #306)
 

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

@@ -0,0 +1,124 @@
+/*
+ * Copyright 2021 FormDev Software GmbH
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.formdev.flatlaf.ui;
+
+import java.awt.Color;
+import java.awt.Component;
+import java.awt.Container;
+import java.awt.Graphics;
+import java.awt.Graphics2D;
+import java.awt.geom.Rectangle2D;
+import javax.swing.JScrollBar;
+import javax.swing.JScrollPane;
+import javax.swing.SwingUtilities;
+import javax.swing.UIManager;
+import javax.swing.table.JTableHeader;
+import javax.swing.table.TableColumn;
+import com.formdev.flatlaf.util.UIScale;
+
+/**
+ * Cell border for {@code sun.swing.table.DefaultTableCellHeaderRenderer}
+ * (used by {@link javax.swing.table.JTableHeader}).
+ * <p>
+ * Uses separate cell margins from UI defaults to allow easy customizing.
+ *
+ * @author Karl Tauber
+ * @since 1.2
+ */
+public class FlatTableHeaderBorder
+	extends FlatEmptyBorder
+{
+	protected Color separatorColor = UIManager.getColor( "TableHeader.separatorColor" );
+	protected Color bottomSeparatorColor = UIManager.getColor( "TableHeader.bottomSeparatorColor" );
+
+	public FlatTableHeaderBorder() {
+		super( UIManager.getInsets( "TableHeader.cellMargins" ) );
+	}
+
+	@Override
+	public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+		JTableHeader header = (JTableHeader) SwingUtilities.getAncestorOfClass( JTableHeader.class, c );
+		boolean leftToRight = (header != null ? header : c).getComponentOrientation().isLeftToRight();
+		boolean paintLeft = !leftToRight;
+		boolean paintRight = leftToRight;
+
+		if( header != null ) {
+			int hx = SwingUtilities.convertPoint( c, x, y, header ).x;
+			if( isDraggedColumn( header, hx ) )
+				paintLeft = paintRight = true;
+			else {
+				if( hx <= 0 && !leftToRight && hideTrailingVerticalLine( header ) )
+					paintLeft = false;
+				if( hx + width >= header.getWidth() && leftToRight && hideTrailingVerticalLine( header ) )
+					paintRight = false;
+			}
+		}
+
+		float lineWidth = UIScale.scale( 1f );
+
+		Graphics2D g2 = (Graphics2D) g.create();
+		try {
+			FlatUIUtils.setRenderingHints( g2 );
+
+			// paint column separator lines
+			g2.setColor( separatorColor );
+			if( paintLeft )
+				g2.fill( new Rectangle2D.Float( x, y, lineWidth, height - lineWidth ) );
+			if( paintRight )
+				g2.fill( new Rectangle2D.Float( x + width - lineWidth, y, lineWidth, height - lineWidth ) );
+
+			// paint bottom line
+			g2.setColor( bottomSeparatorColor );
+			g2.fill( new Rectangle2D.Float( x, y + height - lineWidth, width, lineWidth ) );
+		} finally {
+			g2.dispose();
+		}
+	}
+
+	protected boolean isDraggedColumn( JTableHeader header, int x ) {
+		TableColumn draggedColumn = header.getDraggedColumn();
+		if( draggedColumn == null )
+			return false;
+
+		int draggedDistance = header.getDraggedDistance();
+		if( draggedDistance == 0 )
+			return false;
+
+		int columnCount = header.getColumnModel().getColumnCount();
+		for( int i = 0; i < columnCount; i++ ) {
+			if( header.getHeaderRect( i ).x + draggedDistance == x )
+				return true;
+		}
+
+		return false;
+	}
+
+	protected boolean hideTrailingVerticalLine( JTableHeader header ) {
+		Container viewport = header.getParent();
+		Container viewportParent = (viewport != null) ? viewport.getParent() : null;
+		if( !(viewportParent instanceof JScrollPane) )
+			return true;
+
+		JScrollBar vsb = ((JScrollPane)viewportParent).getVerticalScrollBar();
+		if( vsb == null || !vsb.isVisible() )
+			return true;
+
+		// if "ScrollPane.fillUpperCorner" is true, then javax.swing.ScrollPaneLayout
+		// extends the vertical scrollbar into the upper right/left corner
+		return vsb.getY() == viewport.getY();
+	}
+}

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

@@ -18,20 +18,16 @@ package com.formdev.flatlaf.ui;
 
 import java.awt.Color;
 import java.awt.Component;
-import java.awt.Container;
 import java.awt.Dimension;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
-import java.awt.Rectangle;
 import java.awt.geom.Rectangle2D;
 import java.util.Objects;
 import javax.swing.Icon;
 import javax.swing.JComponent;
 import javax.swing.JLabel;
-import javax.swing.JScrollPane;
 import javax.swing.JTable;
-import javax.swing.ScrollPaneConstants;
 import javax.swing.SwingConstants;
 import javax.swing.UIManager;
 import javax.swing.border.Border;
@@ -39,7 +35,6 @@ import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.UIResource;
 import javax.swing.plaf.basic.BasicTableHeaderUI;
 import javax.swing.table.TableCellRenderer;
-import javax.swing.table.TableColumn;
 import javax.swing.table.TableColumnModel;
 import com.formdev.flatlaf.util.UIScale;
 
@@ -54,17 +49,21 @@ import com.formdev.flatlaf.util.UIScale;
  *
  * <!-- FlatTableHeaderUI -->
  *
- * @uiDefault TableHeader.separatorColor		Color
  * @uiDefault TableHeader.bottomSeparatorColor	Color
  * @uiDefault TableHeader.height				int
  * @uiDefault TableHeader.sortIconPosition		String	right (default), left, top or bottom
  *
+ * <!-- FlatTableHeaderBorder -->
+ *
+ * @uiDefault TableHeader.cellMargins			Insets
+ * @uiDefault TableHeader.separatorColor		Color
+ * @uiDefault TableHeader.bottomSeparatorColor	Color
+ *
  * @author Karl Tauber
  */
 public class FlatTableHeaderUI
 	extends BasicTableHeaderUI
 {
-	protected Color separatorColor;
 	protected Color bottomSeparatorColor;
 	protected int height;
 	protected int sortIconPosition;
@@ -77,7 +76,6 @@ public class FlatTableHeaderUI
 	protected void installDefaults() {
 		super.installDefaults();
 
-		separatorColor = UIManager.getColor( "TableHeader.separatorColor" );
 		bottomSeparatorColor = UIManager.getColor( "TableHeader.bottomSeparatorColor" );
 		height = UIManager.getInt( "TableHeader.height" );
 		switch( Objects.toString( UIManager.getString( "TableHeader.sortIconPosition" ), "right" ) ) {
@@ -93,27 +91,38 @@ public class FlatTableHeaderUI
 	protected void uninstallDefaults() {
 		super.uninstallDefaults();
 
-		separatorColor = null;
 		bottomSeparatorColor = null;
 	}
 
 	@Override
 	public void paint( Graphics g, JComponent c ) {
-		if( header.getColumnModel().getColumnCount() <= 0 )
+		TableColumnModel columnModel = header.getColumnModel();
+		if( columnModel.getColumnCount() <= 0 )
 			return;
 
-		// do not paint borders if JTableHeader.setDefaultRenderer() was used
-		TableCellRenderer defaultRenderer = header.getDefaultRenderer();
-		boolean paintBorders = isSystemDefaultRenderer( defaultRenderer );
-		if( !paintBorders ) {
-			// check whether the renderer delegates to the system default renderer
-			Component rendererComponent = defaultRenderer.getTableCellRendererComponent(
-				header.getTable(), "", false, false, -1, 0 );
-			paintBorders = isSystemDefaultRenderer( rendererComponent );
-		}
+		// compute total width of all columns
+		int columnCount = columnModel.getColumnCount();
+		int totalWidth = 0;
+		for( int i = 0; i < columnCount; i++ )
+			totalWidth += columnModel.getColumn( i ).getWidth();
 
-		if( paintBorders )
-			paintColumnBorders( g, c );
+		if( totalWidth < header.getWidth() ) {
+			// do not paint bottom separator if JTableHeader.setDefaultRenderer() was used
+			TableCellRenderer defaultRenderer = header.getDefaultRenderer();
+			boolean paintBottomSeparator = isSystemDefaultRenderer( defaultRenderer );
+			if( !paintBottomSeparator && header.getTable() != null ) {
+				// check whether the renderer delegates to the system default renderer
+				Component rendererComponent = defaultRenderer.getTableCellRendererComponent(
+					header.getTable(), "", false, false, -1, 0 );
+				paintBottomSeparator = isSystemDefaultRenderer( rendererComponent );
+			}
+
+			if( paintBottomSeparator ) {
+				int w = c.getWidth() - totalWidth;
+				int x = header.getComponentOrientation().isLeftToRight() ? c.getWidth() - w : 0;
+				paintBottomSeparator( g, c, x, w );
+			}
+		}
 
 		// temporary use own default renderer if necessary
 		FlatTableCellHeaderRenderer sortIconRenderer = null;
@@ -130,9 +139,6 @@ public class FlatTableHeaderUI
 			sortIconRenderer.reset();
 			header.setDefaultRenderer( sortIconRenderer.delegate );
 		}
-
-		if( paintBorders )
-			paintDraggedColumnBorders( g, c );
 	}
 
 	private boolean isSystemDefaultRenderer( Object headerRenderer ) {
@@ -141,17 +147,8 @@ public class FlatTableHeaderUI
 			   rendererClassName.equals( "sun.swing.FilePane$AlignableTableHeaderRenderer" );
 	}
 
-	protected void paintColumnBorders( Graphics g, JComponent c ) {
-		int width = c.getWidth();
-		int height = c.getHeight();
+	protected void paintBottomSeparator( Graphics g, JComponent c, int x, int w ) {
 		float lineWidth = UIScale.scale( 1f );
-		float topLineIndent = lineWidth;
-		float bottomLineIndent = lineWidth * 3;
-		TableColumnModel columnModel = header.getColumnModel();
-		int columnCount = columnModel.getColumnCount();
-		int sepCount = columnCount;
-		if( hideLastVerticalLine() )
-			sepCount--;
 
 		Graphics2D g2 = (Graphics2D) g.create();
 		try {
@@ -159,78 +156,7 @@ public class FlatTableHeaderUI
 
 			// paint bottom line
 			g2.setColor( bottomSeparatorColor );
-			g2.fill( new Rectangle2D.Float( 0, height - lineWidth, width, lineWidth ) );
-
-			// paint column separator lines
-			g2.setColor( separatorColor );
-
-			float y = topLineIndent;
-			float h = height - bottomLineIndent;
-
-			if( header.getComponentOrientation().isLeftToRight() ) {
-				int x = 0;
-				for( int i = 0; i < sepCount; i++ ) {
-					x += columnModel.getColumn( i ).getWidth();
-					g2.fill( new Rectangle2D.Float( x - lineWidth, y, lineWidth, h ) );
-				}
-
-				// paint trailing separator (on right side)
-				if( !hideTrailingVerticalLine() )
-					g2.fill( new Rectangle2D.Float( header.getWidth() - lineWidth, y, lineWidth, h ) );
-			} else {
-				Rectangle cellRect = header.getHeaderRect( 0 );
-				int x = cellRect.x + cellRect.width;
-				for( int i = 0; i < sepCount; i++ ) {
-					x -= columnModel.getColumn( i ).getWidth();
-					g2.fill( new Rectangle2D.Float( x - (i < sepCount - 1 ? lineWidth : 0), y, lineWidth, h ) );
-				}
-
-				// paint trailing separator (on left side)
-				if( !hideTrailingVerticalLine() )
-					g2.fill( new Rectangle2D.Float( 0, y, lineWidth, h ) );
-			}
-		} finally {
-			g2.dispose();
-		}
-	}
-
-	private void paintDraggedColumnBorders( Graphics g, JComponent c ) {
-		TableColumn draggedColumn = header.getDraggedColumn();
-		if( draggedColumn == null )
-			return;
-
-		// find index of dragged column
-		TableColumnModel columnModel = header.getColumnModel();
-		int columnCount = columnModel.getColumnCount();
-		int draggedColumnIndex = -1;
-		for( int i = 0; i < columnCount; i++ ) {
-			if( columnModel.getColumn( i ) == draggedColumn ) {
-				draggedColumnIndex = i;
-				break;
-			}
-		}
-
-		if( draggedColumnIndex < 0 )
-			return;
-
-		float lineWidth = UIScale.scale( 1f );
-		float topLineIndent = lineWidth;
-		float bottomLineIndent = lineWidth * 3;
-		Rectangle r = header.getHeaderRect( draggedColumnIndex );
-		r.x += header.getDraggedDistance();
-
-		Graphics2D g2 = (Graphics2D) g.create();
-		try {
-			FlatUIUtils.setRenderingHints( g2 );
-
-			// paint dragged bottom line
-			g2.setColor( bottomSeparatorColor );
-			g2.fill( new Rectangle2D.Float( r.x, r.y + r.height - lineWidth, r.width, lineWidth ) );
-
-			// paint dragged column separator lines
-			g2.setColor( separatorColor );
-			g2.fill( new Rectangle2D.Float( r.x, topLineIndent, lineWidth, r.height - bottomLineIndent ) );
-			g2.fill( new Rectangle2D.Float( r.x + r.width - lineWidth, r.y + topLineIndent, lineWidth, r.height - bottomLineIndent ) );
+			g2.fill( new Rectangle2D.Float( x, c.getHeight() - lineWidth, w, lineWidth ) );
 		} finally {
 			g2.dispose();
 		}
@@ -244,32 +170,6 @@ public class FlatTableHeaderUI
 		return size;
 	}
 
-	protected boolean hideLastVerticalLine() {
-		Container viewport = header.getParent();
-		Container viewportParent = (viewport != null) ? viewport.getParent() : null;
-		if( !(viewportParent instanceof JScrollPane) )
-			return false;
-
-		Rectangle cellRect = header.getHeaderRect( header.getColumnModel().getColumnCount() - 1 );
-
-		// using component orientation of scroll pane here because it is also used in FlatTableUI
-		JScrollPane scrollPane = (JScrollPane) viewportParent;
-		return scrollPane.getComponentOrientation().isLeftToRight()
-			? cellRect.x + cellRect.width >= viewport.getWidth()
-			: cellRect.x <= 0;
-	}
-
-	protected boolean hideTrailingVerticalLine() {
-		Container viewport = header.getParent();
-		Container viewportParent = (viewport != null) ? viewport.getParent() : null;
-		if( !(viewportParent instanceof JScrollPane) )
-			return false;
-
-		JScrollPane scrollPane = (JScrollPane) viewportParent;
-		return viewport == scrollPane.getColumnHeader() &&
-			scrollPane.getCorner( ScrollPaneConstants.UPPER_TRAILING_CORNER ) == null;
-	}
-
 	//---- class FlatTableCellHeaderRenderer ----------------------------------
 
 	/**

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

@@ -642,7 +642,8 @@ Table.dropLineShortColor = @dropLineShortColor
 #---- TableHeader ----
 
 TableHeader.height = 25
-TableHeader.cellBorder = 2,3,2,3
+TableHeader.cellBorder = com.formdev.flatlaf.ui.FlatTableHeaderBorder
+TableHeader.cellMargins = 2,3,2,3
 TableHeader.focusCellBackground = $TableHeader.background
 TableHeader.background = @textComponentBackground
 

flatlaf-testing/dumps/uidefaults/FlatDarkLaf_1.8.0_202.txt

@@ -1067,7 +1067,8 @@ Table.sortIconColor            #adadad    javax.swing.plaf.ColorUIResource [UI]
 
 TableHeader.background         #45494a    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.bottomSeparatorColor #5e6364    javax.swing.plaf.ColorUIResource [UI]
-TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatEmptyBorder [UI]
+TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatTableHeaderBorder [UI]
+TableHeader.cellMargins        2,3,2,3    javax.swing.plaf.InsetsUIResource [UI]
 TableHeader.focusCellBackground #45494a    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.font               [active] $defaultFont [UI]
 TableHeader.foreground         #bbbbbb    javax.swing.plaf.ColorUIResource [UI]

flatlaf-testing/dumps/uidefaults/FlatLightLaf_1.8.0_202.txt

@@ -1072,7 +1072,8 @@ Table.sortIconColor            #afafaf    javax.swing.plaf.ColorUIResource [UI]
 
 TableHeader.background         #ffffff    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.bottomSeparatorColor #e6e6e6    javax.swing.plaf.ColorUIResource [UI]
-TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatEmptyBorder [UI]
+TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatTableHeaderBorder [UI]
+TableHeader.cellMargins        2,3,2,3    javax.swing.plaf.InsetsUIResource [UI]
 TableHeader.focusCellBackground #ffffff    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.font               [active] $defaultFont [UI]
 TableHeader.foreground         #000000    javax.swing.plaf.ColorUIResource [UI]

flatlaf-testing/dumps/uidefaults/FlatTestLaf_1.8.0_202.txt

@@ -1070,7 +1070,8 @@ Table.sortIconColor            #ffff00    javax.swing.plaf.ColorUIResource [UI]
 
 TableHeader.background         #4444ff    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.bottomSeparatorColor #00ff00    javax.swing.plaf.ColorUIResource [UI]
-TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatEmptyBorder [UI]
+TableHeader.cellBorder         [lazy] 2,3,2,3  false    com.formdev.flatlaf.ui.FlatTableHeaderBorder [UI]
+TableHeader.cellMargins        2,3,2,3    javax.swing.plaf.InsetsUIResource [UI]
 TableHeader.focusCellBackground #4444ff    javax.swing.plaf.ColorUIResource [UI]
 TableHeader.font               [active] $defaultFont [UI]
 TableHeader.foreground         #ffffff    javax.swing.plaf.ColorUIResource [UI]

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponents2Test.java

@@ -40,6 +40,7 @@ import javax.swing.tree.DefaultTreeCellRenderer;
 import javax.swing.tree.DefaultTreeModel;
 import javax.swing.tree.TreeCellRenderer;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.icons.FlatMenuArrowIcon;
 import com.formdev.flatlaf.util.UIScale;
 import com.jidesoft.swing.*;
@@ -193,6 +194,15 @@ public class FlatComponents2Test
 			table.setAutoResizeMode( autoResizeMode );
 	}
 
+	private void sortIconPositionChanged() {
+		Object sel = sortIconPositionComboBox.getSelectedItem();
+		if( "right".equals( sel ) )
+			sel = null;
+
+		UIManager.put( "TableHeader.sortIconPosition", sel );
+		FlatLaf.updateUILater();
+	}
+
 	private void dndChanged() {
 		boolean dnd = dndCheckBox.isSelected();
 		list1.setDragEnabled( dnd );
@@ -442,6 +452,8 @@ public class FlatComponents2Test
 		JPanel tableOptionsPanel = new JPanel();
 		JLabel autoResizeModeLabel = new JLabel();
 		autoResizeModeField = new JComboBox<>();
+		JLabel sortIconPositionLabel = new JLabel();
+		sortIconPositionComboBox = new JComboBox<>();
 		showHorizontalLinesCheckBox = new JCheckBox();
 		rowSelectionCheckBox = new JCheckBox();
 		showVerticalLinesCheckBox = new JCheckBox();
@@ -753,6 +765,20 @@ public class FlatComponents2Test
 			autoResizeModeField.addActionListener(e -> autoResizeModeChanged());
 			tableOptionsPanel.add(autoResizeModeField, "cell 0 0 2 1");
 
+			//---- sortIconPositionLabel ----
+			sortIconPositionLabel.setText("Sort icon:");
+			tableOptionsPanel.add(sortIconPositionLabel, "cell 0 0 2 1");
+
+			//---- sortIconPositionComboBox ----
+			sortIconPositionComboBox.setModel(new DefaultComboBoxModel<>(new String[] {
+				"right",
+				"left",
+				"top",
+				"bottom"
+			}));
+			sortIconPositionComboBox.addActionListener(e -> sortIconPositionChanged());
+			tableOptionsPanel.add(sortIconPositionComboBox, "cell 0 0 2 1");
+
 			//---- showHorizontalLinesCheckBox ----
 			showHorizontalLinesCheckBox.setText("show horizontal lines");
 			showHorizontalLinesCheckBox.addActionListener(e -> showHorizontalLinesChanged());
@@ -819,6 +845,7 @@ public class FlatComponents2Test
 	private JCheckBox treeWideSelectionCheckBox;
 	private JCheckBox treePaintSelectionCheckBox;
 	private JComboBox<String> autoResizeModeField;
+	private JComboBox<String> sortIconPositionComboBox;
 	private JCheckBox showHorizontalLinesCheckBox;
 	private JCheckBox rowSelectionCheckBox;
 	private JCheckBox showVerticalLinesCheckBox;

flatlaf-testing/src/main/java/com/formdev/flatlaf/testing/FlatComponents2Test.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "7.0.3.1.342" Java: "15" encoding: "UTF-8"
+JFDML JFormDesigner: "7.0.3.1.342" Java: "16" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -398,6 +398,28 @@ new FormModel {
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 					"value": "cell 0 0 2 1"
 				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "sortIconPositionLabel"
+					"text": "Sort icon:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0 2 1"
+				} )
+				add( new FormComponent( "javax.swing.JComboBox" ) {
+					name: "sortIconPositionComboBox"
+					"model": new javax.swing.DefaultComboBoxModel {
+						selectedItem: "right"
+						addElement( "right" )
+						addElement( "left" )
+						addElement( "top" )
+						addElement( "bottom" )
+					}
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "sortIconPositionChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0 2 1"
+				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "showHorizontalLinesCheckBox"
 					"text": "show horizontal lines"
@@ -484,7 +506,7 @@ new FormModel {
 			} )
 		}, new FormLayoutConstraints( null ) {
 			"location": new java.awt.Point( 0, 0 )
-			"size": new java.awt.Dimension( 950, 600 )
+			"size": new java.awt.Dimension( 1000, 600 )
 		} )
 	}
 }

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

@@ -795,6 +795,7 @@ TableHeader.ancestorInputMap
 TableHeader.background
 TableHeader.bottomSeparatorColor
 TableHeader.cellBorder
+TableHeader.cellMargins
 TableHeader.focusCellBackground
 TableHeader.font
 TableHeader.foreground