List:

- fixed wrong x/width bounds of alternating rows for multi-column lists (PR #939)
- Demo: added "alternating rows" checkboxes to "Data Components" page

CHANGELOG.md

@@ -7,7 +7,8 @@ FlatLaf Change Log
 
 - CheckBox: Support styling indeterminate state of
   [tri-state check boxes](https://www.javadoc.io/doc/com.formdev/flatlaf-extras/latest/com/formdev/flatlaf/extras/components/FlatTriStateCheckBox.html).
-  (issue #919)
+  (PR #936; issue #919)
+- List: Support for alternate row highlighting. (PR #939)
 - Tree: Support for alternate row highlighting. (PR #903)
 - Tree: Support wide cell renderer. (issue #922)
 - Extras: `FlatSVGIcon` color filters now can access painting component to

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

@@ -303,13 +303,24 @@ public class FlatListUI
 	{
 		boolean isSelected = selModel.isSelectedIndex( row );
 
+		// paint alternating rows
+		if( alternateRowColor != null && row % 2 != 0 &&
+			!"ComboBox.list".equals( list.getName() ) ) // combobox does not support alternate row color
+		{
+			g.setColor( alternateRowColor );
+
+			float arc = UIScale.scale( selectionArc / 2f );
+			FlatUIUtils.paintSelection( (Graphics2D) g, rowBounds.x, rowBounds.y, rowBounds.width, rowBounds.height,
+				UIScale.scale( selectionInsets ), arc, arc, arc, arc, 0 );
+		}
+
 		// get renderer component
 		@SuppressWarnings( "unchecked" )
 		Component rendererComponent = cellRenderer.getListCellRendererComponent( list,
 			dataModel.getElementAt( row ), row, isSelected,
 			FlatUIUtils.isPermanentFocusOwner( list ) && (row == leadIndex) );
 
-		//
+		// use smaller cell width if list is used in JFileChooser
 		boolean isFileList = Boolean.TRUE.equals( list.getClientProperty( "List.isFileList" ) );
 		int cx, cw;
 		if( isFileList ) {
@@ -323,18 +334,6 @@ public class FlatListUI
 			cw = rowBounds.width;
 		}
 
-		// combobox does not support alternate row color
-		if( !"ComboBox.list".equals( list.getName() ) ) {
-			if( alternateRowColor != null && row % 2 != 0 ) {
-				g.setColor( alternateRowColor );
-
-				// paint respecting selection arc
-				float arc = UIScale.scale( selectionArc / 2f );
-				FlatUIUtils.paintSelection( (Graphics2D) g, 0, rowBounds.y, list.getWidth(), rowBounds.height,
-						UIScale.scale( selectionInsets ), arc, arc, arc, arc, 0 );
-			}
-		}
-
 		// rounded selection or selection insets
 		if( isSelected &&
 			!isFileList && // rounded selection is not supported for file list

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DataComponentsPanel.java

@@ -22,6 +22,7 @@ import java.awt.datatransfer.DataFlavor;
 import java.awt.datatransfer.StringSelection;
 import java.awt.datatransfer.Transferable;
 import javax.swing.*;
+import javax.swing.UIDefaults.ActiveValue;
 import javax.swing.table.*;
 import javax.swing.tree.*;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -65,6 +66,45 @@ class DataComponentsPanel
 		tree3.putClientProperty( FlatClientProperties.STYLE, "selectionInsets: 0,1,0,1; selectionArc: 6" );
 	}
 
+	private void listAlternatingRowsChanged() {
+		ActiveValue alternateRowColor = null;
+		if( listAlternatingRowsCheckBox.isSelected() ) {
+			alternateRowColor = table -> {
+				Color background = list1.getBackground();
+				return FlatLaf.isLafDark()
+					? ColorFunctions.lighten( background, 0.05f )
+					: ColorFunctions.darken( background, 0.05f );
+			};
+		}
+		UIManager.put( "List.alternateRowColor", alternateRowColor );
+		list1.updateUI();
+		list2.updateUI();
+		list3.updateUI();
+	}
+
+	private void treeWideSelectionChanged() {
+		boolean wideSelection = treeWideSelectionCheckBox.isSelected();
+		tree1.putClientProperty( FlatClientProperties.TREE_WIDE_SELECTION, wideSelection );
+		tree2.putClientProperty( FlatClientProperties.TREE_WIDE_SELECTION, wideSelection );
+		tree3.putClientProperty( FlatClientProperties.TREE_WIDE_SELECTION, wideSelection );
+	}
+
+	private void treeAlternatingRowsChanged() {
+		ActiveValue alternateRowColor = null;
+		if( treeAlternatingRowsCheckBox.isSelected() ) {
+			alternateRowColor = table -> {
+				Color background = tree1.getBackground();
+				return FlatLaf.isLafDark()
+					? ColorFunctions.lighten( background, 0.05f )
+					: ColorFunctions.darken( background, 0.05f );
+			};
+		}
+		UIManager.put( "Tree.alternateRowColor", alternateRowColor );
+		tree1.updateUI();
+		tree2.updateUI();
+		tree3.updateUI();
+	}
+
 	private void dndChanged() {
 		boolean dnd = dndCheckBox.isSelected();
 		DropMode dropMode = dnd ? DropMode.ON_OR_INSERT : DropMode.USE_SELECTION;
@@ -142,18 +182,20 @@ class DataComponentsPanel
 	}
 
 	private void alternatingRowsChanged() {
-		Color alternateRowColor = null;
+		ActiveValue alternateRowColor = null;
 		if( alternatingRowsCheckBox.isSelected() ) {
-			Color background = table1.getBackground();
+			alternateRowColor = table -> {
-			alternateRowColor = FlatLaf.isLafDark()
+				Color background = table1.getBackground();
-				? ColorFunctions.lighten( background, 0.05f )
+				return FlatLaf.isLafDark()
-				: ColorFunctions.darken( background, 0.05f );
+					? ColorFunctions.lighten( background, 0.05f )
+					: ColorFunctions.darken( background, 0.05f );
+			};
 		}
 		UIManager.put( "Table.alternateRowColor", alternateRowColor );
 		table1.repaint();
 	}
 
-	@SuppressWarnings( { "unchecked", "rawtypes" } )
+	@SuppressWarnings( { "rawtypes" } )
 	private void initComponents() {
 		// JFormDesigner - Component initialization - DO NOT MODIFY  //GEN-BEGIN:initComponents
 		JLabel label1 = new JLabel();
@@ -166,6 +208,8 @@ class DataComponentsPanel
 		list3 = new JList<>();
 		JScrollPane scrollPane2 = new JScrollPane();
 		list2 = new JList<>();
+		JPanel listOptionsPanel = new JPanel();
+		listAlternatingRowsCheckBox = new JCheckBox();
 		JLabel treeLabel = new JLabel();
 		JScrollPane scrollPane3 = new JScrollPane();
 		tree1 = new JTree();
@@ -173,6 +217,9 @@ class DataComponentsPanel
 		tree3 = new JTree();
 		JScrollPane scrollPane4 = new JScrollPane();
 		tree2 = new JTree();
+		JPanel treeOptionsPanel = new JPanel();
+		treeWideSelectionCheckBox = new JCheckBox();
+		treeAlternatingRowsCheckBox = new JCheckBox();
 		JLabel tableLabel = new JLabel();
 		JScrollPane scrollPane5 = new JScrollPane();
 		table1 = new JTable();
@@ -273,6 +320,22 @@ class DataComponentsPanel
 		}
 		add(scrollPane2, "cell 3 1");
 
+		//======== listOptionsPanel ========
+		{
+			listOptionsPanel.setLayout(new MigLayout(
+				"insets 0,hidemode 3",
+				// columns
+				"[fill]",
+				// rows
+				"[]"));
+
+			//---- listAlternatingRowsCheckBox ----
+			listAlternatingRowsCheckBox.setText("alternating rows");
+			listAlternatingRowsCheckBox.addActionListener(e -> listAlternatingRowsChanged());
+			listOptionsPanel.add(listAlternatingRowsCheckBox, "cell 0 0");
+		}
+		add(listOptionsPanel, "cell 4 1");
+
 		//---- treeLabel ----
 		treeLabel.setText("JTree:");
 		add(treeLabel, "cell 0 2,aligny top,growy 0");
@@ -334,6 +397,29 @@ class DataComponentsPanel
 		}
 		add(scrollPane4, "cell 3 2");
 
+		//======== treeOptionsPanel ========
+		{
+			treeOptionsPanel.setLayout(new MigLayout(
+				"insets 0,hidemode 3",
+				// columns
+				"[fill]",
+				// rows
+				"[]0" +
+				"[]"));
+
+			//---- treeWideSelectionCheckBox ----
+			treeWideSelectionCheckBox.setText("wide selection");
+			treeWideSelectionCheckBox.setSelected(true);
+			treeWideSelectionCheckBox.addActionListener(e -> treeWideSelectionChanged());
+			treeOptionsPanel.add(treeWideSelectionCheckBox, "cell 0 0");
+
+			//---- treeAlternatingRowsCheckBox ----
+			treeAlternatingRowsCheckBox.setText("alternating rows");
+			treeAlternatingRowsCheckBox.addActionListener(e -> treeAlternatingRowsChanged());
+			treeOptionsPanel.add(treeAlternatingRowsCheckBox, "cell 0 1");
+		}
+		add(treeOptionsPanel, "cell 4 2");
+
 		//---- tableLabel ----
 		tableLabel.setText("JTable:");
 		add(tableLabel, "cell 0 3,aligny top,growy 0");
@@ -379,7 +465,7 @@ class DataComponentsPanel
 			{
 				TableColumnModel cm = table1.getColumnModel();
 				cm.getColumn(2).setCellEditor(new DefaultCellEditor(
-					new JComboBox(new DefaultComboBoxModel(new String[] {
+					new JComboBox<>(new DefaultComboBoxModel<>(new String[] {
 						"January",
 						"February",
 						"March",
@@ -394,7 +480,7 @@ class DataComponentsPanel
 						"December"
 					}))));
 				cm.getColumn(3).setCellEditor(new DefaultCellEditor(
-					new JComboBox(new DefaultComboBoxModel(new String[] {
+					new JComboBox<>(new DefaultComboBoxModel<>(new String[] {
 						"January",
 						"February",
 						"March",
@@ -513,9 +599,12 @@ class DataComponentsPanel
 	private JList<String> list1;
 	private JList<String> list3;
 	private JList<String> list2;
+	private JCheckBox listAlternatingRowsCheckBox;
 	private JTree tree1;
 	private JTree tree3;
 	private JTree tree2;
+	private JCheckBox treeWideSelectionCheckBox;
+	private JCheckBox treeAlternatingRowsCheckBox;
 	private JTable table1;
 	private JCheckBox roundedSelectionCheckBox;
 	private JCheckBox showHorizontalLinesCheckBox;

flatlaf-demo/src/main/java/com/formdev/flatlaf/demo/DataComponentsPanel.jfd

@@ -1,4 +1,4 @@
-JFDML JFormDesigner: "8.2.0.0.331" Java: "21" encoding: "UTF-8"
+JFDML JFormDesigner: "8.3" encoding: "UTF-8"
 
 new FormModel {
 	contentType: "form/swing"
@@ -92,6 +92,25 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 3 1"
 			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+				"$layoutConstraints": "insets 0,hidemode 3"
+				"$columnConstraints": "[fill]"
+				"$rowConstraints": "[]"
+			} ) {
+				name: "listOptionsPanel"
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "listAlternatingRowsCheckBox"
+					"text": "alternating rows"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "listAlternatingRowsChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0"
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 4 1"
+			} )
 			add( new FormComponent( "javax.swing.JLabel" ) {
 				name: "treeLabel"
 				"text": "JTree:"
@@ -192,6 +211,36 @@ new FormModel {
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 3 2"
 			} )
+			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
+				"$layoutConstraints": "insets 0,hidemode 3"
+				"$columnConstraints": "[fill]"
+				"$rowConstraints": "[]0[]"
+			} ) {
+				name: "treeOptionsPanel"
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "treeWideSelectionCheckBox"
+					"text": "wide selection"
+					"selected": true
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "treeWideSelectionChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 0"
+				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "treeAlternatingRowsCheckBox"
+					"text": "alternating rows"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "treeAlternatingRowsChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 1"
+				} )
+			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+				"value": "cell 4 2"
+			} )
 			add( new FormComponent( "javax.swing.JLabel" ) {
 				name: "tableLabel"
 				"text": "JTable:"

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

@@ -494,6 +494,11 @@ public class FlatComponents2Test
 			list.setVisibleRowCount( visibleRowCount );
 	}
 
+	private void listAlternatingRowsChanged() {
+		UIManager.put( "List.alternateRowColor", listAlternatingRowsCheckBox.isSelected() ? Color.YELLOW : null );
+		FlatLaf.updateUILater();
+	}
+
 	private void treeRendererChanged() {
 		Object sel = treeRendererComboBox.getSelectedItem();
 		if( !(sel instanceof String) )
@@ -530,6 +535,11 @@ public class FlatComponents2Test
 			tree.putClientProperty( FlatClientProperties.TREE_WIDE_CELL_RENDERER, wideCellRenderer );
 	}
 
+	private void treeAlternatingRowsChanged() {
+		UIManager.put( "Tree.alternateRowColor", treeAlternatingRowsCheckBox.isSelected() ? Color.cyan : null );
+		FlatLaf.updateUILater();
+	}
+
 	private void treePaintSelectionChanged() {
 		boolean paintSelection = treePaintSelectionCheckBox.isSelected();
 		for( JTree tree : allTrees )
@@ -670,12 +680,14 @@ public class FlatComponents2Test
 		listLayoutOrientationField = new JComboBox<>();
 		JLabel listVisibleRowCountLabel = new JLabel();
 		listVisibleRowCountSpinner = new JSpinner();
+		listAlternatingRowsCheckBox = new JCheckBox();
 		treeOptionsPanel = new JPanel();
 		JLabel treeRendererLabel = new JLabel();
 		treeRendererComboBox = new JComboBox<>();
 		treeWideSelectionCheckBox = new JCheckBox();
 		treeWideCellRendererCheckBox = new JCheckBox();
 		treePaintSelectionCheckBox = new JCheckBox();
+		treeAlternatingRowsCheckBox = new JCheckBox();
 		treePaintLinesCheckBox = new JCheckBox();
 		treeRedLinesCheckBox = new JCheckBox();
 		treeEditableCheckBox = new JCheckBox();
@@ -737,7 +749,7 @@ public class FlatComponents2Test
 				// rows
 				"[]" +
 				"[grow]" +
-				"[]" +
+				"[]0" +
 				"[]"));
 
 			//---- listLabel ----
@@ -780,7 +792,7 @@ public class FlatComponents2Test
 				// rows
 				"[]" +
 				"[grow]" +
-				"[]" +
+				"[]0" +
 				"[]"));
 
 			//---- tableLabel ----
@@ -817,7 +829,7 @@ public class FlatComponents2Test
 				// rows
 				"[]" +
 				"[grow]" +
-				"[]" +
+				"[]0" +
 				"[]"));
 
 			//---- treeLabel ----
@@ -1006,6 +1018,7 @@ public class FlatComponents2Test
 				// rows
 				"[]" +
 				"[]" +
+				"[]" +
 				"[]"));
 
 			//---- listRendererLabel ----
@@ -1043,6 +1056,11 @@ public class FlatComponents2Test
 			listVisibleRowCountSpinner.setModel(new SpinnerNumberModel(8, 0, null, 1));
 			listVisibleRowCountSpinner.addChangeListener(e -> listVisibleRowCountChanged());
 			listOptionsPanel.add(listVisibleRowCountSpinner, "cell 1 2");
+
+			//---- listAlternatingRowsCheckBox ----
+			listAlternatingRowsCheckBox.setText("alternating rows");
+			listAlternatingRowsCheckBox.addActionListener(e -> listAlternatingRowsChanged());
+			listOptionsPanel.add(listAlternatingRowsCheckBox, "cell 0 3 2 1,alignx left,growx 0");
 		}
 		add(listOptionsPanel, "cell 0 4 4 1");
 
@@ -1096,6 +1114,11 @@ public class FlatComponents2Test
 			treePaintSelectionCheckBox.addActionListener(e -> treePaintSelectionChanged());
 			treeOptionsPanel.add(treePaintSelectionCheckBox, "cell 0 2");
 
+			//---- treeAlternatingRowsCheckBox ----
+			treeAlternatingRowsCheckBox.setText("alternating rows");
+			treeAlternatingRowsCheckBox.addActionListener(e -> treeAlternatingRowsChanged());
+			treeOptionsPanel.add(treeAlternatingRowsCheckBox, "cell 0 2");
+
 			//---- treePaintLinesCheckBox ----
 			treePaintLinesCheckBox.setText("paint lines");
 			treePaintLinesCheckBox.addActionListener(e -> treePaintLinesChanged());
@@ -1253,11 +1276,13 @@ public class FlatComponents2Test
 	private JComboBox<String> listRendererComboBox;
 	private JComboBox<String> listLayoutOrientationField;
 	private JSpinner listVisibleRowCountSpinner;
+	private JCheckBox listAlternatingRowsCheckBox;
 	private JPanel treeOptionsPanel;
 	private JComboBox<String> treeRendererComboBox;
 	private JCheckBox treeWideSelectionCheckBox;
 	private JCheckBox treeWideCellRendererCheckBox;
 	private JCheckBox treePaintSelectionCheckBox;
+	private JCheckBox treeAlternatingRowsCheckBox;
 	private JCheckBox treePaintLinesCheckBox;
 	private JCheckBox treeRedLinesCheckBox;
 	private JCheckBox treeEditableCheckBox;
@@ -1363,7 +1388,7 @@ public class FlatComponents2Test
 		@Override
 		public String getElementAt( int index ) {
 			return (index < 20)
-				? "item " + (index + 1)
+				? "item " + (index + 1) + ((index + 1) % 5 == 0 ? " ####" : "")
 				: "item " + (index + 1) + "   " + randomRowString( index );
 		}
 	}

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

@@ -33,7 +33,7 @@ new FormModel {
 			} )
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$columnConstraints": "[fill]"
-				"$rowConstraints": "[][grow][][]"
+				"$rowConstraints": "[][grow][]0[]"
 				"$layoutConstraints": "ltr,insets 0,hidemode 3"
 			} ) {
 				name: "panel1"
@@ -95,7 +95,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "insets 0,hidemode 3"
 				"$columnConstraints": "[fill]"
-				"$rowConstraints": "[][grow][][]"
+				"$rowConstraints": "[][grow][]0[]"
 			} ) {
 				name: "panel3"
 				"$client.FlatLaf.internal.testing.ignore": true
@@ -146,7 +146,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "insets 0,hidemode 3"
 				"$columnConstraints": "[fill]"
-				"$rowConstraints": "[][grow][][]"
+				"$rowConstraints": "[][grow][]0[]"
 			} ) {
 				name: "panel2"
 				"$client.FlatLaf.internal.testing.ignore": true
@@ -385,7 +385,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "insets 8,hidemode 3"
 				"$columnConstraints": "[fill][fill]"
-				"$rowConstraints": "[][][]"
+				"$rowConstraints": "[][][][]"
 			} ) {
 				name: "listOptionsPanel"
 				"border": new javax.swing.border.TitledBorder( "JList Control" )
@@ -455,6 +455,16 @@ new FormModel {
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 					"value": "cell 1 2"
 				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "listAlternatingRowsCheckBox"
+					"text": "alternating rows"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "listAlternatingRowsChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 3 2 1,alignx left,growx 0"
+				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 0 4 4 1"
 			} )
@@ -527,6 +537,16 @@ new FormModel {
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 					"value": "cell 0 2"
 				} )
+				add( new FormComponent( "javax.swing.JCheckBox" ) {
+					name: "treeAlternatingRowsCheckBox"
+					"text": "alternating rows"
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "treeAlternatingRowsChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 2"
+				} )
 				add( new FormComponent( "javax.swing.JCheckBox" ) {
 					name: "treePaintLinesCheckBox"
 					"text": "paint lines"