List: support rounded selection for layout orientations VERTICAL_WRAP and HORIZONTAL_WRAP

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

@@ -22,6 +22,7 @@ import java.awt.EventQueue;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Insets;
+import java.awt.Point;
 import java.awt.Rectangle;
 import java.awt.event.FocusEvent;
 import java.awt.event.FocusListener;
@@ -185,8 +186,8 @@ public class FlatListUI
 		return e -> {
 			superListener.valueChanged( e );
 
-			// for united rounded selection, repaint parts of the rows that adjoin to the changed rows
-			if( useUnitedRoundedSelection() &&
+			// for united rounded selection, repaint parts of the rows/columns that adjoin to the changed rows/columns
+			if( useUnitedRoundedSelection( true, true ) &&
 				!list.isSelectionEmpty() &&
 				(list.getMaxSelectionIndex() - list.getMinSelectionIndex()) >= 1 )
 			{
@@ -196,7 +197,7 @@ public class FlatListUI
 				Rectangle r = getCellBounds( list, firstIndex, lastIndex );
 				if( r != null ) {
 					int arc = (int) Math.ceil( UIScale.scale( selectionArc / 2f ) );
-					list.repaint( r.x, r.y - arc, r.width, r.height + (arc * 2) );
+					list.repaint( r.x - arc, r.y - arc, r.width + (arc * 2), r.height + (arc * 2) );
 				}
 			}
 		};
@@ -359,23 +360,64 @@ public class FlatListUI
 
 	/** @since 3 */
 	protected void paintCellSelection( Graphics g, int row, int x, int y, int width, int height ) {
-		float arcTop, arcBottom;
-		arcTop = arcBottom = UIScale.scale( selectionArc / 2f );
+		float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
+		arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
 
-		if( useUnitedRoundedSelection() ) {
+		if( list.getLayoutOrientation() == JList.VERTICAL ) {
+			// layout orientation: VERTICAL
+			if( useUnitedRoundedSelection( true, false ) ) {
 				if( row > 0 && list.isSelectedIndex( row - 1 ) )
-				arcTop = 0;
+					arcTopLeft = arcTopRight = 0;
 				if( row < list.getModel().getSize() - 1 && list.isSelectedIndex( row + 1 ) )
-				arcBottom = 0;
+					arcBottomLeft = arcBottomRight = 0;
+			}
+		} else {
+			// layout orientation: VERTICAL_WRAP or HORIZONTAL_WRAP
+			Rectangle r = null;
+			if( useUnitedRoundedSelection( true, false ) ) {
+				// vertical: check whether cells above or below are selected
+				r = getCellBounds( list, row, row );
+
+				int topIndex = locationToIndex( list, new Point( r.x, r.y - 1 ) );
+				int bottomIndex = locationToIndex( list, new Point( r.x, r.y + r.height ) );
+
+				if( topIndex >= 0 && topIndex != row && list.isSelectedIndex( topIndex ) )
+					arcTopLeft = arcTopRight = 0;
+				if( bottomIndex >= 0 && bottomIndex != row && list.isSelectedIndex( bottomIndex ) )
+					arcBottomLeft = arcBottomRight = 0;
+			}
+
+			if( useUnitedRoundedSelection( false, true ) ) {
+				// horizontal: check whether cells left or right are selected
+				if( r == null )
+					r = getCellBounds( list, row, row );
+
+				int leftIndex = locationToIndex( list, new Point( r.x - 1, r.y ) );
+				int rightIndex = locationToIndex( list, new Point( r.x + r.width, r.y ) );
+
+				// special handling for the case that last column contains less cells than the other columns
+				boolean ltr = list.getComponentOrientation().isLeftToRight();
+				if( !ltr && leftIndex >= 0 && leftIndex != row && leftIndex == locationToIndex( list, new Point( r.x - 1, r.y - 1 ) ) )
+					leftIndex = -1;
+				if( ltr && rightIndex >= 0 && rightIndex != row && rightIndex == locationToIndex( list, new Point( r.x + r.width, r.y - 1 ) ) )
+					rightIndex = -1;
+
+				if( leftIndex >= 0 && leftIndex != row && list.isSelectedIndex( leftIndex ) )
+					arcTopLeft = arcBottomLeft = 0;
+				if( rightIndex >= 0 && rightIndex != row && list.isSelectedIndex( rightIndex ) )
+					arcTopRight = arcBottomRight = 0;
+			}
 		}
 
 		FlatUIUtils.paintSelection( (Graphics2D) g, x, y, width, height,
-			UIScale.scale( selectionInsets ), arcTop, arcTop, arcBottom, arcBottom, 0 );
+			UIScale.scale( selectionInsets ), arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight, 0 );
 	}
 
-	private boolean useUnitedRoundedSelection() {
+	private boolean useUnitedRoundedSelection( boolean vertical, boolean horizontal ) {
 		return selectionArc > 0 &&
-			(selectionInsets == null || (selectionInsets.top == 0 && selectionInsets.bottom == 0));
+			(selectionInsets == null ||
+			 (vertical && selectionInsets.top == 0 && selectionInsets.bottom == 0) ||
+			 (horizontal && selectionInsets.left == 0 && selectionInsets.right == 0));
 	}
 
 	/**

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

@@ -21,6 +21,7 @@ import java.awt.Component;
 import java.awt.ComponentOrientation;
 import java.awt.Dimension;
 import java.awt.EventQueue;
+import java.awt.Graphics;
 import java.awt.datatransfer.DataFlavor;
 import java.awt.datatransfer.StringSelection;
 import java.awt.datatransfer.Transferable;
@@ -44,6 +45,8 @@ import javax.swing.tree.TreePath;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.icons.FlatMenuArrowIcon;
+import com.formdev.flatlaf.ui.FlatEmptyBorder;
+import com.formdev.flatlaf.ui.FlatListUI;
 import com.formdev.flatlaf.util.UIScale;
 import com.jidesoft.swing.*;
 import com.jidesoft.swing.CheckBoxTreeCellRenderer;
@@ -361,7 +364,38 @@ public class FlatComponents2Test
 				for( JList<String> list : allLists )
 					list.setCellRenderer( new TestLabelListCellRenderer() );
 				break;
+
+			case "labelRounded":
+				for( JList<String> list : allLists )
+					list.setCellRenderer( new TestLabelRoundedListCellRenderer() );
+				break;
 		}
+
+		String style = sel.equals( "labelRounded" )
+			? "selectionArc: 6; selectionInsets: 0,1,0,1"
+			: null;
+		for( JList<String> list : allLists )
+			list.putClientProperty( FlatClientProperties.STYLE, style );
+	}
+
+	private void listLayoutOrientationChanged() {
+		int layoutOrientation = JList.VERTICAL;
+		Object sel = listLayoutOrientationField.getSelectedItem();
+		if( sel instanceof String ) {
+			switch( (String) sel ) {
+				case "vertical": layoutOrientation = JList.VERTICAL; break;
+				case "vertical wrap": layoutOrientation = JList.VERTICAL_WRAP; break;
+				case "horzontal wrap": layoutOrientation = JList.HORIZONTAL_WRAP; break;
+			}
+		}
+		for( JList<?> list : allLists )
+			list.setLayoutOrientation( layoutOrientation );
+	}
+
+	private void listVisibleRowCountChanged() {
+		int visibleRowCount = (Integer) listVisibleRowCountSpinner.getValue();
+		for( JList<?> list : allLists )
+			list.setVisibleRowCount( visibleRowCount );
 	}
 
 	private void treeRendererChanged() {
@@ -508,6 +542,10 @@ public class FlatComponents2Test
 		JPanel panel6 = new JPanel();
 		JLabel listRendererLabel = new JLabel();
 		listRendererComboBox = new JComboBox<>();
+		JLabel listLayoutOrientationLabel = new JLabel();
+		listLayoutOrientationField = new JComboBox<>();
+		JLabel listVisibleRowCountLabel = new JLabel();
+		listVisibleRowCountSpinner = new JSpinner();
 		JPanel treeOptionsPanel = new JPanel();
 		JLabel treeRendererLabel = new JLabel();
 		treeRendererComboBox = new JComboBox<>();
@@ -795,6 +833,8 @@ public class FlatComponents2Test
 				"[fill]" +
 				"[fill]",
 				// rows
+				"[]" +
+				"[]" +
 				"[]"));
 
 			//---- listRendererLabel ----
@@ -805,10 +845,33 @@ public class FlatComponents2Test
 			listRendererComboBox.setModel(new DefaultComboBoxModel<>(new String[] {
 				"default",
 				"defaultSubclass",
-				"label"
+				"label",
+				"labelRounded"
 			}));
 			listRendererComboBox.addActionListener(e -> listRendererChanged());
 			panel6.add(listRendererComboBox, "cell 1 0");
+
+			//---- listLayoutOrientationLabel ----
+			listLayoutOrientationLabel.setText("Orientation:");
+			panel6.add(listLayoutOrientationLabel, "cell 0 1");
+
+			//---- listLayoutOrientationField ----
+			listLayoutOrientationField.setModel(new DefaultComboBoxModel<>(new String[] {
+				"vertical",
+				"vertical wrap",
+				"horzontal wrap"
+			}));
+			listLayoutOrientationField.addActionListener(e -> listLayoutOrientationChanged());
+			panel6.add(listLayoutOrientationField, "cell 1 1");
+
+			//---- listVisibleRowCountLabel ----
+			listVisibleRowCountLabel.setText("Visible row count:");
+			panel6.add(listVisibleRowCountLabel, "cell 0 2");
+
+			//---- listVisibleRowCountSpinner ----
+			listVisibleRowCountSpinner.setModel(new SpinnerNumberModel(8, 0, null, 1));
+			listVisibleRowCountSpinner.addChangeListener(e -> listVisibleRowCountChanged());
+			panel6.add(listVisibleRowCountSpinner, "cell 1 2");
 		}
 		add(panel6, "cell 0 4 4 1");
 
@@ -973,6 +1036,8 @@ public class FlatComponents2Test
 	private JXTreeTable xTreeTable1;
 	private JCheckBox dndCheckBox;
 	private JComboBox<String> listRendererComboBox;
+	private JComboBox<String> listLayoutOrientationField;
+	private JSpinner listVisibleRowCountSpinner;
 	private JComboBox<String> treeRendererComboBox;
 	private JCheckBox treeWideSelectionCheckBox;
 	private JCheckBox treePaintSelectionCheckBox;
@@ -1371,6 +1436,45 @@ public class FlatComponents2Test
 		}
 	}
 
+	//---- class TestLabelRoundedListCellRenderer -----------------------------
+
+	private static class TestLabelRoundedListCellRenderer
+		extends JLabel
+		implements ListCellRenderer<String>
+	{
+		private JList<? extends String> list;
+		private int index;
+		private boolean isSelected;
+
+		TestLabelRoundedListCellRenderer() {
+			setBorder( new FlatEmptyBorder( 1, 6, 1, 6 ) );
+		}
+
+		@Override
+		public Component getListCellRendererComponent( JList<? extends String> list,
+			String value, int index, boolean isSelected, boolean cellHasFocus )
+		{
+			this.list = list;
+			this.index = index;
+			this.isSelected = isSelected;
+
+			setText( String.valueOf( value ) );
+			setBackground( isSelected ? Color.green : list.getBackground() );
+			setForeground( isSelected ? Color.blue : list.getForeground() );
+			return this;
+		}
+
+		@Override
+		protected void paintComponent( Graphics g ) {
+			if( isSelected ) {
+				g.setColor( getBackground() );
+				FlatListUI.paintCellSelection( list, g, index, 0, 0, getWidth(), getHeight() );
+			}
+
+			super.paintComponent( g );
+		}
+	}
+
 	//---- class TestDefaultTreeCellRenderer ----------------------------------
 
 	private static class TestDefaultTreeCellRenderer

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

@@ -318,7 +318,7 @@ new FormModel {
 			add( new FormContainer( "javax.swing.JPanel", new FormLayoutManager( class net.miginfocom.swing.MigLayout ) {
 				"$layoutConstraints": "hidemode 3"
 				"$columnConstraints": "[fill][fill]"
-				"$rowConstraints": "[]"
+				"$rowConstraints": "[][][]"
 			} ) {
 				name: "panel6"
 				"border": new javax.swing.border.TitledBorder( "JList Control" )
@@ -335,6 +335,7 @@ new FormModel {
 						addElement( "default" )
 						addElement( "defaultSubclass" )
 						addElement( "label" )
+						addElement( "labelRounded" )
 					}
 					auxiliary() {
 						"JavaCodeGenerator.variableLocal": false
@@ -343,6 +344,47 @@ new FormModel {
 				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 					"value": "cell 1 0"
 				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "listLayoutOrientationLabel"
+					"text": "Orientation:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 1"
+				} )
+				add( new FormComponent( "javax.swing.JComboBox" ) {
+					name: "listLayoutOrientationField"
+					"model": new javax.swing.DefaultComboBoxModel {
+						selectedItem: "vertical"
+						addElement( "vertical" )
+						addElement( "vertical wrap" )
+						addElement( "horzontal wrap" )
+					}
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+						"JavaCodeGenerator.typeParameters": "String"
+					}
+					addEvent( new FormEvent( "java.awt.event.ActionListener", "actionPerformed", "listLayoutOrientationChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 1 1"
+				} )
+				add( new FormComponent( "javax.swing.JLabel" ) {
+					name: "listVisibleRowCountLabel"
+					"text": "Visible row count:"
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 0 2"
+				} )
+				add( new FormComponent( "javax.swing.JSpinner" ) {
+					name: "listVisibleRowCountSpinner"
+					"model": new javax.swing.SpinnerNumberModel {
+						minimum: 0
+						value: 8
+					}
+					auxiliary() {
+						"JavaCodeGenerator.variableLocal": false
+					}
+					addEvent( new FormEvent( "javax.swing.event.ChangeListener", "stateChanged", "listVisibleRowCountChanged", false ) )
+				}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
+					"value": "cell 1 2"
+				} )
 			}, new FormLayoutConstraints( class net.miginfocom.layout.CC ) {
 				"value": "cell 0 4 4 1"
 			} )