Merge PR #856: Table: rounded selection

CHANGELOG.md

@@ -5,6 +5,7 @@ FlatLaf Change Log
 
 #### New features and improvements
 
+- Table: Support rounded selection. (PR #856)
 - Button and ToggleButton: Added border colors for pressed and selected states.
   (issue #848)
 - Label: Support painting background with rounded corners. (issue #842)

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

@@ -324,8 +324,7 @@ protected void paintCell( Graphics g, int row, Rectangle rowBounds, ListCellRend
 			(rendererComponent instanceof DefaultListCellRenderer ||
 			 rendererComponent instanceof BasicComboBoxRenderer) &&
 			(selectionArc > 0 ||
-			 (selectionInsets != null &&
-			  (selectionInsets.top != 0 || selectionInsets.left != 0 || selectionInsets.bottom != 0 || selectionInsets.right != 0))) )
+			 (selectionInsets != null && !FlatUIUtils.isInsetsEmpty( selectionInsets ))) )
 		{
 			// Because selection painting is done in the cell renderer, it would be
 			// necessary to require a FlatLaf specific renderer to implement rounded selection.
@@ -374,7 +373,15 @@ public void fillRect( int x, int y, int width, int height ) {
 		rendererPane.paintComponent( g, rendererComponent, list, cx, rowBounds.y, cw, rowBounds.height, true );
 	}
 
-	/** @since 3 */
+	/**
+	 * Paints (rounded) cell selection.
+	 * Supports {@link #selectionArc} and {@link #selectionInsets}.
+	 * <p>
+	 * <b>Note:</b> This method is only invoked if either selection arc
+	 *              is greater than zero or if selection insets are not empty.
+	 *
+	 * @since 3
+	 */
 	protected void paintCellSelection( Graphics g, int row, int x, int y, int width, int height ) {
 		float arcTopLeft, arcTopRight, arcBottomLeft, arcBottomRight;
 		arcTopLeft = arcTopRight = arcBottomLeft = arcBottomRight = UIScale.scale( selectionArc / 2f );
@@ -440,7 +447,8 @@ private boolean useUnitedRoundedSelection( boolean vertical, boolean horizontal
 	 * Paints a cell selection at the given coordinates.
 	 * The selection color must be set on the graphics context.
 	 * <p>
-	 * This method is intended for use in custom cell renderers.
+	 * This method is intended for use in custom cell renderers
+	 * to support {@link #selectionArc} and {@link #selectionInsets}.
 	 *
 	 * @since 3
 	 */

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

@@ -65,8 +65,28 @@ public Color getLineColor() {
 		return super.getLineColor();
 	}
 
+	@Override
+	public int getArc() {
+		if( c != null ) {
+			Integer selectionArc = getStyleFromTableUI( c, ui -> ui.selectionArc );
+			if( selectionArc != null )
+				return selectionArc;
+		}
+		return super.getArc();
+	}
+
 	@Override
 	public void paintBorder( Component c, Graphics g, int x, int y, int width, int height ) {
+		if( c != null ) {
+			Insets selectionInsets = getStyleFromTableUI( c, ui -> ui.selectionInsets );
+			if( selectionInsets != null ) {
+				x += selectionInsets.left;
+				y += selectionInsets.top;
+				width -= selectionInsets.left + selectionInsets.right;
+				height -= selectionInsets.top + selectionInsets.bottom;
+			}
+		}
+
 		this.c = c;
 		super.paintBorder( c, g, x, y, width, height );
 		this.c = null;