merged PR #63 (for issue #58) into master (with modifications)

bug: AbstractButton's ContentAreaFilled=false not honored when parent is a CellRendererPane

CHANGELOG.md

@@ -11,6 +11,8 @@ FlatLaf Change Log
 - TabbedPane: New option to allow tab separators to take full height (to enable
   use `UIManager.put( "TabbedPane.tabSeparatorsFullHeight", true );`). (issue
   #59, PR #62)
+- CheckBox and RadioButton: Do not fill background if `contentAreaFilled` is
+  `false`. (issue #58, PR #63)
 
 
 ## 0.26

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

@@ -118,11 +118,13 @@ public class FlatRadioButtonUI
 
 	@Override
 	public void paint( Graphics g, JComponent c ) {
-		// fill background even if opaque if
-		// - used as cell renderer (because of selection background)
-		// - if background was explicitly set to a non-UIResource color
+		// fill background even if not opaque if
+		// - contentAreaFilled is true and
+		//   - used as cell renderer (because of selection background)
+		//   - or if background was explicitly set to a non-UIResource color
 		if( !c.isOpaque() &&
-			(c.getParent() instanceof CellRendererPane || !(c.getBackground() instanceof UIResource)) )
+			((AbstractButton)c).isContentAreaFilled() &&
+			(c.getParent() instanceof CellRendererPane || !(c.getBackground() instanceof UIResource)))
 		{
 			g.setColor( c.getBackground() );
 			g.fillRect( 0, 0, c.getWidth(), c.getHeight() );