Styling: fixed IllegalAccessException when using component specific style [style]Spinner = foreground: #f00 and spinner labels are painted (caused by private subclass of JLabel where getForeground() is overridden)

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

@@ -485,22 +485,34 @@ public class FlatStylingSupport
 		String getterName = buildMethodName( "get", name );
 		String setterName = buildMethodName( "set", name );
 
-		try {
-			Method getter;
+		for(;;) {
 			try {
-				getter = cls.getMethod( getterName );
+				Method getter;
+				try {
+					getter = cls.getMethod( getterName );
+				} catch( NoSuchMethodException ex ) {
+					getter = cls.getMethod( buildMethodName( "is", name ) );
+				}
+				Method setter = cls.getMethod( setterName, getter.getReturnType() );
+				Object oldValue = getter.invoke( obj );
+				setter.invoke( obj, convertToEnum( value, getter.getReturnType() ) );
+				return oldValue;
 			} catch( NoSuchMethodException ex ) {
-				getter = cls.getMethod( buildMethodName( "is", name ) );
+				throw new UnknownStyleException( name );
+			} catch( Exception ex ) {
+				if( ex instanceof IllegalAccessException ) {
+					// this may happen for private subclasses of public Swing classes
+					// that override public property getter/setter
+					// e.g. class JSlider.SmartHashtable.LabelUIResource.getForeground()
+					// --> try again with superclass
+					cls = cls.getSuperclass();
+					if( cls != null && cls != Object.class )
+						continue;
+				}
+
+				throw new IllegalArgumentException( "failed to invoke property methods '" + cls.getName() + "."
+					+ getterName + "()' or '" + setterName + "(...)'", ex );
 			}
-			Method setter = cls.getMethod( setterName, getter.getReturnType() );
-			Object oldValue = getter.invoke( obj );
-			setter.invoke( obj, convertToEnum( value, getter.getReturnType() ) );
-			return oldValue;
-		} catch( NoSuchMethodException ex ) {
-			throw new UnknownStyleException( name );
-		} catch( Exception ex ) {
-			throw new IllegalArgumentException( "failed to invoke property methods '" + cls.getName() + "."
-				+ getterName + "()' or '" + setterName + "(...)'", ex );
 		}
 	}
 

flatlaf-core/src/test/java/com/formdev/flatlaf/ui/TestFlatStyleType.java

@@ -219,6 +219,19 @@ public class TestFlatStyleType
 		assertEquals( new Color( 0x000022 ), c.getForeground() );
 	}
 
+	@Test
+	void slider2() {
+		JSlider c = new JSlider();
+
+		// when slider labels are painted, then a Java private subclass of JLabel
+		// is used that overrides getForeground(), which is not accessible via reflection
+		// see class JSlider.SmartHashtable.LabelUIResource
+		c.setPaintLabels( true );
+		c.setMajorTickSpacing( 50 );
+
+		assertEquals( new Color( 0x000022 ), c.getForeground() );
+	}
+
 	@Test
 	void spinner() {
 		JSpinner c = new JSpinner();