Styling: support enums

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

@@ -414,10 +414,10 @@ public class FlatStylingSupport
 
 						// get old value and set new value
 						Object oldValue = f.get( obj );
-						f.set( obj, value );
+						f.set( obj, convertToEnum( value, f.getType() ) );
 						return oldValue;
 					} catch( IllegalAccessException ex ) {
-						throw new IllegalArgumentException( "failed to access field '" + cls.getName() + "." + fieldName + "'" );
+						throw new IllegalArgumentException( "failed to access field '" + cls.getName() + "." + fieldName + "'", ex );
 					}
 				}
 			} catch( NoSuchFieldException ex ) {
@@ -470,7 +470,7 @@ public class FlatStylingSupport
 			}
 			Method setter = cls.getMethod( setterName, getter.getReturnType() );
 			Object oldValue = getter.invoke( obj );
-			setter.invoke( obj, value );
+			setter.invoke( obj, convertToEnum( value, getter.getReturnType() ) );
 			return oldValue;
 		} catch( NoSuchMethodException ex ) {
 			throw new UnknownStyleException( name );
@@ -490,6 +490,21 @@ public class FlatStylingSupport
 		return new String( chars );
 	}
 
+	@SuppressWarnings( { "unchecked", "rawtypes" } )
+	private static Object convertToEnum( Object value, Class<?> type )
+		throws IllegalArgumentException
+	{
+		// if type is an enum, convert string to enum value
+		if( Enum.class.isAssignableFrom( type ) && value instanceof String ) {
+			try {
+				value = Enum.valueOf( (Class<? extends Enum>) type, (String) value );
+			} catch( IllegalArgumentException ex ) {
+				throw new IllegalArgumentException( "unknown enum value '" + value + "' in enum '" + type.getName() + "'", ex );
+			}
+		}
+		return value;
+	}
+
 	/**
 	 * Applies the given value to an annotated field of the given object
 	 * or to a property of the given component.
@@ -575,7 +590,7 @@ public class FlatStylingSupport
 		try {
 			return borderClass.getDeclaredConstructor().newInstance();
 		} catch( Exception ex ) {
-			throw new IllegalArgumentException( "failed to clone border '" + borderClass.getName() + "'" );
+			throw new IllegalArgumentException( "failed to clone border '" + borderClass.getName() + "'", ex );
 		}
 	}
 
@@ -584,7 +599,7 @@ public class FlatStylingSupport
 		try {
 			return iconClass.getDeclaredConstructor().newInstance();
 		} catch( Exception ex ) {
-			throw new IllegalArgumentException( "failed to clone icon '" + iconClass.getName() + "'" );
+			throw new IllegalArgumentException( "failed to clone icon '" + iconClass.getName() + "'", ex );
 		}
 	}
 

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

@@ -146,6 +146,19 @@ public class FlatUIUtils
 		return (value instanceof Number) ? ((Number)value).floatValue() : defaultValue;
 	}
 
+	/** @since 2 */
+	public static <T extends Enum<T>> T getUIEnum( String key, Class<T> enumType, T defaultValue ) {
+		Object value = UIManager.get( key );
+		if( value instanceof String ) {
+			try {
+				return Enum.valueOf( enumType, (String) value );
+			} catch( IllegalArgumentException ex ) {
+				// ignore
+			}
+		}
+		return defaultValue;
+	}
+
 	/** @since 1.1.2 */
 	public static boolean getBoolean( JComponent c, String systemPropertyKey,
 		String clientPropertyKey, String uiKey, boolean defaultValue )

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

@@ -1282,4 +1282,38 @@ public class TestFlatStyling
 		icon.applyStyleProperty( "searchIconHoverColor", Color.WHITE );
 		icon.applyStyleProperty( "searchIconPressedColor", Color.WHITE );
 	}
+
+	//---- enums --------------------------------------------------------------
+
+	enum SomeEnum { enumValue1, enumValue2 }
+
+	static class ClassWithEnum {
+		SomeEnum enum1;
+	}
+
+	@Test
+	void enumField() {
+		ClassWithEnum c = new ClassWithEnum();
+		FlatStylingSupport.applyToField( c, "enum1", "enum1", "enumValue1" );
+		FlatStylingSupport.applyToField( c, "enum1", "enum1", "enumValue2" );
+	}
+
+	@Test
+	void enumProperty() {
+		JList<Object> c = new JList<>();
+		FlatListUI ui = (FlatListUI) c.getUI();
+		ui.applyStyle( "dropMode: INSERT" );
+	}
+
+	@Test
+	void enumUIDefaults() {
+		UIManager.put( "test.enum", SomeEnum.enumValue1.toString() );
+		assertEquals( SomeEnum.enumValue1, FlatUIUtils.getUIEnum( "test.enum", SomeEnum.class, null ) );
+
+		UIManager.put( "test.enum", "unknown" );
+		assertEquals( null, FlatUIUtils.getUIEnum( "test.enum", SomeEnum.class, null ) );
+
+		UIManager.put( "test.enum", null );
+		assertEquals( SomeEnum.enumValue1, FlatUIUtils.getUIEnum( "test.enum", SomeEnum.class, SomeEnum.enumValue1 ) );
+	}
 }