Styling: use annotation on fields to apply style properties (to avoid boilerplate code)

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

@@ -36,6 +36,7 @@ import javax.swing.plaf.basic.BasicButtonListener;
 import javax.swing.plaf.basic.BasicRadioButtonUI;
 import com.formdev.flatlaf.FlatClientProperties;
 import com.formdev.flatlaf.icons.FlatCheckBoxIcon;
+import com.formdev.flatlaf.ui.FlatStyleSupport.Styleable;
 import com.formdev.flatlaf.util.UIScale;
 
 /**
@@ -62,7 +63,7 @@ public class FlatRadioButtonUI
 	extends BasicRadioButtonUI
 {
 	protected int iconTextGap;
-	protected Color disabledText;
+	@Styleable protected Color disabledText;
 
 	private Color defaultBackground;
 
@@ -158,15 +159,9 @@ public class FlatRadioButtonUI
 	 * @since TODO
 	 */
 	protected Object applyStyleProperty( String key, Object value ) {
-		Object oldValue;
+		//TODO style icon
-		switch( key ) {
-			case "disabledText": oldValue = disabledText; disabledText = (Color) value; break;
 
-			//TODO style icon
+		return FlatStyleSupport.applyToAnnotatedObject( this, key, value );
-
-			default: throw new IllegalArgumentException( "unknown style '" + key + "'" );
-		}
-		return oldValue;
 	}
 
 	private static Insets tempInsets = new Insets( 0, 0, 0, 0 );

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

@@ -37,6 +37,7 @@ import javax.swing.UIManager;
 import javax.swing.plaf.ComponentUI;
 import javax.swing.plaf.basic.BasicSliderUI;
 import com.formdev.flatlaf.FlatClientProperties;
+import com.formdev.flatlaf.ui.FlatStyleSupport.Styleable;
 import com.formdev.flatlaf.util.Graphics2DProxy;
 import com.formdev.flatlaf.util.HiDPIUtils;
 import com.formdev.flatlaf.util.UIScale;
@@ -78,23 +79,23 @@ import com.formdev.flatlaf.util.UIScale;
 public class FlatSliderUI
 	extends BasicSliderUI
 {
-	protected int trackWidth;
+	@Styleable protected int trackWidth;
-	protected Dimension thumbSize;
+	@Styleable protected Dimension thumbSize;
-	protected int focusWidth;
+	@Styleable protected int focusWidth;
 
-	protected Color trackValueColor;
+	@Styleable protected Color trackValueColor;
-	protected Color trackColor;
+	@Styleable protected Color trackColor;
-	protected Color thumbColor;
+	@Styleable protected Color thumbColor;
-	protected Color thumbBorderColor;
+	@Styleable protected Color thumbBorderColor;
 	protected Color focusBaseColor;
-	protected Color focusedColor;
+	@Styleable protected Color focusedColor;
-	protected Color focusedThumbBorderColor;
+	@Styleable protected Color focusedThumbBorderColor;
-	protected Color hoverThumbColor;
+	@Styleable protected Color hoverThumbColor;
-	protected Color pressedThumbColor;
+	@Styleable protected Color pressedThumbColor;
-	protected Color disabledTrackColor;
+	@Styleable protected Color disabledTrackColor;
-	protected Color disabledThumbColor;
+	@Styleable protected Color disabledThumbColor;
-	protected Color disabledThumbBorderColor;
+	@Styleable protected Color disabledThumbBorderColor;
-	protected Color tickColor;
+	@Styleable protected Color tickColor;
 
 	private Color defaultBackground;
 	private Color defaultForeground;
@@ -209,28 +210,7 @@ public class FlatSliderUI
 	 * @since TODO
 	 */
 	protected Object applyStyleProperty( String key, Object value ) {
-		Object oldValue;
+		return FlatStyleSupport.applyToAnnotatedObject( this, key, value );
-		switch( key ) {
-			case "trackWidth": oldValue = trackWidth; trackWidth = (int) value; break;
-			case "thumbSize": oldValue = thumbSize; thumbSize = (Dimension) value; break;
-			case "focusWidth": oldValue = focusWidth; focusWidth = (int) value; break;
-
-			case "trackValueColor": oldValue = trackValueColor; trackValueColor = (Color) value; break;
-			case "trackColor": oldValue = trackColor; trackColor = (Color) value; break;
-			case "thumbColor": oldValue = thumbColor; thumbColor = (Color) value; break;
-			case "thumbBorderColor": oldValue = thumbBorderColor; thumbBorderColor = (Color) value; break;
-			case "focusedColor": oldValue = focusedColor; focusedColor = (Color) value; break;
-			case "focusedThumbBorderColor": oldValue = focusedThumbBorderColor; focusedThumbBorderColor = (Color) value; break;
-			case "hoverThumbColor": oldValue = hoverThumbColor; hoverThumbColor = (Color) value; break;
-			case "pressedThumbColor": oldValue = pressedThumbColor; pressedThumbColor = (Color) value; break;
-			case "disabledTrackColor": oldValue = disabledTrackColor; disabledTrackColor = (Color) value; break;
-			case "disabledThumbColor": oldValue = disabledThumbColor; disabledThumbColor = (Color) value; break;
-			case "disabledThumbBorderColor": oldValue = disabledThumbBorderColor; disabledThumbBorderColor = (Color) value; break;
-			case "tickColor": oldValue = tickColor; tickColor = (Color) value; break;
-
-			default: throw new IllegalArgumentException( "unknown style '" + key + "'" );
-		}
-		return oldValue;
 	}
 
 	@Override

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

@@ -16,6 +16,12 @@
 
 package com.formdev.flatlaf.ui;
 
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.util.HashMap;
 import java.util.LinkedHashMap;
 import java.util.Map;
@@ -34,6 +40,16 @@ import com.formdev.flatlaf.util.StringUtils;
  */
 public class FlatStyleSupport
 {
+	/**
+	 * Indicates that a field is intended to be used by FlatLaf styling support.
+	 * <p>
+	 * <strong>Do not rename fields annotated with this annotation.</strong>
+	 */
+	@Target(ElementType.FIELD)
+	@Retention(RetentionPolicy.RUNTIME)
+	public @interface Styleable {
+	}
+
 	/**
 	 * Parses styles in CSS syntax ("key1: value1; key2: value2; ..."),
 	 * converts the value strings into binary and invokes the given function
@@ -146,6 +162,59 @@ public class FlatStyleSupport
 		return FlatLaf.parseDefaultsValue( key, value );
 	}
 
+	/**
+	 * Applies the given value to an annotated field of the given object.
+	 * The field must be annotated with {@link Styleable}.
+	 *
+	 * @param object the object
+	 * @param key the name of the field
+	 * @param value the new value
+	 * @return the old value of the field
+	 * @throws IllegalArgumentException if object does not have a annotated field with given name
+	 *         or if value type does not fit to expected type 
+	 */
+	public static Object applyToAnnotatedObject( Object obj, String key, Object value )
+		throws IllegalArgumentException
+	{
+		Class<?> cls = obj.getClass();
+
+		for(;;) {
+			try {
+				Field f = cls.getDeclaredField( key );
+				if( f.isAnnotationPresent( Styleable.class ) ) {
+					if( Modifier.isFinal( f.getModifiers() ) )
+						throw new IllegalArgumentException( "field '" + cls.getName() + "." + key + "' is final" );
+
+					try {
+						// necessary to access protected fields in other packages
+						f.setAccessible( true );
+
+						// get old value and set new value
+						Object oldValue = f.get( obj );
+						f.set( obj, value );
+						return oldValue;
+					} catch( IllegalAccessException ex ) {
+						throw new IllegalArgumentException( "failed to access field '" + cls.getName() + "." + key + "'" );
+					}
+				}
+			} catch( NoSuchFieldException ex ) {
+				// field not found in class --> try superclass
+			}
+
+			cls = cls.getSuperclass();
+			if( cls == null )
+				throw newUnknownStyleException( key );
+
+			String superclassName = cls.getName();
+			if( superclassName.startsWith( "java." ) || superclassName.startsWith( "javax." ) )
+				throw newUnknownStyleException( key );
+		}
+	}
+
+	public static IllegalArgumentException newUnknownStyleException( String key ) {
+		return new IllegalArgumentException( "unknown style '" + key + "'" );
+	}
+
 	public static Object getStyle( JComponent c ) {
 		return c.getClientProperty( FlatClientProperties.COMPONENT_STYLE );
 	}