Recalculate geometry after styling in FlatSliderUI

Author: daWoife

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

@@ -227,7 +227,11 @@ protected void installStyle() {
 
 	/** @since 2 */
 	protected void applyStyle( Object style ) {
+	    boolean recalc = ( oldStyleValues != null && !oldStyleValues.isEmpty() );
 		oldStyleValues = FlatStylingSupport.parseAndApply( oldStyleValues, style, this::applyStyleProperty );
+        recalc |= ( oldStyleValues != null && !oldStyleValues.isEmpty() );
+		if( recalc )
+            calculateGeometry();
 	}
 
 	/** @since 2 */