ScrollPane: paint disabled border if view component (e.g. JTextPane) is disabled

CHANGELOG.md

@@ -8,6 +8,8 @@ FlatLaf Change Log
   for improved compatibility with IntelliJ platform themes (e.g. for Vuesion,
   Spacegray and Material Design Dark themes).
 - Button: Fixed help button styling in IntelliJ platform themes.
+- ScrollPane: Paint disabled border if view component (e.g. JTextPane) is
+  disabled.
 
 
 ## 0.20

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

@@ -95,12 +95,23 @@ public class FlatBorder
 	}
 
 	protected Paint getBorderColor( Component c ) {
-		boolean enabled = c.isEnabled() && (!(c instanceof JTextComponent) || ((JTextComponent)c).isEditable());
+		return isEnabled( c )
-		return enabled
 			? (isFocused( c ) ? focusedBorderColor : borderColor)
 			: disabledBorderColor;
 	}
 
+	protected boolean isEnabled( Component c ) {
+		if( c instanceof JScrollPane ) {
+			// check whether view component is disabled
+			JViewport viewport = ((JScrollPane)c).getViewport();
+			Component view = (viewport != null) ? viewport.getView() : null;
+			if( view != null && !isEnabled( view ) )
+				return false;
+		}
+
+		return c.isEnabled() && (!(c instanceof JTextComponent) || ((JTextComponent)c).isEditable());
+	}
+
 	protected boolean isFocused( Component c ) {
 		if( c instanceof JScrollPane ) {
 			JViewport viewport = ((JScrollPane)c).getViewport();