SwingX: fixed NullPointerException in FlatCaret when using org.jdesktop.swingx.prompt.PromptSupport.setPrompt() on a text field and then switching theme

CHANGELOG.md

@@ -98,6 +98,9 @@ FlatLaf Change Log
   color. (issue #409)
 - InternalFrame: Fill background to avoid that parent may shine through internal
   frame if it contains non-opaque components. (better fix for issue #274)
+- SwingX: Fixed `NullPointerException` in `FlatCaret` when using
+  `org.jdesktop.swingx.prompt.PromptSupport.setPrompt()` on a text field and
+  then switching theme.
 
 
 ## 1.6.5

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

@@ -101,6 +101,9 @@ public class FlatCaret
 			//     adds selection highlights to the text component highlighter
 			if( isSelectionVisible() ) {
 				EventQueue.invokeLater( () -> {
+					if( getComponent() == null )
+						return; // was deinstalled
+
 					if( isSelectionVisible() ) {
 						setSelectionVisible( false );
 						setSelectionVisible( true );
@@ -253,6 +256,9 @@ public class FlatCaret
 		// select all
 		if( c instanceof JFormattedTextField ) {
 			EventQueue.invokeLater( () -> {
+				if( getComponent() == null )
+					return; // was deinstalled
+
 				select( 0, doc.getLength() );
 			} );
 		} else {