TextEditor: filter JTextField shows "filter..." in gray when empty and having lost focus.

Author: acardona

src/main/java/org/scijava/ui/swing/script/TextEditor.java

@@ -695,7 +695,12 @@ public TextEditor(final Context context) {
 		});
 		filter.addFocusListener(new FocusListener() {
 			@Override
-			public void focusLost(FocusEvent e) {}
+			public void focusLost(FocusEvent e) {
+				if (0 == filter.getText().length()) {
+					filter.setForeground(Color.gray);
+					filter.setText("filter...");
+				}
+			}
 
 			@Override
 			public void focusGained(FocusEvent e) {