Dialog: some client properties (e.g. JRootPane.titleBarShowTitle) did not work before the dialog was made visible (issue #1081)

Author: DevCharly

CHANGELOG.md

@@ -5,6 +5,8 @@ FlatLaf Change Log
 
 - ComboBox: Added UI property `ComboBox.buttonFocusedEditableBackground`. (issue
   #1068)
+- Dialog: Some client properties (e.g. `JRootPane.titleBarShowTitle`) did not
+  work before the dialog was made visible. (issue #1081)
 - Popup: Fixed scrolling popup painting issue on Windows 10 when a glass pane is
   visible and frame is maximized. (issue #1071)
 - Slider: Styling `thumbSize` or `focusWidth` did not update slider size/layout.

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

@@ -484,7 +484,7 @@ protected void activeChanged( boolean active ) {
 	}
 
 	protected void frameStateChanged() {
-		if( window == null || rootPane.getWindowDecorationStyle() != JRootPane.FRAME )
+		if( window == null || rootPane.getWindowDecorationStyle() == JRootPane.NONE )
 			return;
 
 		updateVisibility();