Fixed incorrect window size/location when using setSize/setPreferredSize.

core/src/main/java/com/github/weisj/darklaf/ui/rootpane/DarkRootPaneUI.java

@@ -196,11 +196,25 @@ public class DarkRootPaneUI extends BasicRootPaneUI implements HierarchyListener
             updateClientDecoration();
         }
         if (e.getChangeFlags() == HierarchyEvent.SHOWING_CHANGED) {
+            if (!window.isShowing()) return;
             /*
              * Force the window peer to relayout and repaint.
              * e.g. on windows this is necessary to properly remove the title bar.
              */
-            window.pack();
+            Rectangle bounds = window.getBounds();
+            Dimension size = bounds.getSize();
+            Point p = bounds.getLocation();
+            if (window.isPreferredSizeSet()) {
+                size = window.getPreferredSize();
+            } else {
+                p.x += size.width / 2;
+                p.y += size.height / 2;
+            }
+            //Resizing triggers #reshapeNativePeer
+            window.setSize(size.width, size.height + 1);
+            window.setSize(size.width, size.height);
+            window.setLocation(p.x - size.width / 2,
+                               p.y - size.height / 2);
         }
     }
 

core/src/main/java/com/github/weisj/darklaf/ui/rootpane/DarkSubstanceRootLayout.java

@@ -144,8 +144,7 @@ class DarkSubstanceRootLayout implements LayoutManager2 {
     }
 
     protected CustomTitlePane getTitlePane(final JRootPane root) {
-        if ((root.getWindowDecorationStyle() != JRootPane.NONE)
+        if (root.getUI() instanceof DarkRootPaneUI) {
-            && (root.getUI() instanceof DarkRootPaneUI)) {
             return ((DarkRootPaneUI) root.getUI()).getTitlePane();
         }
         return null;

macos/src/main/java/com/github/weisj/darklaf/platform/macos/ui/MacOSTitlePane.java

@@ -200,8 +200,7 @@ public class MacOSTitlePane extends CustomTitlePane {
         boolean isFullscreen = JNIDecorationsMacOS.isFullscreen(decorationInformation.windowHandle);
         return (decorationInformation != null && decorationInformation.windowHandle == 0)
             || isFullscreen
-            || getWindowDecorationStyle() == JRootPane.NONE
+            || getWindowDecorationStyle() == JRootPane.NONE;
-            || getTitle().length() == 0;
     }
 
     private boolean useCustomTitle() {

windows/src/main/java/com/github/weisj/darklaf/platform/windows/JNIDecorationsWindows.java

@@ -64,6 +64,7 @@ public class JNIDecorationsWindows {
     }
 
     private static void loadLibrary() {
+        attemptedLoad = true;
         if (!SystemInfo.isWindows || loaded) {
             return;
         }