diff -r b9767cb5b06b -r d2bd73d28ff1 ui/cocoa/MainWindow.m
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ui/cocoa/MainWindow.m	Thu Dec 12 20:01:43 2024 +0100
@@ -0,0 +1,65 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2024 Olaf Wintermann. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   1. Redistributions of source code must retain the above copyright
+ *      notice, this list of conditions and the following disclaimer.
+ *
+ *   2. Redistributions in binary form must reproduce the above copyright
+ *      notice, this list of conditions and the following disclaimer in the
+ *      documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#import "MainWindow.h"
+#import "Container.h"
+#import "GridLayout.h"
+#import "../common/object.h"
+
+@implementation MainWindow
+
+- (MainWindow*)init:(UiObject*)obj {
+    self.uiobj = obj;
+    NSRect frame = NSMakeRect(300, 200, 600, 500);
+    
+    self = [self initWithContentRect:frame
+                           styleMask:NSWindowStyleMaskTitled |
+            NSWindowStyleMaskResizable |
+            NSWindowStyleMaskClosable |
+            NSWindowStyleMaskMiniaturizable
+                             backing:NSBackingStoreBuffered
+                               defer:false];
+    
+    // create a vertical stackview as default container
+    //BoxContainer *vbox = [[BoxContainer alloc] init:NSUserInterfaceLayoutOrientationVertical spacing:0];
+    GridLayout *vbox = [[GridLayout alloc] init];
+    vbox.translatesAutoresizingMaskIntoConstraints = false;
+    [self.contentView addSubview:vbox];
+    [NSLayoutConstraint activateConstraints:@[
+        [vbox.topAnchor constraintEqualToAnchor:self.contentView.topAnchor constant:4],
+        [vbox.leadingAnchor constraintEqualToAnchor:self.contentView.leadingAnchor],
+        [vbox.trailingAnchor constraintEqualToAnchor:self.contentView.trailingAnchor],
+        [vbox.bottomAnchor constraintEqualToAnchor:self.contentView.bottomAnchor]
+    ]];
+    
+    uic_object_push_container(obj, ui_create_container(obj, vbox));
+    
+    return self;
+}
+
+@end