diff --git a/NEG/UI/Area/IArea.cs b/NEG/UI/Area/IArea.cs
index 2c7df06..e9942f9 100644
--- a/NEG/UI/Area/IArea.cs
+++ b/NEG/UI/Area/IArea.cs
@@ -7,6 +7,11 @@ namespace NEG.UI.Area
 {
     public interface IArea : ISlotsHolder, IUiElement
     {
+        /// <summary>
+        /// Open window as child of 
+        /// </summary>
+        /// <param name="window"></param>
+        /// <param name="data"></param>
         void OpenChildWindow(IWindow window, object data = null);
     }
 }
\ No newline at end of file
diff --git a/NEG/UI/Popup/IPopup.cs b/NEG/UI/Popup/IPopup.cs
index 246272a..7d33066 100644
--- a/NEG/UI/Popup/IPopup.cs
+++ b/NEG/UI/Popup/IPopup.cs
@@ -7,16 +7,21 @@ namespace NEG.UI.Popup
     [PublicAPI]
     public interface IPopup
     {
+        /// <summary>
+        /// Event to fire when popup is closed
+        /// </summary>
+        event Action<PopupData> OnPopupClosed;
+
         /// <summary>
         /// Show popup
         /// </summary>
         /// <param name="data">data assigned to popup, used to give info that popup is closed</param>
-        void Show(PopupData data);
+        public void Show(PopupData data);
 
         /// <summary>
         /// Close popup or mark as closed if not visible
         /// </summary>
-        /// <param name="silence">if true hide visually, without firing callbacks</param>
+        /// <param name="silence">if true hide visually, without firing callbacks to properly close</param>
         void Close(bool silence = false);
     }
 }
\ No newline at end of file
diff --git a/NEG/UI/Popup/PopupData.cs b/NEG/UI/Popup/PopupData.cs
index cd8bd24..a936b2a 100644
--- a/NEG/UI/Popup/PopupData.cs
+++ b/NEG/UI/Popup/PopupData.cs
@@ -1,7 +1,15 @@
-namespace NEG.UI.Popup
+using System;
+
+namespace NEG.UI.Popup
 {
     public class PopupData
     {
+        public event Action<PopupData> PopupClosedEvent
+        {
+            add => popup.OnPopupClosed += value;
+            remove => popup.OnPopupClosed -= value;
+        }
+
         public bool IsValid { get; protected set; }
         
         private IPopup popup;
diff --git a/NEG/UI/UiManager.cs b/NEG/UI/UiManager.cs
index 1fdac69..028a212 100644
--- a/NEG/UI/UiManager.cs
+++ b/NEG/UI/UiManager.cs
@@ -1,19 +1,21 @@
+using JetBrains.Annotations;
 using NEG.UI.Area;
 using NEG.UI.Popup;
+using NEG.UI.Window;
 using System;
 using System.Collections.Generic;
 using UnityEngine;
 
 namespace NEG.UI
 {
+    [PublicAPI]
     public abstract class UiManager
     {
-        //TODO: use default unity selection
-        //TODO: window snaping to slots
-        //TODO: Default prefabs?
-
         public static UiManager Instance { get; private set; }
-
+        
+        /// <summary>
+        /// Current area shown on screen.
+        /// </summary>
         public IArea CurrentArea
         {
             get => currentArea;
@@ -26,10 +28,15 @@ namespace NEG.UI
                 currentArea?.SetEnabled(true);
             }
         }
+        
+        /// <summary>
+        /// Current window that is considered main (focused, lastly opened). Can be null.
+        /// </summary>
+        public IWindow CurrentMainWindow { get; protected set; }
 
         private IArea currentArea;
-        protected IDefaultPopup currentDefaultPopup;
         private (PopupData data, int priority) currentShownPopup;
+        protected IDefaultPopup currentDefaultPopup;
 
         private PriorityQueue<PopupData, int> popupsToShow = new();
 
@@ -114,8 +121,8 @@ namespace NEG.UI
             popupsToShow.Enqueue(data, priority);
             UpdatePopupsState(forceShow, priority, data);
         }
-
-        public void PopupClosed(PopupData data)
+        
+        protected void PopupClosed(PopupData data)
         {
             if (currentShownPopup.data != data)
             {
@@ -124,7 +131,7 @@ namespace NEG.UI
             }
             UpdatePopupsState(false);
         }
-
+        
         protected void SetDefaultPopup(IDefaultPopup popup) => currentDefaultPopup = popup;
 
         private void UpdatePopupsState(bool forceShow, int priority = 0, PopupData data = null)
@@ -147,8 +154,14 @@ namespace NEG.UI
 
         private void ShowPopup(PopupData data, int priority)
         {
+            if (currentShownPopup.data != null)
+            {
+                currentShownPopup.data.PopupClosedEvent -= PopupClosed;
+                currentShownPopup.data.Hide();
+            }
             currentShownPopup = (data, priority);
             data.Show();
+            data.PopupClosedEvent += PopupClosed;
         }
     }
 }
diff --git a/NEG/UI/UnityUi/Area/MonoArea.cs b/NEG/UI/UnityUi/Area/MonoArea.cs
index 1baa112..77b2166 100644
--- a/NEG/UI/UnityUi/Area/MonoArea.cs
+++ b/NEG/UI/UnityUi/Area/MonoArea.cs
@@ -13,12 +13,12 @@ namespace NEG.UI.Area
     {
         public IEnumerable<IWindowSlot> AvailableSlots => windowSlots;
         public IWindowSlot DefaultWindowSlot => windowSlots[0];
-
+        
         [SerializeField] private bool setAsDefaultArea;
 
         [SerializeField] private List<MonoWindowSlot> windowSlots;
 
-        [SerializeField] private Queue<IPopup> currentPopups = new();
+        private Queue<IPopup> currentPopups = new();
 
         public virtual void SetEnabled(bool setEnabled) => gameObject.SetActive(setEnabled);
 
diff --git a/NEG/UI/UnityUi/MonoUiManager.cs b/NEG/UI/UnityUi/MonoUiManager.cs
index e74d6e8..6c26ed0 100644
--- a/NEG/UI/UnityUi/MonoUiManager.cs
+++ b/NEG/UI/UnityUi/MonoUiManager.cs
@@ -17,6 +17,9 @@ namespace NEG.UI.UnityUi
     /// </summary>
     public class MonoUiManager : UiManager
     {
+        //TODO: use default unity selection
+        //TODO: window snaping to slots
+        
         private readonly MonoDefaultPopup defaultPopupPrefab;
         private readonly GameObject canvasPrefab;
 
diff --git a/NEG/UI/UnityUi/Popup/MonoPopup.cs b/NEG/UI/UnityUi/Popup/MonoPopup.cs
index 5d4f9eb..425edfb 100644
--- a/NEG/UI/UnityUi/Popup/MonoPopup.cs
+++ b/NEG/UI/UnityUi/Popup/MonoPopup.cs
@@ -6,6 +6,8 @@ namespace NEG.UI.UnityUi.Popup
 {
     public class MonoPopup : MonoBehaviour, IPopup
     {
+        public event Action<PopupData> OnPopupClosed;
+        
         protected PopupData data;
 
         public void Show(PopupData data)
@@ -21,7 +23,7 @@ namespace NEG.UI.UnityUi.Popup
             if(silence)
                 return;
             
-            UiManager.Instance.PopupClosed(data);
+            OnPopupClosed?.Invoke(data);
         }
         
     }
diff --git a/NEG/UI/UnityUi/Window/MonoWindow.cs b/NEG/UI/UnityUi/Window/MonoWindow.cs
index 95db2a4..d13a121 100644
--- a/NEG/UI/UnityUi/Window/MonoWindow.cs
+++ b/NEG/UI/UnityUi/Window/MonoWindow.cs
@@ -1,4 +1,5 @@
 using NEG.UI.Area;
+using NEG.UI.UnityUi.Buttons;
 using NEG.UI.UnityUi.WindowSlot;
 using NEG.UI.Window;
 using NEG.UI.WindowSlot;
@@ -10,13 +11,17 @@ namespace NEG.UI.UnityUi.Window
 {
     public class MonoWindow : MonoBehaviour, IWindow
     {
+        public IEnumerable<IWindowSlot> AvailableSlots => windowSlots;
         public IWindowSlot Parent { get; private set; }
-        public IWindowSlot ChildWindowSlot => childWindowArea;
 
-        [SerializeField] private MonoWindowSlot childWindowArea;
+        public bool IsMainWindow { get; private set; }
+        
+        private IWindowSlot DefaultWindowSlot => windowSlots[0];
+        
+        [SerializeField] private List<MonoWindowSlot> windowSlots;
         [SerializeField] private WindowController controller;
 
-        void IWindow.SetOpenedState(IWindowSlot parentSlot)
+        public void SetOpenedState(IWindowSlot parentSlot)
         {
             gameObject.SetActive(true);
             Parent = parentSlot;
@@ -30,12 +35,11 @@ namespace NEG.UI.UnityUi.Window
                 controller.SetData(data);
         }
 
-        void IWindow.SetClosedState()
+        public void SetClosedState()
         {
             gameObject.SetActive(false);
             Parent = null;
-            if(childWindowArea != null)
-                ChildWindowSlot.CloseAllWindows();
+            ((ISlotsHolder)this).CloseAllWindows();
         }
 
         private void Awake() => ((IWindow)this).SetClosedState();
@@ -46,7 +50,10 @@ namespace NEG.UI.UnityUi.Window
                 controller = GetComponent<WindowController>();
         }
 
-        public IEnumerable<IWindowSlot> AvailableSlots { get; }
-        public void OpenWindow(IWindow window, object data = null) => throw new NotImplementedException();
+        public void OpenWindow(IWindow window, object data = null)
+        {
+            DefaultWindowSlot.AttachWindow(window);
+            window.SetData(data);
+        }
     }
 }
\ No newline at end of file
diff --git a/NEG/UI/UnityUi/WindowSlot/MonoWindowSlot.cs b/NEG/UI/UnityUi/WindowSlot/MonoWindowSlot.cs
index 6525e6b..03e6b55 100644
--- a/NEG/UI/UnityUi/WindowSlot/MonoWindowSlot.cs
+++ b/NEG/UI/UnityUi/WindowSlot/MonoWindowSlot.cs
@@ -16,6 +16,5 @@ namespace NEG.UI.UnityUi.WindowSlot
         public abstract void CloseAllWindows();
         
         [SerializeField] private SerializableInterface<ISlotsHolder> slotsHolder;
-
     }
 }
\ No newline at end of file
diff --git a/NEG/UI/Window/IWindow.cs b/NEG/UI/Window/IWindow.cs
index f3e7262..ad866fb 100644
--- a/NEG/UI/Window/IWindow.cs
+++ b/NEG/UI/Window/IWindow.cs
@@ -7,6 +7,9 @@ namespace NEG.UI.Window
 {
     public interface IWindow : ISlotsHolder
     {
+        /// <summary>
+        /// Parent slot of this window.
+        /// </summary>
         IWindowSlot Parent { get; }
 
         /// <summary>
@@ -15,6 +18,10 @@ namespace NEG.UI.Window
         /// <param name="parentSlot">slot that opens window</param>
         void SetOpenedState(IWindowSlot parentSlot);
 
+        /// <summary>
+        /// Sets data for window, usually used for dynamic content set by external logic controller.
+        /// </summary>
+        /// <param name="data">can be any type, window should cast for expected type</param>
         void SetData(object data);
         
         /// <summary>
@@ -25,7 +32,12 @@ namespace NEG.UI.Window
 
     public static class WindowInterfaceExtensions
     {
-        //Open 
+        /// <summary>
+        /// Opens window as slot child. If slot is null or not provided, as child of current area.
+        /// </summary>
+        /// <param name="window">window to open</param>
+        /// <param name="slot">slot to attach window</param>
+        /// <param name="data">data to send to window</param>
         public static void Open(this IWindow window, IWindowSlot slot = null, object data = null)
         {
             if (slot != null)
@@ -37,8 +49,21 @@ namespace NEG.UI.Window
 
             UiManager.Instance.CurrentArea.OpenWindow(window, data);
         }
-
+        
+        /// <summary>
+        /// Opens window as child of selected area.
+        /// </summary>
+        /// <param name="window">window to open</param>
+        /// <param name="area">area to attach window</param>
+        /// <param name="data">data to send to window</param>
         public static void Open(this IWindow window, IArea area, object data = null) => area.OpenWindow(window, data);
+        
+        /// <summary>
+        /// Open passed window as child of this window.
+        /// </summary>
+        /// <param name="window">parent window</param>
+        /// <param name="windowToOpen">window to open</param>
+        /// <param name="data">data to send to window</param>
         public static void OpenChild(this IWindow window, IWindow windowToOpen, object data = null)
         {
             if (windowToOpen == null)
@@ -48,7 +73,13 @@ namespace NEG.UI.Window
             }
             window.OpenWindow(windowToOpen, data);
         }
-
+        
+        /// <summary>
+        /// Open window as child of provided window. If <typeparamref name="parentWindow"/> is null, as child of current main window in <see cref="UiManager"/>
+        /// </summary>
+        /// <param name="window">window to open</param>
+        /// <param name="parentWindow"></param>
+        /// <param name="data"></param>
         public static void OpenAsChild(this IWindow window, IWindow parentWindow = null, object data = null)
         {
             if (parentWindow != null)