From d3780244cd55379d7d670d4c3b9c717d3ccd92ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Burak=20Kaan=20K=C3=B6se?= <bkaankose@outlook.com>
Date: Sun, 29 Dec 2024 22:30:00 +0100
Subject: [PATCH] Improved calendar rendering, standartization of some
 templates and cleanup of old styles.

---
 .../CalendarPageViewModel.cs                  |  21 ++-
 Wino.Calendar/App.xaml                        |   7 +-
 .../Controls/AllDayItemsControl.xaml          |   6 +-
 .../Controls/AllDayItemsControl.xaml.cs       |  61 +++++---
 .../Controls/CalendarDayItemsControl.cs       | 132 ------------------
 Wino.Calendar/Controls/CalendarItemControl.cs |  42 ------
 Wino.Calendar/Controls/WinoCalendarPanel.cs   | 112 +++++++--------
 .../Styles/CalendarDayItemsControl.xaml       |  21 ---
 .../Styles/CalendarItemControlResources.xaml  |  30 ----
 .../CalendarItemControlResources.xaml.cs      |  12 --
 ...tyles.xaml => CalendarThemeResources.xaml} |   0
 .../Styles/DayColumnControlResources.xaml     | 102 --------------
 .../Styles/DayColumnControlResources.xaml.cs  |  12 --
 .../Styles/WinoCalendarResources.xaml         | 114 ++++++++++++++-
 Wino.Calendar/Styles/WinoCalendarView.xaml    |   2 +-
 Wino.Calendar/Wino.Calendar.csproj            |  22 +--
 .../Collections/CalendarEventCollection.cs    |  73 ++++++++--
 .../Models/Calendar/DayRangeRenderModel.cs    |  45 +++++-
 18 files changed, 333 insertions(+), 481 deletions(-)
 delete mode 100644 Wino.Calendar/Controls/CalendarDayItemsControl.cs
 delete mode 100644 Wino.Calendar/Controls/CalendarItemControl.cs
 delete mode 100644 Wino.Calendar/Styles/CalendarDayItemsControl.xaml
 delete mode 100644 Wino.Calendar/Styles/CalendarItemControlResources.xaml
 delete mode 100644 Wino.Calendar/Styles/CalendarItemControlResources.xaml.cs
 rename Wino.Calendar/Styles/{CalendarRenderStyles.xaml => CalendarThemeResources.xaml} (100%)
 delete mode 100644 Wino.Calendar/Styles/DayColumnControlResources.xaml
 delete mode 100644 Wino.Calendar/Styles/DayColumnControlResources.xaml.cs

diff --git a/Wino.Calendar.ViewModels/CalendarPageViewModel.cs b/Wino.Calendar.ViewModels/CalendarPageViewModel.cs
index 2c9a9605..ca306576 100644
--- a/Wino.Calendar.ViewModels/CalendarPageViewModel.cs
+++ b/Wino.Calendar.ViewModels/CalendarPageViewModel.cs
@@ -63,8 +63,10 @@ namespace Wino.Calendar.ViewModels
             _calendarService = calendarService;
             _accountCalendarStateService = accountCalendarStateService;
             _preferencesService = preferencesService;
+
         }
 
+
         // TODO: Replace when calendar settings are updated.
         // Should be a field ideally.
         private BaseCalendarTypeDrawingStrategy GetDrawingStrategy(CalendarDisplayType displayType)
@@ -225,7 +227,8 @@ namespace Wino.Calendar.ViewModels
                 var range = new DateRange(startDate, endDate);
                 var renderOptions = new CalendarRenderOptions(range, _currentSettings);
 
-                renderModels.Add(new DayRangeRenderModel(renderOptions));
+                var dayRangeHeaderModel = new DayRangeRenderModel(renderOptions);
+                renderModels.Add(dayRangeHeaderModel);
             }
 
             // Dates are loaded. Now load the events for them.
@@ -334,20 +337,24 @@ namespace Wino.Calendar.ViewModels
                     dayRangeRenderModel.Period.End)
                     .ConfigureAwait(false);
 
-                foreach (var calendarItem in events)
+                var groupedEvents = events.GroupBy(a => a.StartTime.Date);
+
+                foreach (var group in groupedEvents)
                 {
-                    var calendarDayModel = dayRangeRenderModel.CalendarDays.FirstOrDefault(a => a.RepresentingDate.Date == calendarItem.StartTime.Date);
+                    var startDate = group.Key;
+
+                    var calendarDayModel = dayRangeRenderModel.CalendarDays.FirstOrDefault(a => a.RepresentingDate.Date == startDate);
 
                     if (calendarDayModel == null) continue;
 
-                    var calendarItemViewModel = new CalendarItemViewModel(calendarItem);
+                    var calendarItemViewModels = group.Select(a => new CalendarItemViewModel(a));
 
                     await ExecuteUIThread(() =>
                     {
-                        // TODO: EventsCollection should not take CalendarItem, but CalendarItemViewModel.
-                        // Enforce it later on.
+                        // Use range-based add for performance.
+                        // No need to report changes since at this point nothing is rendered on the UI.
 
-                        calendarDayModel.EventsCollection.Add(calendarItemViewModel);
+                        calendarDayModel.EventsCollection.AddCalendarItemRange(calendarItemViewModels, reportChange: false);
                     });
                 }
             }
diff --git a/Wino.Calendar/App.xaml b/Wino.Calendar/App.xaml
index a66721ce..1b0db3ef 100644
--- a/Wino.Calendar/App.xaml
+++ b/Wino.Calendar/App.xaml
@@ -14,19 +14,14 @@
 
                 <core:CoreGeneric />
 
-                <!--  Calendar Specific  -->
                 <styles:WinoCalendarResources />
 
-                <ResourceDictionary Source="Styles/CalendarRenderStyles.xaml" />
+                <ResourceDictionary Source="Styles/CalendarThemeResources.xaml" />
 
-                <ResourceDictionary Source="Styles/CalendarDayItemsControl.xaml" />
-                <styles:DayColumnControlResources />
                 <ResourceDictionary Source="Styles/WinoDayTimelineCanvas.xaml" />
                 <ResourceDictionary Source="Styles/WinoCalendarView.xaml" />
                 <ResourceDictionary Source="Styles/WinoCalendarTypeSelectorControl.xaml" />
 
-                <styles:CalendarItemControlResources />
-
                 <!--  Last item must always be the default theme.  -->
                 <ResourceDictionary Source="ms-appx:///Wino.Core.UWP/AppThemes/Mica.xaml" />
             </ResourceDictionary.MergedDictionaries>
diff --git a/Wino.Calendar/Controls/AllDayItemsControl.xaml b/Wino.Calendar/Controls/AllDayItemsControl.xaml
index b25d73b0..820bd279 100644
--- a/Wino.Calendar/Controls/AllDayItemsControl.xaml
+++ b/Wino.Calendar/Controls/AllDayItemsControl.xaml
@@ -15,7 +15,7 @@
             <ItemsControl
                 x:Name="PART_AllDayItemsList"
                 ItemTemplate="{x:Bind AllDayEventTemplate}"
-                ItemsSource="{x:Bind AllDayEvents, Mode=OneWay}" />
+                ItemsSource="{x:Bind EventCollection.AllDayEvents}" />
         </ScrollViewer>
         <Button
             x:Name="AllDayItemsSummaryButton"
@@ -25,7 +25,7 @@
             <Button.Flyout>
                 <Flyout Placement="Bottom">
                     <ScrollViewer>
-                        <ItemsControl ItemTemplate="{x:Bind AllDayEventTemplate}" ItemsSource="{x:Bind AllDayEvents, Mode=OneWay}" />
+                        <ItemsControl ItemTemplate="{x:Bind RegularEventItemTemplate}" ItemsSource="{x:Bind EventCollection.AllDayEvents}" />
                     </ScrollViewer>
                 </Flyout>
             </Button.Flyout>
@@ -42,7 +42,7 @@
                         <Setter Target="AllDayItemsSummaryButton.Content">
                             <Setter.Value>
                                 <TextBlock>
-                                    <Run Text="{x:Bind AllDayEvents.Count, Mode=OneWay, TargetNullValue='0'}" /> <Run Text="{x:Bind domain:Translator.CalendarAllDayEventSummary}" />
+                                    <Run Text="{x:Bind EventCollection.AllDayEvents.Count, Mode=OneWay, TargetNullValue='0'}" /> <Run Text="{x:Bind domain:Translator.CalendarAllDayEventSummary}" />
                                 </TextBlock>
                             </Setter.Value>
                         </Setter>
diff --git a/Wino.Calendar/Controls/AllDayItemsControl.xaml.cs b/Wino.Calendar/Controls/AllDayItemsControl.xaml.cs
index ad33187f..3f44ba77 100644
--- a/Wino.Calendar/Controls/AllDayItemsControl.xaml.cs
+++ b/Wino.Calendar/Controls/AllDayItemsControl.xaml.cs
@@ -1,6 +1,7 @@
-using System.Collections.ObjectModel;
+using System.Collections.Generic;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
+using Wino.Core.Domain.Collections;
 using Wino.Core.Domain.Interfaces;
 
 
@@ -13,19 +14,36 @@ namespace Wino.Calendar.Controls
 
         #region Dependency Properties
 
-        public static readonly DependencyProperty AllDayEventsProperty = DependencyProperty.Register(nameof(AllDayEvents), typeof(ObservableCollection<ICalendarItem>), typeof(AllDayItemsControl), new PropertyMetadata(null, new PropertyChangedCallback(OnAllDayEventsChanged)));
+        public static readonly DependencyProperty EventCollectionProperty = DependencyProperty.Register(nameof(EventCollection), typeof(CalendarEventCollection), typeof(AllDayItemsControl), new PropertyMetadata(null, new PropertyChangedCallback(OnAllDayEventsChanged)));
         public static readonly DependencyProperty AllDayEventTemplateProperty = DependencyProperty.Register(nameof(AllDayEventTemplate), typeof(DataTemplate), typeof(AllDayItemsControl), new PropertyMetadata(null));
+        public static readonly DependencyProperty RegularEventItemTemplateProperty = DependencyProperty.Register(nameof(RegularEventItemTemplate), typeof(DataTemplate), typeof(AllDayItemsControl), new PropertyMetadata(null));
 
+        /// <summary>
+        /// Item template for all-day events to display in summary view area.
+        /// More than 2 events will be shown in Flyout.
+        /// </summary>
         public DataTemplate AllDayEventTemplate
         {
             get { return (DataTemplate)GetValue(AllDayEventTemplateProperty); }
             set { SetValue(AllDayEventTemplateProperty, value); }
         }
 
-        public ObservableCollection<ICalendarItem> AllDayEvents
+        /// <summary>
+        /// Item template for all-day events to display in summary view's Flyout.
+        /// </summary>
+        public DataTemplate RegularEventItemTemplate
         {
-            get { return (ObservableCollection<ICalendarItem>)GetValue(AllDayEventsProperty); }
-            set { SetValue(AllDayEventsProperty, value); }
+            get { return (DataTemplate)GetValue(RegularEventItemTemplateProperty); }
+            set { SetValue(RegularEventItemTemplateProperty, value); }
+        }
+
+        /// <summary>
+        /// Whole collection of events to display.
+        /// </summary>
+        public CalendarEventCollection EventCollection
+        {
+            get { return (CalendarEventCollection)GetValue(EventCollectionProperty); }
+            set { SetValue(EventCollectionProperty, value); }
         }
 
         #endregion
@@ -39,12 +57,12 @@ namespace Wino.Calendar.Controls
         {
             if (d is AllDayItemsControl control)
             {
-                if (e.OldValue != null && e.OldValue is ObservableCollection<ICalendarItem> oldCollection)
+                if (e.OldValue != null && e.OldValue is CalendarEventCollection oldCollection)
                 {
                     control.UnregisterEventCollectionChanged(oldCollection);
                 }
 
-                if (e.NewValue != null && e.NewValue is ObservableCollection<ICalendarItem> newCollection)
+                if (e.NewValue != null && e.NewValue is CalendarEventCollection newCollection)
                 {
                     control.RegisterEventCollectionChanged(newCollection);
                 }
@@ -53,32 +71,35 @@ namespace Wino.Calendar.Controls
             }
         }
 
-        private void RegisterEventCollectionChanged(ObservableCollection<ICalendarItem> collection)
+        private void RegisterEventCollectionChanged(CalendarEventCollection collection)
         {
-            collection.CollectionChanged += EventsCollectionUpdated;
+            collection.CalendarItemAdded += SingleEventUpdated;
+            collection.CalendarItemRemoved += SingleEventUpdated;
+
+            collection.CalendarItemRangeAdded += CollectionOfEventsUpdated;
+            collection.CalendarItemRangeRemoved += CollectionOfEventsUpdated;
         }
 
-        private void UnregisterEventCollectionChanged(ObservableCollection<ICalendarItem> collection)
+        private void UnregisterEventCollectionChanged(CalendarEventCollection collection)
         {
-            collection.CollectionChanged -= EventsCollectionUpdated;
+            collection.CalendarItemAdded -= SingleEventUpdated;
+            collection.CalendarItemRemoved -= SingleEventUpdated;
+
+            collection.CalendarItemRangeAdded -= CollectionOfEventsUpdated;
+            collection.CalendarItemRangeRemoved -= CollectionOfEventsUpdated;
         }
 
-        private void EventsCollectionUpdated(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
-        {
-            UpdateCollectionVisuals();
-        }
+        private void SingleEventUpdated(object sender, ICalendarItem calendarItem) => UpdateCollectionVisuals();
+        private void CollectionOfEventsUpdated(object sender, List<ICalendarItem> calendarItems) => UpdateCollectionVisuals();
 
         private void UpdateCollectionVisuals()
         {
-            if (AllDayEvents == null) return;
+            if (EventCollection == null) return;
 
-            if (AllDayEvents.Count > 1)
+            if (EventCollection.AllDayEvents.Count > 1)
             {
                 // Summarize
-
                 VisualStateManager.GoToState(this, STATE_SummaryView, false);
-
-                // AllDayItemsSummaryButton.Content = $"{AllDayEvents.Count} {Translator.CalendarAllDayEventSummary}";
             }
             else
             {
diff --git a/Wino.Calendar/Controls/CalendarDayItemsControl.cs b/Wino.Calendar/Controls/CalendarDayItemsControl.cs
deleted file mode 100644
index 9e84a122..00000000
--- a/Wino.Calendar/Controls/CalendarDayItemsControl.cs
+++ /dev/null
@@ -1,132 +0,0 @@
-using System.Collections.ObjectModel;
-using System.Collections.Specialized;
-using System.Linq;
-using Windows.UI.Xaml;
-using Windows.UI.Xaml.Controls;
-using Wino.Core.Domain.Interfaces;
-using Wino.Core.Domain.Models.Calendar;
-
-namespace Wino.Calendar.Controls
-{
-    public class CalendarDayItemsControl : Control
-    {
-        private const string PART_CalendarPanel = nameof(PART_CalendarPanel);
-
-        private WinoCalendarPanel CalendarPanel;
-
-        public CalendarDayModel DayModel
-        {
-            get { return (CalendarDayModel)GetValue(DayModelProperty); }
-            set { SetValue(DayModelProperty, value); }
-        }
-
-
-        public static readonly DependencyProperty DayModelProperty = DependencyProperty.Register(nameof(DayModel), typeof(CalendarDayModel), typeof(CalendarDayItemsControl), new PropertyMetadata(null, new PropertyChangedCallback(OnRepresentingDateChanged)));
-
-        private static void OnRepresentingDateChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-        {
-            if (d is CalendarDayItemsControl control)
-            {
-                if (e.OldValue != null && e.OldValue is CalendarDayModel oldCalendarDayModel)
-                {
-                    control.DetachCollection(oldCalendarDayModel.EventsCollection);
-                }
-
-                if (e.NewValue != null && e.NewValue is CalendarDayModel newCalendarDayModel)
-                {
-                    control.AttachCollection(newCalendarDayModel.EventsCollection);
-                }
-
-                control.ResetItems();
-                control.RenderEvents();
-            }
-        }
-
-        public CalendarDayItemsControl()
-        {
-            DefaultStyleKey = typeof(CalendarDayItemsControl);
-        }
-
-        protected override void OnApplyTemplate()
-        {
-            base.OnApplyTemplate();
-
-            CalendarPanel = GetTemplateChild(PART_CalendarPanel) as WinoCalendarPanel;
-
-            RenderEvents();
-        }
-
-        private void ResetItems()
-        {
-            if (CalendarPanel == null) return;
-
-            CalendarPanel.Children.Clear();
-        }
-
-        private void RenderEvents()
-        {
-            if (CalendarPanel == null || CalendarPanel.DayModel == null) return;
-
-            RenderCalendarItems();
-        }
-
-        private void AttachCollection(ObservableCollection<ICalendarItem> newCollection)
-            => newCollection.CollectionChanged += CalendarItemsChanged;
-
-        private void DetachCollection(ObservableCollection<ICalendarItem> oldCollection)
-            => oldCollection.CollectionChanged -= CalendarItemsChanged;
-
-        private void CalendarItemsChanged(object sender, NotifyCollectionChangedEventArgs e)
-        {
-            switch (e.Action)
-            {
-                case NotifyCollectionChangedAction.Add:
-                    foreach (ICalendarItem item in e.NewItems)
-                    {
-                        AddItem(item);
-                    }
-                    break;
-                case NotifyCollectionChangedAction.Remove:
-                    foreach (ICalendarItem item in e.OldItems)
-                    {
-                        var control = GetCalendarItemControl(item);
-                        if (control != null)
-                        {
-                            CalendarPanel.Children.Remove(control);
-                        }
-                    }
-                    break;
-                case NotifyCollectionChangedAction.Reset:
-                    ResetItems();
-                    break;
-                default:
-                    break;
-            }
-        }
-
-        private CalendarItemControl GetCalendarItemControl(ICalendarItem item)
-            => CalendarPanel.Children.Where(c => c is CalendarItemControl calendarItemControl && calendarItemControl.Item == item).FirstOrDefault() as CalendarItemControl;
-
-        private void RenderCalendarItems()
-        {
-            if (DayModel == null || DayModel.EventsCollection == null || DayModel.EventsCollection.Count == 0)
-            {
-                ResetItems();
-                return;
-            }
-
-            foreach (var item in DayModel.EventsCollection)
-            {
-                AddItem(item);
-            }
-        }
-
-        private void AddItem(ICalendarItem item)
-        {
-            CalendarPanel.Children.Add(new CalendarItemControl()
-            {
-                Item = item
-            });
-        }
-    }
-}
diff --git a/Wino.Calendar/Controls/CalendarItemControl.cs b/Wino.Calendar/Controls/CalendarItemControl.cs
deleted file mode 100644
index e244da1e..00000000
--- a/Wino.Calendar/Controls/CalendarItemControl.cs
+++ /dev/null
@@ -1,42 +0,0 @@
-using Windows.UI.Xaml;
-using Windows.UI.Xaml.Controls;
-using Wino.Core.Domain.Interfaces;
-
-namespace Wino.Calendar.Controls
-{
-    public class CalendarItemControl : Control
-    {
-        public ICalendarItem Item
-        {
-            get { return (ICalendarItem)GetValue(ItemProperty); }
-            set { SetValue(ItemProperty, value); }
-        }
-
-        public static readonly DependencyProperty ItemProperty = DependencyProperty.Register(nameof(Item), typeof(ICalendarItem), typeof(CalendarItemControl), new PropertyMetadata(null, new PropertyChangedCallback(OnItemChanged)));
-
-        public CalendarItemControl()
-        {
-            DefaultStyleKey = typeof(CalendarItemControl);
-        }
-
-        private static void OnItemChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-        {
-            if (d is CalendarItemControl control)
-            {
-                control.UpdateDateRendering();
-            }
-        }
-
-        private void UpdateDateRendering()
-        {
-            if (Item == null) return;
-
-            UpdateLayout();
-        }
-
-        public override string ToString()
-        {
-            return Item?.Title ?? "NA";
-        }
-    }
-}
diff --git a/Wino.Calendar/Controls/WinoCalendarPanel.cs b/Wino.Calendar/Controls/WinoCalendarPanel.cs
index a754e7cd..1b646d6e 100644
--- a/Wino.Calendar/Controls/WinoCalendarPanel.cs
+++ b/Wino.Calendar/Controls/WinoCalendarPanel.cs
@@ -7,8 +7,8 @@ using Windows.Foundation;
 using Windows.UI.Xaml;
 using Windows.UI.Xaml.Controls;
 using Wino.Calendar.Models;
+using Wino.Calendar.ViewModels.Data;
 using Wino.Core.Domain.Interfaces;
-using Wino.Core.Domain.Models.Calendar;
 
 namespace Wino.Calendar.Controls
 {
@@ -20,12 +20,13 @@ namespace Wino.Calendar.Controls
         private readonly Dictionary<Guid, CalendarItemMeasurement> _measurements = new Dictionary<Guid, CalendarItemMeasurement>();
 
         public static readonly DependencyProperty EventItemMarginProperty = DependencyProperty.Register(nameof(EventItemMargin), typeof(Thickness), typeof(WinoCalendarPanel), new PropertyMetadata(new Thickness(0, 0, 0, 0)));
-        public static readonly DependencyProperty DayModelProperty = DependencyProperty.Register(nameof(DayModel), typeof(CalendarDayModel), typeof(WinoCalendarPanel), new PropertyMetadata(null, new PropertyChangedCallback(OnDayChanged)));
+        // public static readonly DependencyProperty RepresentingDateProperty = DependencyProperty.Register(nameof(RepresentingDate), typeof(DateTime), typeof(WinoCalendarControl), new PropertyMetadata(DateTime.MinValue));
+        public static readonly DependencyProperty HourHeightProperty = DependencyProperty.Register(nameof(HourHeight), typeof(double), typeof(WinoCalendarPanel), new PropertyMetadata(0d));
 
-        public CalendarDayModel DayModel
+        public double HourHeight
         {
-            get { return (CalendarDayModel)GetValue(DayModelProperty); }
-            set { SetValue(DayModelProperty, value); }
+            get { return (double)GetValue(HourHeightProperty); }
+            set { SetValue(HourHeightProperty, value); }
         }
 
         public Thickness EventItemMargin
@@ -34,51 +35,55 @@ namespace Wino.Calendar.Controls
             set { SetValue(EventItemMarginProperty, value); }
         }
 
-        private static void OnDayChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
-        {
-            if (d is WinoCalendarPanel control)
-            {
-                // We need to listen for new events being added or removed from the collection to reset measurements.
-                if (e.OldValue is CalendarDayModel oldDayModel)
-                {
-                    control.DetachCollection(oldDayModel.EventsCollection);
-                }
+        //private static void OnDayChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        //{
+        //    if (d is WinoCalendarPanel control)
+        //    {
+        //        // We need to listen for new events being added or removed from the collection to reset measurements.
+        //        if (e.OldValue is CalendarDayModel oldDayModel)
+        //        {
+        //            control.DetachCollection(oldDayModel.EventsCollection.RegularEvents);
+        //        }
 
-                if (e.NewValue is CalendarDayModel newDayModel)
-                {
-                    control.AttachCollection(newDayModel.EventsCollection);
-                }
+        //        if (e.NewValue is CalendarDayModel newDayModel)
+        //        {
+        //            control.AttachCollection(newDayModel.EventsCollection.RegularEvents);
+        //        }
 
-                control.ResetMeasurements();
-                control.UpdateLayout();
-            }
-        }
+        //        control.ResetMeasurements();
+        //        control.UpdateLayout();
+        //    }
+        //}
 
-        private void AttachCollection(IEnumerable<ICalendarItem> events)
-        {
-            if (events is INotifyCollectionChanged collection)
-            {
-                collection.CollectionChanged += EventCollectionChanged;
-            }
-        }
+        //private void AttachCollection(IEnumerable<ICalendarItem> events)
+        //{
+        //    if (events is INotifyCollectionChanged collection)
+        //    {
+        //        // var t = new Grid();
 
-        private void DetachCollection(IEnumerable<ICalendarItem> events)
-        {
-            if (events is INotifyCollectionChanged collection)
-            {
-                collection.CollectionChanged -= EventCollectionChanged;
-            }
-        }
+        //        collection.CollectionChanged += EventCollectionChanged;
+        //    }
+        //}
+
+        //private void DetachCollection(IEnumerable<ICalendarItem> events)
+        //{
+        //    if (events is INotifyCollectionChanged collection)
+        //    {
+        //        collection.CollectionChanged -= EventCollectionChanged;
+        //    }
+        //}
 
         private void ResetMeasurements() => _measurements.Clear();
 
         // No need to handle actions. Each action requires a full measurement update.
         private void EventCollectionChanged(object sender, NotifyCollectionChangedEventArgs e) => ResetMeasurements();
 
-        private double GetChildTopMargin(DateTimeOffset childStart, double availableHeight)
+        private double GetChildTopMargin(ICalendarItem calendarItemViewModel, double availableHeight)
         {
+            var childStart = calendarItemViewModel.StartTime;
+
             double totalMinutes = 1440;
-            double minutesFromStart = (childStart - DayModel.RepresentingDate).TotalMinutes;
+            double minutesFromStart = (childStart - childStart.DateTime.Date).TotalMinutes;
             return (minutesFromStart / totalMinutes) * availableHeight;
         }
 
@@ -93,7 +98,7 @@ namespace Wino.Calendar.Controls
         private double GetChildHeight(DateTimeOffset childStart, DateTimeOffset childEnd)
         {
             double totalMinutes = 1440;
-            double availableHeight = DayModel.CalendarRenderOptions.CalendarSettings.HourHeight * 24;
+            double availableHeight = HourHeight * 24;
             double childDuration = (childEnd - childStart).TotalMinutes;
             return (childDuration / totalMinutes) * availableHeight;
         }
@@ -112,31 +117,30 @@ namespace Wino.Calendar.Controls
             double availableHeight = finalSize.Height;
             double availableWidth = finalSize.Width;
 
-            var calendarControls = Children.Cast<CalendarItemControl>();
+            var calendarControls = Children.Cast<ContentPresenter>();
 
-            // We need to exclude all-day events from the layout algorithm.
-            // All-day events are displayed in a separate panel.
+            if (!calendarControls.Any()) return base.ArrangeOverride(finalSize);
 
-            calendarControls = calendarControls.Where(x => x.Item.DurationInMinutes != 1440);
-
-            if (_measurements.Count == 0 && DayModel.EventsCollection.Count > 0)
+            if (_measurements.Count == 0 && calendarControls.Any())
             {
                 // We keep track of this collection when event is added/removed/reset etc.
                 // So if the collection is empty, we must fill it up again for proper calculations.
 
-                LayoutEvents(DayModel.EventsCollection);
+                var events = calendarControls.Select(a => a.Content as CalendarItemViewModel);
+
+                LayoutEvents(events);
             }
 
-            foreach (var child in calendarControls)
+            foreach (var control in calendarControls)
             {
                 // We can't arrange this child. It doesn't have a valid ICalendarItem or measurement.
-                if (child.Item == null || !_measurements.ContainsKey(child.Item.Id)) continue;
+                if (!(control.Content is ICalendarItem child) || !_measurements.ContainsKey(child.Id)) continue;
 
-                var childMeasurement = _measurements[child.Item.Id];
+                var childMeasurement = _measurements[child.Id];
 
-                double childHeight = Math.Max(0, GetChildHeight(child.Item.StartTime, child.Item.StartTime.AddMinutes(child.Item.DurationInMinutes)));
+                double childHeight = Math.Max(0, GetChildHeight(child.StartTime, child.StartTime.AddMinutes(child.DurationInMinutes)));
                 double childWidth = Math.Max(0, GetChildWidth(childMeasurement, finalSize.Width));
-                double childTop = Math.Max(0, GetChildTopMargin(child.Item.StartTime, availableHeight));
+                double childTop = Math.Max(0, GetChildTopMargin(child, availableHeight));
                 double childLeft = Math.Max(0, GetChildLeftMargin(childMeasurement, availableWidth));
 
                 bool isHorizontallyLastItem = childMeasurement.Right == 1;
@@ -147,11 +151,11 @@ namespace Wino.Calendar.Controls
 
                 if (childWidth < 0) childWidth = 1;
 
-                child.Measure(new Size(childWidth, childHeight));
+                control.Measure(new Size(childWidth, childHeight));
 
                 var arrangementRect = new Rect(childLeft + EventItemMargin.Left, childTop + EventItemMargin.Top, Math.Max(childWidth - extraRightMargin, 1), childHeight);
 
-                child.Arrange(arrangementRect);
+                control.Arrange(arrangementRect);
             }
 
             return finalSize;
@@ -179,8 +183,6 @@ namespace Wino.Calendar.Controls
 
             foreach (var ev in events.OrderBy(ev => ev.Period.Start).ThenBy(ev => ev.Period.End))
             {
-                if (ev.Period.Duration.TotalMinutes == 1440) continue;
-
                 if (ev.Period.Start >= lastEventEnding)
                 {
                     PackEvents(columns);
diff --git a/Wino.Calendar/Styles/CalendarDayItemsControl.xaml b/Wino.Calendar/Styles/CalendarDayItemsControl.xaml
deleted file mode 100644
index 4385be31..00000000
--- a/Wino.Calendar/Styles/CalendarDayItemsControl.xaml
+++ /dev/null
@@ -1,21 +0,0 @@
-<ResourceDictionary
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:controls="using:Wino.Calendar.Controls">
-
-    <!--  Calendar day items.  -->
-    <Style TargetType="controls:CalendarDayItemsControl">
-        <Style.Setters>
-            <Setter Property="Template">
-                <Setter.Value>
-                    <ControlTemplate TargetType="controls:CalendarDayItemsControl">
-                        <controls:WinoCalendarPanel
-                            x:Name="PART_CalendarPanel"
-                            DayModel="{TemplateBinding DayModel}"
-                            EventItemMargin="0" />
-                    </ControlTemplate>
-                </Setter.Value>
-            </Setter>
-        </Style.Setters>
-    </Style>
-</ResourceDictionary>
diff --git a/Wino.Calendar/Styles/CalendarItemControlResources.xaml b/Wino.Calendar/Styles/CalendarItemControlResources.xaml
deleted file mode 100644
index f0ae5bfe..00000000
--- a/Wino.Calendar/Styles/CalendarItemControlResources.xaml
+++ /dev/null
@@ -1,30 +0,0 @@
-<ResourceDictionary
-    x:Class="Wino.Calendar.Styles.CalendarItemControlResources"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:controls="using:Wino.Calendar.Controls">
-
-    <!--  CalendarItemControl  -->
-    <Style TargetType="controls:CalendarItemControl">
-        <Style.Setters>
-            <Setter Property="Template">
-                <Setter.Value>
-                    <ControlTemplate TargetType="controls:CalendarItemControl">
-                        <Grid
-                            Margin="1,1,1,1"
-                            Background="#cf2b36"
-                            BorderBrush="Gray"
-                            CornerRadius="3">
-                            <TextBlock
-                                HorizontalAlignment="Center"
-                                VerticalAlignment="Center"
-                                Text="{x:Bind Item.Title, Mode=OneWay}"
-                                TextWrapping="WrapWholeWords" />
-                        </Grid>
-                    </ControlTemplate>
-                </Setter.Value>
-            </Setter>
-        </Style.Setters>
-    </Style>
-
-</ResourceDictionary>
diff --git a/Wino.Calendar/Styles/CalendarItemControlResources.xaml.cs b/Wino.Calendar/Styles/CalendarItemControlResources.xaml.cs
deleted file mode 100644
index 9d0cb0d1..00000000
--- a/Wino.Calendar/Styles/CalendarItemControlResources.xaml.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-using Windows.UI.Xaml;
-
-namespace Wino.Calendar.Styles
-{
-    public sealed partial class CalendarItemControlResources : ResourceDictionary
-    {
-        public CalendarItemControlResources()
-        {
-            InitializeComponent();
-        }
-    }
-}
diff --git a/Wino.Calendar/Styles/CalendarRenderStyles.xaml b/Wino.Calendar/Styles/CalendarThemeResources.xaml
similarity index 100%
rename from Wino.Calendar/Styles/CalendarRenderStyles.xaml
rename to Wino.Calendar/Styles/CalendarThemeResources.xaml
diff --git a/Wino.Calendar/Styles/DayColumnControlResources.xaml b/Wino.Calendar/Styles/DayColumnControlResources.xaml
deleted file mode 100644
index 0ca0dba6..00000000
--- a/Wino.Calendar/Styles/DayColumnControlResources.xaml
+++ /dev/null
@@ -1,102 +0,0 @@
-<ResourceDictionary
-    x:Class="Wino.Calendar.Styles.DayColumnControlResources"
-    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
-    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
-    xmlns:controls="using:Wino.Calendar.Controls"
-    xmlns:data="using:Wino.Calendar.ViewModels.Data"
-    xmlns:interfaces="using:Wino.Core.Domain.Interfaces"
-    xmlns:local="using:Wino.Calendar.Styles">
-    <!--  Top column header DayColumnControl  -->
-    <Style TargetType="controls:DayColumnControl">
-        <Setter Property="Template">
-            <Setter.Value>
-                <ControlTemplate TargetType="controls:DayColumnControl">
-                    <Grid>
-                        <Grid.RowDefinitions>
-                            <RowDefinition Height="25" />
-                            <RowDefinition Height="7" />
-                            <RowDefinition Height="*" />
-                        </Grid.RowDefinitions>
-
-                        <!--  Name of the day. Monday, Tuesday etc. at the top.  -->
-                        <TextBlock
-                            x:Name="PART_ColumnHeaderText"
-                            Margin="8,0,0,0"
-                            FontSize="16"
-                            TextTrimming="CharacterEllipsis" />
-
-                        <Grid
-                            Grid.Row="2"
-                            Grid.RowSpan="2"
-                            BorderBrush="{ThemeResource CalendarSeperatorBrush}"
-                            BorderThickness="1,1,0,1" />
-
-                        <!--  Border for today indication.  -->
-                        <Border
-                            x:Name="PART_IsTodayBorder"
-                            Grid.Row="1"
-                            Height="5"
-                            Margin="2,0,2,0"
-                            HorizontalAlignment="Stretch"
-                            VerticalAlignment="Center"
-                            Background="{ThemeResource SystemAccentColor}"
-                            CornerRadius="2"
-                            Visibility="Collapsed" />
-
-                        <!--  Place where full day events go.  -->
-                        <Grid
-                            x:Name="PART_DayDataAreaGrid"
-                            Grid.Row="2"
-                            Padding="6"
-                            BorderBrush="{ThemeResource CalendarSeperatorBrush}">
-                            <Grid.ColumnDefinitions>
-                                <ColumnDefinition Width="Auto" />
-                                <ColumnDefinition Width="*" />
-                            </Grid.ColumnDefinitions>
-
-                            <Grid.RowDefinitions>
-                                <RowDefinition Height="Auto" />
-                                <RowDefinition Height="*" />
-                            </Grid.RowDefinitions>
-
-                            <!--  Day number  -->
-                            <TextBlock x:Name="PART_HeaderDateDayText" FontSize="17" />
-
-                            <!--  Extras  -->
-                            <StackPanel Grid.Column="1" HorizontalAlignment="Right" />
-
-                            <!--  All-Day Events  -->
-                            <controls:AllDayItemsControl
-                                Grid.Row="1"
-                                Grid.ColumnSpan="2"
-                                AllDayEvents="{Binding EventsCollection.AllDayEvents}">
-                                <controls:AllDayItemsControl.AllDayEventTemplate>
-                                    <!--  All-Day Event template  -->
-                                    <DataTemplate x:DataType="interfaces:ICalendarItem">
-                                        <TextBlock Text="{x:Bind Title}" />
-                                    </DataTemplate>
-                                </controls:AllDayItemsControl.AllDayEventTemplate>
-                            </controls:AllDayItemsControl>
-                        </Grid>
-
-                        <VisualStateManager.VisualStateGroups>
-                            <VisualStateGroup x:Name="TodayOrNotStates">
-                                <VisualState x:Name="NotTodayState" />
-                                <VisualState x:Name="TodayState">
-                                    <VisualState.Setters>
-                                        <Setter Target="PART_IsTodayBorder.Visibility" Value="Visible" />
-                                        <Setter Target="PART_HeaderDateDayText.Foreground" Value="{ThemeResource SystemAccentColor}" />
-                                        <Setter Target="PART_HeaderDateDayText.FontWeight" Value="Semibold" />
-                                        <Setter Target="PART_ColumnHeaderText.FontWeight" Value="Semibold" />
-                                    </VisualState.Setters>
-                                </VisualState>
-                            </VisualStateGroup>
-                        </VisualStateManager.VisualStateGroups>
-                    </Grid>
-                </ControlTemplate>
-            </Setter.Value>
-        </Setter>
-    </Style>
-
-
-</ResourceDictionary>
diff --git a/Wino.Calendar/Styles/DayColumnControlResources.xaml.cs b/Wino.Calendar/Styles/DayColumnControlResources.xaml.cs
deleted file mode 100644
index c62927c9..00000000
--- a/Wino.Calendar/Styles/DayColumnControlResources.xaml.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-using Windows.UI.Xaml;
-
-namespace Wino.Calendar.Styles
-{
-    partial class DayColumnControlResources : ResourceDictionary
-    {
-        public DayColumnControlResources()
-        {
-            InitializeComponent();
-        }
-    }
-}
diff --git a/Wino.Calendar/Styles/WinoCalendarResources.xaml b/Wino.Calendar/Styles/WinoCalendarResources.xaml
index 363d3e05..4472f61c 100644
--- a/Wino.Calendar/Styles/WinoCalendarResources.xaml
+++ b/Wino.Calendar/Styles/WinoCalendarResources.xaml
@@ -4,11 +4,27 @@
     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
     xmlns:controls="using:Wino.Calendar.Controls"
     xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
+    xmlns:data="using:Wino.Calendar.ViewModels.Data"
     xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
     xmlns:models="using:Wino.Core.Domain.Models.Calendar"
     xmlns:muxc="using:Microsoft.UI.Xaml.Controls"
     xmlns:toolkitControls="using:CommunityToolkit.WinUI.Controls">
 
+    <!--  Default Calendar Item View Model Template  -->
+    <DataTemplate x:Key="CalendarItemViewModelItemTemplate" x:DataType="data:CalendarItemViewModel">
+        <Grid Background="Red" CornerRadius="4">
+            <TextBlock
+                HorizontalAlignment="Center"
+                Text="{x:Bind CalendarItem.Title}"
+                TextWrapping="Wrap" />
+        </Grid>
+    </DataTemplate>
+
+    <!--  All-Day Event template  -->
+    <DataTemplate x:Key="AllDayEventItemTemplate" x:DataType="data:CalendarItemViewModel">
+        <TextBlock Text="{x:Bind Title}" />
+    </DataTemplate>
+
     <!--  08:00 or 8 AM/PM on the left etc.  -->
     <DataTemplate x:Key="DayCalendarHourHeaderTemplate" x:DataType="models:DayHeaderRenderModel">
         <Grid Height="{x:Bind HourHeight}">
@@ -21,7 +37,13 @@
 
     <!--  Vertical panel that renders items on canvas.  -->
     <DataTemplate x:Key="DayCalendarItemVerticalRenderTemplate" x:DataType="models:CalendarDayModel">
-        <controls:CalendarDayItemsControl DayModel="{x:Bind}" />
+        <ItemsControl ItemTemplate="{StaticResource CalendarItemViewModelItemTemplate}" ItemsSource="{x:Bind EventsCollection.RegularEvents}">
+            <ItemsControl.ItemsPanel>
+                <ItemsPanelTemplate>
+                    <controls:WinoCalendarPanel HourHeight="{Binding Path=CalendarRenderOptions.CalendarSettings.HourHeight}" />
+                </ItemsPanelTemplate>
+            </ItemsControl.ItemsPanel>
+        </ItemsControl>
     </DataTemplate>
 
     <!--  Equally distributed days of week representation in FlipView.  -->
@@ -103,7 +125,7 @@
         </Grid>
     </DataTemplate>
 
-    <!--  Default style  for WinoCalendarControl  -->
+    <!--  Default style for WinoCalendarControl  -->
     <Style TargetType="controls:WinoCalendarControl">
         <Style.Setters>
             <Setter Property="Template">
@@ -125,8 +147,94 @@
         </Style.Setters>
     </Style>
 
-    <!--  Teaching tip dialog sizing.  -->
+    <!--  Default style for DayColumnControl  -->
+    <Style TargetType="controls:DayColumnControl">
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="controls:DayColumnControl">
+                    <Grid>
+                        <Grid.RowDefinitions>
+                            <RowDefinition Height="25" />
+                            <RowDefinition Height="7" />
+                            <RowDefinition Height="*" />
+                        </Grid.RowDefinitions>
 
+                        <!--  Name of the day. Monday, Tuesday etc. at the top.  -->
+                        <TextBlock
+                            x:Name="PART_ColumnHeaderText"
+                            Margin="8,0,0,0"
+                            FontSize="16"
+                            TextTrimming="CharacterEllipsis" />
+
+                        <Grid
+                            Grid.Row="2"
+                            Grid.RowSpan="2"
+                            BorderBrush="{ThemeResource CalendarSeperatorBrush}"
+                            BorderThickness="1,1,0,1" />
+
+                        <!--  Border for today indication.  -->
+                        <Border
+                            x:Name="PART_IsTodayBorder"
+                            Grid.Row="1"
+                            Height="5"
+                            Margin="2,0,2,0"
+                            HorizontalAlignment="Stretch"
+                            VerticalAlignment="Center"
+                            Background="{ThemeResource SystemAccentColor}"
+                            CornerRadius="2"
+                            Visibility="Collapsed" />
+
+                        <!--  Place where full day events go.  -->
+                        <Grid
+                            x:Name="PART_DayDataAreaGrid"
+                            Grid.Row="2"
+                            Padding="6"
+                            BorderBrush="{ThemeResource CalendarSeperatorBrush}">
+                            <Grid.ColumnDefinitions>
+                                <ColumnDefinition Width="Auto" />
+                                <ColumnDefinition Width="*" />
+                            </Grid.ColumnDefinitions>
+
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto" />
+                                <RowDefinition Height="*" />
+                            </Grid.RowDefinitions>
+
+                            <!--  Day number  -->
+                            <TextBlock x:Name="PART_HeaderDateDayText" FontSize="17" />
+
+                            <!--  Extras  -->
+                            <StackPanel Grid.Column="1" HorizontalAlignment="Right" />
+
+                            <!--  All-Day Events  -->
+                            <controls:AllDayItemsControl
+                                Grid.Row="1"
+                                Grid.ColumnSpan="2"
+                                AllDayEventTemplate="{StaticResource AllDayEventItemTemplate}"
+                                EventCollection="{Binding EventsCollection}"
+                                RegularEventItemTemplate="{StaticResource CalendarItemViewModelItemTemplate}" />
+                        </Grid>
+
+                        <VisualStateManager.VisualStateGroups>
+                            <VisualStateGroup x:Name="TodayOrNotStates">
+                                <VisualState x:Name="NotTodayState" />
+                                <VisualState x:Name="TodayState">
+                                    <VisualState.Setters>
+                                        <Setter Target="PART_IsTodayBorder.Visibility" Value="Visible" />
+                                        <Setter Target="PART_HeaderDateDayText.Foreground" Value="{ThemeResource SystemAccentColor}" />
+                                        <Setter Target="PART_HeaderDateDayText.FontWeight" Value="Semibold" />
+                                        <Setter Target="PART_ColumnHeaderText.FontWeight" Value="Semibold" />
+                                    </VisualState.Setters>
+                                </VisualState>
+                            </VisualStateGroup>
+                        </VisualStateManager.VisualStateGroups>
+                    </Grid>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+
+    <!--  Teaching tip dialog sizing.  -->
     <x:Double x:Key="TeachingTipMinWidth">1000</x:Double>
     <x:Double x:Key="TeachingTipMaxWidth">1000</x:Double>
 
diff --git a/Wino.Calendar/Styles/WinoCalendarView.xaml b/Wino.Calendar/Styles/WinoCalendarView.xaml
index 8d15a1cc..8259f570 100644
--- a/Wino.Calendar/Styles/WinoCalendarView.xaml
+++ b/Wino.Calendar/Styles/WinoCalendarView.xaml
@@ -5,7 +5,7 @@
     xmlns:controls="using:Wino.Calendar.Controls">
 
     <ResourceDictionary.MergedDictionaries>
-        <ResourceDictionary Source="CalendarRenderStyles.xaml" />
+        <ResourceDictionary Source="CalendarThemeResources.xaml" />
     </ResourceDictionary.MergedDictionaries>
 
     <Style TargetType="controls:WinoCalendarView">
diff --git a/Wino.Calendar/Wino.Calendar.csproj b/Wino.Calendar/Wino.Calendar.csproj
index 99401d3e..5fa38ed2 100644
--- a/Wino.Calendar/Wino.Calendar.csproj
+++ b/Wino.Calendar/Wino.Calendar.csproj
@@ -139,8 +139,6 @@
     <Compile Include="Controls\AllDayItemsControl.xaml.cs">
       <DependentUpon>AllDayItemsControl.xaml</DependentUpon>
     </Compile>
-    <Compile Include="Controls\CalendarDayItemsControl.cs" />
-    <Compile Include="Controls\CalendarItemControl.cs" />
     <Compile Include="Controls\CustomCalendarFlipView.cs" />
     <Compile Include="Controls\DayColumnControl.cs" />
     <Compile Include="Controls\DayHeaderControl.cs" />
@@ -161,10 +159,6 @@
     <Compile Include="Services\NavigationService.cs" />
     <Compile Include="Services\ProviderService.cs" />
     <Compile Include="Services\SettingsBuilderService.cs" />
-    <Compile Include="Styles\CalendarItemControlResources.xaml.cs" />
-    <Compile Include="Styles\DayColumnControlResources.xaml.cs">
-      <DependentUpon>DayColumnControlResources.xaml</DependentUpon>
-    </Compile>
     <Compile Include="Styles\WinoCalendarResources.xaml.cs" />
     <Compile Include="Views\Abstract\AccountManagementPageAbstract.cs" />
     <Compile Include="Views\Abstract\AppShellAbstract.cs" />
@@ -260,22 +254,10 @@
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
-    <Page Include="Styles\CalendarDayItemsControl.xaml">
+    <Page Include="Styles\CalendarThemeResources.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
     </Page>
-    <Page Include="Styles\CalendarItemControlResources.xaml">
-      <Generator>MSBuild:Compile</Generator>
-      <SubType>Designer</SubType>
-    </Page>
-    <Page Include="Styles\CalendarRenderStyles.xaml">
-      <Generator>MSBuild:Compile</Generator>
-      <SubType>Designer</SubType>
-    </Page>
-    <Page Include="Styles\DayColumnControlResources.xaml">
-      <SubType>Designer</SubType>
-      <Generator>MSBuild:Compile</Generator>
-    </Page>
     <Page Include="Styles\DayHeaderControl.xaml">
       <Generator>MSBuild:Compile</Generator>
       <SubType>Designer</SubType>
@@ -368,4 +350,4 @@
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
+</Project>
\ No newline at end of file
diff --git a/Wino.Core.Domain/Collections/CalendarEventCollection.cs b/Wino.Core.Domain/Collections/CalendarEventCollection.cs
index 42c826de..653d3f55 100644
--- a/Wino.Core.Domain/Collections/CalendarEventCollection.cs
+++ b/Wino.Core.Domain/Collections/CalendarEventCollection.cs
@@ -1,36 +1,87 @@
 using System;
+using System.Collections.Generic;
 using System.Collections.ObjectModel;
 using Wino.Core.Domain.Interfaces;
 
 namespace Wino.Core.Domain.Collections
 {
-    // TODO: Could be read-only collection in the MVVM package.
-    public class CalendarEventCollection : ObservableRangeCollection<ICalendarItem>
+    public class CalendarEventCollection
     {
-        public ObservableCollection<ICalendarItem> AllDayEvents { get; } = new ObservableCollection<ICalendarItem>();
-        public new void Add(ICalendarItem calendarItem)
+        public event EventHandler<ICalendarItem> CalendarItemAdded;
+        public event EventHandler<ICalendarItem> CalendarItemRemoved;
+
+        public event EventHandler<List<ICalendarItem>> CalendarItemRangeAdded;
+        public event EventHandler<List<ICalendarItem>> CalendarItemRangeRemoved;
+
+        private ObservableRangeCollection<ICalendarItem> _internalRegularEvents = [];
+        private ObservableRangeCollection<ICalendarItem> _internalAllDayEvents = [];
+
+        public ReadOnlyObservableCollection<ICalendarItem> RegularEvents { get; }
+        public ReadOnlyObservableCollection<ICalendarItem> AllDayEvents { get; }
+
+        public CalendarEventCollection()
+        {
+            RegularEvents = new ReadOnlyObservableCollection<ICalendarItem>(_internalRegularEvents);
+            AllDayEvents = new ReadOnlyObservableCollection<ICalendarItem>(_internalAllDayEvents);
+        }
+
+        public void AddCalendarItemRange(IEnumerable<ICalendarItem> calendarItems, bool reportChange = true)
+        {
+            foreach (var calendarItem in calendarItems)
+            {
+                AddCalendarItem(calendarItem, reportChange: false);
+            }
+
+            CalendarItemRangeAdded?.Invoke(this, new List<ICalendarItem>(calendarItems));
+        }
+
+        public void RemoveCalendarItemRange(IEnumerable<ICalendarItem> calendarItems, bool reportChange = true)
+        {
+            foreach (var calendarItem in calendarItems)
+            {
+                RemoveCalendarItem(calendarItem, reportChange);
+            }
+
+            CalendarItemRangeRemoved?.Invoke(this, new List<ICalendarItem>(calendarItems));
+        }
+
+        public void AddCalendarItem(ICalendarItem calendarItem, bool reportChange = true)
         {
             if (calendarItem is not ICalendarItemViewModel)
                 throw new ArgumentException("CalendarItem must be of type ICalendarItemViewModel", nameof(calendarItem));
 
-            base.Add(calendarItem);
-
             if (calendarItem.Period.Duration.TotalMinutes == 1440)
             {
-                AllDayEvents.Add(calendarItem);
+                _internalAllDayEvents.Add(calendarItem);
+            }
+            else
+            {
+                _internalRegularEvents.Add(calendarItem);
+            }
+
+            if (reportChange)
+            {
+                CalendarItemAdded?.Invoke(this, calendarItem);
             }
         }
 
-        public new void Remove(ICalendarItem calendarItem)
+        public void RemoveCalendarItem(ICalendarItem calendarItem, bool reportChange = true)
         {
             if (calendarItem is not ICalendarItemViewModel)
                 throw new ArgumentException("CalendarItem must be of type ICalendarItemViewModel", nameof(calendarItem));
 
-            base.Remove(calendarItem);
-
             if (calendarItem.Period.Duration.TotalMinutes == 1440)
             {
-                AllDayEvents.Remove(calendarItem);
+                _internalAllDayEvents.Remove(calendarItem);
+            }
+            else
+            {
+                _internalRegularEvents.Remove(calendarItem);
+            }
+
+            if (reportChange)
+            {
+                CalendarItemRemoved?.Invoke(this, calendarItem);
             }
         }
     }
diff --git a/Wino.Core.Domain/Models/Calendar/DayRangeRenderModel.cs b/Wino.Core.Domain/Models/Calendar/DayRangeRenderModel.cs
index aa1f3495..139cb8fc 100644
--- a/Wino.Core.Domain/Models/Calendar/DayRangeRenderModel.cs
+++ b/Wino.Core.Domain/Models/Calendar/DayRangeRenderModel.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Linq;
 using Itenso.TimePeriod;
 using Wino.Core.Domain.Enums;
@@ -7,13 +8,15 @@ namespace Wino.Core.Domain.Models.Calendar
 {
     /// <summary>
     /// Represents a range of days in the calendar.
-    /// Usually it's used for day or week, but supports custom ranges.
+    /// Corresponds to 1 view of the FlipView in CalendarPage.
     /// </summary>
     public class DayRangeRenderModel
     {
+        public event EventHandler<CalendarDayModel> CalendarDayEventCollectionUpdated;
+
         public ITimePeriod Period { get; }
-        public List<CalendarDayModel> CalendarDays { get; } = new List<CalendarDayModel>();
-        public List<DayHeaderRenderModel> DayHeaders { get; } = new List<DayHeaderRenderModel>();
+        public List<CalendarDayModel> CalendarDays { get; } = [];
+        public List<DayHeaderRenderModel> DayHeaders { get; } = [];
         public CalendarRenderOptions CalendarRenderOptions { get; }
 
         public DayRangeRenderModel(CalendarRenderOptions calendarRenderOptions)
@@ -46,5 +49,39 @@ namespace Wino.Core.Domain.Models.Calendar
                 DayHeaders.Add(new DayHeaderRenderModel(dayHeader, calendarRenderOptions.CalendarSettings.HourHeight));
             }
         }
+
+        //private void RegisterCalendarDayEvents(CalendarDayModel calendarDayModel)
+        //{
+        //    calendarDayModel.EventsCollection.CalendarItemAdded += CalendarItemAdded;
+        //    calendarDayModel.EventsCollection.CalendarItemRangeRemoved += CalendarItemRangeRemoved;
+        //    calendarDayModel.EventsCollection.CalendarItemRemoved += CalendarItemRemoved;
+        //    calendarDayModel.EventsCollection.CalendarItemRangeAdded += CalendarItemRangeAdded;
+        //}
+
+        //private void CalendarItemRangeAdded(object sender, List<ICalendarItem> e)
+        //    => CalendarDayEventCollectionUpdated?.Invoke(this, sender as CalendarDayModel);
+
+        //private void CalendarItemRemoved(object sender, ICalendarItem e)
+        //    => CalendarDayEventCollectionUpdated?.Invoke(this, sender as CalendarDayModel);
+
+        //private void CalendarItemAdded(object sender, ICalendarItem e)
+        //    => CalendarDayEventCollectionUpdated?.Invoke(this, sender as CalendarDayModel);
+
+        //private void CalendarItemRangeRemoved(object sender, List<ICalendarItem> e)
+        //    => CalendarDayEventCollectionUpdated?.Invoke(this, sender as CalendarDayModel);
+
+        ///// <summary>
+        ///// Unregisters all calendar item change listeners to draw the UI for calendar events.
+        ///// </summary>
+        //public void UnregisterAll()
+        //{
+        //    foreach (var day in CalendarDays)
+        //    {
+        //        day.EventsCollection.CalendarItemRangeRemoved -= CalendarItemRangeRemoved;
+        //        day.EventsCollection.CalendarItemRemoved -= CalendarItemRemoved;
+        //        day.EventsCollection.CalendarItemRangeAdded -= CalendarItemRangeAdded;
+        //        day.EventsCollection.CalendarItemAdded -= CalendarItemAdded;
+        //    }
+        //}
     }
 }