implemented RealizedItemsCount Property for MultiFormatDataView

MultiTerm.Wpf.CustomControl/ExtendedTabControl/ExtendedTabControl.cs

@@ -61,8 +61,7 @@ public class ExtendedTabControl : TabControl
         base.OnApplyTemplate();
 
         // get button from template
-        var button = GetTemplateChild("addButton") as Button;
+        if (GetTemplateChild("addButton") is Button button)
-        if (button != null)
         {
             button.Click += OnAddButtonClicked; ;
         }
@@ -70,7 +69,7 @@ public class ExtendedTabControl : TabControl
 
     private void OnAddButtonClicked(object sender, RoutedEventArgs e)
     {
-        RoutedEventArgs args = new RoutedEventArgs(AddButtonClickedEvent);
+        RoutedEventArgs args = new(AddButtonClickedEvent);
         RaiseEvent(args);
     }
 }

MultiTerm.Wpf.CustomControl/MultiFormatDataView/MultiFormatDataView.cs

@@ -1,10 +1,12 @@
 using MultiTerm.Core.ViewModel;
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Windows;
 using System.Windows.Controls;
 using System.Windows.Data;
+using System.Windows.Threading;
 
 namespace MultiTerm.Wpf.CustomControl;
 
@@ -37,8 +39,10 @@ namespace MultiTerm.Wpf.CustomControl;
 ///     <MyNamespace:MultiFormatDataView/>
 ///
 /// </summary>
+
 public class MultiFormatDataView : Control
 {
+    private static readonly Dictionary<StackPanel, MultiFormatDataView> itemParentPairs = new();
     private const string itemsControlTemplateName = "itemsControl";
     private ItemsControl? itemsControl;
 
@@ -48,6 +52,23 @@ public class MultiFormatDataView : Control
         typeof(IEnumerable), typeof(MultiFormatDataView),
         new PropertyMetadata(null, OnDataSourcePropertyChanged));
 
+    public static readonly DependencyProperty RealizedItemsCountProperty =
+        DependencyProperty.Register("RealizedItemsCount",
+        typeof(uint), typeof(MultiFormatDataView),
+        new PropertyMetadata((uint)0, OnRealizedItemsCountChanged));
+
+    public static readonly DependencyProperty ItemLoadedProperty =
+                                          DependencyProperty.RegisterAttached("ItemLoaded",
+                                          typeof(bool),
+                                          typeof(MultiFormatDataView),
+                                          new UIPropertyMetadata(false, OnItemLoaded));
+
+    public static readonly DependencyProperty ItemUnloadedProperty =
+                                      DependencyProperty.RegisterAttached("ItemUnloaded",
+                                      typeof(bool),
+                                      typeof(MultiFormatDataView),
+                                      new UIPropertyMetadata(false, OnItemUnloaded));
+
     /// <summary>
     /// .NET Property for DataSource.
     /// </summary>
@@ -58,6 +79,16 @@ public class MultiFormatDataView : Control
         set { SetValue(DataSourceProperty, value); }
     }
 
+    /// <summary>
+    /// .NET Property for RealizedItemsCount.
+    /// </summary>
+    [Bindable(true)]
+    public uint RealizedItemsCount
+    {
+        get { return (uint)GetValue(RealizedItemsCountProperty); }
+        set { SetValue(RealizedItemsCountProperty, value); }
+    }
+
     #endregion
 
     static MultiFormatDataView()
@@ -65,6 +96,7 @@ public class MultiFormatDataView : Control
         DefaultStyleKeyProperty.OverrideMetadata(typeof(MultiFormatDataView), new FrameworkPropertyMetadata(typeof(MultiFormatDataView)));
     }
 
+
     public override void OnApplyTemplate()
     {
         base.OnApplyTemplate();
@@ -78,7 +110,6 @@ public class MultiFormatDataView : Control
         {
             throw new Exception($"Implementation fault, {itemsControlTemplateName} not found in template.");
         }
-
     }
 
     private static void OnDataSourcePropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
@@ -100,4 +131,47 @@ public class MultiFormatDataView : Control
         PropertyGroupDescription groupDescription = new(nameof(DataViewModel.LineIdentifier));
         view.GroupDescriptions.Add(groupDescription);
     }
+
+
+    private static void OnRealizedItemsCountChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        // NOP
+    }
+
+    private static void OnItemLoaded(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        // extract instance and guard null
+        if (d is not StackPanel stackPanel) { return; }
+
+        // check if value was set to true
+        if (e.NewValue is bool boolean && boolean == true)
+        {
+            // find visual parent of correct type, throw exception if not found
+            var parentMFDV = UIHelper.FindVisualParent<MultiFormatDataView>(stackPanel) ?? 
+                throw new NullReferenceException($"Could not find parent of type " +
+                    $"{nameof(MultiFormatDataView)} in {nameof(stackPanel)}");
+
+            // add to static dictionary
+            itemParentPairs.Add(stackPanel, parentMFDV);
+            // increment counter
+            parentMFDV.RealizedItemsCount++;
+        }
+    }
+
+    private static void OnItemUnloaded(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        // extract instance and guard null
+        if (d is not StackPanel stackPanel) { return; }
+
+        // check if value was set to true
+        if (e.NewValue is bool boolean && boolean == true)
+        {
+            // get parent from static dictionary
+            var parentMFDV = itemParentPairs[stackPanel];
+            // remove the element from the dictionary
+            itemParentPairs.Remove(stackPanel);
+            // decrement counter
+            parentMFDV.RealizedItemsCount--;
+        }
+    }
 }

MultiTerm.Wpf.CustomControl/MultiFormatDataView/MultiFormatDataView.xaml

@@ -1,15 +1,46 @@
-<ResourceDictionary xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+<ResourceDictionary x:Class="MultiTerm.Wpf.CustomControl.TemplateStackPanel"
+                    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"       
                     xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
                     xmlns:local="clr-namespace:MultiTerm.Wpf.CustomControl"
-                    xmlns:wpftk="clr-namespace:WpfToolkit.Controls;assembly=VirtualizingWrapPanel">
+                    xmlns:vm="clr-namespace:MultiTerm.Core.ViewModel;assembly=MultiTerm.Core"
+                    xmlns:wpftk="clr-namespace:WpfToolkit.Controls;assembly=VirtualizingWrapPanel"
+                    xmlns:sys="clr-namespace:System;assembly=mscorlib">
 
     <Style TargetType="{x:Type local:MultiFormatDataView}">
         <Style.Resources>
             <SolidColorBrush x:Key="CHAR_Background" Color="#B4EBEB"/>
             <SolidColorBrush x:Key="HEX_Background" Color="#C8C8FF"/>
             <SolidColorBrush x:Key="BIN_Background" Color="#C8FFC8"/>
-            <DataTemplate x:Key="dataContainerTemplate">
+            <DataTemplate x:Key="dataContainerTemplate" DataType="vm:DataViewModel">
-                <StackPanel Orientation="Vertical" Margin="0 0 5 0">
+                <StackPanel Orientation="Vertical" Margin="0 0 5 0" x:Name="ItemStackPanel">
+                    <StackPanel.Triggers>
+                        <EventTrigger SourceName="ItemStackPanel" RoutedEvent="Loaded">
+                            <BeginStoryboard>
+                                <Storyboard>
+                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemStackPanel" Storyboard.TargetProperty="(local:MultiFormatDataView.ItemLoaded)">
+                                        <DiscreteObjectKeyFrame KeyTime="0:0:0">
+                                            <DiscreteObjectKeyFrame.Value>
+                                                <sys:Boolean>True</sys:Boolean>
+                                            </DiscreteObjectKeyFrame.Value>
+                                        </DiscreteObjectKeyFrame>
+                                    </ObjectAnimationUsingKeyFrames>
+                                </Storyboard>
+                            </BeginStoryboard>
+                        </EventTrigger>
+                        <EventTrigger SourceName="ItemStackPanel" RoutedEvent="Unloaded">
+                            <BeginStoryboard>
+                                <Storyboard>
+                                    <ObjectAnimationUsingKeyFrames Storyboard.TargetName="ItemStackPanel" Storyboard.TargetProperty="(local:MultiFormatDataView.ItemUnloaded)">
+                                        <DiscreteObjectKeyFrame KeyTime="0:0:0">
+                                            <DiscreteObjectKeyFrame.Value>
+                                                <sys:Boolean>True</sys:Boolean>
+                                            </DiscreteObjectKeyFrame.Value>
+                                        </DiscreteObjectKeyFrame>
+                                    </ObjectAnimationUsingKeyFrames>
+                                </Storyboard>
+                            </BeginStoryboard>
+                        </EventTrigger>
+                    </StackPanel.Triggers>
                     <!-- Character -->
                     <Border BorderThickness="0">
                         <Label Content="{Binding DisplayStringUtf16}">
@@ -83,11 +114,15 @@
                 <ControlTemplate TargetType="{x:Type local:MultiFormatDataView}">
                     <DockPanel>
                         <GroupBox Header="Display Formats" DockPanel.Dock="Top">
-                            <StackPanel Orientation="Horizontal" >
+                            <DockPanel LastChildFill="False">
-                                <CheckBox Content="Character" x:Name="cbCharacter" Padding="20 0" IsChecked="True"/>
+                                <CheckBox DockPanel.Dock="Left" Content="Character" VerticalAlignment="Center" x:Name="cbCharacter" Padding="20 0" IsChecked="True"/>
-                                <CheckBox Content="Hexadecimal" x:Name="cbHex" Padding="20 0"/>
+                                <CheckBox DockPanel.Dock="Left" Content="Hexadecimal" VerticalAlignment="Center" x:Name="cbHex" Padding="20 0"/>
-                                <CheckBox Content="Binary" x:Name="cbBin" Padding="20 0"/>
+                                <CheckBox DockPanel.Dock="Left" Content="Binary" VerticalAlignment="Center" x:Name="cbBin" Padding="20 0"/>
-                            </StackPanel>
+                                <StackPanel DockPanel.Dock="Right" Orientation="Horizontal" VerticalAlignment="Center">
+                                    <Label Content="Realized Items: " Margin="0 0 5 0"/>
+                                    <Label Width="30" Content="{TemplateBinding RealizedItemsCount}"/>
+                                </StackPanel>
+                            </DockPanel>
                         </GroupBox>
                         <ListView Name="itemsControl"
                               ItemsSource="{TemplateBinding DataSource}"
@@ -96,6 +131,7 @@
                               ScrollViewer.PanningMode="VerticalOnly"
                               HorizontalAlignment="Left"
                               VirtualizingPanel.IsVirtualizingWhenGrouping="True"
+                              VirtualizingPanel.CacheLengthUnit="Item"
                               ItemTemplate="{StaticResource dataContainerTemplate}">
 
                             <ListView.ItemContainerStyle>
@@ -104,7 +140,7 @@
                                     <Setter Property="VerticalContentAlignment" Value="Stretch" />
                                 </Style>
                             </ListView.ItemContainerStyle>
-                            
+
                             <ListView.ItemsPanel>
                                 <ItemsPanelTemplate>
                                     <wpftk:VirtualizingWrapPanel

MultiTerm.Wpf.CustomControl/UIHelper.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Media;
+using System.Windows;
+
+namespace MultiTerm.Wpf.CustomControl;
+
+public static class UIHelper
+{
+    /// from https://stackoverflow.com/questions/636383/how-can-i-find-wpf-controls-by-name-or-type
+    /// <summary>
+    /// Finds a parent of a given item on the visual tree.
+    /// </summary>
+    /// <typeparam name="T">The type of the queried item.</typeparam>
+    /// <param name="child">A direct or indirect child of the queried item.</param>
+    /// <returns>The first parent item that matches the submitted type parameter. 
+    /// If not matching item can be found, a null reference is being returned.</returns>
+    public static T? FindVisualParent<T>(DependencyObject child)
+      where T : DependencyObject
+    {
+        // get parent item
+        DependencyObject parentObject = VisualTreeHelper.GetParent(child);
+
+        // we’ve reached the end of the tree
+        if (parentObject == null) return null;
+
+        // check if the parent matches the type we’re looking for
+        if (parentObject is T parent)
+        {
+            return parent;
+        }
+        else
+        {
+            // use recursion to proceed with next level
+            return FindVisualParent<T>(parentObject);
+        }
+    }
+}