pauldipietro · b-straub · May 8, 2019
diff --git a/...ctionViewChallenge/CollectionViewChallenge.Android/CollectionViewChallenge.Android.csproj b/...ctionViewChallenge/CollectionViewChallenge.Android/CollectionViewChallenge.Android.csproj
@@ -15,7 +15,6 @@
     <AndroidManifest>Properties\AndroidManifest.xml</AndroidManifest>
     <MonoAndroidResourcePrefix>Resources</MonoAndroidResourcePrefix>
     <MonoAndroidAssetsPrefix>Assets</MonoAndroidAssetsPrefix>
-    <AndroidUseLatestPlatformSdk>false</AndroidUseLatestPlatformSdk>
     <TargetFrameworkVersion>v8.1</TargetFrameworkVersion>
     <AndroidEnableSGenConcurrent>true</AndroidEnableSGenConcurrent>
     <AndroidHttpClientHandlerType>Xamarin.Android.Net.AndroidClientHandler</AndroidHttpClientHandlerType>
@@ -52,7 +51,7 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Xamarin.Forms" Version="4.0.0.346134-pre9" />
+    <PackageReference Include="Xamarin.Forms" Version="4.0.0.394984-pre10" />
     <PackageReference Include="Xamarin.Android.Support.ViewPager" Version="28.0.0.1" />
     <PackageReference Include="Xamarin.Android.Support.Design" Version="28.0.0.1" />
     <PackageReference Include="Xamarin.Android.Support.v7.AppCompat" Version="28.0.0.1" />
@@ -102,7 +101,7 @@
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\CollectionViewChallenge\CollectionViewChallenge.csproj">
-      <Project>{BA39825E-3CF8-4A31-B120-782B2A651542}</Project>
+      <Project>{9A9DDEE5-8C48-4274-82D7-22EB79C97206}</Project>
       <Name>CollectionViewChallenge</Name>
     </ProjectReference>
   </ItemGroup>

diff --git a/CollectionViewChallenge/CollectionViewChallenge.Android/Properties/AndroidManifest.xml b/CollectionViewChallenge/CollectionViewChallenge.Android/Properties/AndroidManifest.xml
@@ -1,5 +1,5 @@
-<?xml version="1.0" encoding="utf-8"?>
+<?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.companyname.CollectionViewChallenge">
-    <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="27" />
-    <application android:label="CollectionViewChallenge.Android"></application>
-</manifest>
+	<uses-sdk android:minSdkVersion="21" android:targetSdkVersion="27" />
+	<application android:label="CollectionViewChallenge.Android"></application>
+</manifest>
diff --git a/CollectionViewChallenge/CollectionViewChallenge.iOS/CollectionViewChallenge.iOS.csproj b/CollectionViewChallenge/CollectionViewChallenge.iOS/CollectionViewChallenge.iOS.csproj
@@ -133,13 +133,13 @@
     <Reference Include="System.Numerics.Vectors" />
   </ItemGroup>
   <ItemGroup>
-    <PackageReference Include="Xamarin.Forms" Version="4.0.0.346134-pre9" />
+    <PackageReference Include="Xamarin.Forms" Version="4.0.0.394984-pre10" />
     <PackageReference Include="Xamarin.Essentials" Version="1.1.0" />
   </ItemGroup>
   <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
   <ItemGroup>
     <ProjectReference Include="..\CollectionViewChallenge\CollectionViewChallenge.csproj">
-      <Project>{BA39825E-3CF8-4A31-B120-782B2A651542}</Project>
+      <Project>{9A9DDEE5-8C48-4274-82D7-22EB79C97206}</Project>
       <Name>CollectionViewChallenge</Name>
     </ProjectReference>
   </ItemGroup>

diff --git a/CollectionViewChallenge/CollectionViewChallenge/CollectionViewChallenge.csproj b/CollectionViewChallenge/CollectionViewChallenge/CollectionViewChallenge.csproj
@@ -11,8 +11,12 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Xamarin.Forms" Version="4.0.0.346134-pre9" />  
+    <PackageReference Include="Xamarin.Forms" Version="4.0.0.394984-pre10" />  
     <PackageReference Include="Xamarin.Essentials" Version="1.1.0" />
+    <PackageReference Include="NLipsum" Version="1.1.0" />
+    <PackageReference Include="DynamicData" Version="6.9.1.2588" />
+    <PackageReference Include="Fody" Version="5.0.5" />
+    <PackageReference Include="PropertyChanged.Fody" Version="3.0.0" />
   </ItemGroup>
 
   <ItemGroup>

diff --git a/CollectionViewChallenge/CollectionViewChallenge/ViewModels/ViewModel.cs b/CollectionViewChallenge/CollectionViewChallenge/ViewModels/ViewModel.cs
@@ -0,0 +1,53 @@
+using System;
+using System.ComponentModel;
+using System.Runtime.CompilerServices;
+using System.Linq;
+using NLipsum.Core;
+
+namespace CollectionViewChallenge
+{
+	public class ViewModel : INotifyPropertyChanged
+	{
+		public event PropertyChangedEventHandler PropertyChanged;
+
+		public String Column1 { get; set; } = String.Empty;
+		public String Column2 { get; set; } = String.Empty;
+
+		LipsumGenerator lipsum = new LipsumGenerator();
+		Random random = new Random(DateTime.Now.Millisecond);
+		bool collapsed = false;
+
+		public ViewModel()
+		{
+			CreateRandomText();
+		}
+
+		public void Toggle()
+		{
+			collapsed = !collapsed;
+			CreateRandomText();
+		}
+
+		void CreateRandomText()
+		{
+			if (collapsed)
+			{
+				Column1 = "Tap to create random Text!";
+				Column2 = String.Empty;
+			}
+			else
+			{
+				var words = lipsum.GenerateWords(random.Next(5, 50));
+				var text = String.Join(" ", words.ToArray());
+
+				Column1 = text;
+
+				words = lipsum.GenerateWords(random.Next(2, 20));
+				text = String.Join(" ", words.ToArray());
+
+				Column2 = text;
+			}
+		}
+
+	}
+}
diff --git a/CollectionViewChallenge/CollectionViewChallenge/Views/CollectionViewChallengePage.xaml b/CollectionViewChallenge/CollectionViewChallenge/Views/CollectionViewChallengePage.xaml
@@ -1,31 +1,57 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              xmlns:d="http://xamarin.com/schemas/2014/forms/design"
              xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
              mc:Ignorable="d"
              x:Class="CollectionViewChallenge.Views.CollectionViewChallengePage">
+    <ContentPage.ToolbarItems>
+        <ToolbarItem Text="Clear" Clicked="OnClearClicked"/>
+        <ToolbarItem Text="" x:Name="TBUpdating"/>
+    </ContentPage.ToolbarItems>
     <ContentPage.Content>
         <StackLayout>
-            <!-- Use your own layout and functionality here! -->
-            <CollectionView>
-                <CollectionView.ItemsSource>
-                    <x:Array Type="{x:Type x:String}">
-                        <x:String>This is a CollectionView!</x:String>
-                        <x:String>Your feedback on the experience of converting a ListView to a CollectionView is incredibly appreciated.</x:String>
-                        <x:String>Here are three general questions:</x:String>
-                        <x:String>1. How was the experience of converting your existing ListView to a CollectionView?</x:String>
-                        <x:String>2. How is the performance compared to the ListView?</x:String>
-                        <x:String>3. Is there a specific piece of functionality that you'd like to see?</x:String>
-                    </x:Array>
-                </CollectionView.ItemsSource>
+            <CollectionView
+                HorizontalOptions="FillAndExpand" 
+                VerticalOptions="FillAndExpand"
+                Margin="10"
+                ItemSizingStrategy="MeasureAllItems"
+                BackgroundColor="White"
+                ItemsSource="{Binding Data}"
+                SelectionMode="Single"
+                SelectionChanged="OnCollectionViewSelectionChanged">
                 <CollectionView.ItemTemplate>
                     <DataTemplate>
-                        <StackLayout Padding="5">
-                            <Label Text="{Binding .}" d:Text="Design Time Data" FontSize="10"/>
-                        </StackLayout>
+                        <Grid
+                            ColumnSpacing="10"
+                            RowSpacing="10">
+                            <Grid.RowDefinitions>
+                                <RowDefinition Height="Auto" />
+                                <RowDefinition Height="Auto" />
+                            </Grid.RowDefinitions>
+                            <Grid.ColumnDefinitions>
+                                <ColumnDefinition Width="35*" />
+                                <ColumnDefinition Width="65*" />
+                            </Grid.ColumnDefinitions>
+                            <Label Grid.Column="0"
+                                   Text="{Binding Column1}"
+                                   FontAttributes="Bold" />
+                            <Label Grid.Column="1"
+                                   Text="{Binding Column2}"
+                                   FontAttributes="Italic" />
+                        </Grid>
                     </DataTemplate>
                 </CollectionView.ItemTemplate>
+                <CollectionView.EmptyView>
+                    <StackLayout>
+                        <Label Text="No entries!"
+                               Margin="10,25,10,10"
+                               FontAttributes="Bold"
+                               FontSize="18"
+                               HorizontalOptions="Fill"
+                               HorizontalTextAlignment="Center" />
+                    </StackLayout>
+        </CollectionView.EmptyView>
             </CollectionView>
         </StackLayout>
     </ContentPage.Content>

diff --git a/CollectionViewChallenge/CollectionViewChallenge/Views/CollectionViewChallengePage.xaml.cs b/CollectionViewChallenge/CollectionViewChallenge/Views/CollectionViewChallengePage.xaml.cs
@@ -3,6 +3,8 @@
 using System.Linq;
 using System.Text;
 using System.Threading.Tasks;
+using DynamicData;
+using DynamicData.Binding;
 
 using Xamarin.Forms;
 using Xamarin.Forms.Xaml;
@@ -12,9 +14,50 @@ namespace CollectionViewChallenge.Views
     [XamlCompilation(XamlCompilationOptions.Compile)]
     public partial class CollectionViewChallengePage : ContentPage
     {
-        public CollectionViewChallengePage()
+		public IObservableCollection<ViewModel> Data { get; } = new ObservableCollectionExtended<ViewModel>();
+		SourceList<ViewModel> List = new SourceList<ViewModel>();
+
+		public CollectionViewChallengePage()
         {
             InitializeComponent();
-        }
-    }
+
+			List.AddRange(Enumerable.Range(0, 1000).Select(x => new ViewModel()));
+			List.Connect().Bind(Data).DisposeMany().Subscribe();
+
+			BindingContext = this;
+		}
+
+		void OnClearClicked(object sender, EventArgs e)
+		{
+			// verify that PropertyChanged interface works
+			Data.PropertyChanged += (sn, ev) =>
+			{
+				Console.WriteLine("Data changed");
+			};
+
+			List.Clear();		
+		}
+
+		void OnCollectionViewSelectionChanged(object sender, SelectionChangedEventArgs e)
+		{
+			if (e.CurrentSelection.Count == 0)
+				return;
+
+			var item = e.CurrentSelection.FirstOrDefault() as ViewModel;
+			item.Toggle();
+			var colView = sender as CollectionView;
+			UpdateSelection(colView, item);
+		}
+
+		async void UpdateSelection(CollectionView colView, ViewModel item)
+		{
+			TBUpdating.Text = "Updating Selection ...";
+
+			await Task.Delay(1000); // make scroll action visible
+			colView.ScrollTo(item, position: ScrollToPosition.Center);
+			colView.SelectedItem = null;
+
+			TBUpdating.Text = String.Empty;
+		}
+	}
 }