From 69f39fb84c2011425c203c2b5d23a260745dbe05 Mon Sep 17 00:00:00 2001
From: timunie <tim.uniewski@gmail.com>
Date: Mon, 9 Dec 2024 22:19:18 +0100
Subject: [PATCH] WIP

---
 .../ViewModels/SnowFlakeGameViewModel.cs      | 26 +++++-----
 .../Views/MainWindow.axaml                    | 51 ++++++++++---------
 .../MVVM/BasicMvvmSample/README.adoc          |  4 +-
 3 files changed, 43 insertions(+), 38 deletions(-)

diff --git a/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/ViewModels/SnowFlakeGameViewModel.cs b/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/ViewModels/SnowFlakeGameViewModel.cs
index 517d995..687073a 100644
--- a/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/ViewModels/SnowFlakeGameViewModel.cs
+++ b/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/ViewModels/SnowFlakeGameViewModel.cs
@@ -1,5 +1,6 @@
 using System;
 using System.Collections.ObjectModel;
+using System.Diagnostics;
 using Avalonia.Threading;
 using CommunityToolkit.Mvvm.ComponentModel;
 using CommunityToolkit.Mvvm.Input;
@@ -11,35 +12,34 @@ public partial class SnowFlakeGameViewModel : ViewModelBase
 {
     public SnowFlakeGameViewModel()
     {
-        _gameTimer = new DispatcherTimer(TimeSpan.FromMilliseconds(50), DispatcherPriority.Background, OnGameTimerTick);
+        _gameTimer = new DispatcherTimer(TimeSpan.FromMilliseconds(100), DispatcherPriority.Background, OnGameTimerTick);
     }
 
     private void OnGameTimerTick(object? sender, EventArgs e)
     {
-        OnPropertyChanged(nameof(TimeRemaining));
-        OnPropertyChanged(nameof(SecondsRemaining));
+        OnPropertyChanged(nameof(MilliSecondsRemaining));
 
-        if (TimeRemaining < TimeSpan.Zero)
+        if (MilliSecondsRemaining <= 0)
         {
             _gameTimer.Stop();
+            _stopwatch.Stop();
             IsGameRunning = false;
         }
     }
 
     private readonly DispatcherTimer _gameTimer;
-    private DateTime _gameStartTime = DateTime.MinValue;
-
+    private readonly Stopwatch _stopwatch = new Stopwatch();
+    
     public ObservableCollection<SnowFlake> SnowFlakes { get; } = new();
     
     [ObservableProperty] private bool _isGameRunning;
-    [ObservableProperty] private int _Score;
+    [ObservableProperty] private int _score;
 
-    [ObservableProperty] [NotifyPropertyChangedFor(nameof(SecondsGameDuration))]
-    TimeSpan _GameDuration = TimeSpan.Zero;
+    [ObservableProperty] [NotifyPropertyChangedFor(nameof(MilliSecondsGameDuration))]
+    private TimeSpan _gameDuration = TimeSpan.Zero;
 
-    public TimeSpan TimeRemaining => _gameStartTime + GameDuration - DateTime.Now;
-    public double SecondsRemaining => TimeRemaining.TotalSeconds;
-    public double SecondsGameDuration => GameDuration.TotalSeconds;
+    public double MilliSecondsRemaining => (GameDuration - _stopwatch.Elapsed).TotalMilliseconds;
+    public double MilliSecondsGameDuration => GameDuration.TotalMilliseconds;
 
     [RelayCommand]
     private void StartGame()
@@ -56,7 +56,7 @@ private void StartGame()
                 Random.Shared.NextDouble() / 5 + 0.1));
         }
         
-        _gameStartTime = DateTime.Now;
+        _stopwatch.Restart();
         GameDuration = TimeSpan.FromMinutes(1);
         IsGameRunning = true;
         _gameTimer.Start();
diff --git a/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/Views/MainWindow.axaml b/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/Views/MainWindow.axaml
index 0690b51..0f8ae3f 100644
--- a/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/Views/MainWindow.axaml
+++ b/src/Avalonia.Samples/CustomControls/SnowFlakesControlSample/Views/MainWindow.axaml
@@ -10,15 +10,6 @@
         Icon="/Assets/avalonia-logo.ico"
         Title="SnowFlakesControl">
 
-    <Window.Background>
-        <LinearGradientBrush StartPoint="0,0" EndPoint="0%,100%">
-            <GradientStop Offset="0" Color="DarkBlue" />
-            <GradientStop Offset=".85" Color="LightSkyBlue" />
-            <GradientStop Offset=".85" Color="LimeGreen" />
-            <GradientStop Offset="1" Color="DarkGreen" />
-        </LinearGradientBrush>
-    </Window.Background>
-
     <Design.DataContext>
         <!-- This only sets the DataContext for the previewer in an IDE,
              to set the actual DataContext for runtime, set the DataContext property in code (look at App.axaml.cs) -->
@@ -26,27 +17,39 @@
     </Design.DataContext>
 
     <Panel>
+        <!-- Just some Background for a nicer UI -->
+        <Panel.Background>
+            <LinearGradientBrush StartPoint="0,0" EndPoint="0%,100%">
+                <GradientStop Offset="0" Color="DarkBlue" />
+                <GradientStop Offset=".85" Color="LightSkyBlue" />
+                <GradientStop Offset=".85" Color="LimeGreen" />
+                <GradientStop Offset="1" Color="DarkGreen" />
+            </LinearGradientBrush>
+        </Panel.Background>
+
+        <!-- This is our SnowFlakesControl. It can be used like any other Control. -->
         <controls:SnowFlakesControl HorizontalAlignment="Stretch" VerticalAlignment="Stretch"
-                                     IsRunning="{Binding IsGameRunning}"
-                                     SnowFlakes="{Binding SnowFlakes}"
-                                     Score="{Binding Score}"/>
-        
-        <ProgressBar Maximum="{Binding SecondsGameDuration}"
+                                    IsRunning="{Binding IsGameRunning}"
+                                    SnowFlakes="{Binding SnowFlakes}"
+                                    Score="{Binding Score}" />
+
+        <!-- This ProgressBar is rendered above our SnowFlakesControl -->
+        <ProgressBar Maximum="{Binding MilliSecondsGameDuration}"
                      VerticalAlignment="Top"
                      Foreground="Goldenrod"
                      Margin="5"
                      Height="3"
-                     Value="{Binding SecondsRemaining}" />
+                     Value="{Binding MilliSecondsRemaining}" />
+
+        <!-- This Button is only visible when the game is not running. It has a Button to start the game  -->
 
-        <Panel Background="#11FFFFFF"
-               IsVisible="{Binding !IsGameRunning}">
-            <Button Command="{Binding StartGameCommand}"
-                    HorizontalAlignment="Center"
-                    VerticalAlignment="Center"
-                    Content="►"
-                    FontSize="50"
-                    CornerRadius="25" />
-        </Panel>
+        <Button IsVisible="{Binding !IsGameRunning}"
+                Command="{Binding StartGameCommand}"
+                HorizontalAlignment="Center"
+                VerticalAlignment="Center"
+                Content="►"
+                FontSize="50"
+                CornerRadius="25" />
 
     </Panel>
 </Window>
\ No newline at end of file
diff --git a/src/Avalonia.Samples/MVVM/BasicMvvmSample/README.adoc b/src/Avalonia.Samples/MVVM/BasicMvvmSample/README.adoc
index 501c92c..65347d1 100644
--- a/src/Avalonia.Samples/MVVM/BasicMvvmSample/README.adoc
+++ b/src/Avalonia.Samples/MVVM/BasicMvvmSample/README.adoc
@@ -190,6 +190,8 @@ Remember that the `View` implements the User Interface. Our view will only consi
 public SimpleViewModel SimpleViewModel { get; } = new SimpleViewModel();
 ```
 
+NOTE:: Depending on the template and setting used to create your project you may find a class called `MainViewModel` instead of `MainWindowViewModel`. In this case please make sure the correct name.
+
 === Step 4: Setup the View 
 
 Now we can start with the UI layout. Our View will be written in [https://docs.avaloniaui.net/guides/basics/introduction-to-xaml[`XAML`,window=_blank]] which is an XML-based markup language that is used by many UI frameworks. The code modifications shown below will be applied to `MainWindow.axaml`.
@@ -260,7 +262,7 @@ image::_docs/result.png[Result]
 
 == Approach 2 : Using ReactiveUI
 
-We don't need to implement all the boilerplate code on our own over and over again. Instead, we can use any existing `MVVM` framework out there. [https://www.reactiveui.net[ReactiveUI,window=_blank]] is a popular MVVM framework designed for `.NET`.  If you create a new Avalonia MVVM Project, you will have `ReactiveUI` installed by default. So let's see how we can use `ReactiveUI` to achieve the same results as **Approach 1** above.
+We don't need to implement all the boilerplate code on our own over and over again. Instead, we can use any existing `MVVM` framework out there. [https://www.reactiveui.net[ReactiveUI,window=_blank]] is a popular MVVM framework designed for `.NET`.  If you create a new Avalonia MVVM Project, you will have `ReactiveUI` (or `CommunityToolkit.Mvvm` based on your choice) installed by default. So let's see how we can use `ReactiveUI` to achieve the same results as **Approach 1** above.
 
 === Step 1: Create ReactiveViewModel