- fix: memory leak part 1

Nebula.Launcher/ViewModels/ServerListViewModel.cs

@@ -0,0 +1,148 @@
+using System;
+using System.Collections.ObjectModel;
+using Avalonia.Controls;
+using CommunityToolkit.Mvvm.ComponentModel;
+using Nebula.Launcher.Models;
+using Nebula.Launcher.ServerListProviders;
+using Nebula.Launcher.ViewModels.Pages;
+using Nebula.Launcher.Views;
+using Nebula.Shared.ViewHelper;
+
+namespace Nebula.Launcher.ViewModels;
+
+[ViewModelRegister(typeof(ServerListView), false)]
+public partial class ServerListViewModel : ViewModelBase
+{
+    [ObservableProperty] private bool _isLoading;
+
+    public ServerListViewModel()
+    {
+        if (Design.IsDesignMode)
+        {
+            Provider = new TestServerList();
+        }
+    }
+    
+    private IServerListProvider? _provider;
+    
+    public ObservableCollection<IListEntryModelView> ServerList { get; } = new();
+    public ObservableCollection<Exception> ErrorList { get; } = new();
+
+    public IServerListProvider Provider
+    {
+        get => _provider ?? throw new Exception();
+
+        set
+        {
+            _provider = value;
+            _provider.OnDisposed += OnProviderDisposed;
+            if (_provider is IServerListDirtyInvoker invoker)
+            {
+                invoker.Dirty += OnDirty;
+            }
+            
+            if(!_provider.IsLoaded)
+                RefreshFromProvider();
+            else
+            {
+                Clear();
+                PasteServersFromList();
+            }
+        }
+    }
+
+    private void OnProviderDisposed()
+    {
+        Provider.OnLoaded -= RefreshRequired;
+        Provider.OnDisposed -= OnProviderDisposed;
+        if (Provider is IServerListDirtyInvoker invoker)
+        {
+            invoker.Dirty -= OnDirty;
+        }
+        
+        _provider = null;
+    }
+
+    private ServerFilter? _currentFilter;
+
+    public void RefreshFromProvider()
+    {
+        if (IsLoading) 
+            return;
+        
+        Clear();
+        StartLoading();
+        
+        Provider.LoadServerList();
+        
+        if (Provider.IsLoaded) PasteServersFromList();
+        else Provider.OnLoaded += RefreshRequired;
+    }
+
+    public void ApplyFilter(ServerFilter? filter)
+    {
+        _currentFilter = filter;
+        
+        if(IsLoading) 
+            return;
+        
+        foreach (var serverView in ServerList)
+        {
+            if(serverView is IFilterConsumer filterConsumer)
+                filterConsumer.ProcessFilter(filter);
+        }
+    }
+
+    private void OnDirty()
+    {
+        RefreshFromProvider();
+    }
+    
+    private void Clear()
+    {
+        ErrorList.Clear();
+        ServerList.Clear();
+    }
+    
+    private void PasteServersFromList()
+    {
+        foreach (var serverEntry in Provider.GetServers())
+        {
+            ServerList.Add(serverEntry);
+            if(serverEntry is IFilterConsumer serverFilter)
+                serverFilter.ProcessFilter(_currentFilter);
+        }
+        
+        foreach (var error in Provider.GetErrors())
+        {
+            ErrorList.Add(error);
+        }
+        
+        EndLoading();
+    }
+    
+    private void RefreshRequired()
+    {
+        PasteServersFromList();
+        Provider.OnLoaded -= RefreshRequired;
+    }
+
+    private void StartLoading()
+    {
+        Clear();
+        IsLoading = true;
+    }
+
+    private void EndLoading()
+    {
+        IsLoading = false;
+    }
+
+    protected override void InitialiseInDesignMode()
+    {
+    }
+
+    protected override void Initialise()
+    {
+    }
+}