[Launcher] Allow to select Xenko version

sources/launcher/Xenko.Launcher/Resources/Strings.resx

@@ -422,4 +422,8 @@
     <value>Open '{0}'</value>
     <comment>The tooltip for website links.</comment>
   </data>
-</root>
+  <data name="InstallVersion" xml:space="preserve">
+    <value>Install {0}</value>
+    <comment>{0}: long version name</comment>
+  </data>
+</root>

sources/launcher/Xenko.Launcher/ViewModels/LauncherViewModel.cs

@@ -93,7 +93,7 @@ public void Dispose()
 
         public VsixVersionViewModel VsixPackage { get; }
 
-        public XenkoVersionViewModel ActiveVersion { get { return activeVersion; } set { SetValue(ref activeVersion, value, () => Dispatcher.InvokeAsync(() => StartStudioCommand.IsEnabled = (value != null))); } }
+        public XenkoVersionViewModel ActiveVersion { get { return activeVersion; } set { SetValue(ref activeVersion, value); Dispatcher.InvokeAsync(() => StartStudioCommand.IsEnabled = (value != null) && value.CanStart); } }
 
         public ObservableList<RecentProjectViewModel> RecentProjects { get; } = new ObservableList<RecentProjectViewModel>();
 
@@ -195,7 +195,6 @@ public async Task RetrieveAllXenkoVersions()
             await RetrieveLocalXenkoVersions();
             await RetrieveServerXenkoVersions();
             Dispatcher.Invoke(() => IsSynchronizing = false);
-
         }
 
         public async Task RetrieveLocalXenkoVersions()
@@ -231,7 +230,7 @@ public async Task RetrieveLocalXenkoVersions()
                             {
                                 version = (XenkoStoreVersionViewModel)xenkoVersions[index];
                             }
-                            version.UpdateLocalPackage(localPackage);
+                            version.UpdateLocalPackage(localPackage, package);
                             updatedLocalPackages.Add(version);
                         }
                     }
@@ -240,7 +239,7 @@ public async Task RetrieveLocalXenkoVersions()
                     Dispatcher.Invoke(() =>
                     {
                         foreach (var xenkoUninstalledVersion in xenkoVersions.OfType<XenkoStoreVersionViewModel>().Where(x => !updatedLocalPackages.Contains(x)))
-                            xenkoUninstalledVersion.UpdateLocalPackage(null);
+                            xenkoUninstalledVersion.UpdateLocalPackage(null, new NugetLocalPackage[0]);
                     });
 
                     // Update the active version if it is now invalid.
@@ -368,7 +367,7 @@ private async Task RetrieveServerXenkoVersions()
                                 // If yes, update it and remove it from the list of old version
                                 version = (XenkoStoreVersionViewModel)xenkoVersions[index];
                             }
-                            version.UpdateServerPackage(serverPackage);
+                            version.UpdateServerPackage(serverPackage, package);
                         }
                     }
                 }
@@ -516,7 +515,7 @@ public async Task StartStudio(string argument)
             await Task.Delay(5000);
             Dispatcher.Invoke(() =>
             {
-                StartStudioCommand.IsEnabled = ActiveVersion != null;
+                StartStudioCommand.IsEnabled = ActiveVersion != null && ActiveVersion.CanStart;
                 //Save settings because launcher maybe have not been closed
                 LauncherSettings.ActiveVersion = ActiveVersion != null ? ActiveVersion.Name : "";
                 LauncherSettings.Save();

sources/launcher/Xenko.Launcher/ViewModels/XenkoStoreAlternateVersionViewModel.cs

@@ -0,0 +1,74 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using Xenko.Core;
+using Xenko.Core.Annotations;
+using Xenko.Core.Packages;
+using Xenko.Core.Presentation.Commands;
+using Xenko.Core.Presentation.ViewModel;
+
+namespace Xenko.LauncherApp.ViewModels
+{
+    internal sealed class XenkoStoreAlternateVersionViewModel : DispatcherViewModel
+    {
+        private XenkoStoreVersionViewModel xenkoVersion;
+        internal NugetServerPackage ServerPackage;
+        internal NugetLocalPackage LocalPackage;
+
+        public XenkoStoreAlternateVersionViewModel([NotNull] XenkoStoreVersionViewModel xenkoVersion)
+            : base(xenkoVersion.ServiceProvider)
+        {
+            this.xenkoVersion = xenkoVersion;
+
+            SetAsActiveCommand = new AnonymousCommand(ServiceProvider, () =>
+            {
+                xenkoVersion.UpdateLocalPackage(LocalPackage, null);
+                if (LocalPackage == null)
+                {
+                    // If it's a non installed version, offer same version for serverPackage so that it offers to install this specific version
+                    xenkoVersion.UpdateServerPackage(ServerPackage, null);
+                }
+                else
+                {
+                    // Otherwise, offer latest version for update
+                    xenkoVersion.UpdateServerPackage(xenkoVersion.LatestServerPackage, null);
+                }
+
+                xenkoVersion.Launcher.ActiveVersion = xenkoVersion;
+            });
+        }
+
+        /// <summary>
+        /// Gets the command that will set the associated version as active.
+        /// </summary>
+        public CommandBase SetAsActiveCommand { get; }
+
+        public string FullName
+        {
+            get
+            {
+                if (LocalPackage != null)
+                    return $"{LocalPackage.Id} {LocalPackage.Version} (installed)";
+                return $"{ServerPackage.Id} {ServerPackage.Version}";
+            }
+        }
+
+        public PackageVersion Version => LocalPackage?.Version ?? ServerPackage.Version;
+
+        internal void UpdateLocalPackage(NugetLocalPackage package)
+        {
+            OnPropertyChanging(nameof(FullName), nameof(Version));
+            LocalPackage = package;
+            OnPropertyChanged(nameof(FullName), nameof(Version));
+        }
+
+        internal void UpdateServerPackage(NugetServerPackage package)
+        {
+            OnPropertyChanging(nameof(FullName), nameof(Version));
+            ServerPackage = package;
+            OnPropertyChanged(nameof(FullName), nameof(Version));
+        }
+    }
+}

sources/launcher/Xenko.Launcher/ViewModels/XenkoStoreVersionViewModel.cs

@@ -12,6 +12,8 @@
 using Xenko.Core.Presentation.Collections;
 using Xenko.Core.Presentation.Commands;
 using Xenko.Core.Presentation.Services;
+using System.Collections.Generic;
+using System.Linq;
 
 namespace Xenko.LauncherApp.ViewModels
 {
@@ -20,6 +22,7 @@ namespace Xenko.LauncherApp.ViewModels
     /// </summary>
     internal sealed class XenkoStoreVersionViewModel : XenkoVersionViewModel
     {
+        internal NugetServerPackage LatestServerPackage;
         private ReleaseNotesViewModel releaseNotes;
 
         /// <summary>
@@ -57,6 +60,8 @@ public override string FullName
         /// </summary>
         public string ServerVersionFullName => ServerPackage?.Version?.ToString() ?? "";
 
+        public ObservableList<XenkoStoreAlternateVersionViewModel> AlternateVersions { get; } = new ObservableList<XenkoStoreAlternateVersionViewModel>();
+
         /// <summary>
         /// Gets the release notes associated to this version.
         /// </summary>
@@ -77,22 +82,82 @@ public override string FullName
         /// Updates the local package of this version.
         /// </summary>
         /// <param name="package">The local package corresponding to this version.</param>
-        internal void UpdateLocalPackage(NugetLocalPackage package)
+        internal void UpdateLocalPackage(NugetLocalPackage package, IEnumerable<NugetLocalPackage> alternateVersions)
         {
             OnPropertyChanging(nameof(FullName), nameof(Version));
             LocalPackage = package;
             OnPropertyChanged(nameof(FullName), nameof(Version));
             Dispatcher.Invoke(UpdateStatus);
+            if (alternateVersions != null)
+            {
+                Dispatcher.Invoke(() =>
+                    UpdateAlternateVersions(alternateVersions, (alternateVersionViewModel, alternateVersion) =>
+                    {
+                        if (alternateVersion == null && alternateVersionViewModel.ServerPackage == null)
+                            AlternateVersions.Remove(alternateVersionViewModel);
+                        else
+                            alternateVersionViewModel.UpdateLocalPackage(alternateVersion);
+                    }));
+            }
         }
 
         /// <summary>
         /// Updates the server package of this version.
         /// </summary>
         /// <param name="package">The server package corresponding to this version.</param>
-        internal void UpdateServerPackage(NugetServerPackage package)
+        internal void UpdateServerPackage(NugetServerPackage package, IEnumerable<NugetServerPackage> alternateVersions)
         {
+            OnPropertyChanging(nameof(FullName), nameof(Version));
             ServerPackage = package;
+            OnPropertyChanged(nameof(FullName), nameof(Version));
+
+            // Always keep track of highest version
+            if (ServerPackage != null && (LatestServerPackage == null || LatestServerPackage.Version < ServerPackage.Version))
+                LatestServerPackage = ServerPackage;
+
             Dispatcher.Invoke(UpdateStatus);
+            if (alternateVersions != null)
+            {
+                Dispatcher.Invoke(() =>
+                    UpdateAlternateVersions(alternateVersions, (alternateVersionViewModel, alternateVersion) =>
+                    {
+                        if (alternateVersion == null && alternateVersionViewModel.LocalPackage == null)
+                            AlternateVersions.Remove(alternateVersionViewModel);
+                        else
+                            alternateVersionViewModel.UpdateServerPackage(alternateVersion);
+                    }));
+            }
+        }
+
+        private void UpdateAlternateVersions<T>(IEnumerable<T> alternateVersions, Action<XenkoStoreAlternateVersionViewModel, T> updateAction) where T : NugetPackage
+        {
+            var updatedViewModels = new HashSet<XenkoStoreAlternateVersionViewModel>();
+            foreach (var alternateVersion in alternateVersions)
+            {
+
+                int index = AlternateVersions.IndexOf(x => x.Version == alternateVersion.Version);
+                XenkoStoreAlternateVersionViewModel alternateVersionViewModel;
+                if (index < 0)
+                {
+                    // If not, add it
+                    alternateVersionViewModel = new XenkoStoreAlternateVersionViewModel(this);
+                    AlternateVersions.Add(alternateVersionViewModel);
+                }
+                else
+                {
+                    // If yes, update it and remove it from the list of old version
+                    alternateVersionViewModel = AlternateVersions[index];
+                }
+
+                updateAction(alternateVersionViewModel, alternateVersion);
+                updatedViewModels.Add(alternateVersionViewModel);
+            }
+
+            // Update versions that are not installed locally anymore
+            foreach (var alternateVersionViewModel in AlternateVersions.Where(x => !updatedViewModels.Contains(x)).ToList())
+            {
+                updateAction(alternateVersionViewModel, null);
+            }
         }
 
         internal async Task RunPrerequisitesInstaller()
@@ -183,6 +248,8 @@ protected override void AfterDownload()
         {
             base.AfterDownload();
             RunPrerequisitesInstaller().Forget();
+
+            Launcher.ActiveVersion = this;
         }
 
         /// <summary>

sources/launcher/Xenko.Launcher/ViewModels/XenkoVersionViewModel.cs

@@ -12,6 +12,7 @@ namespace Xenko.LauncherApp.ViewModels
     internal abstract class XenkoVersionViewModel : PackageVersionViewModel, IComparable<XenkoVersionViewModel>, IComparable<Tuple<int, int>>
     {
         private bool isVisible;
+        private bool canStart;
 
         internal XenkoVersionViewModel(LauncherViewModel launcher, NugetStore store, NugetLocalPackage localPackage, int major, int minor)
             : base(launcher, store, localPackage)
@@ -58,6 +59,11 @@ internal XenkoVersionViewModel(LauncherViewModel launcher, NugetStore store, Nug
         /// </summary>
         public bool IsVisible { get { return isVisible; } private set { SetValue(ref isVisible, value); } }
 
+        /// <summary>
+        /// Gets whether this version can be started.
+        /// </summary>
+        public bool CanStart { get { return canStart; } private set { SetValue(ref canStart, value); } }
+
         /// <summary>
         /// Builds a string that represents the given version numbers.
         /// </summary>
@@ -92,6 +98,9 @@ protected override void UpdateStatus()
             IsVisible = Launcher.ShowBetaVersions || !IsBeta || CanDelete;
             SetAsActiveCommand.IsEnabled = CanDelete;
             DeleteCommand.IsEnabled = CanDelete;
+            CanStart = CanDelete;
+            if (Launcher.ActiveVersion == this)
+                Launcher.StartStudioCommand.IsEnabled = CanStart;
         }
 
         public int CompareTo(XenkoVersionViewModel other)