fix possible nullref on SetFocusToGrid(), project list: restore selected row and clear search after F5 refresh

Author: unitycoder

UnityLauncherPro/MainWindow.xaml

@@ -302,7 +302,7 @@
 					<Button Style="{StaticResource CustomButton}" ToolTip="Add existing project" x:Name="btnAddProjectFolder" Content="Add Project.." Height="22" Width="78" HorizontalAlignment="Right" VerticalAlignment="Top" Background="#FF3F3F46" Foreground="#FFC1C1C1" Margin="0,4,34,0" Click="BtnAddProjectFolder_Click" BorderBrush="{x:Null}" TabIndex="10" />
 					<Button Style="{StaticResource CustomButton}" ToolTip="Refresh list (F5)" x:Name="btnRefreshProjectList" Content="⟳" Height="22" Width="22" HorizontalAlignment="Right" VerticalAlignment="Top" FontSize="16" Background="#FF3F3F46" Foreground="#FFC1C1C1" Margin="0,4,3,0" Padding="1,-2,1,1" BorderBrush="{x:Null}" Click="BtnRefreshProjectList_Click" TabIndex="11"/>
 
-					<DataGrid x:Name="gridRecent" SelectionMode="Single" Margin="4,30,2,42" Background="{x:Null}" BorderBrush="{x:Null}" ColumnHeaderStyle="{StaticResource HeaderStyle}" Padding="0" HorizontalScrollBarVisibility="Disabled" HeadersVisibility="Column" Foreground="#FFD8D8D8" HorizontalGridLinesBrush="#4C000000" VerticalGridLinesBrush="#19000000" AutoGenerateColumns="False" PreviewKeyDown="GridRecent_PreviewKeyDown" Loaded="GridRecent_Loaded" TabIndex="2" CellEditEnding="GridRecent_CellEditEnding" PreviewMouseDoubleClick="GridRecent_PreviewMouseDoubleClick">
+					<DataGrid x:Name="gridRecent" SelectionMode="Single" Margin="4,30,2,42" Background="{x:Null}" BorderBrush="{x:Null}" ColumnHeaderStyle="{StaticResource HeaderStyle}" Padding="0" HorizontalScrollBarVisibility="Disabled" HeadersVisibility="Column" Foreground="#FFD8D8D8" HorizontalGridLinesBrush="#4C000000" VerticalGridLinesBrush="#19000000" AutoGenerateColumns="False" PreviewKeyDown="GridRecent_PreviewKeyDown" Loaded="GridRecent_Loaded" TabIndex="2" CellEditEnding="GridRecent_CellEditEnding" PreviewMouseDoubleClick="GridRecent_PreviewMouseDoubleClick" >
 						<DataGrid.Columns>
 							<DataGridTextColumn CellStyle="{StaticResource NoFocusCellStyle}" Binding="{Binding Title}" ClipboardContentBinding="{x:Null}" Header="Project" IsReadOnly="True" Width="150"/>
 							<DataGridTextColumn Binding="{Binding Version}" ClipboardContentBinding="{x:Null}" Header="Version" IsReadOnly="True" Width="72">

UnityLauncherPro/MainWindow.xaml.cs

@@ -39,7 +39,7 @@ public partial class MainWindow : Window
         public static readonly string launcherArgumentsFile = "LauncherArguments.txt";
         string _filterString = null;
         const string githubURL = "https://github.com/unitycoder/UnityLauncherPro";
-
+        int lastSelectedProjectIndex = 0;
         Mutex myMutex;
 
         public MainWindow()
@@ -339,14 +339,20 @@ void AddUnityInstallationRootFolder()
             }
         }
 
-        void SetFocusToGrid(DataGrid targetGrid)
+        void SetFocusToGrid(DataGrid targetGrid, int index = 0)
         {
             //e.Handled = true; // if enabled, we enter to first row initially
             if (targetGrid.Items.Count < 1) return;
             targetGrid.Focus();
-            targetGrid.SelectedIndex = 0;
-            DataGridRow row = (DataGridRow)targetGrid.ItemContainerGenerator.ContainerFromIndex(0);
+            DataGridRow row = (DataGridRow)targetGrid.ItemContainerGenerator.ContainerFromIndex(index);
+            if (row == null)
+            {
+                gridRecent.UpdateLayout();
+                gridRecent.ScrollIntoView(gridRecent.Items[index]);
+                row = (DataGridRow)gridRecent.ItemContainerGenerator.ContainerFromIndex(index);
+            }
             row.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));
+            targetGrid.SelectedIndex = index;
         }
 
         async void CallGetUnityUpdates()
@@ -490,17 +496,20 @@ private void OnWindowKeyDown(object sender, KeyEventArgs e)
 
                     switch (e.Key)
                     {
-                        case Key.F5: // refresh projects
-                            projectsSource = GetProjects.Scan(getGitBranch: (bool)chkShowGitBranchColumn.IsChecked, getArguments: (bool)chkShowLauncherArgumentsColumn.IsChecked, showMissingFolders: (bool)chkShowMissingFolderProjects.IsChecked);
-                            gridRecent.ItemsSource = projectsSource;
-                            break;
                         case Key.Escape: // clear project search
                             if (txtSearchBox.Text == "")
                             {
                                 SetFocusToGrid(gridRecent);
                             }
                             txtSearchBox.Text = "";
                             break;
+                        case Key.F5:
+                            txtSearchBox.Text = "";
+                            break;
+                        case Key.Up:
+                        case Key.Left:
+                        case Key.Right:
+                        case Key.Down:
                         case Key.F2: // edit arguments
                             break;
                         default: // any key
@@ -563,8 +572,8 @@ private async void OnTabSelectionChanged(object sender, SelectionChangedEventArg
                 if (updatesSource == null)
                 {
                     var task = GetUnityUpdates.Scan();
+                    if (task.IsCompleted == false) return;
                     var items = await task;
-                    // TODO handle errors?
                     if (items == null) return;
                     updatesSource = GetUnityUpdates.Parse(items);
                     if (updatesSource == null) return;
@@ -661,6 +670,7 @@ private void BtnUpgradeProject_Click(object sender, RoutedEventArgs e)
 
         private void GridRecent_Loaded(object sender, RoutedEventArgs e)
         {
+            //Console.WriteLine("GridRecent_Loaded");
             SetFocusToGrid(gridRecent);
         }
 
@@ -763,6 +773,17 @@ private void GridRecent_PreviewKeyDown(object sender, KeyEventArgs e)
         {
             switch (e.Key)
             {
+                case Key.Up:
+                case Key.Down:
+                    break;
+
+                case Key.F5: // refresh projects
+                    txtSearchBox.Text = "";
+                    lastSelectedProjectIndex = gridRecent.SelectedIndex;
+                    projectsSource = GetProjects.Scan(getGitBranch: (bool)chkShowGitBranchColumn.IsChecked, getArguments: (bool)chkShowLauncherArgumentsColumn.IsChecked, showMissingFolders: (bool)chkShowMissingFolderProjects.IsChecked);
+                    gridRecent.ItemsSource = projectsSource;
+                    SetFocusToGrid(gridRecent, lastSelectedProjectIndex);
+                    break;
                 case Key.Tab:
                     if ((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control)
                     {