SelectExtended: Enhanced Keyboard Navigation While Focused on SearchBox (#170)

* SelectExtended Enhanced Keyboard Navigation While Focused on SearchBox

* Add Tab Key

* SearchBox Margin

Author: mckaragoz

CodeBeam.MudBlazor.Extensions/Components/ListExtended/MudListExtended.razor

@@ -25,7 +25,7 @@
         {
             @if (SearchBox == true)
             {
-                <MudListSubheaderExtended T="T" Style="position: sticky; top: -12px; background-color: var(--mud-palette-background); z-index: 10">
+                <MudListSubheaderExtended T="T" Style="position: sticky; top: 0px; padding-top: 8px; margin-top: -8px; background-color: var(--mud-palette-background); z-index: 10">
 
                     <div @onkeydown:stopPropagation class="mud-list-item-extended">
                         @if (MultiSelection && SelectAll && SelectAllPosition == SelectAllPosition.NextToSearchBox && ParentList == null)

CodeBeam.MudBlazor.Extensions/Components/ListExtended/MudListExtended.razor.cs

@@ -807,6 +807,24 @@ protected internal async Task SearchBoxHandleKeyDown(KeyboardEventArgs obj)
                         await _searchField.SelectAsync();
                     }
                     break;
+                case "ArrowUp":
+                case "ArrowDown":
+                    await HandleKeyDown(obj);
+                    break;
+                case "Enter":
+                case "NumpadEnter":
+                    await HandleKeyDown(obj);
+                    if (MudSelectExtended != null && MultiSelection == false)
+                    {
+                        await MudSelectExtended.CloseMenu();
+                        await MudSelectExtended.FocusAsync();
+                    }
+                    break;
+                case "Tab":
+                    await Task.Delay(10);
+                    await ActiveFirstItem();
+                    StateHasChanged();
+                    break;
             }
         }