Fix Editor crash in test teardown calling set_view_pane_layout

If Atom isn't initialized and able to produce a ViewportContext, the Editor would crash. This attempts to make the initialization fail a bit more gracefully and fixes the crash in the cases I've tested.

Gems/Atom/Tools/AtomToolsFramework/Code/Include/AtomToolsFramework/Viewport/RenderViewportWidget.h

@@ -43,9 +43,16 @@ namespace AtomToolsFramework
         //! Creates a RenderViewportWidget.
         //! Requires the Atom RPI to be initialized in order
         //! to internally construct an RPI::ViewportContext.
-        explicit RenderViewportWidget(AzFramework::ViewportId id = AzFramework::InvalidViewportId, QWidget* parent = nullptr);
+        //! If initializeViewportContext is set to false, nothing will be displayed on-screen until InitiliazeViewportContext is called.
+        explicit RenderViewportWidget(QWidget* parent = nullptr, bool shouldInitializeViewportContext = true);
         ~RenderViewportWidget();
 
+        //! Initializes the underlying ViewportContext, if it hasn't already been.
+        //! If id is specified, the target ViewportContext will be overridden.
+        //! NOTE: ViewportContext IDs must be unique.
+        //! Returns true if the ViewportContext is available
+        //! (i.e. GetViewportContext will return a valid pointer).
+        bool InitializeViewportContext(AzFramework::ViewportId id = AzFramework::InvalidViewportId);
         //! Gets the name associated with this viewport's ViewportContext.
         //! This context name can be used to adjust the current Camera
         //! independently of the underlying viewport.

Gems/Atom/Tools/AtomToolsFramework/Code/Source/Viewport/RenderViewportWidget.cpp

@@ -31,12 +31,35 @@
 
 namespace AtomToolsFramework
 {
-    RenderViewportWidget::RenderViewportWidget(AzFramework::ViewportId id, QWidget* parent)
+    RenderViewportWidget::RenderViewportWidget(QWidget* parent, bool shouldInitializeViewportContext)
         : QWidget(parent)
         , AzFramework::InputChannelEventListener(AzFramework::InputChannelEventListener::GetPriorityDefault())
     {
+        if (shouldInitializeViewportContext)
+        {
+            InitializeViewportContext();
+        }
+
+        setUpdatesEnabled(false);
+        setFocusPolicy(Qt::FocusPolicy::WheelFocus);
+        setMouseTracking(true);
+    }
+
+    bool RenderViewportWidget::InitializeViewportContext(AzFramework::ViewportId id)
+    {
+        if (m_viewportContext != nullptr)
+        {
+            AZ_Assert(id == AzFramework::InvalidViewportId || m_viewportContext->GetId() == id, "Attempted to reinitialize RenderViewportWidget with a different ID");
+            return true;
+        }
+
         auto viewportContextManager = AZ::Interface<AZ::RPI::ViewportContextRequestsInterface>::Get();
-        AZ_Assert(viewportContextManager, "Attempted to construct RenderViewportWidget without ViewportContextManager");
+        AZ_Assert(viewportContextManager, "Attempted to initialize RenderViewportWidget without ViewportContextManager");
+
+        if (viewportContextManager == nullptr)
+        {
+            return false;
+        }
 
         // Before we do anything else, we must create a ViewportContext which will give us a ViewportId if we didn't manually specify one.
         AZ::RPI::ViewportContextRequestsInterface::CreationParameters params;
@@ -46,6 +69,11 @@ namespace AtomToolsFramework
         AzFramework::WindowRequestBus::Handler::BusConnect(params.windowHandle);
         m_viewportContext = viewportContextManager->CreateViewportContext(AZ::Name(), params);
 
+        if (m_viewportContext == nullptr)
+        {
+            return false;
+        }
+
         SetControllerList(AZStd::make_shared<AzFramework::ViewportControllerList>());
 
         AZ::Name cameraName = AZ::Name(AZStd::string::format("Viewport %i Default Camera", m_viewportContext->GetId()));
@@ -58,9 +86,7 @@ namespace AtomToolsFramework
         AZ::TickBus::Handler::BusConnect();
         AzFramework::WindowRequestBus::Handler::BusConnect(params.windowHandle);
 
-        setUpdatesEnabled(false);
-        setFocusPolicy(Qt::FocusPolicy::WheelFocus);
-        setMouseTracking(true);
+        return true;
     }
 
     RenderViewportWidget::~RenderViewportWidget()

Gems/Atom/Tools/MaterialEditor/Code/Source/Viewport/MaterialViewportWidget.cpp

@@ -38,7 +38,7 @@ namespace MaterialEditor
 {
 
     MaterialViewportWidget::MaterialViewportWidget(QWidget* parent)
-        : AtomToolsFramework::RenderViewportWidget(AzFramework::InvalidViewportId, parent)
+        : AtomToolsFramework::RenderViewportWidget(parent)
         , m_ui(new Ui::MaterialViewportWidget)
     {
         m_ui->setupUi(this);