From de9a27597be342516c8bb02036b214f72bec3aa5 Mon Sep 17 00:00:00 2001
From: hultonha <82228511+hultonha@users.noreply.github.com>
Date: Mon, 20 Sep 2021 09:49:01 +0100
Subject: [PATCH] Additional test support for Manipulator Ditto commands
 (#4191)

* additional test support for manipulator ditto

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* tidy-up to changes

Signed-off-by: hultonha <hultonha@amazon.co.uk>

* fix for non-unity build compile error

Signed-off-by: hultonha <hultonha@amazon.co.uk>
---
 Code/Editor/EditorToolsApplication.cpp        |  16 ++-
 Code/Editor/EditorToolsApplication.h          |  10 ++
 Code/Editor/EditorViewportWidget.cpp          |  19 ++--
 Code/Editor/EditorViewportWidget.h            |   4 -
 .../AzFramework/Viewport/ClickDetector.cpp    |  27 ++++-
 .../AzFramework/Viewport/ClickDetector.h      |  14 ++-
 .../ImmediateModeActionDispatcher.h           |  16 +++
 .../Source/ImmediateModeActionDispatcher.cpp  |   2 +
 .../Viewport/ViewportMessages.h               |  18 ++++
 .../EditorTransformComponentSelection.cpp     |  19 +++-
 ...EditorTransformComponentSelectionTests.cpp | 102 +++++++++++++++++-
 11 files changed, 220 insertions(+), 27 deletions(-)

diff --git a/Code/Editor/EditorToolsApplication.cpp b/Code/Editor/EditorToolsApplication.cpp
index 1e5d747e4a..26e608f657 100644
--- a/Code/Editor/EditorToolsApplication.cpp
+++ b/Code/Editor/EditorToolsApplication.cpp
@@ -34,10 +34,14 @@ namespace EditorInternal
         : ToolsApplication(argc, argv)
     {
         EditorToolsApplicationRequests::Bus::Handler::BusConnect();
+        AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusConnect();
+        AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler::BusConnect();
     }
 
     EditorToolsApplication::~EditorToolsApplication()
     {
+        AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler::BusDisconnect();
+        AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusDisconnect();
         EditorToolsApplicationRequests::Bus::Handler::BusDisconnect();
         Stop();
     }
@@ -48,7 +52,6 @@ namespace EditorInternal
         return m_StartupAborted;
     }
 
-
     void EditorToolsApplication::RegisterCoreComponents()
     {
         AzToolsFramework::ToolsApplication::RegisterCoreComponents();
@@ -274,5 +277,14 @@ namespace EditorInternal
         Exit();
     }
 
-}
+    AzToolsFramework::ViewportInteraction::KeyboardModifiers EditorToolsApplication::QueryKeyboardModifiers()
+    {
+        return AzToolsFramework::ViewportInteraction::BuildKeyboardModifiers(QGuiApplication::queryKeyboardModifiers());
+    }
 
+    AZStd::chrono::milliseconds EditorToolsApplication::EditorViewportInputTimeNow()
+    {
+        const auto now = AZStd::chrono::high_resolution_clock::now();
+        return AZStd::chrono::time_point_cast<AZStd::chrono::milliseconds>(now).time_since_epoch();
+    }
+} // namespace EditorInternal
diff --git a/Code/Editor/EditorToolsApplication.h b/Code/Editor/EditorToolsApplication.h
index 422772cbc4..d4e6223445 100644
--- a/Code/Editor/EditorToolsApplication.h
+++ b/Code/Editor/EditorToolsApplication.h
@@ -7,7 +7,9 @@
  */
 
 #pragma once
+
 #include <AzToolsFramework/Application/ToolsApplication.h>
+#include <AzToolsFramework/Viewport/ViewportMessages.h>
 
 #include "Core/EditorMetricsPlainTextNameRegistration.h"
 #include "EditorToolsApplicationAPI.h"
@@ -19,6 +21,8 @@ namespace EditorInternal
     class EditorToolsApplication
         : public AzToolsFramework::ToolsApplication
         , public EditorToolsApplicationRequests::Bus::Handler
+        , public AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler
+        , public AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler
     {
     public:
         EditorToolsApplication(int* argc, char*** argv);
@@ -44,6 +48,12 @@ namespace EditorInternal
         void CreateReflectionManager() override;
         void Reflect(AZ::ReflectContext* context) override;
 
+        // EditorModifierKeyRequestBus overrides ...
+        AzToolsFramework::ViewportInteraction::KeyboardModifiers QueryKeyboardModifiers() override;
+
+        // EditorViewportInputTimeNowRequestBus overrides ...
+        AZStd::chrono::milliseconds EditorViewportInputTimeNow() override;
+
     protected:
         // From EditorToolsApplicationRequests
         bool OpenLevel(AZStd::string_view levelName) override;
diff --git a/Code/Editor/EditorViewportWidget.cpp b/Code/Editor/EditorViewportWidget.cpp
index 1ed901e514..5b5b52d28f 100644
--- a/Code/Editor/EditorViewportWidget.cpp
+++ b/Code/Editor/EditorViewportWidget.cpp
@@ -744,11 +744,15 @@ void EditorViewportWidget::RenderAll()
     {
         namespace AztfVi = AzToolsFramework::ViewportInteraction;
 
+        AztfVi::KeyboardModifiers keyboardModifiers;
+        AztfVi::EditorModifierKeyRequestBus::BroadcastResult(
+            keyboardModifiers, &AztfVi::EditorModifierKeyRequestBus::Events::QueryKeyboardModifiers);
+
         m_debugDisplay->DepthTestOff();
         m_manipulatorManager->DrawManipulators(
             *m_debugDisplay, GetCameraState(),
             BuildMouseInteractionInternal(
-                AztfVi::MouseButtons(AztfVi::TranslateMouseButtons(QGuiApplication::mouseButtons())), QueryKeyboardModifiers(),
+                AztfVi::MouseButtons(AztfVi::TranslateMouseButtons(QGuiApplication::mouseButtons())), keyboardModifiers,
                 BuildMousePick(WidgetToViewport(mapFromGlobal(QCursor::pos())))));
         m_debugDisplay->DepthTestOn();
     }
@@ -959,12 +963,13 @@ QWidget* EditorViewportWidget::GetWidgetForViewportContextMenu()
 
 bool EditorViewportWidget::ShowingWorldSpace()
 {
-    return QueryKeyboardModifiers().Shift();
-}
+    namespace AztfVi = AzToolsFramework::ViewportInteraction;
 
-AzToolsFramework::ViewportInteraction::KeyboardModifiers EditorViewportWidget::QueryKeyboardModifiers()
-{
-    return AzToolsFramework::ViewportInteraction::BuildKeyboardModifiers(QGuiApplication::queryKeyboardModifiers());
+    AztfVi::KeyboardModifiers keyboardModifiers;
+    AztfVi::EditorModifierKeyRequestBus::BroadcastResult(
+        keyboardModifiers, &AztfVi::EditorModifierKeyRequestBus::Events::QueryKeyboardModifiers);
+
+    return keyboardModifiers.Shift();
 }
 
 void EditorViewportWidget::SetViewportId(int id)
@@ -1039,7 +1044,6 @@ void EditorViewportWidget::ConnectViewportInteractionRequestBus()
 {
     AzToolsFramework::ViewportInteraction::MainEditorViewportInteractionRequestBus::Handler::BusConnect(GetViewportId());
     AzToolsFramework::ViewportInteraction::EditorEntityViewportInteractionRequestBus::Handler::BusConnect(GetViewportId());
-    AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusConnect();
     m_viewportUi.ConnectViewportUiBus(GetViewportId());
 
     AzFramework::InputSystemCursorConstraintRequestBus::Handler::BusConnect();
@@ -1050,7 +1054,6 @@ void EditorViewportWidget::DisconnectViewportInteractionRequestBus()
     AzFramework::InputSystemCursorConstraintRequestBus::Handler::BusDisconnect();
 
     m_viewportUi.DisconnectViewportUiBus();
-    AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusDisconnect();
     AzToolsFramework::ViewportInteraction::EditorEntityViewportInteractionRequestBus::Handler::BusDisconnect();
     AzToolsFramework::ViewportInteraction::MainEditorViewportInteractionRequestBus::Handler::BusDisconnect();
 }
diff --git a/Code/Editor/EditorViewportWidget.h b/Code/Editor/EditorViewportWidget.h
index 6b46524394..49930a2a13 100644
--- a/Code/Editor/EditorViewportWidget.h
+++ b/Code/Editor/EditorViewportWidget.h
@@ -92,7 +92,6 @@ class SANDBOX_API EditorViewportWidget final
     , private AzFramework::InputSystemCursorConstraintRequestBus::Handler
     , private AzToolsFramework::ViewportInteraction::MainEditorViewportInteractionRequestBus::Handler
     , private AzToolsFramework::ViewportInteraction::EditorEntityViewportInteractionRequestBus::Handler
-    , private AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler
     , private AzFramework::AssetCatalogEventBus::Handler
     , private AZ::RPI::SceneNotificationBus::Handler
 {
@@ -212,9 +211,6 @@ private:
     // EditorEntityViewportInteractionRequestBus overrides ...
     void FindVisibleEntities(AZStd::vector<AZ::EntityId>& visibleEntities) override;
 
-    // EditorModifierKeyRequestBus overrides ...
-    AzToolsFramework::ViewportInteraction::KeyboardModifiers QueryKeyboardModifiers() override;
-
     // Camera::EditorCameraRequestBus overrides ...
     void SetViewFromEntityPerspective(const AZ::EntityId& entityId) override;
     void SetViewAndMovementLockFromEntityPerspective(const AZ::EntityId& entityId, bool lockCameraMovement) override;
diff --git a/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.cpp b/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.cpp
index b909689c22..1b3645630e 100644
--- a/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.cpp
+++ b/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.cpp
@@ -9,8 +9,19 @@
 #include <AzFramework/Viewport/ClickDetector.h>
 #include <AzFramework/Viewport/ScreenGeometry.h>
 
+#include <AzCore/std/chrono/clocks.h>
+
 namespace AzFramework
 {
+    ClickDetector::ClickDetector()
+    {
+        m_timeNowFn = []
+        {
+            const auto now = AZStd::chrono::high_resolution_clock::now();
+            return AZStd::chrono::time_point_cast<AZStd::chrono::milliseconds>(now).time_since_epoch();
+        };
+    }
+
     ClickDetector::ClickOutcome ClickDetector::DetectClick(const ClickEvent clickEvent, const ScreenVector& cursorDelta)
     {
         const auto previousDetectionState = m_detectionState;
@@ -26,11 +37,13 @@ namespace AzFramework
 
         if (clickEvent == ClickEvent::Down)
         {
-            const auto now = std::chrono::steady_clock::now();
+            const auto now = m_timeNowFn();
             if (m_tryBeginTime)
             {
-                const std::chrono::duration<float> diff = now - m_tryBeginTime.value();
-                if (diff.count() < m_doubleClickInterval)
+                using FloatingPointSeconds = AZStd::chrono::duration<float, AZStd::chrono::seconds::period>;
+
+                const auto diff = now - m_tryBeginTime.value();
+                if (FloatingPointSeconds(diff).count() < m_doubleClickInterval)
                 {
                     return ClickOutcome::Nil;
                 }
@@ -43,7 +56,8 @@ namespace AzFramework
         }
         else if (clickEvent == ClickEvent::Up)
         {
-            const auto clickOutcome = [detectionState = m_detectionState] {
+            const auto clickOutcome = [detectionState = m_detectionState]
+            {
                 if (detectionState == DetectionState::WaitingForMove)
                 {
                     return ClickOutcome::Click;
@@ -66,4 +80,9 @@ namespace AzFramework
 
         return ClickOutcome::Nil;
     }
+
+    void ClickDetector::OverrideTimeNowFn(AZStd::function<AZStd::chrono::milliseconds()> timeNowFn)
+    {
+        m_timeNowFn = AZStd::move(timeNowFn);
+    }
 } // namespace AzFramework
diff --git a/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.h b/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.h
index f95924550a..70bdeb4619 100644
--- a/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.h
+++ b/Code/Framework/AzFramework/AzFramework/Viewport/ClickDetector.h
@@ -8,6 +8,7 @@
 
 #pragma once
 
+#include <AzCore/std/functional.h>
 #include <AzCore/std/optional.h>
 
 #include <chrono>
@@ -21,10 +22,9 @@ namespace AzFramework
     //! (mouse down with movement and then mouse up).
     class ClickDetector
     {
-        //! Alias for recording time of mouse down events
-        using Time = std::chrono::time_point<std::chrono::steady_clock>;
-
     public:
+        ClickDetector();
+
         //! Internal representation of click event (map from external event for this when
         //! calling DetectClick).
         enum class ClickEvent
@@ -51,6 +51,10 @@ namespace AzFramework
         void SetDoubleClickInterval(float doubleClickInterval);
         //! Override the dead zone before a 'move' outcome will be triggered.
         void SetDeadZone(float deadZone);
+        //! Override how the current time is retrieved.
+        //! This is helpful to override when it comes to simulating different passages of
+        //! time to avoid double click issues in tests for example.
+        void OverrideTimeNowFn(AZStd::function<AZStd::chrono::milliseconds()> timeNowFn);
 
     private:
         //! Internal state of ClickDetector based on incoming events.
@@ -65,7 +69,9 @@ namespace AzFramework
         float m_deadZone = 2.0f; //!< How far to move before a click is cancelled (when Move will fire).
         float m_doubleClickInterval = 0.4f; //!< Default double click interval, can be overridden.
         DetectionState m_detectionState; //!< Internal state of ClickDetector.
-        AZStd::optional<Time> m_tryBeginTime; //!< Mouse down time (happens each mouse down, helps with double click handling).
+        //! Mouse down time (happens each mouse down, helps with double click handling).
+        AZStd::optional<AZStd::chrono::milliseconds> m_tryBeginTime;
+        AZStd::function<AZStd::chrono::milliseconds()> m_timeNowFn; //!< Interface to query the current time.
     };
 
     inline void ClickDetector::SetDoubleClickInterval(const float doubleClickInterval)
diff --git a/Code/Framework/AzManipulatorTestFramework/Include/AzManipulatorTestFramework/ImmediateModeActionDispatcher.h b/Code/Framework/AzManipulatorTestFramework/Include/AzManipulatorTestFramework/ImmediateModeActionDispatcher.h
index 7eddd8b915..5d1f606e8c 100644
--- a/Code/Framework/AzManipulatorTestFramework/Include/AzManipulatorTestFramework/ImmediateModeActionDispatcher.h
+++ b/Code/Framework/AzManipulatorTestFramework/Include/AzManipulatorTestFramework/ImmediateModeActionDispatcher.h
@@ -18,6 +18,7 @@ namespace AzManipulatorTestFramework
     class ImmediateModeActionDispatcher
         : public ActionDispatcher<ImmediateModeActionDispatcher>
         , public AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler
+        , public AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler
     {
         using KeyboardModifier = AzToolsFramework::ViewportInteraction::KeyboardModifier;
         using KeyboardModifiers = AzToolsFramework::ViewportInteraction::KeyboardModifiers;
@@ -50,6 +51,9 @@ namespace AzManipulatorTestFramework
         // EditorModifierKeyRequestBus overrides ...
         KeyboardModifiers QueryKeyboardModifiers() override;
 
+        // EditorViewportInputTimeNowRequestBus overrides ...
+        AZStd::chrono::milliseconds EditorViewportInputTimeNow() override;
+
     protected:
         // ActionDispatcher ...
         void SetSnapToGridImpl(bool enabled) override;
@@ -79,6 +83,9 @@ namespace AzManipulatorTestFramework
 
         mutable AZStd::unique_ptr<MouseInteractionEvent> m_event;
         ManipulatorViewportInteraction& m_viewportManipulatorInteraction;
+
+        //! Current time that ticks up after each call to EditorViewportInputTimeNow.
+        AZStd::chrono::milliseconds m_timeNow = AZStd::chrono::milliseconds(0);
     };
 
     template<typename ActualT, typename ExpectedT>
@@ -106,4 +113,13 @@ namespace AzManipulatorTestFramework
     {
         return GetMouseInteractionEvent()->m_mouseInteraction.m_keyboardModifiers;
     }
+
+    inline AZStd::chrono::milliseconds ImmediateModeActionDispatcher::EditorViewportInputTimeNow()
+    {
+        // step the time for each call to be greater than the minimum time required for a double click to register
+        // note: the time increment is very high to ensure any potential system changes to settings such as double
+        // click interval will not be impacted
+        m_timeNow += AZStd::chrono::milliseconds(10000);
+        return m_timeNow;
+    }
 } // namespace AzManipulatorTestFramework
diff --git a/Code/Framework/AzManipulatorTestFramework/Source/ImmediateModeActionDispatcher.cpp b/Code/Framework/AzManipulatorTestFramework/Source/ImmediateModeActionDispatcher.cpp
index 08db7497f4..c122a941c4 100644
--- a/Code/Framework/AzManipulatorTestFramework/Source/ImmediateModeActionDispatcher.cpp
+++ b/Code/Framework/AzManipulatorTestFramework/Source/ImmediateModeActionDispatcher.cpp
@@ -33,10 +33,12 @@ namespace AzManipulatorTestFramework
         : m_viewportManipulatorInteraction(viewportManipulatorInteraction)
     {
         AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusConnect();
+        AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler::BusConnect();
     }
 
     ImmediateModeActionDispatcher::~ImmediateModeActionDispatcher()
     {
+        AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Handler::BusDisconnect();
         AzToolsFramework::ViewportInteraction::EditorModifierKeyRequestBus::Handler::BusDisconnect();
     }
 
diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/ViewportMessages.h b/Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/ViewportMessages.h
index c9438e640d..9d2f7e9b90 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/ViewportMessages.h
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/Viewport/ViewportMessages.h
@@ -282,6 +282,24 @@ namespace AzToolsFramework
             return keyboardModifiers;
         }
 
+        //! An interface to deal with time requests relating to viewports.
+        //! @note The bus is global and not per viewport.
+        class EditorViewportInputTimeNowRequests : public AZ::EBusTraits
+        {
+        public:
+            static const AZ::EBusAddressPolicy AddressPolicy = AZ::EBusAddressPolicy::Single;
+            static const AZ::EBusHandlerPolicy HandlerPolicy = AZ::EBusHandlerPolicy::Single;
+
+            //! Returns the current time in seconds.
+            //! This interface can be overridden for the purposes of testing to simplify viewport input requests.
+            virtual AZStd::chrono::milliseconds EditorViewportInputTimeNow() = 0;
+
+        protected:
+            ~EditorViewportInputTimeNowRequests() = default;
+        };
+
+        using EditorViewportInputTimeNowRequestBus = AZ::EBus<EditorViewportInputTimeNowRequests>;
+
         //! Viewport requests for managing the viewport cursor state.
         class ViewportMouseCursorRequests
         {
diff --git a/Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.cpp b/Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.cpp
index 5820eaafe1..27a77f9ce7 100644
--- a/Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.cpp
+++ b/Code/Framework/AzToolsFramework/AzToolsFramework/ViewportSelection/EditorTransformComponentSelection.cpp
@@ -253,10 +253,10 @@ namespace AzToolsFramework
                  mouseInteraction.m_mouseInteraction.m_keyboardModifiers.Ctrl());
         }
 
-        static bool ManipulatorDitto(const ViewportInteraction::MouseInteractionEvent& mouseInteraction)
+        static bool ManipulatorDitto(
+            const AzFramework::ClickDetector::ClickOutcome clickOutcome, const ViewportInteraction::MouseInteractionEvent& mouseInteraction)
         {
-            return mouseInteraction.m_mouseEvent == ViewportInteraction::MouseEvent::Down &&
-                mouseInteraction.m_mouseInteraction.m_mouseButtons.Left() &&
+            return clickOutcome == AzFramework::ClickDetector::ClickOutcome::Click &&
                 mouseInteraction.m_mouseInteraction.m_keyboardModifiers.Ctrl() &&
                 mouseInteraction.m_mouseInteraction.m_keyboardModifiers.Alt();
         }
@@ -1054,6 +1054,17 @@ namespace AzToolsFramework
         RegisterActions();
         SetupBoxSelect();
         RefreshSelectedEntityIdsAndRegenerateManipulators();
+
+        // ensure the click detector uses the EditorViewportInputTimeNowRequests interface to retrieve elapsed time
+        // note: this is to facilitate overriding this functionality for purposes such as testing
+        m_clickDetector.OverrideTimeNowFn(
+            []
+            {
+                AZStd::chrono::milliseconds timeNow;
+                AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::BroadcastResult(
+                    timeNow, &AzToolsFramework::ViewportInteraction::EditorViewportInputTimeNowRequestBus::Events::EditorViewportInputTimeNow);
+                return timeNow;
+            });
     }
 
     EditorTransformComponentSelection::~EditorTransformComponentSelection()
@@ -1883,7 +1894,7 @@ namespace AzToolsFramework
             }
 
             // set manipulator pivot override translation or orientation (update manipulators)
-            if (Input::ManipulatorDitto(mouseInteraction))
+            if (Input::ManipulatorDitto(clickOutcome, mouseInteraction))
             {
                 PerformManipulatorDitto(entityIdUnderCursor);
                 return false;
diff --git a/Code/Framework/AzToolsFramework/Tests/EditorTransformComponentSelectionTests.cpp b/Code/Framework/AzToolsFramework/Tests/EditorTransformComponentSelectionTests.cpp
index c94e174108..449c4549be 100644
--- a/Code/Framework/AzToolsFramework/Tests/EditorTransformComponentSelectionTests.cpp
+++ b/Code/Framework/AzToolsFramework/Tests/EditorTransformComponentSelectionTests.cpp
@@ -783,7 +783,8 @@ namespace UnitTest
         const auto entity2ScreenPosition = AzFramework::WorldToScreen(m_entity2WorldTranslation, m_cameraState);
 
         // click the entity in the viewport
-        m_actionDispatcher->SetStickySelect(true)->CameraState(m_cameraState)
+        m_actionDispatcher->SetStickySelect(true)
+            ->CameraState(m_cameraState)
             ->MousePosition(entity2ScreenPosition)
             ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Control)
             ->MouseLButtonDown()
@@ -1018,6 +1019,105 @@ namespace UnitTest
         EXPECT_THAT(selectedEntitiesAfter, UnorderedElementsAre(m_entityId1));
     }
 
+    class EditorTransformComponentSelectionViewportPickingManipulatorTestFixtureParam
+        : public EditorTransformComponentSelectionViewportPickingManipulatorTestFixture
+        , public ::testing::WithParamInterface<bool>
+    {
+    };
+
+    TEST_P(
+        EditorTransformComponentSelectionViewportPickingManipulatorTestFixtureParam,
+        StickyAndUnstickyDittoManipulatorToOtherEntityChangesManipulatorAndDoesNotChangeSelection)
+    {
+        PositionEntities();
+        PositionCamera(m_cameraState);
+
+        AzToolsFramework::SelectEntity(m_entityId1);
+
+        // calculate the position in screen space of the second entity
+        const auto entity2ScreenPosition = AzFramework::WorldToScreen(m_entity2WorldTranslation, m_cameraState);
+
+        // single click select entity2
+        m_actionDispatcher->SetStickySelect(GetParam())
+            ->CameraState(m_cameraState)
+            ->MousePosition(entity2ScreenPosition)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Control)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Alt)
+            ->MouseLButtonDown()
+            ->MouseLButtonUp();
+
+        // entity1 is still selected
+        using ::testing::UnorderedElementsAre;
+        auto selectedEntitiesAfter = SelectedEntities();
+        EXPECT_THAT(selectedEntitiesAfter, UnorderedElementsAre(m_entityId1));
+
+        AZStd::optional<AZ::Transform> manipulatorTransform;
+        AzToolsFramework::EditorTransformComponentSelectionRequestBus::EventResult(
+            manipulatorTransform, AzToolsFramework::GetEntityContextId(),
+            &AzToolsFramework::EditorTransformComponentSelectionRequestBus::Events::GetManipulatorTransform);
+
+        EXPECT_THAT(manipulatorTransform->GetTranslation(), IsClose(m_entity2WorldTranslation));
+    }
+
+    TEST_P(
+        EditorTransformComponentSelectionViewportPickingManipulatorTestFixtureParam,
+        StickyAndUnstickyDittoManipulatorToOtherEntityChangesManipulatorAndClickOffResetsManipulator)
+    {
+        PositionEntities();
+        PositionCamera(m_cameraState);
+
+        AzToolsFramework::SelectEntity(m_entityId1);
+
+        // calculate the position in screen space of the second entity
+        const auto entity2ScreenPosition = AzFramework::WorldToScreen(m_entity2WorldTranslation, m_cameraState);
+
+        // position in space above the entities
+        const auto clickOffPositionWorld = AZ::Vector3(5.0f, 15.0f, 12.0f);
+        // calculate the screen space position of the click
+        const auto clickOffPositionScreen = AzFramework::WorldToScreen(clickOffPositionWorld, m_cameraState);
+
+        using ::testing::UnorderedElementsAre;
+        // single click select entity2, then click off
+        m_actionDispatcher->SetStickySelect(GetParam())
+            ->CameraState(m_cameraState)
+            ->MousePosition(entity2ScreenPosition)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Control)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Alt)
+            ->MouseLButtonDown()
+            ->MouseLButtonUp()
+            ->ExecuteBlock(
+                [this]()
+                {
+                    auto selectedEntitiesAfter = SelectedEntities();
+                    EXPECT_THAT(selectedEntitiesAfter, UnorderedElementsAre(m_entityId1));
+
+                    AZStd::optional<AZ::Transform> manipulatorTransform;
+                    AzToolsFramework::EditorTransformComponentSelectionRequestBus::EventResult(
+                        manipulatorTransform, AzToolsFramework::GetEntityContextId(),
+                        &AzToolsFramework::EditorTransformComponentSelectionRequestBus::Events::GetManipulatorTransform);
+
+                    EXPECT_THAT(manipulatorTransform->GetTranslation(), IsClose(m_entity2WorldTranslation));
+                })
+            ->MousePosition(clickOffPositionScreen)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Control)
+            ->KeyboardModifierDown(AzToolsFramework::ViewportInteraction::KeyboardModifier::Alt)
+            ->MouseLButtonDown()
+            ->MouseLButtonUp();
+
+        auto selectedEntitiesAfter = SelectedEntities();
+        EXPECT_THAT(selectedEntitiesAfter, UnorderedElementsAre(m_entityId1));
+
+        AZStd::optional<AZ::Transform> manipulatorTransform;
+        AzToolsFramework::EditorTransformComponentSelectionRequestBus::EventResult(
+            manipulatorTransform, AzToolsFramework::GetEntityContextId(),
+            &AzToolsFramework::EditorTransformComponentSelectionRequestBus::Events::GetManipulatorTransform);
+
+        // manipulator transform is reset
+        EXPECT_THAT(manipulatorTransform->GetTranslation(), IsClose(m_entity1WorldTranslation));
+    }
+
+    INSTANTIATE_TEST_CASE_P(All, EditorTransformComponentSelectionViewportPickingManipulatorTestFixtureParam, testing::Values(true, false));
+
     using EditorTransformComponentSelectionManipulatorTestFixture =
         IndirectCallManipulatorViewportInteractionFixtureMixin<EditorTransformComponentSelectionFixture>;