Add deleteElement to C++ API

Add possibility to delete elements that have been added with
createElement.

Task-number: QT3DS-3374
Change-Id: I701e565241d18294171cd63ef934083f627b89aa
Reviewed-by: Tomi Korpipää <tomi.korpipaa@qt.io>

9 files changed, 144 insertions, 7 deletions

diff --git a/src/Runtime/Source/engine/Qt3DSRenderRuntimeBindingImpl.h b/src/Runtime/Source/engine/Qt3DSRenderRuntimeBindingImpl.h
index c174d4a7..92cb8658 100644
--- a/src/Runtime/Source/engine/Qt3DSRenderRuntimeBindingImpl.h
+++ b/src/Runtime/Source/engine/Qt3DSRenderRuntimeBindingImpl.h
@@ -190,8 +190,8 @@ namespace render {
 
         static Qt3DSTranslator *GetTranslatorFromGraphNode(SGraphObject &inObject);
         static Qt3DSTranslator *CreateTranslatorForElement(Q3DStudio::TElement &inElement,
-                                                          SGraphObject &inGraphObject,
-                                                          NVAllocatorCallback &inAlloc);
+                                                           SGraphObject &inGraphObject,
+                                                           NVAllocatorCallback &inAlloc);
         static Q3DStudio::IPresentation *
         GetPresentationFromPresentation(SPresentation &inPresentation);
         static void InitializePointerTags(IStringTable &inTable);
diff --git a/src/Runtime/Source/engine/Qt3DSRuntimeView.cpp b/src/Runtime/Source/engine/Qt3DSRuntimeView.cpp
index abff8f09..9863031d 100644
--- a/src/Runtime/Source/engine/Qt3DSRuntimeView.cpp
+++ b/src/Runtime/Source/engine/Qt3DSRuntimeView.cpp
@@ -217,6 +217,7 @@ public:
 
     void createElement(const QString &parentElementPath, const QString &slideName,
                        const QHash<QString, QVariant> &properties) override;
+    void deleteElement(const QString &elementPath) override;
     void SetAttribute(const char *elementPath, const char *attributeName,
                       const char *value) override;
     bool GetAttribute(const char *elementPath, const char *attributeName, void *value) override;
@@ -615,7 +616,7 @@ float CRuntimeView::dataInputMin(const QString &name) const
 }
 
 void CRuntimeView::createElement(const QString &parentElementPath, const QString &slideName,
-                             const QHash<QString, QVariant> &properties)
+                                 const QHash<QString, QVariant> &properties)
 {
     if (m_Application) {
         Q3DStudio::CQmlEngine &theBridgeEngine
@@ -625,7 +626,18 @@ void CRuntimeView::createElement(const QString &parentElementPath, const QString
     }
 }
 
-void CRuntimeView::SetAttribute(const char *elementPath, const char *attributeName, const char *value)
+void CRuntimeView::deleteElement(const QString &elementPath)
+{
+    if (m_Application) {
+        Q3DStudio::CQmlEngine &theBridgeEngine
+                = static_cast<Q3DStudio::CQmlEngine &>(m_RuntimeFactoryCore->GetScriptEngineQml());
+        theBridgeEngine.deleteElement(elementPath,
+                                      &m_RuntimeFactory->GetQt3DSRenderContext().GetRenderer());
+    }
+}
+
+void CRuntimeView::SetAttribute(const char *elementPath, const char *attributeName,
+                                const char *value)
 {
     if (m_Application) {
         if (!elementPath || !attributeName || !value)
diff --git a/src/Runtime/Source/engine/Qt3DSRuntimeView.h b/src/Runtime/Source/engine/Qt3DSRuntimeView.h
index 3626fd52..776fbea2 100644
--- a/src/Runtime/Source/engine/Qt3DSRuntimeView.h
+++ b/src/Runtime/Source/engine/Qt3DSRuntimeView.h
@@ -191,6 +191,7 @@ public:
     virtual float dataInputMin(const QString &name) const = 0;
     virtual void createElement(const QString &parentElementPath, const QString &slideName,
                                const QHash<QString, QVariant> &properties) = 0;
+    virtual void deleteElement(const QString &elementPath) = 0;
     virtual void SetAttribute(const char *elementPath, const char *attributeName,
                               const char *value) = 0;
     virtual bool GetAttribute(const char *elementPath, const char *attributeName, void *value) = 0;
diff --git a/src/Runtime/Source/runtime/Qt3DSIScriptBridge.h b/src/Runtime/Source/runtime/Qt3DSIScriptBridge.h
index 3b26abd2..2aa59339 100644
--- a/src/Runtime/Source/runtime/Qt3DSIScriptBridge.h
+++ b/src/Runtime/Source/runtime/Qt3DSIScriptBridge.h
@@ -161,6 +161,8 @@ public: // Elements
     virtual void createElement(const QString &parentElementPath, const QString &slideName,
                                const QHash<QString, QVariant> &properties,
                                qt3ds::render::IQt3DSRenderer *renderer) = 0;
+    virtual void deleteElement(const QString &elementPath,
+                               qt3ds::render::IQt3DSRenderer *renderer) = 0;
 
 public: // Components
     virtual void GotoSlide(const char *component, const char *slideName,
diff --git a/src/Runtime/Source/runtime/Qt3DSQmlEngine.cpp b/src/Runtime/Source/runtime/Qt3DSQmlEngine.cpp
index 23a097a7..86f68bdd 100644
--- a/src/Runtime/Source/runtime/Qt3DSQmlEngine.cpp
+++ b/src/Runtime/Source/runtime/Qt3DSQmlEngine.cpp
@@ -420,6 +420,8 @@ public:
     void createElement(const QString &parentElementPath, const QString &slideName,
                        const QHash<QString, QVariant> &properties,
                        qt3ds::render::IQt3DSRenderer *renderer) override;
+    void deleteElement(const QString &elementPath,
+                       qt3ds::render::IQt3DSRenderer *renderer) override;
     //void createMaterial() override; // TODO (QT3DS-3377)
     //void createMesh() override; // TODO (QT3DS-3378)
 
@@ -1042,7 +1044,6 @@ void CQmlEngineImpl::createElement(const QString &parentElementPath, const QStri
         return;
     }
 
-
     // First check if we can resolve the referenced material before creating any graph objects
     // Find a match in material container
     // If the specified material is not available in original presentation, or was not specified,
@@ -1086,7 +1087,7 @@ void CQmlEngineImpl::createElement(const QString &parentElementPath, const QStri
         }
     }
 
-    // Create new SGraphObject (SNode)
+    // Create model SGraphObject
     NVAllocatorCallback &allocator = presentation->GetScene()->allocator();
     qt3ds::render::SModel *newObject = QT3DS_NEW(allocator, qt3ds::render::SModel)();
     newObject->m_Id = strTable.RegisterStr((QByteArrayLiteral("_newObject_")
@@ -1124,6 +1125,77 @@ void CQmlEngineImpl::createElement(const QString &parentElementPath, const QStri
     renderer->ChildrenUpdated(parentObject);
 }
 
+// Only supports deleting element types that can be added via createElement.
+void CQmlEngineImpl::deleteElement(const QString &elementPath,
+                                   qt3ds::render::IQt3DSRenderer *renderer)
+{
+    // Resolve element
+    QByteArray thePath = elementPath.toUtf8();
+    TElement *element = getTarget(thePath.constData());
+
+    if (!element) {
+        qWarning() << __FUNCTION__ <<  "Invalid element:" << elementPath;
+        return;
+    }
+
+    // Remove element recursively from slide system
+    IPresentation *presentation = element->GetBelongedPresentation();
+    TElement &component = element->GetComponentParent();
+    ISlideSystem &slideSystem = presentation->GetSlideSystem();
+    slideSystem.removeElement(component, *element);
+
+    TElement *parentElement = element->GetParent();
+    Q_ASSERT(parentElement);
+
+    NVAllocatorCallback &allocator = presentation->GetScene()->allocator();
+
+    // Recursive deleter for translators and graph objects
+    std::function<void(TElement *)> deleteRenderObjects;
+    deleteRenderObjects = [&](TElement *elem)  {
+        TElement *child = elem->m_Child;
+        while (child) {
+            TElement *sibling = child->m_Sibling;
+            deleteRenderObjects(child);
+            child = sibling;
+        }
+
+        auto translator = static_cast<qt3ds::render::Qt3DSTranslator *>(elem->GetAssociation());
+        if (translator) {
+            if (translator->GetUIPType() == qt3ds::render::GraphObjectTypes::Model) {
+                auto model = static_cast<qt3ds::render::SModel *>(&translator->RenderObject());
+                // Delete material
+                if (model->m_FirstMaterial) {
+                    auto material = static_cast<qt3ds::render::SReferencedMaterial *>(
+                                model->m_FirstMaterial);
+                    QT3DS_FREE(allocator, material);
+                }
+                QT3DS_FREE(allocator, model);
+            }
+            QT3DS_FREE(allocator, translator);
+        }
+    };
+
+    qt3ds::render::SNode *node = nullptr;
+    qt3ds::render::SNode *parentNode = nullptr;
+    auto translator = static_cast<qt3ds::render::Qt3DSTranslator *>(element->GetAssociation());
+
+    if (translator) {
+        node = &static_cast<qt3ds::render::SNode &>(translator->RenderObject());
+        auto parentTranslator = static_cast<qt3ds::render::Qt3DSTranslator *>(
+                    parentElement->GetAssociation());
+        if (parentTranslator) {
+            parentNode = &static_cast<qt3ds::render::SNode &>(parentTranslator->RenderObject());
+            parentNode->RemoveChild(*node);
+            renderer->ChildrenUpdated(*parentNode);
+        }
+        // Release child element graph objects/translators
+        deleteRenderObjects(element);
+    }
+
+    // Remove element recursively
+    m_Application->GetElementAllocator().ReleaseElement(*element, true);
+}
+
 void CQmlEngineImpl::GotoSlide(const char *component, const char *slideName,
                                const SScriptEngineGotoSlideArgs &inArgs)
 {
diff --git a/src/Runtime/Source/runtime/Qt3DSSlideSystem.cpp b/src/Runtime/Source/runtime/Qt3DSSlideSystem.cpp
index 3e2f95c2..33c7544d 100644
--- a/src/Runtime/Source/runtime/Qt3DSSlideSystem.cpp
+++ b/src/Runtime/Source/runtime/Qt3DSSlideSystem.cpp
@@ -255,7 +255,6 @@ struct SSlideSystem : public ISlideSystem
         }
     }
 
-
     // The parent element must be found from target slide.
     // Elements cannot be added to the master slide.
     bool addSlideElement(element::SElement &inComponent, int slideIndex,
@@ -314,6 +313,46 @@ struct SSlideSystem : public ISlideSystem
         return true;
     }
 
+    void removeElementRecursive(SSlide *slide, element::SElement &inElement)
+    {
+        element::SElement *child = inElement.m_Child;
+        while (child) {
+            removeElementRecursive(slide, *child);
+            child = child->m_Sibling;
+        }
+
+        SSlideElement *slideElement = slide->m_FirstElement;
+        SSlideElement *previousElement = nullptr;
+        while (slideElement) {
+            if (slideElement->m_ElementHandle == inElement.m_Handle) {
+                if (slide->m_FirstElement == slideElement)
+                    slide->m_FirstElement = slideElement->m_NextElement;
+                if (slide->m_lastElement == slideElement)
+                    slide->m_lastElement = previousElement;
+                if (previousElement)
+                    previousElement->m_NextElement = slideElement->m_NextElement;
+                m_SlideElements.deallocate(slideElement);
+                break;
+            }
+            previousElement = slideElement;
+            slideElement = slideElement->m_NextElement;
+        }
+    }
+
+    // Removes element and its children from all slides
+    void removeElement(element::SElement &inComponent, element::SElement &inElement) override
+    {
+        TComponentSlideHash::const_iterator theFindResult = m_Slides.find(&inComponent);
+        if (theFindResult == m_Slides.end()) {
+            qWarning() << __FUNCTION__ << "Could not find slides for component";
+            return;
+        }
+
+        SSlide *slide = theFindResult->second;
+        for (; slide; slide = slide->m_NextSlide)
+            removeElementRecursive(slide, inElement);
+    }
+
     void AddSlideAttribute(Q3DStudio::SAttributeKey inKey, Q3DStudio::UVariant inValue) override
     {
         if (m_CurrentSlideElement) {
diff --git a/src/Runtime/Source/runtime/Qt3DSSlideSystem.h b/src/Runtime/Source/runtime/Qt3DSSlideSystem.h
index 3aa2a011..d3accbd3 100644
--- a/src/Runtime/Source/runtime/Qt3DSSlideSystem.h
+++ b/src/Runtime/Source/runtime/Qt3DSSlideSystem.h
@@ -128,6 +128,8 @@ namespace runtime {
         virtual void AddSlideElement(element::SElement &inElement, bool inActive) = 0;
         virtual bool addSlideElement(element::SElement &inComponent, int slideIndex,
                                      element::SElement &inElement, bool eyeBall) = 0;
+        virtual void removeElement(element::SElement &inComponent,
+                                   element::SElement &inElement) = 0;
         virtual void AddSlideAttribute(Q3DStudio::SAttributeKey inKey,
                                        Q3DStudio::UVariant inValue) = 0;
         virtual SSlideAnimAction *AddSlideAnimAction(bool inAnimation, QT3DSI32 inIndex,
diff --git a/src/Runtime/Source/viewer/Qt3DSViewerApp.cpp b/src/Runtime/Source/viewer/Qt3DSViewerApp.cpp
index 005eedcd..4dd5dbd9 100644
--- a/src/Runtime/Source/viewer/Qt3DSViewerApp.cpp
+++ b/src/Runtime/Source/viewer/Qt3DSViewerApp.cpp
@@ -803,6 +803,14 @@ void Q3DSViewerApp::createElement(const QString &parentElementPath, const QStrin
     m_Impl.m_view->createElement(parentElementPath, slideName, properties);
 }
 
+void Q3DSViewerApp::deleteElement(const QString &elementPath)
+{
+    if (!m_Impl.m_view)
+        return;
+
+    m_Impl.m_view->deleteElement(elementPath);
+}
+
 Q3DSViewerApp &Q3DSViewerApp::Create(void *glContext, Q3DStudio::IAudioPlayer *inAudioPlayer,
                                      QElapsedTimer *startupTimer)
 {
diff --git a/src/Runtime/Source/viewer/Qt3DSViewerApp.h b/src/Runtime/Source/viewer/Qt3DSViewerApp.h
index a4bdc2e3..66a40e76 100644
--- a/src/Runtime/Source/viewer/Qt3DSViewerApp.h
+++ b/src/Runtime/Source/viewer/Qt3DSViewerApp.h
@@ -361,6 +361,7 @@ public:
 
     void createElement(const QString &parentElementPath, const QString &slideName,
                        const QHash<QString, QVariant> &properties);
+    void deleteElement(const QString &elementPath);
 
     QString error();