Gui: add new API ViewProviderDocumentObject::allowOverride()

This API is used to delcare if a view provider can be used as an override for a give object. Conflicts: src/App/DocumentObject.h
FreeCAD · Oct 6, 2019 · 6663d62 · 6663d62
1 parent 4775def
commit 6663d62
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Showing 10 changed files with 89 additions and 103 deletions.
diff --git a/src/App/Document.cpp b/src/App/Document.cpp
@@ -3540,17 +3540,8 @@ DocumentObject * Document::addObject(const char* sType, const char* pObjectName,
 
     pcObject->setStatus(ObjectStatus::PartialObject, isPartial);
 
-    // If an object does not allow to override its view provider then ignore any
-    // input of the Document.xml or from Python as this information could be wrong.
-    // In this case the default type from getViewProviderName() is used.
-    if (pcObject->allowOverrideViewProviderName()) {
-        if (!viewType || viewType[0] == '\0') {
-            viewType = pcObject->getViewProviderNameOverride();
-        }
-    }
-    else {
-        viewType = pcObject->getViewProviderName();
-    }
+    if (!viewType || viewType[0] == '\0')
+        viewType = pcObject->getViewProviderNameOverride();
 
     if (viewType && viewType[0] != '\0')
         pcObject->_pcViewProviderName = viewType;
@@ -3644,16 +3635,8 @@ std::vector<DocumentObject *> Document::addObjects(const char* sType, const std:
         // mark the object as new (i.e. set status bit 2) and send the signal
         pcObject->setStatus(ObjectStatus::New, true);
 
-        // If an object does not allow to override its view provider then use
-        // getViewProviderName() instead.
-        if (pcObject->allowOverrideViewProviderName()) {
-            const char *viewType = pcObject->getViewProviderNameOverride();
-            pcObject->_pcViewProviderName = viewType ? viewType : "";
-        }
-        else {
-            const char *viewType = pcObject->getViewProviderName();
-            pcObject->_pcViewProviderName = viewType ? viewType : "";
-        }
+        const char *viewType = pcObject->getViewProviderNameOverride();
+        pcObject->_pcViewProviderName = viewType ? viewType : "";
 
         signalNewObject(*pcObject);
 
@@ -3711,16 +3694,8 @@ void Document::addObject(DocumentObject* pcObject, const char* pObjectName)
     // mark the object as new (i.e. set status bit 2) and send the signal
     pcObject->setStatus(ObjectStatus::New, true);
 
-    // If an object does not allow to override its view provider then use
-    // getViewProviderName() instead.
-    if (pcObject->allowOverrideViewProviderName()) {
-        const char *viewType = pcObject->getViewProviderNameOverride();
-        pcObject->_pcViewProviderName = viewType ? viewType : "";
-    }
-    else {
-        const char *viewType = pcObject->getViewProviderName();
-        pcObject->_pcViewProviderName = viewType ? viewType : "";
-    }
+    const char *viewType = pcObject->getViewProviderNameOverride();
+    pcObject->_pcViewProviderName = viewType ? viewType : "";
 
     signalNewObject(*pcObject);
 
@@ -3751,16 +3726,8 @@ void Document::_addObject(DocumentObject* pcObject, const char* pObjectName)
             d->activeUndoTransaction->addObjectDel(pcObject);
     }
 
-    // If an object does not allow to override its view provider then use
-    // getViewProviderName() instead.
-    if (pcObject->allowOverrideViewProviderName()) {
-        const char *viewType = pcObject->getViewProviderNameOverride();
-        pcObject->_pcViewProviderName = viewType ? viewType : "";
-    }
-    else {
-        const char *viewType = pcObject->getViewProviderName();
-        pcObject->_pcViewProviderName = viewType ? viewType : "";
-    }
+    const char *viewType = pcObject->getViewProviderNameOverride();
+    pcObject->_pcViewProviderName = viewType ? viewType : "";
 
     // send the signal
     signalNewObject(*pcObject);

diff --git a/src/App/DocumentObject.h b/src/App/DocumentObject.h
@@ -114,22 +114,15 @@ class AppExport DocumentObject: public App::TransactionalObject
      * This function is introduced to allow Python feature override its view provider.
      * The default implementation just returns \ref getViewProviderName().
      *
-     * If this method is reimplemented in sub-classes then also reimplement \ref
-     * allowOverrideViewProviderName() accordingly.
+     * The core will only accept the overridden view provider if it returns
+     * true when calling Gui::ViewProviderDocumentObject::allowOverride(obj).
+     * If not, the view provider will be reverted to the one returned from \ref
+     * getViewProviderName().
      */
     virtual const char *getViewProviderNameOverride() const {
         return getViewProviderName();
     }
-    /**
-     * The function indicates whether the object type allows to define a view provider type
-     * different than the standard type. The default implementation returns false.
-     * The function can be overridden by Python feature to return true where the type can be
-     * retrieved from its proxy object.
-     * \sa getViewProviderNameOverride()
-     */
-    virtual bool allowOverrideViewProviderName() const {
-        return false;
-    }
+
     /// Constructor
     DocumentObject(void);
     virtual ~DocumentObject();

diff --git a/src/App/FeaturePython.cpp b/src/App/FeaturePython.cpp
@@ -435,11 +435,6 @@ int FeaturePythonImp::setElementVisible(const char *element, bool visible) {
     }
 }
 
-bool FeaturePythonImp::allowOverrideViewProviderName() const
-{
-    return true;
-}
-
 std::string FeaturePythonImp::getViewProviderName()
 {
     _FC_PY_CALL_CHECK(getViewProviderName,return(std::string()));

diff --git a/src/App/FeaturePython.h b/src/App/FeaturePython.h
@@ -57,7 +57,6 @@ class AppExport FeaturePythonImp
     bool onBeforeChangeLabel(std::string &newLabel);
     void onChanged(const Property* prop);
     void onDocumentRestored();
-    bool allowOverrideViewProviderName() const;
     std::string getViewProviderName();
     PyObject *getPyObject(void);
 
@@ -200,9 +199,6 @@ class FeaturePythonT : public FeatureT
         }
         return DocumentObject::StdReturn;
     }
-    virtual bool allowOverrideViewProviderName() const {
-        return imp->allowOverrideViewProviderName();
-    }
     virtual const char* getViewProviderNameOverride(void) const override {
         viewProviderName = imp->getViewProviderName();
         if(viewProviderName.size())

diff --git a/src/Gui/Document.cpp b/src/Gui/Document.cpp
@@ -621,44 +621,52 @@ void Document::slotNewObject(const App::DocumentObject& Obj)
     if (!pcProvider) {
         //Base::Console().Log("Document::slotNewObject() called\n");
         std::string cName = Obj.getViewProviderNameStored();
-        if (cName.empty()) {
-            // handle document object with no view provider specified
-            Base::Console().Log("%s has no view provider specified\n", Obj.getTypeId().getName());
-            return;
+        for(;;) {
+            if (cName.empty()) {
+                // handle document object with no view provider specified
+                FC_LOG(Obj.getFullName() << " has no view provider specified");
+                return;
+            }
+            Base::BaseClass* base = static_cast<Base::BaseClass*>(
+                    Base::Type::createInstanceByName(cName.c_str(),true));
+            pcProvider = Base::freecad_dynamic_cast<ViewProviderDocumentObject>(base);
+            if (!pcProvider) {
+                // type not derived from ViewProviderDocumentObject!!!
+                FC_ERR("Invalid view provider type '" << cName << "' for " << Obj.getFullName());
+                delete base;
+                return;
+            } else if (cName!=Obj.getViewProviderName() && !pcProvider->allowOverride(Obj)) {
+                FC_WARN("View provider type '" << cName << "' does not support " << Obj.getFullName());
+                delete base;
+                pcProvider = 0;
+                cName = Obj.getViewProviderName();
+            } else
+                break;
         }
 
         setModified(true);
-        Base::BaseClass* base = static_cast<Base::BaseClass*>(Base::Type::createInstanceByName(cName.c_str(),true));
-        if (base) {
-            // type not derived from ViewProviderDocumentObject!!!
-            assert(base->getTypeId().isDerivedFrom(Gui::ViewProviderDocumentObject::getClassTypeId()));
-            pcProvider = static_cast<ViewProviderDocumentObject*>(base);
-            d->_ViewProviderMap[&Obj] = pcProvider;
-            d->_CoinMap[pcProvider->getRoot()] = pcProvider;
-            pcProvider->setStatus(Gui::ViewStatus::TouchDocument, d->_changeViewTouchDocument);
+        d->_ViewProviderMap[&Obj] = pcProvider;
+        d->_CoinMap[pcProvider->getRoot()] = pcProvider;
+        pcProvider->setStatus(Gui::ViewStatus::TouchDocument, d->_changeViewTouchDocument);
 
-            try {
-                // if successfully created set the right name and calculate the view
-                //FIXME: Consider to change argument of attach() to const pointer
-                pcProvider->attach(const_cast<App::DocumentObject*>(&Obj));
-                pcProvider->updateView();
-                pcProvider->setActiveMode();
-            }
-            catch(const Base::MemoryException& e){
-                FC_ERR("Memory exception in " << Obj.getFullName() << " thrown: " << e.what());
-            }
-            catch(Base::Exception &e){
-                e.ReportException();
-            }
-#ifndef FC_DEBUG
-            catch(...){
-                FC_ERR("Unknown exception in Feature " << Obj.getFullName() << " thrown");
-            }
-#endif
+        try {
+            // if successfully created set the right name and calculate the view
+            //FIXME: Consider to change argument of attach() to const pointer
+            pcProvider->attach(const_cast<App::DocumentObject*>(&Obj));
+            pcProvider->updateView();
+            pcProvider->setActiveMode();
+        }
+        catch(const Base::MemoryException& e){
+            FC_ERR("Memory exception in " << Obj.getFullName() << " thrown: " << e.what());
         }
-        else {
-            FC_WARN("no view provider for the object " << cName << " found");
+        catch(Base::Exception &e){
+            e.ReportException();
+        }
+#ifndef FC_DEBUG
+        catch(...){
+            FC_ERR("Unknown exception in Feature " << Obj.getFullName() << " thrown");
         }
+#endif
     }else{
         try {
             pcProvider->reattach(const_cast<App::DocumentObject*>(&Obj));

diff --git a/src/Gui/ViewProviderDocumentObject.h b/src/Gui/ViewProviderDocumentObject.h
@@ -139,6 +139,14 @@ class GuiExport ViewProviderDocumentObject : public ViewProvider
 
     virtual std::string getFullName() const override;
 
+    /** Allow this class to be used as an override for the original view provider of the given object
+     *
+     * @sa App::DocumentObject::getViewProviderNameOverride()
+     */
+    virtual bool allowOverride(const App::DocumentObject &) const {
+        return false;
+    }
+
 protected:
     /*! Get the active mdi view of the document this view provider is part of.
       @note The returned mdi view doesn't need to be a 3d view but can be e.g.

diff --git a/src/Gui/ViewProviderLink.cpp b/src/Gui/ViewProviderLink.cpp
@@ -1711,15 +1711,22 @@ QPixmap ViewProviderLink::getOverlayPixmap() const {
 void ViewProviderLink::onChanged(const App::Property* prop) {
     if(prop==&ChildViewProvider) {
         childVp = freecad_dynamic_cast<ViewProviderDocumentObject>(ChildViewProvider.getObject().get());
-        if(childVp) {
-            childVp->setPropertyPrefix("ChildViewProvider.");
-            childVp->Visibility.setValue(getObject()->Visibility.getValue());
-            childVp->attach(getObject());
-            childVp->updateView();
-            childVp->setActiveMode();
-            if(pcModeSwitch->getNumChildren()>1){
-                childVpLink = LinkInfo::get(childVp,0);
-                pcModeSwitch->replaceChild(1,childVpLink->getSnapshot(LinkView::SnapshotTransform));
+        if(childVp && getObject()) {
+            if(strcmp(childVp->getTypeId().getName(),getObject()->getViewProviderName())!=0
+                    && !childVp->allowOverride(*getObject()))
+            {
+                FC_ERR("Child view provider type '" << childVp->getTypeId().getName()
+                        << "' does not support " << getObject()->getFullName());
+            } else {
+                childVp->setPropertyPrefix("ChildViewProvider.");
+                childVp->Visibility.setValue(getObject()->Visibility.getValue());
+                childVp->attach(getObject());
+                childVp->updateView();
+                childVp->setActiveMode();
+                if(pcModeSwitch->getNumChildren()>1){
+                    childVpLink = LinkInfo::get(childVp,0);
+                    pcModeSwitch->replaceChild(1,childVpLink->getSnapshot(LinkView::SnapshotTransform));
+                }
             }
         }
     }else if(!isRestoring()) {

diff --git a/src/Gui/ViewProviderLink.h b/src/Gui/ViewProviderLink.h
@@ -265,6 +265,10 @@ class GuiExport ViewProviderLink : public ViewProviderDocumentObject
     virtual ViewProviderDocumentObject *getLinkedViewProvider(
             std::string *subname=0, bool recursive=false) const override;
 
+    virtual bool allowOverride(const App::DocumentObject &) const override {
+        return true;
+    }
+
 protected:
     bool setEdit(int ModNum) override;
     void setEditViewer(View3DInventorViewer*, int ModNum) override;

diff --git a/src/Mod/Part/Gui/ViewProviderExt.cpp b/src/Mod/Part/Gui/ViewProviderExt.cpp
@@ -467,6 +467,12 @@ void ViewProviderPartExt::onChanged(const App::Property* prop)
     ViewProviderGeometryObject::onChanged(prop);
 }
 
+bool ViewProviderPartExt::allowOverride(const App::DocumentObject &) const {
+    // Many derived view providers still uses static_cast to get object
+    // pointer, so check for exact type here.
+    return getTypeId() == ViewProviderPartExt::getClassTypeId();
+}
+
 void ViewProviderPartExt::attach(App::DocumentObject *pcFeat)
 {
     // call parent attach method

diff --git a/src/Mod/Part/Gui/ViewProviderExt.h b/src/Mod/Part/Gui/ViewProviderExt.h
@@ -134,6 +134,8 @@ class PartGuiExport ViewProviderPartExt : public Gui::ViewProviderGeometryObject
     }
     virtual void forceUpdate(bool enable = true) override;
 
+    virtual bool allowOverride(const App::DocumentObject &) const override;
+
     /** @name Edit methods */
     //@{
     void setupContextMenu(QMenu*, QObject*, const char*) override;