Use TWeakObjectPtr to better handle server deletion.

Author: kring

Source/CesiumEditor/Private/CesiumIonServerManager.cpp

@@ -86,11 +86,15 @@ void CesiumIonServerManager::Initialize() {
 }
 
 void CesiumIonServerManager::ResumeAll() {
-  const TArray<TObjectPtr<UCesiumIonServer>>& servers = this->GetServerList();
-  for (const TObjectPtr<UCesiumIonServer>& pServer : servers) {
-    std::shared_ptr<CesiumIonSession> pSession = this->GetSession(pServer);
-    pSession->resume();
-    pSession->refreshProfileIfNeeded();
+  const TArray<TWeakObjectPtr<UCesiumIonServer>>& servers =
+      this->GetServerList();
+  for (const TWeakObjectPtr<UCesiumIonServer>& pWeakServer : servers) {
+    UCesiumIonServer* pServer = pWeakServer.Get();
+    if (pServer) {
+      std::shared_ptr<CesiumIonSession> pSession = this->GetSession(pServer);
+      pSession->resume();
+      pSession->refreshProfileIfNeeded();
+    }
   }
 }
 
@@ -122,7 +126,7 @@ std::shared_ptr<CesiumIonSession> CesiumIonServerManager::GetCurrentSession() {
   return this->GetSession(this->GetCurrentServer());
 }
 
-const TArray<TObjectPtr<UCesiumIonServer>>&
+const TArray<TWeakObjectPtr<UCesiumIonServer>>&
 CesiumIonServerManager::GetServerList() {
   this->RefreshServerList();
   return this->_servers;
@@ -191,12 +195,13 @@ void CesiumIonServerManager::OnAssetRemoved(const FAssetData& asset) {
   UCesiumIonServer* pServer = Cast<UCesiumIonServer>(asset.GetAsset());
   if (pServer && this->GetCurrentServer() == pServer) {
     // Current server is being removed, so select a different one.
-    TObjectPtr<UCesiumIonServer>* ppNewServer = this->_servers.FindByPredicate(
-        [pServer](const TObjectPtr<UCesiumIonServer>& pCandidate) {
-          return pCandidate != pServer;
-        });
+    TWeakObjectPtr<UCesiumIonServer>* ppNewServer =
+        this->_servers.FindByPredicate(
+            [pServer](const TWeakObjectPtr<UCesiumIonServer>& pCandidate) {
+              return pCandidate.Get() != pServer;
+            });
     if (ppNewServer != nullptr) {
-      this->SetCurrentServer(*ppNewServer);
+      this->SetCurrentServer(ppNewServer->Get());
     } else {
       this->SetCurrentServer(nullptr);
     }

Source/CesiumEditor/Private/CesiumIonServerManager.h

@@ -21,7 +21,7 @@ class CESIUMEDITOR_API CesiumIonServerManager {
   std::shared_ptr<CesiumIonSession> GetSession(UCesiumIonServer* Server);
   std::shared_ptr<CesiumIonSession> GetCurrentSession();
 
-  const TArray<TObjectPtr<UCesiumIonServer>>& GetServerList();
+  const TArray<TWeakObjectPtr<UCesiumIonServer>>& GetServerList();
   void RefreshServerList();
 
   UCesiumIonServer* GetCurrentServer();
@@ -41,5 +41,5 @@ class CESIUMEDITOR_API CesiumIonServerManager {
   };
 
   TArray<ServerSession> _sessions;
-  TArray<TObjectPtr<UCesiumIonServer>> _servers;
+  TArray<TWeakObjectPtr<UCesiumIonServer>> _servers;
 };

Source/CesiumEditor/Private/CesiumIonServerSelector.cpp

@@ -11,7 +11,7 @@ void CesiumIonServerSelector::Construct(const FArguments& InArgs) {
       [SNew(SHorizontalBox) +
        SHorizontalBox::Slot().FillWidth(1.0f).VAlign(
            EVerticalAlignment::VAlign_Center)
-           [SNew(SComboBox<TObjectPtr<UCesiumIonServer>>)
+           [SNew(SComboBox<TWeakObjectPtr<UCesiumIonServer>>)
                 .OptionsSource(
                     &FCesiumEditorModule::serverManager().GetServerList())
                 .OnGenerateWidget(
@@ -39,12 +39,12 @@ void CesiumIonServerSelector::Construct(const FArguments& InArgs) {
 namespace {
 
 FText GetNameFromCesiumIonServerAsset(
-    const TObjectPtr<UCesiumIonServer>& pServer) {
-  if (!pServer)
+    const TWeakObjectPtr<UCesiumIonServer>& pServer) {
+  if (!pServer.IsValid())
     return FText::FromString("Error: No Cesium ion server configured.");
 
   std::shared_ptr<CesiumIonSession> pSession =
-      FCesiumEditorModule::serverManager().GetSession(pServer);
+      FCesiumEditorModule::serverManager().GetSession(pServer.Get());
 
   // Get the profile here, which will trigger it to load if it hasn't been
   // loaded already.
@@ -80,16 +80,16 @@ FText CesiumIonServerSelector::GetServerValueAsText() const {
 }
 
 TSharedRef<SWidget> CesiumIonServerSelector::OnGenerateServerEntry(
-    TObjectPtr<UCesiumIonServer> pServerAsset) {
+    TWeakObjectPtr<UCesiumIonServer> pServerAsset) {
   return SNew(STextBlock).Text_Lambda([pServerAsset]() {
     return GetNameFromCesiumIonServerAsset(pServerAsset);
   });
 }
 
 void CesiumIonServerSelector::OnServerSelectionChanged(
-    TObjectPtr<UCesiumIonServer> InItem,
+    TWeakObjectPtr<UCesiumIonServer> InItem,
     ESelectInfo::Type InSeletionInfo) {
-  FCesiumEditorModule::serverManager().SetCurrentServer(InItem);
+  FCesiumEditorModule::serverManager().SetCurrentServer(InItem.Get());
   FCesiumEditorModule::serverManager().GetCurrentSession()->resume();
 }
 

Source/CesiumEditor/Private/CesiumIonServerSelector.h

@@ -15,12 +15,12 @@ class CesiumIonServerSelector : public SCompoundWidget {
 
 private:
   TSharedRef<SWidget>
-  OnGenerateServerEntry(TObjectPtr<UCesiumIonServer> pServer);
+  OnGenerateServerEntry(TWeakObjectPtr<UCesiumIonServer> pServerAsset);
 
   FText GetServerValueAsText() const;
 
   void OnServerSelectionChanged(
-      TObjectPtr<UCesiumIonServer> InItem,
+      TWeakObjectPtr<UCesiumIonServer> InItem,
       ESelectInfo::Type InSeletionInfo);
   void OnBrowseForServer();
 };