fix: show loading spinner instead of hanging in open project dialog when user click open button

src/components/Toolbar.tsx

@@ -29,6 +29,7 @@ import { KEY_SIGNATURE_MAP } from '../constants/coreConstants';
 import { KGOfflineRenderer } from '../core/audio-interface/KGOfflineRenderer';
 import KGDropdown from './common/KGDropdown';
 import FileImportModal from './common/FileImportModal';
+import LoadingOverlay from './common/LoadingOverlay';
 import OpenProjectModal from './common/OpenProjectModal';
 import { clearChatHistoryAndUI } from '../util/chatUtil';
 import PianoIcon from './common/icons/PianoIcon';
@@ -77,6 +78,7 @@ const Toolbar: React.FC = () => {
 
   // State for open project modal
   const [showOpenProject, setShowOpenProject] = React.useState(false);
+  const [isOpeningProject, setIsOpeningProject] = React.useState(false);
   
   // Close zoom slider on click outside
   React.useEffect(() => {
@@ -205,12 +207,7 @@ const Toolbar: React.FC = () => {
   };
 
   const handleOpenProjectSelect = async (projectNameToLoad: string) => {
-    const confirmed = await showConfirm(
-      'Open this project? Any unsaved changes in the current project will be lost.'
-    );
-    if (!confirmed) {
-      return false;
-    }
+    setIsOpeningProject(true);
 
     try {
       const storage = KGProjectStorage.getInstance();
@@ -218,18 +215,25 @@ const Toolbar: React.FC = () => {
 
       if (!loadedProject) {
         await showAlert(`Project "${projectNameToLoad}" not found.`);
-        return false;
+        return;
       }
 
       await loadProjectFromData(loadedProject, `Project "${projectNameToLoad}"`, projectNameToLoad);
-      return true;
     } catch (error) {
       console.error("Error loading project:", error);
       await showAlert(`An error occurred while loading the project: ${error}`);
-      return false;
+    } finally {
+      setIsOpeningProject(false);
     }
   };
 
+  const handleConfirmOpenProject = async (_projectNameToLoad: string) => {
+    const confirmed = await showConfirm(
+      'Open this project? Any unsaved changes in the current project will be lost.'
+    );
+    return confirmed;
+  };
+
   const handleSaveProject = async () => {
     if (DEBUG_MODE.TOOLBAR) {
       console.log("user clicked save button");
@@ -1207,9 +1211,15 @@ const Toolbar: React.FC = () => {
       description="Drag and drop your project file here"
     />
 
+    <LoadingOverlay
+      visible={isOpeningProject}
+      message="Opening project..."
+    />
+
     {showOpenProject && (
       <OpenProjectModal
         onClose={() => setShowOpenProject(false)}
+        onConfirmOpenProject={handleConfirmOpenProject}
         onOpenProject={handleOpenProjectSelect}
         currentProjectName={savedProjectName}
         onCreateNewProject={createNewProject}

src/components/common/OpenProjectModal.tsx

@@ -7,7 +7,8 @@ import { showAlert, showConfirm, showPrompt } from '../../util/dialogUtil';
 
 interface OpenProjectModalProps {
   onClose: () => void;
-  onOpenProject: (projectName: string) => Promise<boolean>;
+  onConfirmOpenProject: (projectName: string) => Promise<boolean>;
+  onOpenProject: (projectName: string) => Promise<void>;
   currentProjectName: string | null;
   onCreateNewProject: () => void;
 }
@@ -44,12 +45,19 @@ const formatDate = (timestamp: number): string => {
   });
 };
 
-const OpenProjectModal: React.FC<OpenProjectModalProps> = ({ onClose, onOpenProject, currentProjectName, onCreateNewProject }) => {
+const OpenProjectModal: React.FC<OpenProjectModalProps> = ({
+  onClose,
+  onConfirmOpenProject,
+  onOpenProject,
+  currentProjectName,
+  onCreateNewProject
+}) => {
   const [projects, setProjects] = useState<ProjectMeta[]>([]);
   const [isLoading, setIsLoading] = useState(true);
   const [filter, setFilter] = useState('');
   const [isClosing, setIsClosing] = useState(false);
   const mouseDownOnOverlay = useRef(false);
+  const pendingOpenProjectName = useRef<string | null>(null);
 
   const [sortField, setSortField] = useState<SortField>('updatedAt');
   const [sortDirection, setSortDirection] = useState<SortDirection>('desc');
@@ -61,9 +69,16 @@ const OpenProjectModal: React.FC<OpenProjectModalProps> = ({ onClose, onOpenProj
   const handleAnimationEnd = useCallback((e: React.AnimationEvent) => {
     if (e.target !== e.currentTarget) return;
     if (!isClosing) return;
+
+    const projectNameToOpen = pendingOpenProjectName.current;
+    pendingOpenProjectName.current = null;
     setIsClosing(false);
     onClose();
-  }, [isClosing, onClose]);
+
+    if (projectNameToOpen) {
+      void onOpenProject(projectNameToOpen);
+    }
+  }, [isClosing, onClose, onOpenProject]);
 
   const fetchProjects = useCallback(async (mode: ViewMode) => {
     setIsLoading(true);
@@ -121,10 +136,11 @@ const OpenProjectModal: React.FC<OpenProjectModalProps> = ({ onClose, onOpenProj
   }, [projects, filter, sortField, sortDirection]);
 
   const handleOpen = async (projectName: string) => {
-    const opened = await onOpenProject(projectName);
-    if (opened) {
+    const confirmed = await onConfirmOpenProject(projectName);
+    if (!confirmed) return;
+
+    pendingOpenProjectName.current = projectName;
     startClose();
-    }
   };
 
   const handleDuplicate = async (e: React.MouseEvent, projectName: string) => {
@@ -141,11 +157,12 @@ const OpenProjectModal: React.FC<OpenProjectModalProps> = ({ onClose, onOpenProj
     try {
       const storage = KGProjectStorage.getInstance();
       const finalName = await storage.resolveUniqueName(trimmed);
+      const confirmed = await onConfirmOpenProject(finalName);
+      if (!confirmed) return;
+
       await storage.duplicate(projectName, finalName);
-      const opened = await onOpenProject(finalName);
-      if (opened) {
+      pendingOpenProjectName.current = finalName;
       startClose();
-      }
     } catch (error) {
       console.error('Error duplicating project:', error);
       await showAlert(`Failed to duplicate project: ${error}`);