fix: dashboard tree drag&drop on folder items + collapsible + subfolders + context menu

frontend/src/pages/Dashboard.tsx

@@ -5,8 +5,6 @@ import { useState, useEffect, useCallback, useMemo } from 'react';
 import { useAuth } from '../contexts/AuthContext';
 import { NotificationPanel } from '../components/NotificationPanel';
 import { ShareDialog } from '../components/ShareDialog';
-import TreeView from '../components/TreeView';
-import type { TreeNode } from '../types/ui.types';
 import {
   getProjects, deleteProject, updateProject,
   getProjectFolders, createProjectFolder, renameProjectFolder, deleteProjectFolder,
@@ -15,7 +13,7 @@ import {
 } from '../services/api';
 
 const API_BASE = import.meta.env.VITE_API_BASE || '';
-const ROOT_FOLDER_ID = '__root__';
+const UNFILED_ID = '__unfiled__';
 
 interface DashboardProps {
   onOpenProject: (projectId: string) => void;
@@ -31,7 +29,7 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
   const [newName, setNewName] = useState('');
   const [newDesc, setNewDesc] = useState('');
   const [shareProjectId, setShareProjectId] = useState<string | null>(null);
-  const [selectedFolderId, setSelectedFolderId] = useState<string | null>(ROOT_FOLDER_ID);
+  const [selectedFolderId, setSelectedFolderId] = useState<string | null>(null);
   const [selectedProjectId, setSelectedProjectId] = useState<string | null>(null);
   const [shares, setShares] = useState<ProjectShare[]>([]);
   const [sharesLoading, setSharesLoading] = useState(false);
@@ -46,6 +44,7 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
   const [editingProjectDesc, setEditingProjectDesc] = useState('');
   const [savingProject, setSavingProject] = useState(false);
   const [dragOverFolderId, setDragOverFolderId] = useState<string | null>(null);
+  const [expandedFolders, setExpandedFolders] = useState<Set<string>>(new Set());
 
   const fetchAll = useCallback(async () => {
     if (!token) return;
@@ -68,10 +67,17 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     fetchAll();
   }, [fetchAll]);
 
+  // Default: expand all folders on first load or when folders change
   useEffect(() => {
-    if (selectedFolderId === ROOT_FOLDER_ID) {
+    if (folders.length > 0 && expandedFolders.size === 0) {
+      setExpandedFolders(new Set(folders.map(f => f.id)));
+    }
+  }, [folders, expandedFolders.size]);
+
+  useEffect(() => {
+    if (selectedFolderId === null) {
       setProjects(allProjects);
-    } else if (selectedFolderId === null) {
+    } else if (selectedFolderId === UNFILED_ID) {
       setProjects(allProjects.filter(p => p.folder_id === null));
     } else {
       setProjects(allProjects.filter(p => p.folder_id === selectedFolderId));
@@ -102,45 +108,31 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     }
   }, [selectedProject]);
 
-  const treeNodes = useMemo((): TreeNode[] => {
-    const rootProjectsCount = allProjects.filter(p => p.folder_id === null).length;
-    const root: TreeNode = {
-      id: ROOT_FOLDER_ID,
-      name: 'Alle Projekte',
-      count: allProjects.length,
-      expanded: true,
-      children: [
-        { id: '__unfiled__', name: 'Ohne Ordner', count: rootProjectsCount },
-      ],
-    };
-    const buildFolderNode = (folder: ProjectFolder): TreeNode => {
-      const childFolders = folders.filter(f => f.parent_id === folder.id);
-      const projCount = allProjects.filter(p => p.folder_id === folder.id).length;
-      return {
-        id: folder.id,
-        name: folder.name,
-        count: projCount,
-        expanded: true,
-        children: childFolders.map(buildFolderNode),
-      };
-    };
-    const topFolders = folders.filter(f => f.parent_id === null);
-    root.children!.push(...topFolders.map(buildFolderNode));
-    return [root];
-  }, [folders, allProjects]);
-
   const folderNameById = useMemo(() => {
     const map = new Map<string, string>();
-    map.set(ROOT_FOLDER_ID, 'Alle Projekte');
-    map.set('__unfiled__', 'Ohne Ordner');
+    map.set(UNFILED_ID, 'Ohne Ordner');
     for (const f of folders) map.set(f.id, f.name);
     return map;
   }, [folders]);
 
+  const currentFolderName = useMemo(() => {
+    if (selectedFolderId === null) return 'Alle Projekte';
+    return folderNameById.get(selectedFolderId) ?? 'Projekte';
+  }, [selectedFolderId, folderNameById]);
+
+  const toggleFolder = (id: string) => {
+    setExpandedFolders(prev => {
+      const next = new Set(prev);
+      if (next.has(id)) next.delete(id);
+      else next.add(id);
+      return next;
+    });
+  };
+
   const handleCreate = async () => {
     if (!newName.trim() || !token) return;
     try {
-      const folderId = selectedFolderId === ROOT_FOLDER_ID || selectedFolderId === '__unfiled__'
+      const folderId = selectedFolderId === null || selectedFolderId === UNFILED_ID
         ? null : selectedFolderId;
       const res = await fetch(`${API_BASE}/api/projects`, {
         method: 'POST',
@@ -171,20 +163,13 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     }
   };
 
-  const handleFolderSelect = (id: string) => {
-    if (id === ROOT_FOLDER_ID) {
-      setSelectedFolderId(ROOT_FOLDER_ID);
-    } else if (id === '__unfiled__') {
-      setSelectedFolderId(null);
-    } else {
-      setSelectedFolderId(id);
-    }
+  const handleFolderSelect = (id: string | null) => {
+    setSelectedFolderId(id);
   };
 
   const handleCreateFolder = async () => {
     if (!newFolderName.trim() || !token) return;
-    const parentId = newFolderParent === ROOT_FOLDER_ID || newFolderParent === '__unfiled__'
-      ? null : newFolderParent;
+    const parentId = newFolderParent === UNFILED_ID ? null : newFolderParent;
     try {
       await createProjectFolder(token, newFolderName, parentId);
       setNewFolderName('');
@@ -213,7 +198,7 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     if (!confirm('Ordner loeschen? Projekte darin werden nach "Ohne Ordner" verschoben.')) return;
     try {
       await deleteProjectFolder(token, id);
-      if (selectedFolderId === id) setSelectedFolderId(ROOT_FOLDER_ID);
+      if (selectedFolderId === id) setSelectedFolderId(null);
       fetchAll();
     } catch {
       // ignore
@@ -247,25 +232,24 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     e.dataTransfer.setData('text/plain', `project:${projectId}`);
   };
 
-  const handleFolderDragOver = (e: React.DragEvent, folderId: string) => {
+  const handleFolderDragOver = (e: React.DragEvent, folderId: string | null) => {
     if (!draggedProjectId) return;
     e.preventDefault();
     e.dataTransfer.dropEffect = 'move';
     setDragOverFolderId(folderId);
   };
 
-  const handleFolderDragLeave = (_e: React.DragEvent, folderId: string) => {
+  const handleFolderDragLeave = (folderId: string | null) => {
     if (dragOverFolderId === folderId) {
       setDragOverFolderId(null);
     }
   };
 
-  const handleFolderDrop = async (e: React.DragEvent, folderId: string) => {
+  const handleFolderDrop = async (e: React.DragEvent, folderId: string | null) => {
     e.preventDefault();
     e.stopPropagation();
-    (e.currentTarget as HTMLElement).classList.remove('tree-drop-target');
     if (!draggedProjectId || !token) return;
-    const targetFolderId = folderId === ROOT_FOLDER_ID || folderId === '__unfiled__' ? null : folderId;
+    const targetFolderId = folderId === UNFILED_ID ? null : folderId;
     try {
       await moveProjectToFolder(token, draggedProjectId, targetFolderId);
       fetchAll();
@@ -288,6 +272,9 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     if (action === 'new') {
       setNewFolderParent(folderId);
       setShowCreateFolder(true);
+    } else if (action === 'newSubfolder' && folderId) {
+      setNewFolderParent(folderId);
+      setShowCreateFolder(true);
     } else if (action === 'rename' && folderId) {
       const folder = folders.find(f => f.id === folderId);
       if (folder) {
@@ -306,29 +293,89 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
     });
   };
 
-  const renderFolderActions = (node: TreeNode) => {
-    if (node.id === ROOT_FOLDER_ID || node.id === '__unfiled__') return null;
+  const folderIcon = (
+    <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth="2">
+      <path d="M3 7a2 2 0 0 1 2-2h4l2 2h7a2 2 0 0 1 2 2v8a2 2 0 0 1-2 2H5a2 2 0 0 1-2-2z" />
+    </svg>
+  );
+
+  const renderFolderItem = (folder: ProjectFolder, depth: number): React.ReactNode => {
+    const children = folders.filter(f => f.parent_id === folder.id);
+    const isExpanded = expandedFolders.has(folder.id);
+    const projectCount = allProjects.filter(p => p.folder_id === folder.id).length;
+    const isSelected = selectedFolderId === folder.id;
+    const isDragOver = dragOverFolderId === folder.id;
+    const isRenaming = renamingFolderId === folder.id;
+
     return (
-      <span className="folder-action-buttons">
-        <button
-          className="folder-action-btn"
-          title="Umbenennen"
-          onClick={(e) => {
-            e.stopPropagation();
-            setRenamingFolderId(node.id);
-            const folder = folders.find(f => f.id === node.id);
-            if (folder) setRenameValue(folder.name);
-          }}
-        >✎</button>
-        <button
-          className="folder-action-btn delete"
-          title="Loeschen"
-          onClick={(e) => {
-            e.stopPropagation();
-            handleDeleteFolder(node.id);
-          }}
-        >✕</button>
-      </span>
+      <div key={folder.id}>
+        <div
+          className={`folder-tree-item${isSelected ? ' selected' : ''}${isDragOver ? ' drag-over' : ''}`}
+          draggable
+          onDragOver={(e) => handleFolderDragOver(e, folder.id)}
+          onDragLeave={() => handleFolderDragLeave(folder.id)}
+          onDrop={(e) => handleFolderDrop(e, folder.id)}
+          onClick={() => handleFolderSelect(folder.id)}
+          onContextMenu={(e) => handleContextMenu(e, folder.id)}
+          style={{ paddingLeft: `${depth * 16 + 8}px` }}
+        >
+          {children.length > 0 ? (
+            <button
+              className="folder-chevron"
+              onClick={(e) => { e.stopPropagation(); toggleFolder(folder.id); }}
+              aria-label={isExpanded ? 'Einklappen' : 'Ausklappen'}
+            >
+              {isExpanded ? '▼' : '▶'}
+            </button>
+          ) : (
+            <span className="folder-chevron-placeholder" />
+          )}
+          {folderIcon}
+          {isRenaming ? (
+            <input
+              className="folder-rename-inline"
+              type="text"
+              value={renameValue}
+              onChange={e => setRenameValue(e.target.value)}
+              onKeyDown={e => {
+                if (e.key === 'Enter') handleRenameFolder(folder.id);
+                if (e.key === 'Escape') { setRenamingFolderId(null); setRenameValue(''); }
+              }}
+              onBlur={() => {
+                if (renameValue.trim()) handleRenameFolder(folder.id);
+                else { setRenamingFolderId(null); setRenameValue(''); }
+              }}
+              onClick={e => e.stopPropagation()}
+              autoFocus
+            />
+          ) : (
+            <span className="folder-tree-name">{folder.name}</span>
+          )}
+          {projectCount > 0 && <span className="folder-count">({projectCount})</span>}
+          {!isRenaming && (
+            <span className="folder-action-buttons">
+              <button
+                className="folder-action-btn"
+                title="Umbenennen"
+                onClick={(e) => {
+                  e.stopPropagation();
+                  setRenamingFolderId(folder.id);
+                  setRenameValue(folder.name);
+                }}
+              >✎</button>
+              <button
+                className="folder-action-btn delete"
+                title="Loeschen"
+                onClick={(e) => {
+                  e.stopPropagation();
+                  handleDeleteFolder(folder.id);
+                }}
+              >✕</button>
+            </span>
+          )}
+        </div>
+        {isExpanded && children.map(child => renderFolderItem(child, depth + 1))}
+      </div>
     );
   };
 
@@ -360,7 +407,7 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
             <div className="folder-create-form">
               <input
                 type="text"
-                placeholder="Ordnername"
+                placeholder={newFolderParent ? 'Unterordnername' : 'Ordnername'}
                 value={newFolderName}
                 onChange={e => setNewFolderName(e.target.value)}
                 onKeyDown={e => { if (e.key === 'Enter') handleCreateFolder(); if (e.key === 'Escape') setShowCreateFolder(false); }}
@@ -368,47 +415,50 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
               />
               <div className="folder-create-actions">
                 <button onClick={handleCreateFolder}>OK</button>
-                <button onClick={() => { setShowCreateFolder(false); setNewFolderName(''); }}>×</button>
+                <button onClick={() => { setShowCreateFolder(false); setNewFolderName(''); setNewFolderParent(null); }}>×</button>
               </div>
             </div>
           )}
 
-          <TreeView
-            nodes={treeNodes}
-            selectedId={selectedFolderId ?? undefined}
-            onSelect={handleFolderSelect}
-            renderActions={renderFolderActions}
-          />
-
-          {renamingFolderId && (
-            <div className="folder-rename-form">
-              <input
-                type="text"
-                value={renameValue}
-                onChange={e => setRenameValue(e.target.value)}
-                onKeyDown={e => { if (e.key === 'Enter') handleRenameFolder(renamingFolderId); if (e.key === 'Escape') { setRenamingFolderId(null); setRenameValue(''); } }}
-                onBlur={() => { if (renameValue.trim()) handleRenameFolder(renamingFolderId); else { setRenamingFolderId(null); setRenameValue(''); } }}
-                autoFocus
-              />
-            </div>
-          )}
-
-          <div className="treeview-drop-overlay">
-            {folders.map(folder => (
-              <div
-                key={folder.id}
-                className={`treeview-drop-zone${dragOverFolderId === folder.id ? ' drag-over' : ''}`}
-                onDragOver={(e) => handleFolderDragOver(e, folder.id)}
-                onDragLeave={(e) => handleFolderDragLeave(e, folder.id)}
-                onDrop={(e) => handleFolderDrop(e, folder.id)}
-              />
-            ))}
+          {/* Root: Alle Projekte */}
+          <div
+            className={`folder-tree-item${selectedFolderId === null ? ' selected' : ''}${dragOverFolderId === null && draggedProjectId ? ' drag-over' : ''}`}
+            onClick={() => handleFolderSelect(null)}
+            onDragOver={(e) => handleFolderDragOver(e, null)}
+            onDragLeave={() => handleFolderDragLeave(null)}
+            onDrop={(e) => handleFolderDrop(e, null)}
+            onContextMenu={(e) => handleContextMenu(e, null)}
+            style={{ paddingLeft: '8px' }}
+          >
+            <span className="folder-chevron-placeholder" />
+            {folderIcon}
+            <span className="folder-tree-name">Alle Projekte</span>
+            <span className="folder-count">({allProjects.length})</span>
           </div>
+
+          {/* Ohne Ordner node */}
+          <div
+            className={`folder-tree-item${selectedFolderId === UNFILED_ID ? ' selected' : ''}${dragOverFolderId === UNFILED_ID ? ' drag-over' : ''}`}
+            onClick={() => handleFolderSelect(UNFILED_ID)}
+            onDragOver={(e) => handleFolderDragOver(e, UNFILED_ID)}
+            onDragLeave={() => handleFolderDragLeave(UNFILED_ID)}
+            onDrop={(e) => handleFolderDrop(e, UNFILED_ID)}
+            onContextMenu={(e) => handleContextMenu(e, null)}
+            style={{ paddingLeft: '24px' }}
+          >
+            <span className="folder-chevron-placeholder" />
+            {folderIcon}
+            <span className="folder-tree-name">Ohne Ordner</span>
+            <span className="folder-count">({allProjects.filter(p => p.folder_id === null).length})</span>
+          </div>
+
+          {/* Top-level folders rendered recursively */}
+          {folders.filter(f => !f.parent_id).map(folder => renderFolderItem(folder, 1))}
         </div>
 
         <div className="dashboard-content">
           <div className="dashboard-section-header">
-            <h2>{folderNameById.get(selectedFolderId ?? ROOT_FOLDER_ID) ?? 'Projekte'}</h2>
+            <h2>{currentFolderName}</h2>
             <button className="dashboard-create-btn" onClick={() => setShowCreate(!showCreate)}>
               + Neues Projekt
             </button>
@@ -561,7 +611,13 @@ export function Dashboard({ onOpenProject }: DashboardProps) {
               className="context-menu-item"
               onClick={() => handleContextAction('new', contextMenu.folderId)}
             >Neuer Ordner</button>
-            {contextMenu.folderId && contextMenu.folderId !== ROOT_FOLDER_ID && contextMenu.folderId !== '__unfiled__' && (
+            {contextMenu.folderId && (
+              <button
+                className="context-menu-item"
+                onClick={() => handleContextAction('newSubfolder', contextMenu.folderId)}
+              >Neuer Unterordner</button>
+            )}
+            {contextMenu.folderId && (
               <>
                 <button
                   className="context-menu-item"

frontend/src/styles/auth.css

@@ -282,18 +282,90 @@
 .folder-action-btn:hover { color: var(--color-primary); background: rgba(37, 99, 235, 0.1); }
 .folder-action-btn.delete:hover { color: #e74c3c; background: rgba(231, 76, 60, 0.1); }
 
-/* Drag-over visual feedback on tree nodes */
-.tree-node.drag-over {
-  background: var(--color-primary) !important;
+/* Folder tree items (recursive, native drag targets) */
+.folder-tree-item {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+  padding: 6px 8px;
+  border-radius: 4px;
+  cursor: pointer;
+  font-size: 13px;
+  color: var(--color-text);
+  transition: background 0.15s;
+  user-select: none;
+}
+
+.folder-tree-item:hover {
+  background: var(--color-surface-2);
+}
+
+.folder-tree-item.selected {
+  background: var(--color-primary);
+  color: white;
+}
+
+.folder-tree-item.drag-over {
+  background: var(--color-primary);
   opacity: 0.7;
   border: 2px dashed var(--color-primary);
   border-radius: 4px;
 }
 
-.treeview-drop-zone.drag-over {
-  background: rgba(37, 99, 235, 0.15);
-  outline: 2px dashed var(--color-primary);
-  border-radius: 4px;
+.folder-chevron {
+  background: none;
+  border: none;
+  cursor: pointer;
+  color: var(--color-text-muted);
+  padding: 0;
+  width: 16px;
+  font-size: 10px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  flex-shrink: 0;
+}
+
+.folder-chevron:hover {
+  color: var(--color-text);
+}
+
+.folder-tree-item.selected .folder-chevron {
+  color: rgba(255, 255, 255, 0.8);
+}
+
+.folder-chevron-placeholder {
+  width: 16px;
+  flex-shrink: 0;
+}
+
+.folder-tree-name {
+  flex: 1;
+  overflow: hidden;
+  text-overflow: ellipsis;
+  white-space: nowrap;
+}
+
+.folder-count {
+  font-size: 11px;
+  color: var(--color-text-muted);
+  flex-shrink: 0;
+}
+
+.folder-tree-item.selected .folder-count {
+  color: rgba(255, 255, 255, 0.7);
+}
+
+.folder-rename-inline {
+  flex: 1;
+  padding: 2px 4px;
+  border: 1px solid var(--color-primary);
+  border-radius: 3px;
+  background: var(--color-surface);
+  color: var(--color-text);
+  font-size: 13px;
+  outline: none;
+  box-sizing: border-box;
 }
 
 .context-menu-overlay {