File System

Differences from upstream

• Same export name, FileSystem. class is accepted alongside the upstream className.
• One tree view only. The icons, list, columns, and gallery views (defaultView, view, onViewChange) are not ported, nor are back/forward navigation, search, sort, filters, thumbnails and the page pager (loadPreviewImageUrl, renderFilePreview), lazy loadChildren, and the built-in viewer dialog.
• onFileOpen is called when a file is double-clicked or opened with Enter, with its url or the getFileUrl result. Without it, nothing opens (upstream falls back to its built-in viewer). Double-click or Enter on a folder expands it in place instead of navigating into it.
• Upstream preview fields on file items (previewImageUrl, previewImageUrls, previewPageCount, previewAspectRatio) are accepted but not shown.
• Dark mode is set by the parent through isDark; the tree has no theme switch.
• defaultPath expands the folders down to that path in the tree instead of opening a view inside that folder, since the tree has no inside-a-folder view.
• Types for unported features are not exported: FileSystemView, FileSystemLoadChildrenArgs, FileSystemLoadChildrenResult, FileSystemViewerKind, FileSystemSortKey, and FileSystemFilterType.
• Port additions: bind:selectedPath, onRename, and renamable (inline rename with F2).
• Port-only exports, the tree-building helpers and normalized entry types (upstream keeps them private): ancestorFolderPaths, buildFileSystemIndex, flattenVisibleEntries, normalizeFolderPath, pathName, pathParent, FileSystemIndex, VisibleRow, FileEntry, FolderEntry, and FileSystemEntry.