Null Viewer

Displays a placeholder view for unsupported, empty, or unrecognized document types.

Remarks

Overview

The Null Viewer control provides a simple placeholder interface when a document cannot be displayed in the Grooper web client. It is used for unsupported file types, empty documents, or cases where no suitable viewer is available. The control informs users that the content cannot be rendered and may display basic file information such as filename and MIME type for context.

Purpose

• Notify users when a document cannot be displayed due to unsupported format or missing content.
• Provide basic metadata (filename, MIME type) to help users identify the file.

Usage Guidance

1. When a document cannot be rendered, the Null Viewer is shown automatically.
2. Review the displayed file information to identify the unsupported or empty document.
3. Use the filename and MIME type to determine if the file should be converted, replaced, or reviewed elsewhere.

Example

┌───────────── Null Viewer ──────────────┐
│                                        │
│   This document cannot be displayed.   │
├────────────────────────────────────────┤
│      Filename: filename.ext            │
│      MIME Type:  mime/type             │
└────────────────────────────────────────┘

Notes

• The control is automatically selected when no other viewer is suitable for the document type.
• No editing, downloading, or other actions are available in this view.
• Use the file information to assist with troubleshooting or file management.
• The Null Viewer ensures a consistent user experience even when content cannot be rendered.

Used By

Document Viewer