dsh-preview-snip

Circle a region of an image/PDF preview, or quote selected text, and put it into the DSH composer.

What it does

The plugin adds two actions to the right-Sidebar document-preview header:

• 圈选 / Snip — for images and PDF canvases; drag a rectangle over the visible preview, and the selected pixels become a PNG attachment in the composer, with a short default question.
• 引用选中 / Quote selection — quote the current text selection into the composer as a Markdown blockquote.

Nothing is sent automatically: the attachment and text land in the composer, and you finish the question and press send.

Install

dsh plugin --profile <profile> add dsh-preview-snip

Then open an image or PDF in the right Sidebar. The buttons appear in the preview header.

How it works

• Uses the sidebar.right.tab.document.actions slot; no Host routes and no external screenshot library.
• For images it maps the selection through object-fit: contain; for PDFs it uses the rendered page canvas.
• Creates the PNG in the browser and hands it to conversation.createDrafts / inputActions.addAttachments, the same draft attachment path as a pasted image.
• Quoting uses the browser's text selection and inputActions.setDraft.

Limits

• Pixel snip supports DOM <img> and <canvas> previews. WebGL/3D previews and video frames are not captured yet.
• Quoting works on any preview whose text is selectable, including PDF text layers.
• The capture is a client-side canvas crop; cross-origin images that taint the canvas will fail with a notice.

Compatibility

• DSH 0.2.0-rc.2 (and 0.2.1-rc.2).
• Client-only plugin; no Host configuration.