dsh-preview-snip

Snip, annotate or quote any document preview in DSH and put the result into the composer.

What it does

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

• 圈选 / Snip — drag a rectangle; the selection becomes a PNG attachment in the composer. The quick path only adds the image; it does not fill in a question.
• 全能圈选 / Annotate — drag a rectangle, then open an editor and add a box, circle/ellipse, arrow or text, choose a color, undo/clear, and insert the annotated PNG.
• 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.

Works on every preview type

• Pixels: <img>, <video> current frame and <canvas> — images, PDF pages, video frames and WebGL viewports (the first-party Blender/STL viewers keep their drawing buffer).
• DOM screenshot: text, Markdown, code and HTML previews are serialized to an SVG foreignObject and rasterized in the browser; the current pane stylesheet is embedded, so the screenshot keeps the preview's appearance.
• Quote: any preview whose text is selectable.

Annotation editor

After a full snip you get a canvas editor:

• box, ellipse, arrow, text;
• red / amber / blue / green;
• undo, clear, cancel, insert;
• text is entered inline (not a browser prompt);
• the inserted image is the annotated canvas, not the original crop.

Sidebar browser (desktop)

When a webpage is open in DSH's right-side browser tab, a small floating 圈选 / 全能圈选 group appears over the webview. It captures through Electron's webview.capturePage() and then uses the same crop, annotation and composer-attachment path.

• This is the browser tab (sidebar.right.pane.tab key browser), not a document preview.
• In browser/web mode the page is a cross-origin iframe, so the group does not appear; a browser extension would be needed there.

Install

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

Open any file in the right Sidebar. The three buttons appear as one segmented group in the preview header.

How it works

• Uses sidebar.right.tab.document.actions for file previews and a conversation.session.header.utilities bridge for the desktop sidebar browser; no Host routes and no external screenshot library.
• Pixel crops map through object-fit: contain for images/video, and use the canvas bitmap for PDF/WebGL.
• Sidebar-browser capture uses webview.capturePage(); the selected viewport rectangle is cropped from the returned NativeImage.
• DOM previews are cloned, the pane's CSS rules are embedded, and the clone is drawn through an SVG foreignObject.
• 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 text selection and inputActions.setDraft.

Limits

• DOM screenshots skip cross-origin stylesheets and cross-origin background images; text and layout still render.
• Video captures the current frame; it does not record.
• WebGL capture needs the viewer to keep its drawing buffer; the first-party Blender and STL viewers do. A third-party WebGL preview that clears its buffer may capture blank.
• Cross-origin images that taint the canvas fail with a notice.
• Sidebar-browser capture is desktop-only; it needs a <webview> with capturePage. Browser/iframe mode cannot capture a cross-origin page.
• The editor is client-side only; the original file is never modified.

Compatibility

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