Mermaid Canvas

An Obsidian plugin that turns every mermaid code block into an interactive canvas — zoom, pan, fullscreen, copy, export, and a built-in split editor. No more squinting at cramped diagrams.

Preview

Inline canvas — clean view

Hover to reveal controls

Fullscreen mode

Split editor — code left, live preview right

Features

• Adaptive canvas — SVG renders at natural size, fills available width, no hardcoded constraints
• Smooth zoom & pan — Ctrl/Cmd + scroll wheel to zoom toward cursor, drag to pan
• Control bar — hover to reveal Zoom In / Zoom Out / Fullscreen / Fit / Copy / Delete
• Export bar — hover bottom-center to export as PNG or SVG
• Fullscreen mode — expand any diagram to fill the viewport, Esc to exit
• Fit to canvas — one click to auto-scale the diagram to fit the available space
• Copy code — copy the raw mermaid source to clipboard
• Export PNG / SVG — download the diagram directly from the canvas
• Delete block — remove the entire code block with one click (available in editing mode only)
• Split editor — use the Mermaid Canvas command (or type / and search for it) to insert a block and open a live split-view editor
• Edit interception — click Obsidian's native edit button on any mermaid block to open the split editor pre-loaded with the correct code
• Auto-refresh — saving in the split editor immediately updates the reading view
• Error resilience — invalid or empty blocks are gracefully skipped

Usage

Action	How
Insert + edit	Mermaid Canvas command (Command Palette or / search)
Edit existing	Click the ✏️ edit button on any rendered mermaid block
Zoom	Ctrl/Cmd + scroll wheel (or two-finger pinch on trackpad)
Pan	Click and drag the diagram
Fullscreen	Hover → click Maximize button, Esc to exit
Fit to canvas	Hover → click Fit button
Copy code	Hover → click Copy button
Export PNG	Hover bottom-center → click Image button
Export SVG	Hover bottom-center → click Download button
Delete block	Hover → click Trash button (editing mode only)

Installation

Manual

1. Download the latest main.js, styles.css, and manifest.json from Releases
2. Copy them into your-vault/.obsidian/plugins/mermaid-canvas/
3. Reload Obsidian and enable the plugin in Settings → Community Plugins

From Source

git clone https://github.com/cheney12138/mermaid-canvas-plugin.git
cd mermaid-canvas-plugin
npm install
npm run build
# Then copy main.js, styles.css, manifest.json to your vault's plugins folder

Settings

• Zoom sensitivity (1–10) — how fast the scroll wheel zooms

License

MIT