Module WebviewProvider 

WebviewProvider: creates and manages sandboxed webview panels.

WebviewProvider (Environment)

Implements the WebviewProvider trait for MountainEnvironment, providing the core logic for creating, managing, and securing Webview panels.

Architecture

Extension → CreateWebviewPanel → WebviewProvider → Tauri WebviewWindow
                    │                              │
                    └→ IPC → Cocoon ◄───────────┘

Webview types

• Panel - sidebar or panel webview (non-floating)
• Editor - webview as custom editor (full editor area)
• Modal - modal dialog webview (blocks interaction)
• Widget - small embedded webview (e.g., diff viewer)

Lifecycle

1. CreateWebviewPanel - build Tauri WebviewWindow, set up event handlers, record in ApplicationState.Feature.Webviews.
2. SetWebviewHTML / SetWebviewOptions - configure content and title.
3. RevealWebviewPanel - show and focus.
4. PostMessageToWebview - bidirectional IPC between host and webview.
5. DisposeWebviewPanel - close window and clean up state.

Security

Webview runs in a sandboxed process (no Node.js). All postMessage calls are validated; origins are checked to prevent XSS. Memory footprint is ~50-100 MB per webview - reuse panels when possible.

VS Code reference

• vs/workbench/contrib/webview/browser/webviewService.ts
• vs/workbench/api/browser/mainThreadWebview.ts

Modules

Configuration 🔒

WebviewProvider - Configuration Operations

Lifecycle 🔒

WebviewProvider - Lifecycle Operations

Messaging 🔒

WebviewProvider - Messaging Operations

WebviewLifecycleState

Lifecycle state of a webview panel. Roughly mirrors the VS Code webview state machine (Unloaded → Loading → Loaded → Visible / Hidden → Disposed).

WebviewMessage

Webview message envelope: identifier, type tag, payload, and an optional source identifier. Used for host ↔ webview message passing routed through the Tauri event bus.

Structs

WebviewMessageContext 🔒

Webview message handler context. Private - only the dispatch machinery in Messaging.rs consumes it.