Module UserInterfaceProvider 

UserInterfaceProvider (Environment)

Implements the UserInterfaceProvider trait for MountainEnvironment, orchestrating all modal UI interactions like dialogs, messages, and quick picks by communicating with the Sky frontend.

RESPONSIBILITIES

1. Modal Dialogs

• Open file/folder selection dialogs (OpenDialog)
• Save file dialogs (SaveDialog)
• Message boxes (ShowMessage, ShowErrorMessage)
• Input boxes for text entry (InputBox)
• Quick pick lists for selection (QuickPick)

2. Request-Response Pattern

• Send UI requests to Sky frontend via IPC
• Track pending requests with unique IDs
• Wait for responses with timeout handling
• Resolve results via ResolveUIRequest callback

3. Thread Safety

• All methods are async and safe for concurrent access
• Pending requests stored in ApplicationState.UI.PendingUserInterfaceRequests
• Uses tokio::sync::oneshot for request-response coordination

ARCHITECTURAL ROLE

UserInterfaceProvider is the UI bridge for Mountain:

Provider ──► UI Request ──► Sky Frontend ──► User Interaction ──► ResolveUIRequest

Position in Mountain

• Environment module: UI capability provider
• Implements CommonLibrary::UserInterface::UserInterfaceProvider trait
• Accessible via Environment.Require<dyn UserInterfaceProvider>()

Dependencies

• ApplicationState: Pending request tracking
• IPCProvider: For sending messages to Sky
• tauri::AppHandle: For window/parent references

Dependents

• Any command that needs to show UI dialogs
• DispatchLogic::ResolveUIRequest: Completes the request-response cycle
• Error handlers: Show error messages to users

DTO STRUCTURES

All UI operations use DTOs for type-safe options:

• OpenDialogOptionsDTO: File/folder selection options
• SaveDialogOptionsDTO: Save file dialog options
• QuickPickOptionsDTO: Quick pick list configuration
• InputBoxOptionsDTO: Input box configuration
• MessageSeverity: Info, Warning, Error levels

REQUEST FLOW

1. Provider method called (e.g., ShowMessage)
2. Generate unique request ID
3. Store oneshot::Sender in PendingUserInterfaceRequests map
4. Send IPC message to Sky with request ID and options
5. Sky shows UI and waits for user action
6. User responds → Sky calls ResolveUIRequest Tauri command
7. ResolveUIRequest looks up sender by ID and sends result
8. Provider method returns result to caller

ERROR HANDLING

• IPC failures: CommonError::IPCError
• Timeout: CommonError::RequestTimeout
• User cancellation: None result (not error)
• Invalid arguments: CommonError::InvalidArgument

PERFORMANCE

• Requests are async and non-blocking
• Timeouts prevent indefinite waiting (default ~30s)
• Request IDs are time-based for uniqueness
• Pending request map uses Arc<Mutex<>> for thread safety

VS CODE REFERENCE

Borrowed from VS Code’s UI system:

• vs/platform/dialogs/common/dialogs.ts - Dialog service API
• vs/platform/prompt/common/prompt.ts - Input and quick pick
• vs/workbench/services/decorator/common/decorator.ts - Message service

TODO

• Add support for custom dialog buttons and layouts
• Implement file/folder filters with glob patterns
• Add dialog position and sizing controls
• Support modal vs non-modal dialogs
• Add accessibility features (screen reader support)
• Implement dialog theming (dark/light mode)
• Add file type/extension selection in save dialog
• Support multi-select in quick pick and file dialogs
• Add async progress reporting during long operations
• Implement custom input validation (regex, etc.)

MODULE CONTENTS

• UserInterfaceProvider: Main struct implementing the trait
• Dialog-specific methods: ShowMessage, OpenDialog, SaveDialog
• Selection methods: QuickPick, InputBox
• Request-response coordination logic

Structs

UserInterfaceRequest 🔒

Functions

SendUserInterfaceRequest 🔒

A generic helper function to send a request to the Sky UI and wait for a response.