-

docs/plans/2026-01-29-slint-lsp-integration-design.md

@@ -0,0 +1,108 @@
+# Slint LSP Integration Design
+
+**Date:** 2026-01-29
+**Status:** Approved
+**Phase:** Phase 1 - Core LSP Features
+
+## Overview
+
+Implement complete Slint LSP integration into IntelliJ IDEA, enabling standard LSP features (diagnostics, completion, goto definition, hover, formatting, etc.) through IntelliJ's built-in LSP framework.
+
+## Architecture
+
+### Component Structure
+
+```
+IntelliJ IDEA (LSP Client)
+    ↓
+SlintLspServerSupportProvider (Entry point)
+    ↓
+SlintLspServerDescriptor (Server configuration)
+    ↓
+Slint LSP Server (External process)
+```
+
+### Core Components
+
+1. **File Type System**
+   - `SlintLanguage`: Language definition
+   - `SlintFileType`: File type definition with .slint extension
+   - File icon and description
+
+2. **LSP Server Integration**
+   - `SlintLspServerSupportProvider`: LSP entry point (exists, needs refinement)
+   - `SlintLspServerDescriptor`: Server configuration (rename from FooLspServerDescriptor)
+   - Automatic capability negotiation via LSP initialize handshake
+
+3. **Syntax Highlighting**
+   - Use TextMate grammar from official Slint VSCode extension
+   - `SlintTextMateProvider`: TextMate bundle provider
+
+4. **LSP Feature Mapping** (automatic via IntelliJ)
+   - Diagnostics → Error/warning annotations
+   - Completion → Code completion UI
+   - Goto Definition → Ctrl+Click navigation
+   - Hover → Quick documentation
+   - Formatting → Code formatting actions
+   - References → Find usages
+   - Rename → Refactor rename
+
+## Implementation Plan
+
+### 1. File Type System
+
+**Files to create:**
+- `src/main/kotlin/me/zhouxi/slint/lang/SlintLanguage.kt`
+- `src/main/kotlin/me/zhouxi/slint/lang/SlintFileType.kt`
+
+**Changes to plugin.xml:**
+- Register `<fileType>` extension
+
+### 2. LSP Server Configuration
+
+**Files to modify:**
+- `src/main/kotlin/me/zhouxi/slint/lsp/SlintLspServerSupportProvider.kt`
+  - Rename `FooLspServerDescriptor` → `SlintLspServerDescriptor`
+  - Use `file.fileType == SlintFileType` instead of string comparison
+
+### 3. Syntax Highlighting
+
+**Resources to add:**
+- Download `slint.tmLanguage.json` from Slint GitHub
+- Place in `src/main/resources/textmate/`
+
+**Files to create:**
+- `src/main/kotlin/me/zhouxi/slint/lang/syntax/SlintTextMateProvider.kt`
+
+**Changes to plugin.xml:**
+- Register `<textMate.bundleProvider>` extension
+
+### 4. Testing
+
+**Test files to create:**
+- Sample .slint files for manual testing
+- Verify: diagnostics, completion, goto definition, hover, formatting
+
+## Design Decisions
+
+- **Use IntelliJ LSP Framework**: Leverage built-in LSP client, no manual protocol implementation
+- **TextMate for Syntax**: Use official grammar, zero maintenance
+- **Minimal Custom Code**: Only implement required extension points
+- **Type-Safe File Detection**: Use FileType comparison instead of string extension checks
+
+## Out of Scope (Phase 2)
+
+- Live Preview integration (Slint-specific feature)
+- Custom UI components
+- Advanced project configuration
+
+## Success Criteria
+
+- .slint files recognized by IntelliJ
+- LSP server starts automatically when .slint file opened
+- Syntax highlighting works
+- Code completion provides suggestions
+- Diagnostics show errors/warnings
+- Goto definition navigates correctly
+- Hover shows documentation
+- Code formatting works