ObsiViewer/CODE_BLOCK_FIXES.md

# Code Block Component - Fixes Applied

## Issues Fixed ✅

### 1. Line Numbers Not Working
**Problem**: Line numbers were displayed but the code content overlapped them because there was no padding.

**Solution**: 
- Added dynamic padding to the `<pre>` element based on `props.showLineNumbers`
- When line numbers are shown: `padding: 12px 12px 12px 48px` (48px left padding for line numbers)
- When line numbers are hidden: `padding: 12px`
- Applied the same font family to line numbers to ensure proper alignment

### 2. Font Selection Menu Missing
**Problem**: There was no way to change the font of the code block.

**Solution**:
- Added `availableFonts` array with popular monospace fonts:
  - JetBrains Mono
  - Fira Code
  - Consolas
  - Monaco
  - Courier New
  - Monospace
- Added font selection menu in the "More" dropdown
- Implemented `onFontChange()` method to update the font
- Implemented `getFontFamily()` method to apply the selected font
- Font is applied via `[style.font-family]="getFontFamily()"`

### 3. Language Detection Not Working
**Problem**: There was no automatic language detection feature.

**Solution**:
- Implemented `detectLanguageInternal()` method with pattern matching for 16+ languages
- Auto-detection runs on component initialization if no language is set
- Added "Auto-detect Language" button in the menu
- Detection patterns include:
  - JavaScript, TypeScript, Python, Java, C#, C++, C, Go, Rust
  - PHP, Ruby, HTML, CSS, JSON, XML, YAML
  - SQL, Bash, Dockerfile, Markdown

### 4. Theme Selection Doesn't Change Text Color
**Problem**: Theme selection menu was missing.

**Solution**:
- Added theme selection menu in the "More" dropdown
- Lists all available themes from `CodeThemeService`
- Implemented `onThemeChange()` method
- Fixed `getThemeClass()` to use 'darcula' as default theme
- Theme CSS class is properly applied to the code container

### 5. Preview/Collapse Option Missing
**Problem**: The header didn't have a collapse/preview toggle like the file block.

**Solution**:
- Complete UI restructure following the file block pattern
- Added header button with:
  - 💻 emoji icon
  - Language label
  - Line count display
  - "More" menu (⋮ button)
  - Collapse/Preview label
- Implemented `toggleCollapse()`, `isCollapsed()` methods
- Code editor is conditionally rendered based on `!isCollapsed()`
- Uses `props.collapsed` to track state

## New Features Added 🎁

### Enhanced Menu System
- Created comprehensive dropdown menu with sections:
  - **Language Selection**: All supported languages with visual checkmarks
  - **Theme Selection**: All available themes
  - **Font Selection**: Multiple monospace font options
  - **Options**: Toggle line numbers and word wrap
  - **Actions**: Copy to clipboard and auto-detect language

### Better UX
- Menu closes automatically after selection
- Menu positioning follows cursor
- Escape key closes menu
- Click outside closes menu
- Visual feedback (checkmarks) for selected options

### Keyboard Accessibility
- Header button supports Enter and Space keys
- ARIA attributes for screen readers
- Focus management

### Additional Utilities
- `getLineCount()`: Shows number of lines in the header
- `getLanguageLabel()`: Displays friendly language name
- `copyToClipboard()`: One-click code copying
- `onBlur()`: Updates line numbers after editing

## Architecture Improvements

### Consistent with File Block
The component now follows the same pattern as the file block:
- Same header structure
- Same menu positioning logic
- Same collapse/expand behavior
- Better visual consistency across the app

### Better State Management
- All props updates go through `this.update.emit()`
- Menu state managed with `menuOpen` and `menuPos`
- Proper cleanup with `@HostListener` decorators

## Testing Recommendations

1. **Test Line Numbers**: 
   - Toggle line numbers on/off
   - Add/remove lines and verify numbers update
   - Check alignment with different fonts

2. **Test Themes**:
   - Switch between all available themes
   - Verify text color changes properly
   - Check that default theme (Darcula) loads correctly

3. **Test Fonts**:
   - Try each font option
   - Verify line numbers align correctly with each font
   - Check that font persists after editing

4. **Test Language Detection**:
   - Paste code in different languages
   - Click "Auto-detect Language"
   - Verify correct language is detected

5. **Test Collapse/Expand**:
   - Click header to collapse
   - Verify content hides
   - Verify "Preview/Collapse" label updates
   - Expand and verify content shows

6. **Test Menu**:
   - Open menu and click outside to close
   - Press Escape to close
   - Select options and verify menu closes
   - Check menu positioning on different screen sizes

## Known Limitations

1. **Language Detection**: The detection is pattern-based and may not be 100% accurate for ambiguous code snippets.
2. **Font Loading**: Custom fonts (JetBrains Mono, Fira Code) need to be loaded in your app for them to work properly. Consider adding them to your global styles.
3. **Syntax Highlighting**: This component uses CSS themes but doesn't have actual syntax highlighting (would need a library like Prism or Highlight.js for that).

## Next Steps (Optional Enhancements)

1. Add syntax highlighting with Prism.js or Highlight.js
2. Add line highlighting feature
3. Add search/replace functionality
4. Add code folding
5. Load custom fonts via CDN or local assets
6. Add more sophisticated language detection (using a library)
7. Add export functionality (download as file)