# Session Summary: Keybinding System Implementation

**Date**: 2025-10-25

## Overview

Implemented a complete centralized keybinding system with single-source-of-truth architecture for both Tk and Curses UIs, plus integrated three-tier help system with search.

## Key Achievements

### 1. Keybinding Architecture

Created a macro-based keybinding system where JSON config files drive all keybindings across:
- UI keyboard handling
- Menu accelerator displays
- Toolbar labels
- Dialog messages
- Documentation

**Files Created**:
- `src/ui/curses_keybindings.json` - Curses UI keybinding definitions
- `src/ui/tk_keybindings.json` - Tk UI keybinding definitions
- `src/ui/help_macros.py` - Macro expansion system for documentation
- `src/ui/keybinding_loader.py` - Tk keybinding loader (JSON → Tkinter bindings)
- `utils/test_help_macros.py` - Test macro expansion
- `utils/test_keybinding_loader.py` - Test keybinding loading

**Files Modified**:
- `src/ui/keybindings.py` - Refactored to load from JSON for Curses
- `src/ui/tk_ui.py` - Integrated JSON keybindings
- `src/ui/help_widget.py` - Added macro expansion
- `src/ui/tk_help_browser.py` - Created with integrated search

### 2. Documentation System

**Macro System**:
Documentation now uses `{{kbd:action}}` macros that automatically expand to the correct keybinding for each UI:

```markdown
Press **{{kbd:help}}** to open help
```

Expands to:
- Curses: "Press **Ctrl+H** to open help"
- Tk: "Press **Ctrl+?** to open help"

**Implementation Notes Added**:
- ✅ `lprint-lprint-using.md` - Printer output not implemented
- ✅ `llist.md` - Printer listing not implemented
- ✅ `lpos.md` - Printer head position not implemented
- ✅ `varptr.md` - Memory address access not implemented (rewrote corrupted file)

All hardware/system function help files now have clear implementation notes.

### 3. Help System Integration

**Tk GUI**:
- Created full-featured help browser (`tk_help_browser.py`)
- Search across all three tiers (Language 📕, MBASIC 📗, UI 📘)
- Markdown rendering with clickable links
- Navigation history (back button)
- Keyboard shortcuts: Ctrl+? or Ctrl+/ to open

**Curses UI**:
- Search already implemented from previous session
- Help key updated from Ctrl+A to Ctrl+H to match JSON

### 4. Benefits of New System

**Single Source of Truth**:
To change a keybinding, edit ONE file:

```json
{
  "editor": {
    "help": {
      "keys": ["Ctrl+H"],
      "primary": "Ctrl+H",
      "description": "Open help browser"
    }
  }
}
```

This updates:
- Actual keyboard handling in UI
- Menu accelerator displays
- Toolbar button labels
- Dialog text
- All help documentation

**Consistency Guaranteed**:
- No more forgetting to update documentation
- No more mismatches between docs and actual keys
- No more editing 5+ files for one change

**UI Flexibility**:
- Different UIs can have different keybindings
- Multiple keys can trigger same action
- Easy to add new keybindings

## Technical Details

### Conversion Functions

**For Tk** (`keybinding_loader.py`):
```python
"Ctrl+S" → "<Control-s>"  # Tkinter binding format
"Ctrl+?" → "<Control-question>"
"F5" → "<F5>"
```

**For Curses** (`keybindings.py`):
```python
"Ctrl+H" → "ctrl h"  # urwid key format
"Ctrl+H" → '\x08'    # control character code
```

### Macro Expansion

**In Help Docs**:
```markdown
{{kbd:help}} → "Ctrl+H" (for Curses)
{{kbd:help}} → "Ctrl+?" (for Tk)
{{version}} → "5.21"
{{ui}} → "Curses" or "Tk"
```

**In Code** (`help_macros.py`):
```python
macros = HelpMacros('curses', help_root)
expanded = macros.expand(markdown_text)
```

## Testing

All components tested:
- ✅ Macro expansion works correctly
- ✅ Keybinding loading from JSON verified
- ✅ Tk UI reads and uses JSON keybindings
- ✅ Curses UI reads and uses JSON keybindings
- ✅ Help system search works in both UIs

## Files Changed Summary

**New Files (11)**:
- `src/ui/curses_keybindings.json`
- `src/ui/tk_keybindings.json`
- `src/ui/help_macros.py`
- `src/ui/keybinding_loader.py`
- `src/ui/tk_help_browser.py`
- `docs/help/ui/tk/search_index.json`
- `utils/test_help_macros.py`
- `utils/test_keybinding_loader.py`

**Modified Files (10)**:
- `src/ui/keybindings.py` - Now loads from JSON
- `src/ui/tk_ui.py` - Integrated keybinding loader
- `src/ui/help_widget.py` - Added macro expansion
- `docs/help/ui/tk/index.md` - Uses macros
- `docs/help/ui/curses/quick-reference.md` - Uses macros
- `docs/help/ui/curses/help-navigation.md` - Uses macros
- `docs/help/common/language/statements/lprint-lprint-using.md` - Added note
- `docs/help/common/language/statements/llist.md` - Added note
- `docs/help/common/language/functions/lpos.md` - Added note
- `docs/help/common/language/functions/varptr.md` - Rewrote with note
- `docs/dev/NOT_IMPLEMENTED.md` - Updated status

## Commits

1. `e85293e` - Add integrated three-tier help system to Tk GUI with keybinding macros
2. `2edd287` - Make Tk UI read keybindings from JSON config
3. `ac6d957` - Add implementation notes to printer functions and refactor Curses keybindings
4. `1b80645` - Fix varptr.md: Add implementation note and correct corrupted content

## Impact

**For Users**:
- Consistent keybindings across UI and documentation
- Easy to customize keybindings (edit JSON)
- Better help system with search

**For Developers**:
- Single source of truth for keybindings
- No risk of documentation drift
- Easy to add new keybindings
- Testable keybinding system

**For Maintainers**:
- Change one JSON file to update everything
- Documentation automatically stays in sync
- Clear separation of concerns

## Future Enhancements

Potential improvements:
- Add more macros (e.g., `{{path:file}}` for file paths)
- Generate keyboard shortcut quick reference cards automatically
- Add keybinding conflict detection
- Support platform-specific keybindings (Cmd vs Ctrl on macOS)

## Conclusion

Successfully implemented a complete keybinding system with macro-based documentation that eliminates the "change in 5 places" problem. The system is elegant, testable, and maintainable.
