# StatusLine Spacing Implementation Summary

**Date:** 2026-01-02
**Feature:** Spacing presets for gap between left and right Powerlevel10k segments
**Status:** ✅ Complete (Phase 1 & 2)

---

## What Was Implemented

### Phase 1: Core Gap System ✅

1. **Config Schema** (4 new settings in `src/aiterm/statusline/config.py`)
   - `spacing.mode` - Preset selection (minimal/standard/spacious)
   - `spacing.min_gap` - Minimum gap in chars (default: 10)
   - `spacing.max_gap` - Maximum gap in chars (default: 40)
   - `spacing.show_separator` - Show centered `…` separator (default: true)

2. **SPACING_PRESETS Constant** (`src/aiterm/statusline/renderer.py`)
   ```python
   SPACING_PRESETS = {
       'minimal': {'base_percent': 0.15, 'min_gap': 5, 'max_gap': 20},
       'standard': {'base_percent': 0.20, 'min_gap': 10, 'max_gap': 40},
       'spacious': {'base_percent': 0.30, 'min_gap': 15, 'max_gap': 60}
   }
   ```

3. **Gap Calculation** (`_calculate_gap()` method)
   - Dynamic gap sizing: `gap = terminal_width * base_percent`
   - Min/max constraints applied
   - Config overrides supported

4. **Gap Rendering** (`_render_gap()` method)
   - Optional centered separator (`…`) in dim gray
   - Fallback to plain spaces when separator disabled
   - Smart handling of small gaps (< 3 chars)

5. **Updated Line Alignment** (`_align_line()` method)
   - Uses new spacing system instead of fixed padding
   - Graceful degradation for narrow terminals
   - Fallback to left-only when insufficient space

### Phase 2: CLI & Polish ✅

6. **CLI Command** (`src/aiterm/cli/statusline.py`)
   - `ait statusline config spacing <preset>` - Quick preset switching
   - Validates preset names
   - Shows before/after values
   - Helpful examples and descriptions

7. **Comprehensive Tests** (`tests/test_statusline_renderer.py`)
   - 12 new tests covering all spacing functionality
   - Gap calculation tests (3)
   - Min/max constraint tests (2)
   - Config override tests (1)
   - Gap rendering tests (3)
   - Alignment integration tests (3)
   - All tests passing ✅

8. **Visual Testing**
   - Verified rendering with `ait statusline test`
   - CLI command works correctly
   - StatusLine displays properly with spacing

---

## Test Results

**Total Tests:** 32 (20 existing + 12 new)
**Status:** All passing ✅

```
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_standard_preset PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_minimal_preset PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_spacious_preset PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_min_constraint PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_max_constraint PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_calculate_gap_config_overrides PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_render_gap_with_separator PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_render_gap_without_separator PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_render_gap_too_small_for_separator PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_align_line_with_spacing PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_align_line_narrow_terminal PASSED
tests/test_statusline_renderer.py::TestSpacingFeatures::test_align_line_fallback_to_left_only PASSED
```

---

## Files Modified

### Core Implementation
- `src/aiterm/statusline/config.py` - Added 4 spacing config settings (lines 317-341)
- `src/aiterm/statusline/renderer.py` - Added SPACING_PRESETS constant and 3 new methods (lines 19-347)

### CLI
- `src/aiterm/cli/statusline.py` - Added spacing command (lines 520-575)

### Tests
- `tests/test_statusline_renderer.py` - Added TestSpacingFeatures class with 12 tests (lines 278-455)

---

## Usage Examples

### Quick Preset Switching
```bash
# Tight spacing (15% gap, 5-20 chars)
ait statusline config spacing minimal

# Balanced spacing (20% gap, 10-40 chars) [default]
ait statusline config spacing standard

# Wide spacing (30% gap, 15-60 chars)
ait statusline config spacing spacious

# Preview changes
ait statusline test
```

### Manual Config
```bash
# Set custom min/max gap
ait statusline config set spacing.min_gap 12
ait statusline config set spacing.max_gap 50

# Disable separator
ait statusline config set spacing.show_separator false
```

### Visual Example
```
Terminal width: 120 cols
Standard preset: 120 * 0.20 = 24 char gap

Before (fixed padding):
╭─ ░▒▓ 📁 aiterm  main ▓▒░                               ░▒▓ (wt) feature ▓▒░
                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                        (variable, fills to terminal width)

After (spacing preset):
╭─ ░▒▓ 📁 aiterm  main ▓▒░            …           ░▒▓ (wt) feature ▓▒░
                        ^^^^^^^^^^^^^^^^^^^^^^^^
                        (24 chars, centered separator)
```

---

## Implementation Time

**Total:** ~2.5 hours (as estimated in spec)
- Phase 1 (Core Gap System): ~1 hour
- Phase 2 (CLI & Tests): ~1.5 hours

---

## What's Next (Optional Future Enhancements)

These are **not critical** and can be prioritized based on user feedback:

1. **Smart Gap Calculation** (Medium Priority)
   - Adjust gap based on content length
   - Ensure consistent spacing across different lines

2. **Theme Integration** (Low Priority)
   - Different separator characters per theme
   - Theme-specific gap styling

3. **Documentation** (Medium Priority)
   - Add spacing section to statusline guide
   - Update configuration reference

---

## Related Documents

- **Spec:** `docs/specs/SPEC-statusline-spacing-2026-01-02.md`
- **Brainstorm:** `BRAINSTORM-statusline-spacing-2026-01-02.md`
- **Tests:** `tests/test_statusline_renderer.py::TestSpacingFeatures`

---

**✅ All Phase 1 and Phase 2 tasks complete!**
**✅ All tests passing!**
**✅ StatusLine spacing system is production-ready!**
