mattercontrol/research/09-settings-management.md

# Settings Management

## Summary

MatterControl uses a hierarchical settings system managing printer configurations, slicer parameters, and user preferences. Settings are organized into profiles with inheritance, preset support, and real-time validation.

## Technical Description

### Architecture

```
ProfileManager
├── ActiveProfiles (list of printer profiles)
└── PrinterSettings (per printer)
    ├── BaseLayer (OEM defaults)
    ├── OemLayer (manufacturer overrides)
    ├── UserLayer (user customizations)
    └── MaterialPresets / QualityPresets
```

### PrinterSettings Class

Central settings container with layered overrides:

```csharp
public class PrinterSettings
{
    public SettingsLayer OemLayer { get; }
    public SettingsLayer UserLayer { get; }
    public List<SettingsLayer> MaterialPresets { get; }
    public List<SettingsLayer> QualityPresets { get; }

    public string GetValue(string key);
    public T GetValue<T>(string key);
    public void SetValue(string key, string value);
}
```

### Settings Layers

Settings resolution from highest to lowest priority:

1. **UserLayer** - User customizations
2. **ActiveQualityPreset** - Quality preset (Draft/Normal/Fine)
3. **ActiveMaterialPreset** - Material preset (PLA/ABS/etc.)
4. **OemLayer** - Manufacturer overrides
5. **BaseLayer** - Application defaults

### SettingsKey Constants

All settings keys defined in `SettingsKey` static class:

| Category | Sample Keys |
|----------|-------------|
| Printer | `printer_name`, `build_height`, `bed_size` |
| Layer | `layer_height`, `first_layer_height` |
| Perimeters | `perimeters`, `external_perimeter_speed` |
| Infill | `fill_density`, `infill_type` |
| Support | `support_material`, `support_type` |
| Temperature | `temperature`, `bed_temperature` |
| Speed | `travel_speed`, `perimeter_speed` |
| Retraction | `retract_length`, `retract_speed` |
| G-code | `start_gcode`, `end_gcode` |

### Profile Management

`ProfileManager` handles profile lifecycle:

```csharp
public class ProfileManager
{
    public static ProfileManager Instance { get; }
    public IEnumerable<PrinterInfo> ActiveProfiles { get; }

    public static Task<PrinterSettings> LoadSettingsAsync(string profileId);
    public void SaveSettings(PrinterSettings settings);
    public void DeleteProfile(string profileId);
}
```

### Settings Validation

`SettingsValidation` checks configuration consistency:

| Check | Description |
|-------|-------------|
| Temperature bounds | Min/max temperature limits |
| Speed limits | Reasonable speed ranges |
| Layer height | Compatible with nozzle diameter |
| Retraction | Valid retraction settings |
| Bed size | Build volume constraints |

### UI Components

**SliceSettingsWidget:**
```
SliceSettingsWidget
├── Category Tabs (General, Infill, Support, etc.)
├── Settings Sections
│   └── SliceSettingsRow (individual settings)
└── PresetsToolbar
    ├── Material Preset Selector
    └── Quality Preset Selector
```

**SliceSettingsRow:**
- Label and value editor
- Reset to default button
- Override indicator
- Help tooltip

### Preset System

**Material Presets:**
- PLA, ABS, PETG, TPU, etc.
- Temperature profiles
- Retraction settings
- Fan settings

**Quality Presets:**
- Draft (fast, low quality)
- Normal (balanced)
- Fine (slow, high quality)
- Custom user presets

### OEM Customization

Manufacturers can provide custom profiles via:

```
StaticData/
├── Printers/
│   └── {Manufacturer}/
│       └── {Model}.printer
│           ├── base.ini
│           ├── material_pla.ini
│           └── quality_normal.ini
└── OEMSettings/
    └── OEMProfile.json
```

### Settings Events

| Event | Description |
|-------|-------------|
| `SettingChanged` | Individual setting modified |
| `AnyPrinterSettingChanged` | Static event for any printer |
| `ActiveProfileModified` | Active profile changed |

### Design Rationale

**Layered Settings**: Inheritance hierarchy provides:
- Clear override semantics
- Easy reset to defaults
- Manufacturer customization
- User freedom to modify

**Preset System**: Separating presets allows:
- Quick switching between materials/quality
- Consistent printing results
- OEM-tuned profiles

**Key-Value Model**: String-based settings enable:
- Flexible storage
- Easy serialization
- Runtime modification

## Reference

### Core Classes

| Class | Location | Description |
|-------|----------|-------------|
| `PrinterSettings` | [SlicerConfiguration/Settings/PrinterSettings.cs](MatterControlLib/SlicerConfiguration/Settings/PrinterSettings.cs) | Settings container |
| `SettingsLayer` | [SlicerConfiguration/Settings/SettingsLayer.cs](MatterControlLib/SlicerConfiguration/Settings/SettingsLayer.cs) | Settings layer |
| `ProfileManager` | [SlicerConfiguration/Settings/ProfileManager.cs](MatterControlLib/SlicerConfiguration/Settings/ProfileManager.cs) | Profile manager |
| `SettingsKey` | [SlicerConfiguration/Settings/SettingsKey.cs](MatterControlLib/SlicerConfiguration/Settings/SettingsKey.cs) | Key constants |

### UI Components

| Class | Location | Description |
|-------|----------|-------------|
| `SliceSettingsWidget` | [SlicerConfiguration/SliceSettingsWidget.cs](MatterControlLib/SlicerConfiguration/SliceSettingsWidget.cs) | Settings panel |
| `SliceSettingsRow` | [SlicerConfiguration/SliceSettingsRow.cs](MatterControlLib/SlicerConfiguration/SliceSettingsRow.cs) | Settings row |
| `PresetSelectorWidget` | [SlicerConfiguration/PresetSelectorWidget.cs](MatterControlLib/SlicerConfiguration/PresetSelectorWidget.cs) | Preset dropdown |

### Application Settings

| Class | Location | Description |
|-------|----------|-------------|
| `ApplicationSettings` | [SettingsManagement/ApplicationSettings.cs](MatterControlLib/SettingsManagement/ApplicationSettings.cs) | App-level settings |
| `UserSettings` | [SettingsManagement/UserSettings.cs](MatterControlLib/SettingsManagement/UserSettings.cs) | User preferences |
| `OemSettings` | [SettingsManagement/OemSettings.cs](MatterControlLib/SettingsManagement/OemSettings.cs) | OEM config |