DP44/enriched-qwen3-coder-next/DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.ChartOptions/ViewModel.md

---
source_files:
  - DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.ChartOptions/ViewModel/ChartOptionsViewModel.cs
generated_at: "2026-04-16T13:55:59.501828+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "7f2f2e90f6f17587"
---

# Documentation: ChartOptionsViewModel

## 1. Purpose

`ChartOptionsViewModel` is a Prism-based ViewModel that manages chart configuration options for the DTS Viewer application. It serves as an intermediary between chart views and the event system, handling axis range settings, unit type selection (EU, mV, ADC), cursor visibility controls, and publishing chart option changes to other application components. The module supports multiple parent contexts including `IViewerMainViewModel` and `IPSDReportMainViewModel`, with different initialization behaviors for each.

---

## 2. Public Interface

### Constructor
```csharp
public ChartOptionsViewModel(
    IChartOptionsView view, 
    IRegionManager regionManager, 
    IEventAggregator eventAggregator, 
    IUnityContainer unityContainer)
```
Initializes the ViewModel, sets up interaction requests, and subscribes to `ChartAxisChangedEvent`.

### Properties

| Property | Type | Description |
|----------|------|-------------|
| `Parent` | `IBaseViewModel` | Reference to the parent ViewModel. |
| `NotificationRequest` | `InteractionRequest<Notification>` | Prism interaction request for notifications. |
| `ConfirmationRequest` | `InteractionRequest<Confirmation>` | Prism interaction request for confirmations. |
| `View` | `IBaseView` | Associated view instance. |
| `Model` | `IChartOptionsModel` | The chart options model; setter triggers `OnPropertyChanged("Model")`. |
| `ContextSearchRegion` | `object` | Region context for search functionality. |
| `IsMenuIncluded` | `bool` | Hides base member; menu inclusion flag. |
| `IsNavigationIncluded` | `bool` | Hides base member; navigation inclusion flag. |
| `IsBusy` | `bool` | Hides base member; busy state indicator. |
| `IsDirty` | `bool` | Hides base member; dirty state (get-only). |
| `ChartOptionsVisability` | `bool` | Controls visibility of chart options UI; defaults to `false`. |
| `ClearMarkersCommand` | `DelegateCommand` | Command that invokes `ClearMarkersMethod()`. |

### Methods

| Method | Signature | Description |
|--------|-----------|-------------|
| `Initialize` | `override void Initialize()` | Empty override; no implementation. |
| `Initialize` | `override void Initialize(object parameter)` | Main initialization accepting `IViewerMainViewModel` or `Tuple<IBaseViewModel, string>` containing `IPSDReportMainViewModel`. Sets up model, subscriptions, and configures based on parameter type. |
| `ShowMinMaxCursor` | `void ShowMinMaxCursor(bool value)` | Publishes `CursorShowMinMaxChangedEvent` with the boolean value. |
| `ResetZoomMethod` | `void ResetZoomMethod()` | Sets `Model.YRange` to `AutoRange` and publishes `ResetZoomChangedEvent(true)`. |
| `ResetTMethod` | `void ResetTMethod()` | Publishes `ResetZoomChangedEvent(false)`. |
| `SaveToPDFMethod` | `void SaveToPDFMethod()` | Publishes `SaveToPDFRequestedEvent` with the `Directory` path. |
| `PublishChanges` | `void PublishChanges()` | Publishes `ChartOptionsChangedEvent` with `ChartOptionsChangedEventArg` containing `ParentVM`, `Model`, and `ChartType`. |
| `ShowCusor` | `void ShowCusor(bool value)` | Publishes `CursorShowChangedEvent` with the boolean value. |
| `OnPropertyChanged` | `new void OnPropertyChanged(string propertyName)` | Raises `PropertyChanged` event. |

---

## 3. Invariants

1. **Model Resolution**: `Model` must be resolved via `_unityContainer.Resolve<IChartOptionsModel>()` before use; it is not resolved in the constructor but in `Initialize(object parameter)`.

2. **Parent Matching for Events**: Event handlers (`OnChartAxisChangedEvent`, `OnGraphSelectedChannelsChanged`) check `args?.ParentVM != Parent` and return early if the event is not intended for this instance.

3. **Publish Control**: `Model.CanPublishChanges` must be `true` for changes to propagate via `PublishChanges()`. It is set to `false` during batch configuration updates.

4. **Unit Type Fallback**: If channels do not support ADC or mV (determined by `AllChannelsSupportADC` / `AllChannelsSupportmV`), the `UnitType` falls back to `ChartUnitTypeEnum.EU`.

5. **ADC/mV Support Detection**: Both `AllChannelsSupportADC` and `AllChannelsSupportmV` return `false` if any channel's parent module has a TSR AIR serial number (checked via `HardwareConstants.IsTSRAIRSerialNumber`).

6. **Graph Chart Type Constraints**: When `chartType == "Graph"`, the model is configured with:
   - `UnitType = ChartUnitTypeEnum.PSD`
   - `YRange = YRangeScaleEnum.Fixed`
   - `MaxFixedY = 1`
   - `MinFixedY = 1e-12` (non-zero for log scale)
   - `DecimateData = false`

---

## 4. Dependencies

### This Module Depends On:
- `DTS.Common.Base` - `BaseViewModel<IChartOptionsViewModel>`
- `DTS.Common.Enums.Viewer` - `ChartUnitTypeEnum`, `YRangeScaleEnum`, `FilterOptionEnum`
- `DTS.Common.Events` - `ChartAxisChangedEvent`, `CursorsAlailableChangedEvent`, `GraphSelectedChannelsNotification`, `CursorShowMinMaxChangedEvent`, `ResetZoomChangedEvent`, `SaveToPDFRequestedEvent`, `ChartOptionsChangedEvent`, `CursorShowChangedEvent`, `CursorsClearChangedEvent`
- `DTS.Common.Interface` - `IChartOptionsViewModel`, `IChartOptionsModel`, `IChartOptionsView`, `IBaseViewModel`, `IBaseView`, `IViewerMainViewModel`, `IPSDReportMainViewModel`, `ITestChannel`
- `DTS.Common.Interactivity` - Interaction requests
- `DTS.Common.Enums.Hardware` - `HardwareConstants.IsTSRAIRSerialNumber()`
- `Prism.Events` - `IEventAggregator`
- `Prism.Regions` - `IRegionManager`
- `Prism.Commands` - `DelegateCommand`
- `Unity` - `IUnityContainer`

### What Depends On This Module:
- Not explicitly shown in source; inferred consumers include:
  - `IChartOptionsView` implementations
  - `IViewerMainViewModel` implementations
  - `IPSDReportMainViewModel` implementations

---

## 5. Gotchas

1. **Misleading XML Documentation**: The constructor's XML comment references `TestSummaryViewModel` instead of `ChartOptionsViewModel` — appears to be copy-paste tech debt.

2. **`new` Keyword Hiding**: Multiple members (`IsMenuIncluded`, `IsNavigationIncluded`, `IsBusy`, `IsDirty`, `ConfirmationRequest`, `Model`, `PropertyChanged`, `OnPropertyChanged`) use the `new` keyword to hide base class members. This can cause unexpected behavior when casting to base types.

3. **Typo in Property Name**: `ChartOptionsVisability` should be `ChartOptionsVisibility`.

4. **Typo in Method Name**: `ShowCusor` should be `ShowCursor`.

5. **Typo in Event Handler**: `OnCursorsAlailableChanged` and `CursorsAlailableChangedEvent` misspell "Available" as "Alailable".

6. **Identical ADC/mV Logic**: `AllChannelsSupportADC` and `AllChannelsSupportmV` have identical implementations. The comment in `AllChannelsSupportADC` suggests this may be placeholder logic based on serial numbers, with future sophistication planned.

7. **Unused/Private Fields**: Several ReSharper suppressions (`UnassignedGetOnlyAutoProperty`, `NotAccessedField.Local`, `UnusedAutoPropertyAccessor.Local`) suggest dead code or incomplete implementations.

8. **Commented-Out Constructor Code**: Lines resolving and assigning `Model` in the constructor are commented out, suggesting initialization was moved to `Initialize(object parameter)`.

9. **Directory Property Purpose Unclear**: The `Directory` property is set from the first selected channel's `BinaryFilePath` and used only in `SaveToPDFMethod()`. The relationship between chart options and this directory is not documented.