---
source_files:
  - Common/DTS.CommonCore/Interface/DTS.Viewer/Navigation/INavigationView.cs
  - Common/DTS.CommonCore/Interface/DTS.Viewer/Navigation/INavigationViewModel.cs
generated_at: "2026-04-16T02:32:50.807752+00:00"
model: "Qwen/Qwen3-Coder-Next-FP8"
schema_version: 1
sha256: "3183c8a5d454e0e2"
---

# Navigation

## 1. Purpose  
This module defines foundational interfaces for navigation-related view and view model components within the `DTS.Common.Interface` namespace. Specifically, it establishes `INavigationView` as a marker interface extending `IBaseView`, and `INavigationViewModel` as a view model interface that enforces a contract for accessing its associated shell view via the `NavigationView` property. These interfaces serve as abstractions to decouple navigation logic from concrete UI implementations, likely supporting MVVM (Model-View-ViewModel) patterns in a viewer application.

## 2. Public Interface  

### `INavigationView`  
- **Signature**: `public interface INavigationView : IBaseView`  
- **Behavior**: A marker interface indicating that a concrete view class participates in the navigation system. It inherits from `IBaseView`, implying it adheres to the base view contract (e.g., lifecycle, data context, or rendering responsibilities defined elsewhere). No additional members are declared in this interface.

### `INavigationViewModel`  
- **Signature**: `public interface INavigationViewModel : IBaseViewModel`  
- **Behavior**: Extends `IBaseViewModel` and requires implementers to expose a read-only property `NavigationView` of type `INavigationView`. This property provides access to the *Shell View*—the top-level navigation container (e.g., a window or master layout) that hosts navigation content.  
- **Property**:  
  - `INavigationView NavigationView { get; }`  
    - **Purpose**: Retrieves the associated navigation shell view.  
    - **Constraints**: Must not be `null` (implied by documentation and typical usage, though not explicitly stated in source).

## 3. Invariants  
- `INavigationView` must be implemented by a class that also satisfies `IBaseView` (inherited contract).  
- `INavigationViewModel` must be implemented by a class that also satisfies `IBaseViewModel` (inherited contract).  
- For any valid instance of `INavigationViewModel`, the `NavigationView` property must return a non-null reference to an object implementing `INavigationView`.  
- The `NavigationView` property is read-only; no setter is defined, implying the association is established at construction and immutable thereafter.

## 4. Dependencies  
- **Depends on**:  
  - `DTS.Common.Base.IBaseView` (via `INavigationView`)  
  - `DTS.Common.Base.IBaseViewModel` (via `INavigationViewModel`)  
- **Depended on by**:  
  - *Not explicitly stated in the provided source*, but any concrete navigation view/view model implementations (e.g., `ShellView`, `ShellViewModel`) would depend on these interfaces.  
  - Likely consumed by navigation infrastructure (e.g., a navigation service or router) to bind views and view models, though such consumers are not visible in this file.

## 5. Gotchas  
- **Ambiguity in "Shell View"**: The XML documentation states `NavigationView` "Gets the Shell View," but the term *Shell View* is not defined here. Its semantics (e.g., whether it is the root window, a navigation frame, or a specific UI container) are not clarified in the source and must be inferred from context or other modules.  
- **No validation guarantees**: While `NavigationView` is expected to be non-null, the interface does not enforce this via contracts or attributes (e.g., `[NotNull]`). Implementers must ensure null-safety.  
- **No navigation operations defined**: The interfaces themselves contain no methods for navigation (e.g., `NavigateTo`, `GoBack`). Navigation logic is likely handled by separate services or view model methods outside this scope.  
- **No versioning or extensibility hooks**: As minimal marker interfaces, future enhancements (e.g., adding lifecycle callbacks) would require breaking changes unless new interfaces are introduced.  
- **None identified from source alone.**