ViewModel

1. Purpose

This module provides the ViewModel component for the Power and Battery settings UI within the SystemSettings feature area. It follows the MVVM pattern using Prism and MEF, serving as a placeholder view model that integrates with the application's navigation, event aggregation, and dependency injection infrastructure. The module currently provides minimal domain-specific functionality but establishes the structural foundation for power and battery configuration management.

2. Public Interface

Class: PowerAndBatteryViewModel

Inherits: BasePropertyChanged
Implements: IPowerAndBatteryViewModel
MEF Export: [Export(typeof(IPowerAndBatteryView))] with [PartCreationPolicy(CreationPolicy.Shared)] (singleton scope)

Constructor:

public PowerAndBatteryViewModel(IPowerAndBatteryView view, IRegionManager regionManager, IEventAggregator eventAggregator, IUnityContainer unityContainer)

Initializes the view model, sets the View's DataContext to itself, creates interaction requests, and subscribes to RaiseNotification and BusyIndicatorChangeNotification events.

Lifecycle Methods:

void Cleanup() - Empty implementation
Task CleanupAsync() - Returns Task.CompletedTask
void Initialize() - Empty implementation
void Initialize(object parameter) - Empty implementation
void Initialize(object parameter, object model) - Empty implementation
Task InitializeAsync() - Returns Task.CompletedTask
Task InitializeAsync(object parameter) - Returns Task.CompletedTask
void Activated() - Empty implementation

Properties:

IPowerAndBatteryView View { get; } - The associated view instance
InteractionRequest<Notification> NotificationRequest { get; } - For raising notification dialogs
InteractionRequest<Confirmation> ConfirmationRequest { get; } - For raising confirmation dialogs
bool IsDirty { get; private set; } - Tracks unsaved changes state
bool IsBusy { get; set; } - Busy indicator state, bound to UI
bool IsMenuIncluded { get; set; } - Menu inclusion flag
bool IsNavigationIncluded { get; set; } - Navigation inclusion flag
string HeaderInfo { get; } - Returns hardcoded "MainRegion"

Private Event Handlers:

void OnBusyIndicatorNotification(bool eventArg) - Sets IsBusy property from event
void OnRaiseNotification(NotificationContentEventArgs eventArgsWithTitle) - Raises notification dialog via NotificationRequest.Raise()

3. Invariants

The View property is set at construction and never reassigned.
View.DataContext is always set to this (the ViewModel instance) during construction.
NotificationRequest and ConfirmationRequest are initialized at construction and never null.
Event subscriptions use ThreadOption.PublisherThread for BusyIndicatorChangeNotification with keepSubscriberReferenceAlive: true.
HeaderInfo always returns the literal string "MainRegion".

4. Dependencies

Imports (this module depends on):

DTS.Common.Base - BasePropertyChanged base class
DTS.Common.Events - RaiseNotification, BusyIndicatorChangeNotification, NotificationContentEventArgs
DTS.Common.Interactivity - InteractionRequest<T>, Notification, Confirmation
DTS.Common.Interface - IPowerAndBatteryView, IPowerAndBatteryViewModel
Prism.Events - IEventAggregator, ThreadOption
Prism.Regions - IRegionManager
Unity - IUnityContainer
System.ComponentModel.Composition - MEF attributes

Dependents (inferred):

The View component (PowerAndBatteryView) which is injected via constructor
Shell/Bootstrapper that discovers and loads this MEF export

5. Gotchas

Stale XML documentation: The constructor's XML comment references "TechnologyDomainEditViewModel" which appears to be a copy-paste error from another module.
Empty lifecycle methods: All Initialize and Cleanup methods are empty shells. The module does not perform any initialization or cleanup logic.
Unused ConfirmationRequest: While instantiated, ConfirmationRequest is never raised anywhere in this class.
Hardcoded HeaderInfo: Returns "MainRegion" which may be misleading as it suggests region identification but is a static string.

4.4 KiB Raw Blame History