DP44/enriched-partialglm/DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.GraphList/ViewModel.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
DTS Viewer/DTS.Viewer.Modules/DTS.Viewer.GraphList/ViewModel/GraphMainViewModel.cs	2026-04-16T11:10:28.732851+00:00	zai-org/GLM-5-FP8	1	09077834bf97663d

Documentation: GraphMainViewModel.cs

1. Purpose

The GraphMainViewModel class acts as the presentation logic controller for the Graph List module within the DTS Viewer application. It is responsible for managing the lifecycle of test channels—retrieving them from test summaries, organizing them into a hierarchical tree structure (Test > Group > Channel), and handling user interactions for selecting or locking channels for visualization. It serves as a bridge between the data layer (test summaries, metadata) and the UI layer, publishing events to notify other parts of the system when channels are selected, locked, or cleared.

2. Public Interface

Public Properties

• IFilterView FilterView: Gets the filter view instance associated with this ViewModel.
• IGraphMainView View: Gets or sets the associated view interface.
• IBaseViewModel Parent: Gets or sets the parent ViewModel (used to scope events and behavior).
• InteractionRequest<Notification> NotificationRequest: Used to raise notification dialogs.
• InteractionRequest<Confirmation> ConfirmationRequest: Used to raise confirmation dialogs (hides base member).
• List<ITestChannel> LockedChannelList: Gets or sets the list of channels currently locked by the user.
• List<ITestChannel> SelectedChannelList: Gets or sets the list of channels currently selected by the user.
• ObservableCollection<ITestChannel> ChannelList: The master list of all available channels.
• ObservableCollection<ITestChannel> FilteredChannelList: The list of channels displayed to the user after filtering is applied.
• ObservableCollection<TreeViewChannels> TestChannelsTree: The hierarchical structure of channels bound to the UI TreeView.
• bool IsFilterEnabled: Indicates if the filter UI should be enabled (true if ChannelList has items).
• string SelectedGroupName: The name of the currently selected group.
• string LockedGroupName: The name of the currently locked group.
• bool TestModified: Indicates if the underlying test data has been modified.

Public Methods

• void Initialize(): Overrides base method; currently empty.
• void Initialize(object parameter): Initializes the ViewModel, sets the Parent, determines if locked-only mode is active (if Parent is IPSDReportMainViewModel), initializes the filter view, and subscribes to events.
• void PublishSelectedChannels(): Publishes the GraphSelectedChannelsNotification and GraphSelectedChannelCountNotification events containing the current lists of locked and/or selected channels.
• void AddLockedGroupChannels(string testName, string groupName, List<ITestChannel> channels, bool isLocked): Adds or removes a group of channels to/from the LockedChannelList.
• void AddLockedChannel(ITestChannel channel, bool isLocked): Adds or removes a single channel to/from the LockedChannelList.
• void AddSelectedGroupChannels(string groupName, List<ITestChannel> channels): Selects a specific group of channels, resetting previous selections.
• void AddSelectedGroup(TestGroup group): Marks a specific TestGroup as selected.
• void AddSelectedChannel(ITestChannel channel, bool reset): Adds a single channel to the SelectedChannelList. If reset is true, previous selections are cleared.
• void AddSelectedChannel(ITestChannel channel): Overload that resets previous selections before adding the new channel.
• void OnFilterChanged(FilterParameterArgs args): Filters the ChannelList based on a string parameter and updates FilteredChannelList.
• void Activated(): Overrides base method; publishes an empty FilterParameterChangedEvent to reset the filter.

3. Invariants

• Maximum Locked Channels: The system enforces a hard limit of 8 locked channels (MAX_LOCKED_CHANNELS). The UpdateChannelLocks method disables the ability to lock further channels once this limit is reached.
• Mutual Exclusivity: A channel cannot be simultaneously in the SelectedChannelList and LockedChannelList. Locking a channel removes it from the selected list.
• Color Assignment: Channels are assigned colors from a fixed palette (_graphColors). The GetNextColor method ensures colors are unique if available, or cycles through the palette if the channel count exceeds the color count.
• Parent Scoping: Event handlers (e.g., OnTestSummaryChanged) check if the event's ParentVM matches the ViewModel's Parent property to ensure the event is relevant to this specific instance.
• Locked-Only Mode: If the Parent is of type IPSDReportMainViewModel, the _lockedOnly flag is set to true. In this mode, PublishSelectedChannels only publishes locked channels, ignoring selected channels.

4. Dependencies

External Dependencies

• Prism: IEventAggregator, IRegionManager (for event pub/sub and region navigation).
• Unity: IUnityContainer (for dependency resolution).
• System.Windows.Media: Color, Colors (for channel visualization).

Internal Dependencies (Inferred)

• DTS.Common.Interface: ITestChannel, ITestSummary, IGraphMainView, IFilterView, ITestModificationModel.
• DTS.Common.Events: TestSummaryChangeNotificationArg, GraphClearNotificationArg, FilterParameterArgs, etc.
• DTS.Common.Enums.Sensors: CalibrationBehaviors, IsoViewMode.
• DTS.Serialization: Referenced via Utils.SetChannelInfo for lazy loading channel metadata.

Events Consumed

• RaiseNotification
• FilterParameterChangedEvent
• TestSummaryChangeNotification
• TestModificationChangedEvent
• CalibrationBehaviorSettingChangedEvent
• CalibrationBehaviorSettableInViewerChangedEvent
• ChannelCodesViewChangedEvent

Events Published

• GraphClearNotification
• GraphLoadedCountNotification
• GraphSelectedChannelCountNotification
• GraphSelectedChannelsNotification
• BusyIndicatorChangeNotification
• FilterParameterChangedEvent

5. Gotchas

• Member Hiding: The class uses the new keyword to hide base members (ConfirmationRequest, PropertyChanged, OnPropertyChanged, IsBusy, IsDirty). Accessing these via a base class reference will bypass the logic defined in GraphMainViewModel.
• Explicit GC Collection: The CleanSelection method explicitly calls GC.Collect(). This is generally discouraged in .NET development and could introduce performance pauses.
• Lazy Loading Side Effect: Inside OnTestSummaryChanged, there is a check if (l.Channels.FirstOrDefault() == null). If true, it triggers Utils.SetChannelInfo, which modifies l.Channels, l.Graphs, and l.CalculatedChannels in place. This suggests the data object passed via the event is mutable and potentially incomplete prior to this handler executing.
• Calibration Logic Mutation: The OnTestSummaryChanged method modifies the tsChannels list (removing items or modifying ChannelDescriptionString) based on calibrationBehaviorSetting. This alters the data before it is displayed, specifically handling Linear vs. NonLinear calibration duplicates.
• Dead Code / Empty Handlers:
  • The subscription to GraphChannelsReadCompletedNotification is commented out with the note "It does not work".
  • Event handlers TestChannelsTree_PropertyChanged and GraphList_PropertyChanged contain empty if blocks (e.g., if (e.PropertyName != "TestChannelsTree") { }), which appears to be incomplete logic.
  • OnCalibrationBehaviorSettableInViewerChanged is subscribed but has an empty implementation body.