DP44/enriched-partialglm/Common/DTS.CommonCore/BusyIndicatorManager.md

source_files, generated_at, model, schema_version, sha256

source_files	generated_at	model	schema_version	sha256
Common/DTS.CommonCore/BusyIndicatorManager/xBusyIndicator.xaml.cs Common/DTS.CommonCore/BusyIndicatorManager/BusyIndicatorManager.cs	2026-04-16T11:56:30.835743+00:00	zai-org/GLM-5-FP8	1	85046dce961f12c2

Documentation: DTS.Common.BusyIndicatorManager

1. Purpose

This module provides a centralized mechanism for managing busy indicator UI state across an application. It implements a singleton-based manager (BusyIndicatorManager) that tracks multiple concurrent busy operations by unique ID, allowing different parts of the application to show/hide busy indicators without conflicting with each other. The xBusyIndicator class serves as a WPF user control for displaying the busy indicator UI.

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2. Public Interface

BusyIndicatorManager (class)

Inherits from: NotificationObject (Microsoft.Practices.Prism.ViewModel)

Singleton Access

public static BusyIndicatorManager Instance { get; }

Returns the singleton instance of BusyIndicatorManager. Thread-safe via lock synchronization on SyncRoot.

Properties

public bool IsBusy { get; }

Indicates whether any busy operation is currently active. Read-only from external callers; set internally via ShowBusy/CloseBusy. Raises PropertyChanged notification.

public string Message { get; }

The current message to display in the busy indicator. Read-only from external callers. Raises PropertyChanged notification.

Methods

public void ShowBusy(int id, string busyMessage)

Registers a busy operation with the given id and displays busyMessage. If the id already exists, updates the message. Sets IsBusy to true and updates Message.

public void CloseBusy(int id)

Removes the busy operation identified by id. If no busy operations remain, sets IsBusy to false and clears Message. If other operations remain, keeps IsBusy as true and sets Message to the last entry's value in busyParameters.

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xBusyIndicator (class)

Inherits from: Not explicitly shown; appears to be a WPF partial class (likely UserControl).

public xBusyIndicator()

Default constructor that calls InitializeComponent().

public void Connect(int connectionId, object target)

Method present in the class but implementation is empty. Purpose unclear from source alone.

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3. Invariants

• Singleton guarantee: Only one instance of BusyIndicatorManager can exist per process. Access is always through BusyIndicatorManager.Instance.
• Thread-safe initialization: The singleton is lazily initialized with lock-based synchronization.
• ID uniqueness: Each busy operation is identified by a unique int ID. Callers are responsible for ensuring IDs do not collide.
• State consistency: IsBusy is true if and only if busyParameters.Count > 0.
• Message consistency: When IsBusy is false, Message is an empty string. When IsBusy is true, Message reflects the most recently added/updated busy message.
• Property change notifications: IsBusy and Message raise PropertyChanged via RaisePropertyChanged() when modified.

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4. Dependencies

This module depends on:

• Microsoft.Practices.Prism.ViewModel — specifically NotificationObject for INotifyPropertyChanged implementation
• System.Collections.Generic — Dictionary<TKey, TValue>
• System.Linq — Enumerable.Last() extension method
• System.Windows.Controls — referenced in xBusyIndicator
• Xceed.Wpf.Toolkit — referenced in xBusyIndicator (likely provides the actual busy indicator control)

What depends on this module:

• Cannot be determined from source alone. Consumers would bind to BusyIndicatorManager.Instance.IsBusy and Message properties, or instantiate xBusyIndicator in XAML views.

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5. Gotchas

1. xBusyIndicator.Connect is empty: The method signature suggests it may be generated code (common in WPF for IComponentConnector), but the empty implementation has no documented purpose.

2. Dictionary ordering assumption: CloseBusy uses busyParameters.Last().Value to determine the next message to display. While .NET Framework 4.7+ and .NET Core preserve insertion order in Dictionary, this is not guaranteed by the interface contract. The "last" message may not be the most recently added in all runtime environments.

3. No validation of busyMessage: ShowBusy accepts any string, including null or empty strings, without validation.

4. No exception handling for missing IDs in CloseBusy: The method silently ignores calls to close non-existent IDs (it checks ContainsKey before removing).

5. Message always updated on ShowBusy: Even if an ID already exists with the same message, Message is reassigned and property change notification fires, which may trigger unnecessary UI updates.