---
source_files:
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/RefreshTestRequestEvent.cs
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/ShowT0CursorEvent.cs
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/TestModificationChangedEvent.cs
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/SetUseZeroForUnfilteredEvent.cs
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/TestModificationEvent.cs
  - Common/DTS.Common/Events/DTS.Viewer/TestModification/ShiftT0Event.cs
generated_at: "2026-04-17T16:03:15.426783+00:00"
model: "zai-org/GLM-5-FP8"
schema_version: 1
sha256: "f69e333ecbb396d6"
---

# TestModification

### Purpose
This module defines a set of Prism events for coordinating test modification operations within the DTS Viewer system. It provides a loosely-coupled messaging mechanism for components to communicate changes to test data, T0 cursor state, and filtering behavior without direct references. All events inherit from `CompositePresentationEvent<T>` from the legacy Microsoft.Practices.Prism library.

### Public Interface

**RefreshTestRequestEvent**
- Signature: `public class RefreshTestRequestEvent : CompositePresentationEvent<string>`
- Payload: `string` (test ID)
- Behavior: Published to request a refresh of a specific test identified by its ID.

**ShowT0CursorEvent**
- Signature: `public class ShowT0CursorEvent : CompositePresentationEvent<bool>`
- Payload: `bool` (true to show, false to hide)
- Behavior: Controls visibility of the T0 cursor in the viewer.

**TestModificationChangedEvent**
- Signature: `public class TestModificationChangedEvent : CompositePresentationEvent<ITestModificationModel>`
- Payload: `ITestModificationModel`
- Behavior: Notifies subscribers when the data folder or test modification model has changed.

**SetUseZeroForUnfilteredEvent**
- Signature: `public class SetUseZeroForUnfilteredEvent : CompositePresentationEvent<bool>`
- Payload: `bool`
- Behavior: Controls whether 0 or P is used in the isocode filter field when modifying an isocode from a filter.

**TestModificationEvent**
- Signature: `public class TestModificationEvent : CompositePresentationEvent<TestModificationArgs>`
- Payload: `TestModificationArgs`
- Behavior: Published whenever a test is modified by the viewer. Used by DataPro to regenerate an ROI when an event is modified.

**TestModificationArgs**
- Properties:
  - `string DataSetDirectory { get; private set; }` - Path to the DTS file
  - `string TestId { get; private set; }` - Identifier of the modified test
- Constructor: `TestModificationArgs(string dtsFilePath, string testId)`

**ShiftT0Event**
- Signature: `public class ShiftT0Event : CompositePresentationEvent<ShiftT0EventArguments>`
- Payload: `ShiftT0EventArguments`
- Behavior: Published to shift the T0 marker position.

**ShiftT0EventArguments**
- Properties:
  - `double T0Time { get; }` - The T0 time value
  - `bool IsInitialization { get; }` - Whether this shift is part of initialization
  - `int T0Steps { get; }` - Steps/samples from T0 to shift
  - `bool IsKeyPress { get; }` - Whether shift was caused by arrow key press
- Constructors:
  - `ShiftT0EventArguments(double t0, bool isInitialization)` - Sets T0Time, defaults T0Steps=0, IsKeyPress=false
  - `ShiftT0EventArguments(int steps, bool isInitialization, bool isKeyPress)` - Sets T0Steps, defaults T0Time=0D

### Invariants
- `TestModificationArgs.DataSetDirectory` and `TestId` are set only at construction and cannot be modified.
- `ShiftT0EventArguments` properties are immutable after construction.
- When using the time-based constructor for `ShiftT0EventArguments`, `T0Steps` is always 0 and `IsKeyPress` is always false.
- When using the steps-based constructor for `ShiftT0EventArguments`, `T0Time` is always 0D.

### Dependencies
- **Depends on**: `Microsoft.Practices.Prism.Events` (legacy Prism event aggregation), `DTS.Common.Interface` (for `ITestModificationModel`)
- **Depended on by**: Unclear from source alone; likely consumed by viewer components, DataPro, and any module that modifies test data.

### Gotchas
- The XML comment for `TestModificationChangedEvent` states "The Data Folder changed event" which appears inconsistent with the class name and payload type (`ITestModificationModel`).
- Several files use `// ReSharper disable CheckNamespace` suggesting namespace inconsistencies that were suppressed rather than fixed.
- The `ShiftT0EventArguments` class has two mutually exclusive constructors; the time-based and steps-based approaches cannot be combined in a single instance.

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