* Add comprehensive unit tests for WindowsKeyConverter - Implement 118 parallelizable unit tests for WindowsKeyConverter - Cover ToKey and ToKeyInfo methods with full bidirectional testing - Test basic characters, modifiers, special keys, function keys - Test VK_PACKET Unicode/IME input - Test OEM keys, NumPad keys, and lock states - Include round-trip conversion tests - All tests passing successfully Fixes #4389 * Rename `start` parameter to `viewportXOffset` for clarity The `start` parameter in several methods and interfaces has been renamed to `viewportXOffset` to better reflect its purpose as the horizontal offset of the viewport during string rendering. - Updated method signatures in `ListViewWithSelection` to use `viewportXOffset` instead of `start`, including default values. - Modified the `RenderUstr` method in `ListViewWithSelection` to use `viewportXOffset` for calculating the starting index. - Renamed the `start` parameter to `viewportXOffset` in the `IListDataSource` interface and updated its documentation. - Replaced all occurrences of `start` with `viewportXOffset` in the `ListWrapper<T>` class, including method calls and logic. - Updated the `RenderUstr` method in `ListWrapper<T>` to use `viewportXOffset` for substring calculations. - Adjusted the test method in `ListViewTests.cs` to reflect the parameter name change. These changes improve code readability and make the parameter's role in rendering logic more explicit. * Remove WindowsKeyConverterTests class that was added by mistake * Modernized ListView and IListDataSource - Tons of new unit tests Refactored `ListView` and `IListDataSource` to improve readability, maintainability, and functionality. Introduced `ListWrapper<T>` as a default implementation of `IListDataSource` for easier integration with standard collections. Enhanced `ListView` with better handling of marking, selection, and scrolling. Replaced `viewportXOffset` with `viewportX` for horizontal scrolling. Added `EnsureSelectedItemVisible` to maintain visibility of the selected item. Updated `IListDataSource` with detailed XML documentation and added `SuspendCollectionChangedEvent` for bulk updates. Improved null safety with nullable reference types. Added comprehensive unit tests for `ListWrapper<T>` and `IListDataSource` to ensure robustness. Modernized the codebase with C# features like expression-bodied members and pattern matching. Fixed bugs related to `SelectedItem` validation and rendering artifacts. * Improve index validation in ComboBox and ListView Enhance robustness by adding stricter checks for valid indices in ComboBox and ListView. Updated conditions in the `_listview.SelectedItemChanged` event handler to ensure `e.Item` is non-negative before accessing `_searchSet`. Modified the `SetValue` method to use `e.Item` instead of `_listview.SelectedItem`. In ListView, updated the `OnSelectedChanged` method to validate that `SelectedItem` is non-negative (`>= 0`) before accessing the `Source` list. These changes prevent potential out-of-range errors and improve code safety. * Refactor and enhance test coverage across modules Refactored and added new tests to improve coverage, readability, and consistency across multiple test files. Key changes include: - **ShortcutTests.cs**: Added tests for `BindKeyToApplication` and removed redundant tests. - **SourcesManagerTests.cs**: Renamed `Update_*` tests to `Load_*` for clarity. - **ArrangementTests.cs**: Reintroduced `MouseGrabHandler` tests, added `ViewArrangement` flag tests, and improved structure. - **NeedsDrawTests.cs**: Replaced `Application.Screen.Size` with fixed dimensions for better isolation. - **DimAutoTests.cs**: Updated layout tests to use fixed dimensions. - **FrameTests.cs**: Standardized object initialization and validated frame behavior. - **SubViewTests.cs**: Improved formatting and modernized event handling. - **NumericUpDownTests.cs**: Decoupled layout tests from screen size. General improvements: - Enhanced formatting and removed redundant tests. - Added comments for clarity. - Introduced `ITestOutputHelper` for better debugging in `ArrangementTests`. * Refactor to use nullable types for better null safety Enabled nullable reference types across the codebase to improve null safety and prevent potential null reference issues. Refactored `SelectedItem` and related properties from `int` to `int?` to represent no selection with `null` instead of `-1`. Updated logic, event arguments, and method signatures to handle nullable values consistently. Simplified object initialization using modern C# syntax and improved code readability with interpolated strings. Added null checks and early returns to prevent runtime errors. Enhanced error handling by throwing `ArgumentOutOfRangeException` for invalid values. Updated tests to reflect the changes, replacing assertions for `-1` with `null` and ensuring proper handling of nullable values. Cleaned up redundant code and improved formatting for better maintainability. * on` functionality has been deprecated, refactored, or removed from the `Shortcut` class. * Refactor: Transition to instance-based architecture Updated `Run-LocalCoverage.ps1` to increase `--blame-hang-timeout` from 10s to 60s. Improved null safety in `GuiTestContext` by adding null-conditional operators. Commented out problematic code in `SetupFakeApplicationAttribute.cs` to prevent test hangs. Excluded `ViewBase` files from `UnitTests.Parallelizable.csproj` and removed redundant folder declarations. Simplified event handling in `IListDataSourceTests.cs` and updated `ListViewTests.cs` to use nullable reference types. Enhanced documentation to emphasize the transition to an instance-based application architecture. Updated examples in `application.md`, `multitasking.md`, and `navigation.md` to reflect the use of `Application.Create()` and `View.App`. Clarified the obsolescence of the static `Application` class. Revised table of contents in `toc.yml` to include new sections like "Application Deep Dive" and "Scheme Deep Dive." Added `dotnet-tools.json` for tool configuration. These changes improve maintainability, testability, and alignment with modern C# practices. * Refactor ListViewTests to use Terminal.Gui framework The `ListViewTests` class has been refactored to replace the `AutoInitShutdown` attribute with explicit application lifecycle management using `IApplication` and `app.Init()` from the `Terminal.Gui` framework. Key changes include: - Rewriting tests to use `Terminal.Gui`'s application lifecycle. - Adding a private `_output` field for logging test output via `ITestOutputHelper`. - Updating `DriverAssert.AssertDriverContentsWithFrameAre` to include `app.Driver` for UI verification. - Rewriting tests like `Clicking_On_Border_Is_Ignored`, `EnsureSelectedItemVisible_SelectedItem`, and others to align with the new framework. - Adding explicit calls to `app.Shutdown()` for proper cleanup. - Enabling nullable reference types with `#nullable enable`. - Updating `using` directives and `namespace` to reflect the new structure. These changes improve test maintainability, compatibility, and diagnostics. * Update Terminal.Gui/Views/CollectionNavigation/CollectionNavigatorBase.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update Terminal.Gui/Views/CollectionNavigation/CollectionNavigatorBase.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update Examples/UICatalog/UICatalogTop.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update Terminal.Gui/Views/ListWrapper.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Update Terminal.Gui/Views/ListWrapper.cs Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com> * Updated the `SetMark` method to return `Source.IsMarked(SelectedItem.Value)` for consistency and removed an outdated comment questioning its correctness. Enhanced the exception message in the `SelectedItem` property setter to provide clearer guidance when the value is out of range. * Add comprehensive ListView behavior test coverage Added multiple test methods to validate `ListView` behavior: - `Vertical_ScrollBar_Hides_And_Shows_As_Needed`: Ensures the vertical scrollbar auto-hides/shows based on content height. - `Mouse_Wheel_Scrolls`: Verifies vertical scrolling with the mouse wheel updates `TopItem`. - `SelectedItem_With_Source_Null_Does_Nothing`: Confirms no exceptions occur when setting `SelectedItem` with a `null` source. - `Horizontal_Scroll`: Tests horizontal scrolling, including programmatic and mouse wheel interactions, ensuring `LeftItem` updates correctly. - `SetSourceAsync_SetsSource`: Validates the asynchronous `SetSourceAsync` method updates the source and item count. - `AllowsMultipleSelection_Set_To_False_Unmarks_All_But_Selected`: Ensures disabling multiple selection unmarks all but the selected item. - `Source_CollectionChanged_Remove`: Confirms `SelectedItem` and source count update correctly when items are removed from the source collection. --------- Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Terminal.Gui UI Catalog
UI Catalog is a comprehensive sample library for Terminal.Gui. It attempts to satisfy the following goals:
- Be an easy-to-use showcase for Terminal.Gui concepts and features.
- Provide sample code that illustrates how to properly implement said concepts & features.
- Make it easy for contributors to add additional samples in a structured way.
Motivation
The original demo.cs sample app for Terminal.Gui is neither good to showcase, nor does it explain different concepts. In addition, because it is built on a single source file, it has proven to cause friction when multiple contributors are simultaneously working on different aspects of Terminal.Gui.
See Issue #368 for more background.
API Reference
How To Use
Build and run UI Catalog by typing dotnet run from the UI Catalog folder or by using the Terminal.Gui Visual Studio solution.
Program.cs is the main UI Catalog app and provides a UI for selecting and running Scenarios. Each *Scenario is implemented as a class derived from Scenario and Program.cs uses reflection to dynamically build the UI.
Scenarios are tagged with categories using the [ScenarioCategory] attribute. The left pane of the main screen lists the categories. Clicking on a category shows all the scenarios in that category.
Scenarios can be run either from the UICatalog.exe app UI or by being specified on the command line:
UICatalog.exe <Scenario Name>
e.g.
UICatalog.exe Buttons
Hitting ENTER on a selected Scenario or double-clicking on a Scenario runs that scenario as though it were a stand-alone Terminal.Gui app.
When a Scenario is run, it runs as though it were a standalone Terminal.Gui app. However, scaffolding is provided (in the Scenario base class) that (optionally) takes care of Terminal.Gui initialization.
Contributing by Adding Scenarios
To add a new Scenario simply:
- Create a new
.csfile in theScenariosdirectory that derives fromScenario. - Add a
[ScenarioMetaData]attribute to the class specifying the scenario's name and description. - Add one or more
[ScenarioCategory]attributes to the class specifying which categories the sceanrio belongs to. If you don't specify a category the sceanrio will show up in "All". - Implement the
Setupoverride which will be called when a user selects the scenario to run. - Optionally, implement the
Initand/orRunoverrides to provide a custom implementation.
The sample below is provided in the .\UICatalog\Scenarios directory as a generic sample that can be copied and re-named:
namespace UICatalog {
[ScenarioMetadata (Name: "Generic", Description: "Generic sample - A template for creating new Scenarios")]
[ScenarioCategory ("Controls")]
class MyScenario : Scenario {
public override void Setup ()
{
// Put your scenario code here, e.g.
Win.Add (new Button () {
Text = "Press me!",
X = Pos.Center (),
Y = Pos.Center (),
Clicked = () => MessageBox.Query (20, 7, "Hi", "Neat?", "Yes", "No")
});
}
}
}
Scenario provides Win, a Window object that provides a canvas for the Scenario to operate.
The default Window shows the Scenario name and supports exiting the Scenario through the Esc key.
To build a more advanced scenario, where control of the Toplevel and Window is needed (e.g. for scenarios using MenuBar or StatusBar), simply use Application.Top per normal Terminal.Gui programming, as seen in the Notepad scenario.
For complete control, the Init and Run overrides can be implemented. The base.Init creates Win. The base.Run simply calls Application.Run(Application.Top).
Contribution Guidelines
- Provide a terse, descriptive
NameforScenarios. Keep them short. - Provide a clear
Description. - Comment
Scenariocode to describe to others why it's a usefulScenario. - Annotate
Scenarioswith[ScenarioCategory]attributes. Minimize the number of new categories created. - Use the
Bug RepoCategory forScenariosthat reproduce bugs.- Include the Github Issue # in the Description.
- Once the bug has been fixed in
developsubmit another PR to remove theScenario(or modify it to provide a good regression test/sample).
- Tag bugs or suggestions for
UI CatalogasTerminal.GuiGithub Issues with "UICatalog: ".

