Interface IReadLineProvider

Namespace

InteractiveReadLine

Assembly

InteractiveReadLine.dll

The underlying contract for any object which is to provide ReadLine functionality to the input handler.

public interface IReadLineProvider : IDisposable

Inherited Members

IDisposable.Dispose()

Extension Methods

ExtensionMethods.Read(IReadLineProvider, ReadLineConfig?, CancellationToken)

ExtensionMethods.ReadAsync(IReadLineProvider, ReadLineConfig?, CancellationToken)

ExtensionMethods.ReadLine(IReadLineProvider, ReadLineConfig?, CancellationToken)

ExtensionMethods.ReadLineAsync(IReadLineProvider, ReadLineConfig?, CancellationToken)

Remarks

Any object which is to provide a functioning backend on which the ReadLineHandler can act must implement these features: returning a single ConsoleKeyInfo when asked, both synchronously and asynchronously, writing out text and a cursor position on the currently active line (clearing whatever was there before), and inserting text to some output without interfering with the active display line.

Finally, the provider must implement IDisposable; as it will be disposed by the handler when the input of a line has been completed. The provider must then clean up the view in some fashion (on a standard System.Console provider this involves writing a newline to the console)

Methods

InsertText(FormattedText)

Inserts text to the console out in the spot where the current read line input is, then immediately re-displays the line input on the next row. This is used to interrupt the user with a message or information while the ReadLine is still active

void InsertText(FormattedText text)

Parameters

text FormattedText

The text to write to the console, a newline char will be added automatically

ReadKey(CancellationToken)

Waits synchronously for a ConsoleKeyInfo to be returned from some underlying input source.

ConsoleKeyInfo ReadKey(CancellationToken cancellationToken = default)

Parameters

cancellationToken CancellationToken

A token that cancels the wait. An implementation whose underlying wait cannot be interrupted should poll for input becoming available rather than blocking, so that the token can be observed.

Returns

ConsoleKeyInfo

Information about the key that was read.

Exceptions

OperationCanceledException

The token was canceled before a key arrived.

ReadKeyAsync(CancellationToken)

Waits asynchronously for a ConsoleKeyInfo to be returned from some underlying input source.

Task<ConsoleKeyInfo> ReadKeyAsync(CancellationToken cancellationToken = default)

Parameters

cancellationToken CancellationToken

A token that cancels the wait.

Returns

Task<ConsoleKeyInfo>

A task producing information about the key that was read.

Remarks

A backend whose input arrives through an event or an already asynchronous API should implement this natively. A backend whose ReadKey does not block, such as one reading from an already populated queue, may return Task.FromResult(ReadKey(cancellationToken)). Avoid wrapping a blocking read in Task.Run because it occupies a thread until the user presses a key, and the token cannot interrupt it.

Exceptions

OperationCanceledException

The token was canceled before a key arrived.

SetDisplay(LineDisplayState)

Displays the LineDisplayState to the visual output, including the cursor position

void SetDisplay(LineDisplayState state)

Parameters

state LineDisplayState

The line display state (prefix, suffix, text, and cursor position) to be displayed