ScrollingSection class

A fixed-height scrolling output region anchored at the bottom of the terminal.

Lines appended with appendLine scroll within at most rows visual rows: only the most recent rows lines are shown, older lines scroll out of view. The region renders in place and leaves any output above it untouched, so it is well suited for tailing the output of a long-running subprocess.

When done, call finish with a success flag. Body retention comes from successRetention / failureRetention, or from finish's overrideRetention when one is passed.

An optional heading is rendered immediately above the scrolling lines, prefixed with an animated braille spinner and suffixed with an elapsed-time counter (e.g. ⠹ Building (1.2s)). When the section is finished, the spinner is replaced with a success (✓) or failure (✗) icon and the heading is replaced with successMessage or failedMessage when the relevant message is non-null; otherwise the heading is left in place. The final elapsed time is kept either way.

Constructors

ScrollingSection({required InlineTerminal terminal, int rows = 5, bool dim = true, String? heading, String? successMessage, String? failedMessage, RetainSection? successRetention, RetainSection? failureRetention, bool captureOutput = false, Duration spinnerInterval = _defaultSpinnerInterval, Duration? elapsed()?, SpinnerScheduler? scheduleTicker}): Creates a scrolling section rendered to terminal.

Properties

capturedOutput → List<String>: All lines appended to the section, oldest first.
no setter
captureOutput → bool: Whether every appended line is retained (in addition to the rows visible ones) so the complete output can be re-displayed, e.g. on failure.
final
dim → bool: Whether to render the scrolled lines dimmed (only when the terminal supports color).
final
failedMessage → String?: The message that replaces the heading when finish is called with success: false. Ignored when null.
final
failureRetention → RetainSection: What happens to the body when finish is called with success: false.
final
hashCode → int: The hash code for this object.
no setterinherited
isFinished → bool: Whether the section has been finished with finish.
no setter
rows → int: The maximum number of visual rows the section occupies.
final
runtimeType → Type: A representation of the runtime type of the object.
no setterinherited
successMessage → String?: The message that replaces the heading when finish is called with success: true. Ignored when null.
final
successRetention → RetainSection: What happens to the body when finish is called with success: true.
final
visibleLines → List<String>: The lines currently visible in the section, oldest first.
no setter

Methods

appendLine(String line) → void: Appends line to the section and re-renders.
finish({required bool success, RetainSection? overrideRetention}) → void: Finishes the section.
noSuchMethod(Invocation invocation) → dynamic: Invoked when a nonexistent method or property is accessed.
inherited
toString() → String: A string representation of this object.
inherited
updateHeading(String newHeading) → void: Updates the heading text and re-renders.

Operators

operator ==(Object other) → bool: The equality operator.
inherited

Static Methods

runSpinner<T>(InlineTerminal terminal, {required String heading, required Stream<T> stream, String toMessage(T)?, bool isSuccess(T)?, String? successMessage, String? failedMessage, Duration spinnerInterval = _defaultSpinnerInterval, Duration? elapsed()?, SpinnerScheduler? scheduleTicker}) → Future<T>: Runs a heading-only spinner (no scrolling output lines) while consuming stream.