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, choose one of:

  • keep to leave the last visible lines in place (or, with full: true and captureOutput enabled, the complete output), or
  • clear to remove the section so the area can be overwritten.

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 (on clear) or failedMessage (on keep) 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, 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 the section is finished with keep (i.e. on failure). Ignored when null.
final
hashCode → int
The hash code for this object.
no setterinherited
heading → String?
An optional heading rendered undimmed immediately above the scrolling lines.
final
isFinished → bool
Whether the section has been finished with keep or clear.
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 the section is finished with clear (i.e. on success). Ignored when null.
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.
clear() → void
Finishes the section by clearing the scrolling lines so the area can be overwritten.
keep({bool full = false}) → void
Finishes the section, leaving the currently visible lines in place and moving the cursor below them.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
toString() → String
A string representation of this object.
inherited

Operators

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