Changelog

Element generators (vbox, hbox, box, text, input, button, line, viewport) and the node model.

Layout (intrinsic sizing, placement, clamping/scrolling helpers).

Buffer rendering and diffing (cell/char buffers, SGR styling, ANSI emission, frame diff → ops → ANSI).

Component walker for standard Fulcro defsc components whose render returns terminal nodes (factory, computed-factory, render-instance/tree/root).

Focus management, text input editing, and key routing.

Terminal protocol with a JLine-backed terminal and a fake/string terminal for tests.

The driver (application creation, attach/mount/render, step, run loop, quit).

Arrow-key navigation and caret movement.

Line wrapping for read-only and editable text.

Multiline text-area editing (Enter inserts newline, visual-line caret movement, self-scrolling).

Viewport scrolling with follow-focus.

Built-in, babashka-safe profiler (…tui.perf): compile-time-gated p/profile points (zero overhead unless -Dfulcro.tui.perf is set), self-time report, and auto-profiling of a run-blocking! session. See the Guide’s Measuring performance section.

Extensible rendering: the per-tag render seams engine/content-size, engine/place, and engine/paint are multimethods on ::engine/tag, so a custom low-level rendered element can be added with defmethod (no engine fork) using the public painter/layout toolkit. Built-in tags keep their fast case path. See the Guide’s Extending: custom rendered elements section.