TUI Rendering, Layout, Performance, and Alternate Screen Lifecycle

Use this skill when a TUI draws incorrectly, flickers, wastes CPU, mishandles resize, corrupts scrollback, or needs a robust rendering architecture.

Rendering principles

1. Render from state. The view should be a pure projection of current state and terminal dimensions.
2. Batch writes. Build a frame, diff or queue updates, then flush once. Avoid many small writes.
3. Minimize terminal control churn. Repeated style resets, cursor moves, and full clears are expensive and visible over remote links.
4. Throttle high-frequency sources. Coalesce logs, metrics, mouse motion, resize storms, and progress updates.
5. Define frame ownership. A full-screen renderer owns the screen while active; background output goes elsewhere.

Layout rules

• Compute layout from width and height every frame or on every resize event.
• Establish minimum usable dimensions and render a clear small-screen message below that threshold.
• Prefer constraints, flex, grid, splits, or framework layout primitives over magic coordinates.
• Keep focus, selection, viewport offset, and cursor position in UI state.
• Test narrow, wide, tall, tiny, and odd terminal sizes.