1. Flyology TUI
  2. Components
  3. Trees

Data

Trees

Navigate a validated bounded preorder tree with stable expansion state.

Generated previewCharm
Dedicated Trees example rendered in the Charm skin

The site build compiles the dedicated Ada component example, constructs Trees through its public API, and exports that exact styled surface. Read the capture source.

When to use it

Use a tree for hierarchical data whose children can expand and collapse in place.

State and ownership

The Flyology_TUI.Components.Trees package defines this component.

The model validates the complete preorder depth sequence before it changes state. Expansion, selection, focus, and viewport survive replacement by stable ID.

  • The application model owner applies updates during serial event dispatch.
  • Appearance and skin values are borrowed only while the component renders.

Input and updates

Left collapses or moves to the parent. Right expands or moves to the first child. Rows also support mouse and wheel input.

Integration sequence

  1. Create the bounded model and populate it with caller-owned data.
  2. Route the current keyboard or local mouse event through the component handler.
  3. Apply the typed result, then render from the updated model with the current appearance.

See the linked package reference for its exact declarations and contracts.

Responsive and accessible behavior

  • Use dimensions and regions from the current layout or presentation value.
  • When a component owns mouse capture, route its matching release even when the pointer leaves the original bounds.
  • Retain a glyph, label, border, or text-attribute cue when the terminal reduces color.