widget_compose_demo Directory Reference

Directory dependency graph for widget_compose_demo:

Directories
	src

Detailed Description

A nested ra8_widget tree composited on the live GLCDC panel. Where widget_app_demo shows the full ra8_widget + ra8_app launcher, this app isolates the structural piece issue #145 added: a container that is itself a widget, which is what turns a flat widget array into a tree.

root (column panel)
|- status   (leaf, fixed)   title + a live frame counter
|- body     (ROW PANEL)     a nested panel ...
|   |- left  tile (leaf, flex)
|   |- right tile (leaf, flex)
|- footer   (leaf, fixed)   a hint line

body is the primitive in action: a ra8_widget_panel nested inside the root ra8_widget_panel. One ra8_widget_panel_compose() lays the children out, computes the minimal damage rectangle and refresh hint, and renders only the dirty children; a dirty nested panel repaints its whole subtree.

The deterministic self-check pins both ends. A full compose dirties all three root children, flushes the whole frame with the quality hint, and composites both tiles – per-tile render counters confirm it. Bumping the frame counter and invalidating only the status bar dirties exactly one child, damages just the status rect with the fast hint, leaves the tiles un-rendered, and changes the composite CRC. That is the acceptance bullet: a status-only change flushes only the status rect. After the banner the loop keeps bumping the counter and partial-composing, so the panel visibly updates its top band.

The RGB565 framebuffer lives in SRAM and composites top-left over the GLCDC background plane; the full 1024x600 panel needs SDRAM, a separate task. No SDRAM, touch, SD or buttons – it is a pure compositor demo.