How a widget reaches the screen

A widget draws through a painter; the painter decides whether that becomes pixels or terminal cells; a back-end presents the result.

Three layers, and each knows only the one below it:

toolkit widget tree          Button, Table, Agenda, VBox ...  (or a skin.Object)
        │  Draw(p painter.Painter, theme *Theme)
        ▼
painter.Painter              FillRect, StrokeRect, Text, PutPixel, ...
        │
        ├─ PixelPainter  → an RGBA []byte   → window, browser canvas, PNG, Android
        └─ CellPainter   → a grid of cells  → a terminal, as 24-bit ANSI

A widget never learns which painter it was handed. A back-end never learns which widgets drew. That is the whole reason one widget tree can be shown in a native window, a browser and a terminal without a line of conditional code.


The painter seam	the primitives, the optional capabilities, the two painters
The toolkit	the widget set, themes, layouts, text and accessibility
Skins	describe a widget’s parts and states as data instead of Go

Created on October 9, 2026 by tannevaled

Modified on October 9, 2026 by tannevaled