Module spans 

Runs of different treatment inside one Text.

Not a widget. A paragraph with a bold phrase and a link in it is one piece of text, and splitting it into three widgets to say so would break line wrapping at the seams: the renderer would wrap each piece on its own and the phrase would never share a line with what surrounds it.

So the spans travel beside the string, as a blob of fixed-length records in the same shape a Canvas carries its commands. Nothing new crosses the boundary to do it.

Markdown is a convenience on this side. TextSpans::from_markdown turns a small, closed subset into spans, and the Renderer never hears the word.

Structs

TextSpan

One run, given in bytes into the string rather than characters.

TextSpans

An encoded list of spans, ready to travel.

Constants

SPAN_LEN

Bytes of one span record: two ranges’ worth of offsets, a role, flags, a paint and a handler. Four-byte aligned throughout, which is the protocol’s invariant.