VgsStyleVisualTransformation

Visual transformation that applies SpanStyles (color, weight, letter spacing, etc.) to fixed ranges of the displayed text, without ever exposing the text itself.

styles only ever describes positions — it never has access to the field's characters — so it can be used on any field, masked or not, without creating a way to read back sensitive input. Ranges are relative to whatever text this transformation receives: the raw field value when used on its own, or the already-transformed text of an earlier step when composed via VgsChainedVisualTransformation (e.g. after VgsMaskVisualTransformation).

Ranges outside the current text length are clamped, so a rule written for the field's expected final length is safe to use while the value is still shorter (e.g. mid-typing).

Placed earlier in a VgsChainedVisualTransformation, the styles applied here still reach the final output — VgsPasswordVisualTransformation and VgsMaskVisualTransformation both carry forward whatever's already on their input — but at unchanged indices, not repositioned for what a later step inserts. Chain this after both for exact positions; placed before VgsMaskVisualTransformation, a range that spans one of its separators lands a little short of the intended characters.

Parameters