Rotulus is a GTK4 scrollback view for text-stream chat that stays fast and stable however long the scrollback gets.

The widget is RotulusView. Put it in a GtkScrolledWindow, set it up through its properties, and add rows to it.

Adding rows

From C, build a RotulusRow on the stack and pass it to rotulus_view_append(). From a language binding, build a RotulusMessage call by call and pass it to rotulus_view_append_message():

import gi
gi.require_version("Rotulus", "1")
from gi.repository import Rotulus

view = Rotulus.View()
msg = Rotulus.Message.new(Rotulus.RowKind.MESSAGE)
msg.set_speaker(42, "alice")
msg.add_text("hello", Rotulus.COLOR_DEFAULT, Rotulus.ATTR_BOLD)
view.append_message(msg)

Rows are structured data, never text with escape codes in it, so nothing a remote user sends can restyle the transcript. IRC formatting codes go through rotulus_message_add_mirc(), which converts them to styled runs.

Every append returns a RotulusMark, a weak handle to the row, for inserting history before it, replacing it, or removing it.

Reacting

The application answers the view’s signals: a link clicked or right-clicked, a speaker clicked, a request for older rows, an inline image clicked, a reply’s quote clicked, a reaction clicked, a row right-clicked, the selection changing.

Using it

C programs link librotulus-1 through pkg-config:

cc app.c $(pkg-config --cflags --libs rotulus-1)

Rust programs use the rotulus crate.

How the widget works, and why it is shaped the way it is, is in the design notes.