As far as I'm aware, there isn't a simple way to get that offset without writing some sort of layout algorithm from scratch.Html uses theText.rich widget under the hood to lay everything out, which relies heavily on the Flutter engine's text layout algorithms which are deeply baked into the Flutter ecosystem. Basically this means that if you can do it with aText.rich widget, you can do it with theHtml widget.

You could possibly do some sort of hack withrtl text and aWidgetSpan to achieve something like this, but if you are just trying to put a child widget on the right side of theHtml widget, it would be a lot simpler just to use aStack and place whatever widget you want to down in that bottom right corner.

Some more info about what you are trying to achieve could help us provide some better workarounds!

Stack doesn't work in this situation because sometimes there is not enough space and the "float-right" widget should go to the next line.

Here's my original question in StackOverflow: (the image in the first post describes the situation)
https://stackoverflow.com/questions/70802737/flutter-chat-text-align-like-whatsapp-or-telegram

The answers on that question are suggestions using aRenderBox and they are usingTextPainter to paint the text and get its size. The problem is that those answers are assuming that I have plain text so theTextPainter is used to calculate the offset. I'm usingHtml() and I can't use theTextPainer to calculate the renderedHtml.

Knowing the remaining space on the last line ofHtml is key to this problem.

if (space is enough)
{
// UseStack()
}
else
{
// UseWrap()
}

Ah, thank you for the StackOverflow link. I wasn't super familiar withTextPainter, so that code sample gave me some insight. I'll need to play around with it for a little while, but I might be able to get something that works. The trick is going to be getting the PlaceholderDimensions of Widgets within the Html. I'll probably have to get some inspiration from theRichText widget. I'll keep you posted!

I wasn't home. Sorry for the late reply.

This is great news. Can't wait to see some sort of solution. Thanks for the effort, :)

Just wanted to follow up. Did you manage to play around with RichText? Any progress?