Pure Elm rich text editor

[rupert]

@dkodaj

The real limitation of the pure Elm approach seems to be performance. You can paste a whole novel into mweiss’s ContentEditable-based editor and it works just fine, whereas this one breaks down around 2000 words. Perhaps there is some performance hack that I missed, but I’m already using keyed nodes and lazy view.

I think you must have missed the posts I made around this at the end of last year? And I have preserved the work in a series of GitHub repos too.

This is for text buffers, where the text is always the same size. For rich text with variable sized fonts its going to get more complicated, but I think the techniques are still relevant.

This is looking at custom scroll bars, to reduce the amount of Html rendered when the document gets large, by only rendering the visible region:

Custom Scroll Bar Logic

I’m currently doing a spike on setting up custom scrolling logic in Elm. The idea is that if you have a large file to display, perhaps a log or a large file in an editor, rendering the full view for it each time, can be slow. The default way of using overflow: scroll on the div works, but is not optimal. Instead scroll bars are set up in separate divs to the one showing the content, their scroll events are hooked up, and custom logic will take a slice of the content and render a smaller view ju…

GitHub - rupertlssmith/elm-scroll-spike: Scroll bars with custom logic in Elm

And this is looking at making the implementation of the text buffer more efficient:

Efficient Text Editing Buffer

If a simple Array is used to hold lines of text, whenever a line is edited, the array will need to be sliced, lines modified, then put back together again. It works fine up to a limit at which point the editor becomes noticeably unresponsive. I scratched my head over this one for a while, thinking about various tree structures, or skip lists, and so on. Then the answer came to me - make a data structure like a zip list, but use arrays instead of lists. There are lots of packages implementing zi…

GitHub - rupertlssmith/elm-buffer-spike