Compose Text Editor

Compose has been missing a Rich Text Editor since its inception. I've taken a crack at this previously, as have others.

However they have all suffered from fundamental limitations in BasicTextField, the foundation of all text entry in Compose.

This project is an attempt to re-implement text entry from scratch to finally have a solution to the various problems.

Why?

I've been trying to implement a spell checking text field in Compose, and keep running up against the limitations of BasicTextField. Pretty much out of options, I decided to see what it might take to replace BasicTextField with something that solved all of my needs.

tl;dr it's hard, but maybe not as hard as I had thought.

This is not ready for prime time, but if anyone is interested in collaborating, I think it could actually work. It just needs some more time and attention.

Maybe it's ready? 🤷 Give it a try here.

What is working:

• Rich text rendering and editable
  • Semi-efficient rendering for long form text (only renders what is visible)
  • Semi-efficient data structure for text storage & editing. (but not nearly as efficient as the Gap Buffer BTF2 uses under the hood)
• Cursor movement, clicking, keyboard short cuts, ect
• Text selection (highlighting and edit ops)
• copy/cut/paste
• Exposed scroll state, so we can render scroll bars (BTF1 can't do this)
• Doesn't copy and return full contents on each edit, so again better for longer form text. (BTF2 also works this way, but BTF2 doesn't support AnnotatedString for rich content)
• Support custom Rich Span drawing (this allows us to render the traditional Spell Check red squiggle)
• Emits edit events: so if a single character is inserted, you can collect a Flow, and know exactly what change was made. This makes managing Spell Check much more efficient as you can just respell-check the single word that was changed, rather than everything. Currently neither BTF1 or BTF2 offers this.

Platforms

So far I have support for JVM/Desktop, Android, Web. The others should probably also work, but I haven't had time to add the targets and test them.

Work left to do:

• Copy/Paste of rich text always strips the formatting (this is a Compose MP bug)
• Right-to-Left text is probably broken

Want to try it?

Text Editor:

implementation("com.darkrockstudios:composetexteditor:0.7.0")

Text Editor with Spell Checking:

implementation("com.darkrockstudios:composetexteditorspellcheck:0.7.0")