When one has a lot of highlighted lines in a big Epub, PDF, etc, document, being able to export them to a simple txt, or maybe markdown (in case one wants to keep format for titles, bullets, etc), would be a great way to have résumés, summaries, guides for presentations, talks, etc, without having to copy & paste hundreds of times. When you have a 400 pages document is a real PITA, just exporting would make life much more beautiful.
It is easy to copy all text right now with Ctrl+A then right-click and select "Copy text". Would it be an appropriate solution for you?
Created attachment 121337 [details] Okular, highlighted text
I was referring to the highlighted text. That text you mark using the highlighter tool in Okular. Perhaps isn't called "highlighter" in english: the tool you get pressing F6 and then 4. Sorry if I didn't explain myself better in my first comment. Since an image is word 1000 words, I'm attaching a screenshot of a real use case. I hope it avoids misunderstantdengs. Thanks for you good will though.