A DESCRIPTION OF THE REQUEST :
Here I request creating a control for editing code. I know about RichTextFx, but this one becomes unresponsive on large files. The new control should be able to handle large files
- does not read all text in memory
- may parse one time the complete file to know where are multiline strings or comments, but not more
- line numbering, search/replace would be nice.
For a good implementation in Swing I recommend having a look on www.jidesoft.com, they have a link to run directly a sample application.
Having this may encourage also IDE's to migrate to JavaFx, which will motivate also the others.

JUSTIFICATION :
 I would also migrate my application to JavaFx, but because I miss this I have to wait.