If you are looking for the decompiler itself, visit https://github.com/jindrapetrik/jpexs-decompiler
NEW : We have got a new blog where we post some interesting SWF internals info.List of issues
#1942 Select function to syntax highlight
There is a limit for syntax highlighting in characters which makes it very slow to syntax highlight big files. I suggest there to be a way to highlight a certain function inside actionscript code so that it is quicker than waiting for entire file to be highlighted in syntax. Maybe you can right click on a function and press button which will highlight it in syntax? Or drag your mouse with left click and right click to attempt syntax highlighting on selected piece of code.
I don't think there is a way to highlight document only partially. The document needs to be parsed as a whole to properly determine all tokens. We use JSyntaxPane component for this. I don't think it can do it.
Oh that's unfortunate.