I added png and jpg files because people wanted to be able to open them in Textastic so they can upload it to a server. Obviously they shouldn't be registered as plain text files. I'll change that.

Just use the remote preview feature. You can enter an arbitrary url there.

Well, Textastic tells the system that all the programming files like .html, .cpp etc. are plain text files. Those editors claim that they can open plain text files. That's why they appear in the list.

No, there is no official API from Apple for shortcuts like that.

It should be even easier with ssh-keygen.

You can use a command line like this to import (-i) your pem file and convert to OpenSSH format:

ssh-keygen -i -f infile.pem > outfile

You could try this tip from the manual:

Puttygen should also be able to load the .pem file using the Conversions - Import Key menu item.

"Textastic expects the key file to be in the format used by the OpenSSH utility "ssh-keygen". If you instead have a key in PuTTY's format (.ppk), you can use PuTTYgen to convert it to OpenSSH format:

Visit the PuTTY website and download puttygen.exe (on your PC). Open it, and using the File menu, load your .ppk that you already use, and type in your passphrase. Now go to the Conversions menu and export the key as an OpenSSH key. You can now use the converted key with Textastic."

There is a TextMate bundle for SAS at https://github.com/jakob-stoeck/sas.tmbundle

Have a look at the manual to see how you can install it:

How to install syntax definitions

I'll have a look.

Ok, thanks for the detailed explanation. I'll try to setup a similar environment.

The speed of highlighting also depends on a lot of factors like file size, file type, file complexity and device type. It can't be predicted how long it takes to highlight the first few lines. Also, the app does not just display the plain text, but also starts to layout the text to calculate the line height after word wrap. It's a little more complex than what the user sees on the screen.