I am looking for a solution to a specific use case:
When I read something on my browser or pdf reader, I want to take notes without switching windows. I want to type right on my browser or pdf reader, but the typed text should go to the background text editor like notepad.
Is this possible?
Do you know any existing automation script that handles this use case?
You should create an application that uses some keylogger-like techniques (e.g. global hooks) to monitor the keypresses and, depending on some condition (a setting you may have set, the currenctly active window, ...), it may pass them normally to the application or suppress them to store them in a buffer. Such buffer, then, would be shown to the user as needed.
Still, in my opinion a much more convenient way to perform a similar task would be to create an application consisting of a semitransparent edit box, that could be shown and hide simply with a hotkey. This would avoid all the hooks stuff and the potential problems that may arise from them.
you might try using autohotkey scripting language... I can write a little script that would do exactly what you need and afaik in this particular case it wouldnt need keyboard hooks.
--EDIT-- Autohotkey is VERY simple to use/learn so even if you want to do the script yourself you can do it in a very short time even if you dont have any knowledge of ahk. Then again, I can help you with it.