How do i prevent interface behaviour set by text

I am implementing a web chat aplication using Ckeditor. I have a problem with interface buttons.
When user is writing text he can change text behaviour by presing buttons(bold, italic,...)

But user can than take mouse and go over bold text witch is not italic and italic buttun is automaticly set off.

I want to say that the buttons behave acording to text. If user go over colered text or text in diferent font interface elements(buttons) automaticly corespond to that.

But i realy do not like that. I want to change behaviour of buttons so when user go over the text they will not turn on or off acording to the text.

The bigest problems is when user press enter. I empty the input field and the buttons are stil on how user select them. But whenI use focus evrything is lost becouse butons bahave to text and there is no text in empty input box.

I want that user press the buttons and they are pressed until user turn them off. So for example if user press button for bold that button must be pressed until user and only user change it.

Is there a way to change that with configuation? Or the source code is the only way.