TL;DR
When right-clicking a non-focused, single line textbox select the text contained therein.What ?
The current behavior for non focused single line textboxes is that when you click them they get focused, which allows you to type in them. There is no difference between using the left or right mouse button.I suggest to slightly change the right mouse click to not only focus the textbox, but also select the text contained therein.
Example
Take the text box in the combinator constant value entry dialog. Currently changing the number requires the user to click the textbox, hit backspace several times and then enter the new value.(Or double click it, which clears it, which I did not know about)
Why ?
This behavior seems to be the common behavior in modded minecraft. It allows the user to:- quickly change the value, as entering a new value will replace the selected text.
- quickly copy it by hitting ctrl+c.