Question: How can text fields in apps (eg. news stories) be sized?

[Ryyk]

I have noticed, on occasion with my S3, that by some combination of touches, or button pushes the text field in some applications becomes sizeable by using the left side toggle button (normally used for volume control, etc). I have not yet discovered how it gets into that mode, i.e. most of the time, when pressed, the toggle on the left side just displays and adjusts the volume. Does anyone have an understanding of how to purposefully place the left toggle button into a mode to adjust text size, or for that matter, any other method to adjust text size (other than the normal methods accessible through app menus) - Thanks, Ryyk