Aptana Studio 3 - Browse/Read-only mode

Aptana Studio 3:

Two simple questions...

From Project Explorer:

How do you open the HTML editor in browse/read-only mode? Why doesn't the "*" di开发者_StackOverflowsappear in the HTML editor if there are no more undo's?

Aptana Studio (as well as Eclipse) opens files in read-only mode when files are read-only on a filesystem. "*" (star) at the editor tab means file has been modified since opening and on close you will be prompted to either save or close w/o saving.

Cheers, Max