I'm reading a lot about modal dialogs.
I know(?) what modal means, having read Raskin's "The Humane Interface". I can understand what's modal about a toolbar in a drawing program (select mode, draw mode...), VI modes, caps lock... but in what way a modal dialog is modal?
I get that their intended use is for exceptional cases (errors, warnings), or when there's an unpostponable choice to make (ex: a sequence of actions as when we save an image and choose parameters and format). It seems that they force a single way of interaction (by negating all others), they're not changing the way input is interpreted. Is this to be intended as a mode?