Unlike rdesktop, when I press ALT + F4 in remmina, it doesn't react in the Windows system, but instead closes the remmina window.
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems. It only takes a minute to sign up.Sign up to join this community
Remmina has this configurable in the 'Preferences' -> tab 'Keyboard' -> Field 'Grab keyboard'. On my Ubuntu installation this is the right Ctrl key.
Works for me and seems to behave like a toggle key. Pressing it again makes modifier keys working on the local machine again.
Depending on your client environment, using a keybinding to toggle the 'grab keyboard' might not work for a number of reasons.
As an alternative, you can use the 'grab all keyboard events' button in the toolbar when in fullscreen mode.