KMagnifier automatically uses all your default shortcuts for saving file, opening new window, printing, starting/stoping refresh (reload button in konqueror), zoom-in, zoom-out etc. By default, the following shortcuts are used:
Ctrl-S This will save the contents of the zoom window to a file.
F5 This will start the refresh of the zoom window if it is stopped, or stops the refresh of the zoom window if the refresh is currently on.
Ctrl-P This will open the print dialogue for printing to the contents of the zoom window.
Ctrl-C This will copy the zoom window contents to the clipboard.
Ctrl-- Zoom out.
Ctrl-Shift-+ Zoom in.