On 04.01.2018 18:57, Paolo Bonzini wrote: > On 04/01/2018 18:45, Samuel Thibault wrote: >> Paolo Bonzini, on jeu. 04 janv. 2018 18:11:00 +0100, wrote: >>> On 04/01/2018 16:56, Samuel Thibault wrote: >>>>> However, adding magic to "-device usb-braille" that creates both a >>>>> front-end and a back-end is completely the opposite of sane... >>>> Well, this is also what happens with -device usb-mouse, usb-kbd etc.: >>>> they also plug with keyboard & mouse pipes of the qemu graphical >>>> frontend. braille is just the same vein for the user. >>> >>> No, they don't create a new UI object magically that wasn't there >>> before. They just let you add a device, e.g. a USB tablet, that listens >>> on an _existing_ UI (GTK+ or SDL or similar). >> >> Technically for the qemu developper, yes. >> >> But for the user, no. > > That's not true. With or without "-usbdevice tablet", you use the same > mouse or keyboard device as the input source.
But from a users point of view: Why are the mouse and keyboard input sources available out of the box, while braille has to be specified manually? I think Samuel has a point here... So just another idea: Instead of adding the magic sugar code to the usb-braille device, we could also add some code to vl.c or somewhere else that checks whether a braille guest device is available and then wires it up automatically with a braille host device (unless -no-defaults has been specified, or the user already set chardev=... there). Would that make more sense in your eyes than to put this code into the usb-braille device directly? Thomas
