[virt-tools-list] Possible fix for Missing Characters @ (Alt-GR Q) and | (Alt-GR <) on german locale

[Marc-André Lureau]

Hi

----- Mensaje original -----
> Running virt-viewer-x64-0.5.6.msi, on Windows 7, connecting to QEMU using
> spice, AltGR key combinations fails (using Swedish keyboard layout both at
> server and client).
> 
> I suspect that this is a variant of
> https://bugzilla.redhat.com/show_bug.cgi?id=904092 .
> 

and https://bugzilla.redhat.com/show_bug.cgi?id=956686

> After some debugging, I realized that there is an extra VK_LCONTROL keypress
> sent by Windows. This extra VK_LCONTROL will then make the key e.g. AltGr-<
> actually be Control-AltGr-<, which is not interpreted as a | sign.
> 
> So in spice-widget.c : keyboard_hook_cb(), I added SPICE_DEBUG lines which
> printed out the hooked->scanCode, and realized that this extra VK_LCONTROL
> has a very suspect scanCode with bit 9 set. If I instead press the left Ctrl
> key, it will also emit VK_LCONTROL, but with bit 9 cleared.

Funny, I haven't noticed that bit 9 difference. And neither Xwin people. I proposed a Gdk patch similar to Xwin approach:

https://bugzilla.gnome.org/show_bug.cgi?id=699787

> So I just made sure that keyboard_hook_cb(), silently dropped these strange
> VK_LCONTROL events, which seems to work for me.
> 
> 
> case VK_NUMLOCK:
> case VK_LSHIFT:
> case VK_RSHIFT:
> - case VK_LCONTROL:
> case VK_RCONTROL:
> case VK_LMENU:
> case VK_RMENU:
> break;
> + case VK_LCONTROL:
> + // When pressing AltGr, an extra VK_LCONTROL with a special scancode with
> bit 9 set is sent.
> + // Lets ignore the extra VK_LCONTROL, as that will make AltGr missbehave.
> + if (hooked->scanCode & 0x200)
> + return 1;
> + break;
> default:
> SendMessage(win32_window, wparam, hooked->vkCode, dwmsg);
> return 1;
> }

It looks like a good solution too, especially if we can't fix it in gdk.