[Spice-devel] [spice-gtk v2] widget: Do not ignore unsupported keys from keyboard

[Frediano Ziglio]

> 
> If Windows layout does not support a given key the resulting virtual code
> is set to 0xFF. To avoid losing this raw key (causing the key not been
> sent to remote machine) detect this condition and handle the key.
> The check for raw scancode is there to understand if we can handle
> correctly the key in following code.
> This problem can happen for instance using a 106 key Japanese keyboard
> while the layout is set in English; in this case keys like CONVERT not
> forwarded correctly.
> 
> Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> ---
>  src/spice-widget.c | 38 ++++++++++++++++++++------------------
>  1 file changed, 20 insertions(+), 18 deletions(-)
> 
> Changes from v1:
> - avoid to rewrite scancodes;
> - tested again (code were not used as my mingw64-gtk3 was updated
>   and gdk_event_get_scancode was not supported).
> 

Some note on how to reproduce and test this problem.

Physical way:
1- get a 106 key Japanese keyboard for your Windows client machine;
2- setup your client to English keyboard layout;
3- connect to a Linux machine (no matter the distro or version or
   keyboard configuration);
4- open "xinput test-xi2 <device>" command on Linux (device is
   the AT device in this case);
5- press CONVERT or other keys not present on an English keyboard.

Virtual way (Windows machine on a VM):
- set machine remote to VNC;
- assure Qmeu has lock-key-sync=off option to vnc;
- connect to Windows machine with a VNC client (I suggest TigerVNC
  as remote-viewer do some keyboard insertion);
- do steps 2, 3, 4 above
- press the CONVERT key. If you don't have you can simulate, either
  - change VNC client code to insert scancode 0x70 instead of another
    key and press this key;
  - disconnect main VNC client and use some tool to inject keys
    (I use a modifier version of vncdotool);
  - yes, above steps are not described completely... if somebody is
    interested I can post some more information.

Frediano

> diff --git a/src/spice-widget.c b/src/spice-widget.c
> index 51a2055..b5936bc 100644
> --- a/src/spice-widget.c
> +++ b/src/spice-widget.c
> @@ -1406,7 +1406,7 @@ static gboolean key_event(GtkWidget *widget,
> GdkEventKey *key)
>  {
>      SpiceDisplay *display = SPICE_DISPLAY(widget);
>      SpiceDisplayPrivate *d = display->priv;
> -    int scancode;
> +    int scancode = 0;
>  #ifdef G_OS_WIN32
>      int native_scancode;
>      WORD langid = LOWORD(GetKeyboardLayout(0));
> @@ -1414,8 +1414,23 @@ static gboolean key_event(GtkWidget *widget,
> GdkEventKey *key)
>  #endif
>  
>  #ifdef G_OS_WIN32
> +    /* Try to get scancode with gdk_event_get_scancode.
> +     * This API is available from 3.22 or if backported.
> +     */
> +#if HAVE_GDK_EVENT_GET_SCANCODE
> +    native_scancode = gdk_event_get_scancode((GdkEvent *) key);
> +    if (native_scancode) {
> +        scancode = native_scancode & 0x1ff;
> +        /* Windows always set extended attribute for these keys */
> +        if (scancode == (0x100|DIK_NUMLOCK) || scancode ==
> (0x100|DIK_RSHIFT))
> +            scancode &= 0xff;
> +    }
> +#else
> +    native_scancode = 0;
> +#endif
> +
>      /* on windows, we ought to ignore the reserved key event? */
> -    if (key->hardware_keycode == 0xff)
> +    if (!native_scancode && key->hardware_keycode == 0xff)
>          return false;
>  
>      if (!d->keyboard_grab_active) {
> @@ -1455,23 +1470,10 @@ static gboolean key_event(GtkWidget *widget,
> GdkEventKey *key)
>      if (!d->inputs)
>          return true;
>  
> -    scancode = vnc_display_keymap_gdk2xtkbd(d->keycode_map,
> d->keycode_maplen,
> -                                            key->hardware_keycode);
> +    if (!scancode)
> +        scancode = vnc_display_keymap_gdk2xtkbd(d->keycode_map,
> d->keycode_maplen,
> +                                                key->hardware_keycode);
>  #ifdef G_OS_WIN32
> -    /* Try to get scancode with gdk_event_get_scancode.
> -     * This API is available from 3.22 or if backported.
> -     */
> -#if HAVE_GDK_EVENT_GET_SCANCODE
> -    native_scancode = gdk_event_get_scancode((GdkEvent *) key);
> -    if (native_scancode) {
> -        scancode = native_scancode & 0x1ff;
> -        /* Windows always set extended attribute for these keys */
> -        if (scancode == (0x100|DIK_NUMLOCK) || scancode ==
> (0x100|DIK_RSHIFT))
> -            scancode &= 0xff;
> -    }
> -#else
> -    native_scancode = 0;
> -#endif
>      if (!native_scancode) {
>          native_scancode = MapVirtualKey(key->hardware_keycode,
>          MAPVK_VK_TO_VSC);
>          /* MapVirtualKey doesn't return scancode with needed higher byte */
> --
> 2.7.4
> 
>