Re: [Qemu-devel] [PATCH 2/2] vnc: Support for LED state extension

[Anthony Liguori <aliguori@us.ibm.com>]

Lei Li <lilei@linux.vnet.ibm.com> writes:

> Signed-off-by: Lei Li <lilei@linux.vnet.ibm.com>
> ---
>  ui/vnc.c |   50 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  ui/vnc.h |    3 ++-
>  2 files changed, 52 insertions(+), 1 deletions(-)
>
> diff --git a/ui/vnc.c b/ui/vnc.c
> index fa7ab94..b9b3766 100644
> --- a/ui/vnc.c
> +++ b/ui/vnc.c
> @@ -1529,6 +1529,33 @@ static void press_key(VncState *vs, int keysym)
>      kbd_put_keycode(keycode | SCANCODE_UP);
>  }
>  
> +static int current_led_state(VncState *vs)
> +{
> +    int ledstate = 0;
> +
> +    if (vs->modifiers_state[0x46]) {
> +        ledstate |= QEMU_SCROLL_LOCK_LED;
> +    }
> +    if (vs->modifiers_state[0x45]) {
> +        ledstate |= QEMU_NUM_LOCK_LED;
> +    }
> +    if (vs->modifiers_state[0x3a]) {
> +        ledstate |= QEMU_CAPS_LOCK_LED;
> +    }
> +
> +    return ledstate;
> +}
> +
> +static void vnc_led_state_change(VncState *vs, int ledstate)
> +{
> +    vnc_lock_output(vs);
> +    vnc_write_u8(vs, VNC_MSG_SERVER_QEMU);
> +    vnc_write_u8(vs, VNC_MSG_SERVER_QEMU_LED_STATE);
> +    vnc_write_u8(vs, ledstate);
> +    vnc_unlock_output(vs);
> +    vnc_flush(vs);
> +}

Please use a pseudo-encoding and include a document describing the
psuedo-encoding in the docs/ directory.

> +
>  static void kbd_leds(void *opaque, int ledstate)
>  {
>      VncState *vs = opaque;
> @@ -1547,6 +1574,11 @@ static void kbd_leds(void *opaque, int ledstate)
>      if (vs->modifiers_state[0x46] != scr) {
>          vs->modifiers_state[0x46] = scr;
>      }
> +
> +    /* Sending the current led state message to the client */
> +    if (ledstate != current_led_state(vs)) {
> +        vnc_led_state_change(vs, current_led_state(vs));
> +    }
>  }
>  
>  static void do_key_event(VncState *vs, int down, int keycode, int sym)
> @@ -1831,6 +1863,20 @@ static void send_ext_audio_ack(VncState *vs)
>      vnc_flush(vs);
>  }
>  
> +static void send_ext_leds_state_ack(VncState *vs)
> +{
> +    vnc_lock_output(vs);
> +    vnc_write_u8(vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
> +    vnc_write_u8(vs, 0);
> +    vnc_write_u16(vs, 1);
> +    vnc_framebuffer_update(vs, 0, 0,
> +                           surface_width(vs->vd->ds),
> +                           surface_height(vs->vd->ds),
> +                           VNC_ENCODING_LED_STATE);
> +    vnc_unlock_output(vs);
> +    vnc_flush(vs);
> +}

I don't think the ack is really necessary.  You should encode the
current led state in this pseudo-encoding data and just send the current
led state once after set_encodings and then whenever the state changes
again.

Regards,

Anthony Liguori

> +
>  static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
>  {
>      int i;
> @@ -1897,6 +1943,10 @@ static void set_encodings(VncState *vs, int32_t *encodings, size_t n_encodings)
>          case VNC_ENCODING_AUDIO:
>              send_ext_audio_ack(vs);
>              break;
> +        case VNC_ENCODING_LED_STATE:
> +            send_ext_leds_state_ack(vs);
> +            vnc_led_state_change(vs, current_led_state(vs));
> +            break;
>          case VNC_ENCODING_WMVi:
>              vs->features |= VNC_FEATURE_WMVI_MASK;
>              break;
> diff --git a/ui/vnc.h b/ui/vnc.h
> index 58e002e..709cbab 100644
> --- a/ui/vnc.h
> +++ b/ui/vnc.h
> @@ -386,6 +386,7 @@ enum {
>  #define VNC_ENCODING_EXT_KEY_EVENT        0XFFFFFEFE /* -258 */
>  #define VNC_ENCODING_AUDIO                0XFFFFFEFD /* -259 */
>  #define VNC_ENCODING_TIGHT_PNG            0xFFFFFEFC /* -260 */
> +#define VNC_ENCODING_LED_STATE            0XFFFFFEFB /* -261 */
>  #define VNC_ENCODING_WMVi                 0x574D5669
>  
>  /*****************************************************************************
> @@ -475,7 +476,7 @@ enum {
>  
>  /* QEMU server -> client message IDs */
>  #define VNC_MSG_SERVER_QEMU_AUDIO                 1
> -
> +#define VNC_MSG_SERVER_QEMU_LED_STATE             2
>  
>  
>  /* QEMU client -> server audio message IDs */
> -- 
> 1.7.7.6