[PATCH] Bug fix client apps because of output change

[Wang, Quanxian]

>-----Original Message-----
>From: Pekka Paalanen [mailto:ppaalanen at gmail.com]
>Sent: Monday, March 10, 2014 7:05 PM
>To: Wang, Quanxian
>Cc: wayland-devel at lists.freedesktop.org
>Subject: Re: [PATCH] Bug fix client apps because of output change
>
>On Mon, 10 Mar 2014 10:58:00 +0000
>"Wang, Quanxian" <quanxian.wang at intel.com> wrote:
>
>>
>>
>> >-----Original Message-----
>> >From: Pekka Paalanen [mailto:ppaalanen at gmail.com]
>> >Sent: Monday, March 10, 2014 5:58 PM
>> >To: Wang, Quanxian
>> >Cc: wayland-devel at lists.freedesktop.org
>> >Subject: Re: [PATCH] Bug fix client apps because of output change
>> >
>> >On Mon, 10 Mar 2014 08:23:45 +0000
>> >"Wang, Quanxian" <quanxian.wang at intel.com> wrote:
>> >
>> >> Thanks Pq. Comments below.
>> >...
>> >> >> @@ -1145,6 +1154,45 @@ desktop_destroy_outputs(struct desktop
>> >> >> *desktop) }
>> >> >>
>> >> >>  static void
>> >> >> +update_output(struct output *output) {
>> >> >> +	struct panel *panel = output->panel;
>> >> >> +	struct background *background = output->background;
>> >> >> +	int width, height;
>> >> >> +
>> >> >> +	if (!output)
>> >> >
>> >> >You already dereferenced 'output' above, checking for NULL here is
>> >> >useless. 'output' can never be NULL anyway, right?
>> >> [Wang, Quanxian] right.
>> >> >
>> >> >> +		return;
>> >> >> +
>> >> >> +	width = output->mode.width;
>> >> >> +	height = output->mode.height;
>> >> >> +
>> >> >> +	switch (output->transform) {
>> >> >> +	case WL_OUTPUT_TRANSFORM_90:
>> >> >> +	case WL_OUTPUT_TRANSFORM_270:
>> >> >> +	case WL_OUTPUT_TRANSFORM_FLIPPED_90:
>> >> >> +	case WL_OUTPUT_TRANSFORM_FLIPPED_270:
>> >> >> +		/* Swap width and height */
>> >> >> +		width = output->mode.height;
>> >> >> +		height = output->mode.width;
>> >> >> +		break;
>> >> >> +	default:
>> >> >> +		break;
>> >> >> +	}
>> >> >> +
>> >> >> +	if (output->scale != 0) {
>> >> >
>> >> >If scale was initialized to 1, there would be no need for 'if'.
>> >> >Right?
>> >> [Wang, Quanxian] in testing, this cause the error because scale is
>> >> set to 0, it happens when weston is started at the very beginning.
>> >> Here we need to do that.
>> >
>> >Why does that happen? Is Weston sending an event with scale=0? If so,
>> >then that is a Weston bug and should be fixed. Until you get any
>> >event the scale is 1, because that is the implicit scale in interface version 1.
>> [Wang, Quanxian] yes. Got geometry event with scale=0.
>
>What do you mean? wl_output.geometry does not carry scale at all, hence until
>you receive the first wl_output.scale you should assume scale=1.
>The easiest way to do that is to initialize output::scale to 1 in create_output(). You
>should never have zero.
[Wang, Quanxian] sorry, is scale event instead of geometry. Yes, I can initialize scale to be 1, but at the same time, I need to get the scale event from server. Basically I still need to do some checking for that.
After that, I will check why scale(0) is sent by wl_output and push the patch to fix that. 
>
>
>Thanks,
>pq