Re: [PATCH] Illuminators and status LED controls

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 09/09/2010 08:55 AM, Hans Verkuil wrote:
> On Tuesday, September 07, 2010 23:14:10 Hans de Goede wrote:

<snip>

>> How about a compromise, we add a set of standard defines for menu
>> index meanings, with a note that these are present as a way to standardize
>> things between drivers, but that some drivers may deviate and that
>> apps should always use VIDIOC_QUERYMENU ?
>
> Let's use boolean for these illuminator controls instead. Problem solved :-)

Erm, no. If you take a look at the current qx5 microscope support code in the
cpia2 driver it currently is a menu with the following possible values:
Off
Top
Bottom
Both

So now lets say we create standard controls for illuminators and make them
booleans and use 2 booleans. And then modify the cpia2 driver to follow the
new standard.

The user behavior then goes from:
- user things lets switch from top to bottom lighting
- go to control
- click menu drops down select top / bottom
-> easy

To:
- user things lets switch from top to bottom lighting
- go to control
- heuh 2 checkboxes ?
- click one check box off
- clock other check box on
-> not easy

If I were a user I would call this change a regression, and as such I find
the boolean proposal unacceptable. Maybe we should call the control
V4L2_CID_MICROSCOPE_ILLUMINATOR

To make it more clear that the menu variant of this is meant for
microscopes (which typically have either only a bottom illuminator
or both a bottom and a top one). And if we then ever need to support
some other kind of illuminator we can add a separate cid for that/

Otherwise I think it might be best to just keep this as a private control.

Regards,

Hans