Re: [Qemu-devel] [PATCH 0/6] Add GTK UI to enable basic accessibility

[Anthony Liguori <anthony@codemonkey.ws>]

On 02/20/2012 06:47 AM, Kevin Wolf wrote:
> Am 20.02.2012 13:17, schrieb Kevin Wolf:
>> Am 20.02.2012 00:44, schrieb Anthony Liguori:
>>> Hi,
>>>
>>> I realize UIs are the third rail of QEMU development, but over the years I've
>>> gotten a lot of feedback from users about our UI.  I think everyone struggles
>>> with the SDL interface and its lack of discoverability but it's worse than I
>>> think most people realize for users that rely on accessibility tools.
>>>
>>> The two pieces of feedback I've gotten the most re: accessibility are the lack
>>> of QEMU's enablement for screen readers and the lack of configurable
>>> accelerators.
>>>
>>> Since we render our own terminal using a fixed sized font, we don't respect
>>> system font settings which means we ignore if the user has configured large
>>> print.
>>>
>>> We also don't integrate at all with screen readers which means that for blind
>>> users, the virtual consoles may as well not even exist.
>>>
>>> We also don't allow any type of configuration of accelerators.  For users with
>>> limited dexterity (this is actually more common than you would think), they may
>>> use an input device that only inputs one key at a time.  Holding down two keys
>>> at once is not possible for these users.
>>>
>>> These are solved problems though and while we could reinvent all of this
>>> ourselves with SDL, we would be crazy if we did.  Modern toolkits, like GTK,
>>> solve these problems.
>>>
>>> By using GTK, we can leverage VteTerminal for screen reader integration and font
>>> configuration.  We can also use GTK's accelerator support to make accelerators
>>> configurable (Gnome provides a global accelerator configuration interface).
>>>
>>> I'm not attempting to make a pretty desktop virtualization UI.  Maybe we'll go
>>> there eventually but that's not what this series is about.
>>>
>>> This is just attempting to use a richer toolkit such that we can enable basic
>>> accessibility support.  As a consequence, the UI is much more usable even for a
>>> user without accessibility requirements so it's a win-win.
>>
>> It's not quite obvious what the build dependencies are. In my case I had
>> to install vte-devel. Especially if we're going to make it the default,
>> I think configure should print a helpful warning. (In fact, SDL has the
>> same problem and I have answered too many questions of users that
>> wondered why no window appeared, not understanding that they built only
>> VNC).
>>
>> I think the series is a good start, just some random thoughts and things
>> that I noticed:
>>
>> * git complains about some trailing whitespace
>>
>> * Half of the menu entries appears to be translated by the libraries
>>    used. Give me something that is all German or something that is all
>>    English. Mixed languages looks unprofessional.
>>
>> * Ctrl-Alt-= as shortcut for Zoom In isn't easy to remember and only
>>    makes some sense on a US keyboard layout.
>>
>> * The monitor display size always has the same size as the VGA tab now.
>>    That can be quite small in text mode and you can't resize any more.
>>
>> * The window has a button for maximising, but it doesn't really do
>>    anything.
>>
>> * Ctrl-PgDn/PgUp does change the tab as I expected on VGA, it's ignored
>>    by the monitor and the serial0 tabs. parallel0 segfaults on any key
>>    press.
>>
>> * When the tab bar is enables, the cursor up key in the VGA tab selects
>>    the tab bar. It also is sent to the guest the first time, but when
>>    the tab bar is selected, the guest doesn't get any input any more.
>>    Makes it rather hard to use the shell history in the guest.
>
> There's more fun...
>
> * The F10 key activates the menu instead of being passed to the guest.
>    Just like cursor up even when the keyboard is grabbed. Makes sendkey
>    close to the primary interface for keyboard. :-(

Yes, this is all because of return TRUE on keyboard handling.

> * On one start something went wrong, apparently with the zoom (at least
>    I saw for a moment how half a letter was rendered over the whole
>    screen). Hung my machine until the OOM killer came to the rescue...

Interesting, will look into this.

Regards,

Anthony Liguori

> Kevin
>