Re: gvncviewer improvement - input grab problems

[Michal Suchanek <hramrach centrum cz>]

2009/8/21 Daniel P. Berrange <dan berrange com>:
> On Tue, Aug 18, 2009 at 11:04:02PM +0200, Michal Suchanek wrote:
>> 2009/8/17 Michal Suchanek <hramrach centrum cz>:
>> > 2009/8/17 Daniel P. Berrange <dan berrange com>:
>> >> On Sat, Aug 08, 2009 at 04:02:11PM +0200, Michal Suchanek wrote:
>> >>> Debian package installs the gvncviewer example as an application so I
>> >>> was trying to use it as a vnc viewer instead of the xvncviewer and
>> >>> found that it has some advantages and problems.
>> >>>
>> >>> The major advantage over xvncviewer version in Debian is support for
>> >>> resizing the remote desktop.
>> >>>
>> >>> The drawback which is easily resolved is that with gvncviewer one
>> >>> cannot specify local vnc server by display number only.
>> >>>
>> >>> There is also another issue that the vnc viewer reports "disconnected
>> >>> from server" when it in fact did not manage to connect at all.
>> >>>
>> >>> The problem I did not manage to resolve is that the viewer grabs the
>> >>> input on some occasions and I did not manage to turn off this feature
>> >>> completely.
>> >>>
>> >>> The grab comes in two flavours - one is grabbing the keyboard while
>> >>> the mouse is over the remote display area which prevents using window
>> >>> manager shortcuts.
>> >>>
>> >>> The other is grabbing both keyboard and pointer when Ctrl+Alt is pressed.
>> >
>> > Is it also possible to turn off this feature?
>> >
>>
>> It's possible with this patch (applies on top of the previous three -
>> specifically the menu item is required).
>>
>> It works for me at least for booting grub.
>
> I still don't think this is a good approach. Toggling the key grab is fine,
> but not the mouse grab. If operating in relative mouse mode we should always
> honour the mouse grab key sequence.
>
> I'm assuming you want to disable this because Ctrl-Alt clashes with a
> sequence you use on the host. In which case we'd be better off making
> the grab sequence configuration in some way. eg, allow the app to provide
> a pair, or triple of GDK keysyms to be used for grabs.

It's not as simple as that.

Firstly I only use absolute mouse or no mouse at all, and I do not see
mouse grabbed except by this key combination. It clearly gets in my
way and provides no benefit for my configuration. The key combination
clashes in the sense that I might want to press Ctrl+Alt+some other
key (most often Delete) which toggles the grab and locks me inside the
viewer.

Secondly providing two keysyms would not suffice to detect the
combination in the way it is done currently. It is checked by reading
the modifier mask and comparing the keysym. If the modifier mask
contains one of the keys and the pressed keysym is the other the
feature is activated.

Thanks

Michal