Panel on SVN does not seem to be working with multihead 100%

[Jasper Huijsmans]

Joao Pedrosa schreef:
> Hello,
> 
>     It would be very helpful if you could try out the latest SVN version.
>     You will need to update libxfcegui4 and xfce4-panel. It should be quite
>     a bit better now, but I still expect there to be plenty of problems.
> 
> 
> I just tried it for 10 minutes or so and I see the improvement of 
> starting a new panel with its own independent configuration, also I see 
> that now when I click on the monitor switcher, the panel follows the 
> choice accordingly. But the main issues are still there, like:

Ok, good to hear there's at least a little improvement ;-) Anyway, I 
didn't have time to work on this yet, but let me comment quickly on some 
of the problems you noted.

> 
> 1. When deleting the ".config" and ".cache" and starting from a fresh 
> install, all the new panels (two for each monitor, or 4 in total) go to 
> the first monitor (":0.0"), but the two of them that belong to the 
> monitor on the right, behave as if they were on the monitor on the 
> right, but appear on the monitor on the left.

Ok, this shouldn't really have been possible :( For the new panel there 
should be only one instance possible for every display. I need to have a 
look at that.

The other issues are indeed to be expected. The default panel currently 
only shows up on the first screen and the plugins (like tasklist) have 
not been updated yet to properly handle multiple screens.

> 
> 1.1. Even when I configure the panels that belong to the monitor on the 
> right for them to appear on the monitor on the right, they still behave 
> a little bit weirdly, showing the wrong tasks on the tasklists.
> 

Yes. I need to fix the plugins separately.

> 2. The wordaround that I learned yesterday after talking to you -- to 
> start a second panel that worked fine until I had to restart Xfce,-- 
> doesn't work anymore. And I don't seem to find a good workaround this time.
> 

Anything anyone may remember about the xfce panel and multihead should 
be discarded ;-) The new panel is completely different.

You only start the panel once and then you can add panels and move them 
to other monitors. The current default configuration only shows up on 
the first screen, but my plan is to change this to use the default 
config for every screen.

> In sum, I see the improvements but the issues changed a little bit with 
> them.
> 
> Solution I propose:
> 
> 1. When starting the panel, the "DISPLAY" environment variable should 
> have higher priority over the configuration of the panel. This is 
> important because it will always be used in a fresh install and during 
> the session restarts, I think.

I don't want to bother the user with setting DISPLAY variables and such. 
The session manager should be able to simply start the panel and 
everything should work.

> 
> 2. It's hard to sincronize and control the panel creations from a single 
> instance of the panel. Somehow you have started doing this, but to fine 
> tune this would take some testing and time. I think it's advisable to 
> streamline this process:
> 

Yes, indeed, time and testing. So far you have been a great help ;-)

> - promote the independence of the panels, relying on the way that they 
> are created by default, which means respecting the "DISPLAY" variable 
> for example.
> 

Panels are not started by running anything, normally. In a default Xfce 
setup the session manager will start the basic Xfce components including 
the panel. There will be only one instance of the panel running on a 
display.

> - tag the panel with some random number to its configuration. Use the 
> random number in the session to load the configuration. I'm not quite 
> sure how you save and load the configuration, so I could be way off. :P
> 
> - use the DISPLAY variable in the storing and reloading of the panel 
> configuration, if it helps to identify the configuration for the panel. 
> Instead of ".config/xfce4/panel", use ".config/xfce4/display_0/panel/", 
> ".config/xfce4/display_1/panel/", etc.
> 
> - when swapping the panel between monitors, maybe it would be better to 
> kill the panel and restart it with the new "DISPLAY" environment 
> variable, this way it would appear on the right monitor and control the 
> right monitor, luckily.
> 

This shouldn't be necessary when things work as I intended:
- One xfce4-panel instance to manage all panels on all screens.
- Initial default configuration shown on each screen
- The user can add panels and move them to different monitors from the
   user interface

If the plugins are fixed as well, do you think this would work for you?

> I really can't code this much and try it myself, but maybe you will have 
> the time and patience to look at it. :-) For incentive, think about the 
> schools that will use Xfce in machines with maybe four monitors, four 
> keyboards and four mouses. :-) I don't know how they do that, by the way.

They have a special version of X that can support this, I think. These 
are different XDisplays though, not just different screens, so it 
shouldn't affect us.

	Jasper