Display Dialog: Call for Testing

[Simon Steinbeiß]

Hey everyone!

Sean and I have been working on implementing a long-wanted feature into the display-dialog: the socalled "extended desktop"-mode.
So far, users were only able to clone their display, hopefully by 4.12 they will be able to use a UI to position their monitors next to each other. We consider the current state to be feature-complete, but not really bug/issue-free. Nevertheless, we feel that it's time to get some feedback/testing from you, to help us get things in shape for a merge to master. It's totally possible we'll need more testing later :)
Our code currently resides in the bluesabre/display-settings branch.

What to test:
We mostly want you to test whether all functions related to using the "extended desktop"-mode (disable mirror-mode, change positions) work as expected. If e.g. a resolution that your display should support isn't (and wasn't) showing up in the dialog, please report a bug, but it's not really what we're after here.

Some testing advice:
What would be helpful is building the dialog with ./autogen.sh --enable-debug=full and then you might have to not only make and execute the dialog, but in fact sudo make install it to get the desired debugging output. (Note: You might have to kill xfsettingsd and restart it without daemon but with debug-option.) If you run into problems (especially such that are not mentioned on the list below!), be sure to run "xrandr --current --verbose" before and after to give us some idea of what's happening on your end. Another log that might hold useful information is your .xsession-errors. And finally – apart from including the debugging output that the dialog prints itself – please include your ~/.config/xfce4/xfconf/xfce-perchannel-xml/displays.xml.

If you send us testing-feedback – just feel free to email Sean or me directly – please include all steps necessary to reproduce your problem. Please don't leave out what graphics card you have, what drivers you use (open or closed) and in what version. I know this is quite a bit, but thanks a lot in advance!

So here's a brief overview of what came about during the last few weeks:
 * Added comboboxes to control the position of displays relative to each other (left-of, right-of, above, below)
 * Added socalled "display identification popups" to give the user a direct visual connection between the labels/displays that are being shown in the treeview and the physical displays (should make positioning easier)
 * Improved the minimal-mode to support extended desktop and added explanatory icons to be more newbie-friendly

Here's a list of currently known issues, we're still working towards resolving those:
 * The identification-popup doesn't play very nice with disabling displays or mirror mode (sometimes disabling a display results in a wrong label)
 * The identification-popup currently flickers a bit when the display-selection is changed
 * The identification-popup's corners aren't nicely rendered without compositing
 * There's a warning about xfconf bindings when exiting the dialog
 * In the minimal-mode, first setting mirror-mode and the right-of results in a segfault
 * In the minimal-mode, users don't get the timout-popup that resets the settings, which might help prevent bad things from happening

Two more things deserve mention:
1) If you're using closed-source drivers (ATI, Nvidia), there might be (random) problems with getting the settings applied. At least for Nvidia I can say from my own experience that their RandR support seems to be a bit flaky still. As their drivers are closed, we can't really make too many promises there (although we should be able to make things work equally nice as with xrandr).
2) We haven't been able to conduct any tests with more than 2 displays, unfortunately these setups seem to be really rare and e.g. my laptop's graphic card can only handle two active displays at once. If any of you can test 3 or more displays, that'd be great! Theoretically, things should still work fine even with more than 3 displays, but this remains our hypothesis as long as we have no real-life proof :)

Finally, there are obviously plans for further development, like using something like an icon-view to represent display-positions rather than the treeview and allowing drag-and-drop for re-ordering them, or support for xfce4-notifyd's themes etc. but we'll most probably keep the dialog as it is now feature-wise for 4.12.
If you're interested in our plans, feel free to keep on reading here: http://wiki.xfce.org/design/xfce4-settings/display

Thanks for your attention and sorry for making this so long,
Simon and Sean