My reminders for Thunderbird's Lightning calendar add on pop up behind the current window I am focused on (such as a web browser). This makes it very difficult to notice a reminder is happening, especially if my headphones are off so I cant hear its "beep". Ive nearly missed 2 meetings due to this recently, and only noticed because my panel indicator changed colors, then I noticed in my unity launcher that Thunderbird had a second window open, so I had to cycle through its windows to get the reminder to pop up. That being said, everything else is working fine with Lightning/reminders - just that the reminder window appears 'hidden' behind a pile of other open application windows.
I am now using Ubuntu 14.04 LTS, though I had this working as expected when I was using 13.04 and 13.10 (I had to fresh install, instead of upgrade, because as usual, Ubiquity installer crashed during the install, destroying my prior system). I post this here, because I recall I had to mess with one of the random obfuscated settings in compiz, dconf, some-tweak-or-another tool, and cant seem to find it now.
I was searching on duckduckgo/google all morning for this, and I could have sworn this was trivial for me to search and find the last time I solved this.
How can I force a Lightning/Thunderbird reminder to always be the topmost window, regardless of the application in which I am focused?
with CCSM (CompizConfig Settings Manager) open General Options > Focus & Raise Behaviour > Focus Prevention Windows
If this this is empty, enter: "!(class=Thunderbird)" else if non empty, add "& !(class=Thunderbird)"
This tells Thunderbird to ignore the focus prevention rules, which will cause Thunderbird's reminders to pop up wherever you have focus.
Alternatively you can just set "Focus Prevention Level" to "Off" which will allow any new window to steal focus.