How to remove annoying 'Unable to mount android phone' pop up window on Ubuntu 14.04

My Android phone dies in half a day, so I have to plug it onto my desktop whenever I am at my desk. I have Ubuntu 14.04 installed and it kept complaining 'Unable to mount android phone' via a pop up window. What was worse, tens of that window poped up and I had to close them one by one.

After a Google search, the reason seemed to be that Ubuntu 14.04 doesn't come with a MTP fs package by default, and Android uses MTP(Media Transfer Protocol) to share contents with computers. If you want to access files on your phone, you may choose to install a MTP package, e.g.,

sudo apt-get install mtpfs

But if you are like me and you just want to charge your phone, simply go to your phone's settings and disable MTP.

Settings > Storage > Upper Right Corner (⋮) > USB Computer Connection > Media Device.

Uncheck 'Media Device'.


Other sources:

http://askubuntu.com/questions/463015/ubuntu-14-04-and-android-cant-see-phone-on-my-computer
http://ubuntuforums.org/showthread.php?t=2231161

Launch GUI applications from a 'screen' terminal

I recently got addicted to the linux 'screen' command, which manages multiple sessions nicely. But even running locally, I had problems launching a GUI program from the command line, e.g., I'd like to view a html file by 'firefox index.html &', and it always gave me an error like this:

(process:15413): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed
Error: no display specified

Google gave answers like 'export DISPLAY=localhost:0.0' and 'export DISPLAY={myhostname}:0.0', but the one that really works is 'export DISPLAY=:0'.

My environment:

Ubuntu 14.04
Screen version 4.02.01 (GNU) 28-Apr-14