Atom editor window appearing outside of screen boundaries

If one disconnects an external monitor / projector the Atom editor window has a tendency to show up outside of the screen boundaries – just as if the external monitor was still attached. It took a while to figure out how to get it back again:

  1. Select the Atom window (using Alt-Tab or mouse)
  2. Open the context menu with Alt-Space
  3. Select move using “m”
  4. Press any of the arrow keys
  5. The Atom window will now be possible to drag back to the main monitor using the mouse

This was mentioned in a GitHub thread here: https://github.com/atom/atom/issues/6939