Possible to add a "Refresh" or "Reload from Disk" option in toolbar?

[gitmeister]

When editing outside of the IDE it would prevent having to close/re-open the Sketch since the IDE doesn't prompt to reload a file when it notices a change (like Notepad++ would).

[mischnic]

The setting "Use external editor" should reload the Sketch when the Arduino window regains focus.

[gitmeister]

I tried this but the IDE will proceed to "lock-out" edits done in the IDE. It may not be great practice to have both the IDE and an external editor accessing the same file but the dialog indicating that "An external program has changed this file do you want to reload" is supported by the various OS's. To avoid having to deal with file-change-events a "refresh" (like you see in File Explorers) could just reload. There are many work-arounds for now, I keep a dummy project open so that when I close the externally edited project I can just use the dummy project to "open recent". Closing/Restarting the IDE is considerably slower.

[per1234]

Just a note that there is another issue for the sketch modified notification in the IDE feature request, which is related but not a duplicate of this issue:
#4551