E4: load and save instrument-specific layout positions

[Tom-Willemsen]

As a scientist, I would like to make the most of the fact that windows in E4 can be moved and resized. I would like to be able to define my instrument's default layout and save it. When I press the reset layout button it should bring back my instrument's default layout rather than the generic layout.

This has been asked for by several scientists (independently) at the E4/nicos demo sessions

[Tom-Willemsen]

Note: the scope of this ticket is just to save/reset a modified perspective layout, not to open new views in a perspective (that will be covered in #852 )

[Tom-Willemsen]

I tried creating a squish test for this, but I couldn't figure out how to make squish click and drag without just relying on pixel offsets (which would be too brittle for the test to be reliable). I will add a manual test instead.

Note that this ticket used some of the work from #3506 as I needed a later version of eclipse, so ideally that ticket should be reviewed first (though this should not block the review of this ticket).

[DominicOram]

At first glance there are a few things that think this needs:

• The perspective should be able to be reloaded without restarting the GUI
• It would be good if the user could be told when the layout no longer matches the saved layout
• Rather than try and upgrade layouts ourselves can we just tell the user that something is out of date and they will need to reload their perspective?

[Tom-Willemsen]

As part of the review it's been decided to add the acceptance criteria:

• I must be able to reload the saved layout without restarting the user interface

Unfortunately this means that this ticket is no longer technically feasible. I will document what's been done and close this ticket as a wontfix

[DominicOram]

After discussion the 1st criteria above would increase the time required for this ticket to make it unrealistic. Instead:

• Make perspective layouts persist between restarts as part of this ticket
• Document why this is so hard and everything that we have learnt in doing this ticket