Show already exported activities

[manuel-mauky]

It would be great to mark activities that were already exported in the past.
My usage scenario is like this: Once in a while (maybe once a week) I wan't to download activities from withings and export them to strava. Of cause I'd like to only download those activites that are new. However, at the moment it's not easy to see which ones were already downloaded the last time.

I can think of 2 possible solutions:

1. use the preferences I've added in Save the path of the last time a gpx file was exported #9 to store a timestamp and an id when an activity is exported and use these information to show in the list
2. look into the default directory/last used directory to see which files are already there. This has the downside that if you delete the files locally it couldn't be detected anymore and it would assume that you store all files in the same directory (which is the case for me personally but most likely it's not for everyone else)

[vertongen]

Good remark! I started on preparing a solution for it on the activity-download-indicator branch.
I like your first suggestion to save it in the preferences.

[manuel-mauky]

I've been playing around with the preferences approach in here. It kind of works but the list of activities is not rerendered so you see the notice only when you reload the activities the next time (after restarting the app). I would have to select the div of the exported activity and update it's content accordingly.
Also the styling could be improved.

I will take a look at your branch to see your approach.