OK, here is design question:
You are loading chart directories (Options->Charts->Chart files)
1. You load one directory, exit options, and all is well.
2. You go to Options and load another directory.
3. Depending on your chart directory layout and what directory you select, the second directory contains, in the tree somewhere, a chart with the exact same name and timestamp as a chart that is already in place from step(1). This can happen, for instance, if you download and install NOAA raster charts
by region, one-by-one. Some small scale charts
will appear in several Region collections as downloaded from NOAA.
What is the "right" thing to do?
In OCPN today, we load both charts. The logic is that if you use groups sorted by Region, say, you want the small scale duplicates to appear in each Region. As a result of this logic, when you show "all Available Charts" group you will see duplicates in the chart selector bar. This is confusing. Try it and you will see.
Alternatively, we could elect not to load duplicates. But that might break someone's idea of Group layout by Region/directory.
I prefer not to bring up a cryptic dialog while loading, asking the user what policy they want. Loading charts is an area where novices get bogged down pretty quickly. Talking of groups and duplicates perhaps minutes after they have installed O for the first time will be "not friendly". We should choose a policy and just do it quietly.
So, what say ye?