Warn if user install multiple maps for the same geographic area

[scaidermern]

Having more than one map installed for the same region leads to strange navigation instructions and possibly other problems (see for example car route: too many WRONG “turn slightly left” every hundred meters).

OsmAnd should present a warning to the use if more than one map for the same location will be installed.

[sonora]

Yes, I also observe many rather obscure user issues around the areas of

• OsmAnd Live
• Roads-only maps vs. Full maps
• and regionally overlapping maps since we started to make them available for the sake of offering also smaller downloads.

Not quite clear if we could maybe automatically detect and resolve this at least for the purpose of routing when a user starts one. But a warning would be a good first step.

[vshcherb]

That's of course annoying but also it's a product issue.

• We try to detect and disable road only maps during rendering if you have normal maps already.
• If you have 2 consistent maps we remove duplicate roads by ids.
• OsmAnd live is monitored and attached to the regions and automatically disabled if you have newer map

But of course there are unsupported combinations such as different update time for large vs small region.

[sonora]

We may want to give that some priority thinking, though. I know of users who for a long time had the impression that OsmAnd's navigation capabilities are completely useless. In many cases, after debugging, it simply boiled down to this issue... See also the forum link @scaidermern included above.

[scaidermern]

I fully agree with @sonora. Issues that impact user experience should get a higher priority than fancy new features.

[vshcherb]

Hm... But that needs to be explained properly we have warnings before download but it might be an issue that people don't notice warnings and forget later, so it needs to be constant check after start?

[sonora]

I think it may need to be a check+warning when a user starts a route calculation, because that is when it has the worst effect?

[scaidermern]

Sounds good. Probably a setting is needed to deactivate this check if people do obscure things with custom maps.

[dmpr0]

I propose to remove duplicated maps.
For example, for Belgium, we propose Standard map full country map, and additionally Standard map for two regions, downloading all standard maps (whole country + regions) will lead to duplicates.

We already remove whole country maps for some countries due to the size, we need to do the same for all countries divided into regions.

Additionally we will need to update UI for Updates map and Live updates screens. Add options to update only one country or select only needed regions.

[vshcherb]

Related to #16299

[scaidermern]

This ticket gets moved from version to version without a fix. Fixing it doesn't seem like a big deal to me. This problem is constantly annoying various users. Please fix it finally.

[vshcherb]

The fix is on the table - delete combined maps. They shouldn't exist as create too much troubles, so the proper fix would require treating Collection of Germany maps as 1 UI item and refactoring lots of UI.

However simple fix is to delete combined maps leaving only unique - I'm not sure users will appreciate it.

[sonora]

Question is how to know about this strategy - how to know which maps to keep and which to remove. Perhaps we could somehow mark "unsupported/trouble maps" in red color or something.

[vshcherb]

well if map won't be updated it's a subject to delete locally :-) Though I don't like when you need to deal with 50 items instaed of 1. However it's already a deal for example Ukraine Indonesia it's subdivided > 20 items and that need to represented in UI as 1 element.

I don't know whether we will have any drawbacks regarding 50+ files - US as 1 item, Obviously the deal comes that partial updates will be an issue, like during update only half of the states were downloaded

[sonora]

It's not so much about how big we bundle. I think our issue started when we began to offer overlapping maps, e.g. offered an entire country, but alternatively also separate maps of its regions, and or even of its cities.Users are not keeping track of what they have, so may start with a city, later download the country, and thus create the issue. If all else fails, perhaps we have to go back to strictly offer overlap-free again, finding some compromise in terms of chunk size. But never offer 2 standard maps covering an identical point.

[scaidermern]

What I imagined:

• Warn whenever the user tries to download a map that covers a region of another already installed map (should be easy)
• Warn whenever route calculation detects two data sources for the same region (not sure how easy that is)

This probably only needs to be done for routable maps / official maps. Some users may use custom maps that overlap with others but these should get ignored during these checks.

[vshcherb]

Created separate task #21801 that could be considered as subtask