AlpineQuest & OfflineMaps

I think I requested this feature a couple of years ago, so now I'd like to give it a big bump...

The way I would see it working would be to present exactly the same slider as with the Store Area function, but in this case the slider would represent the zooms levels of the contained area to be preserved. All zoom levels beyond the slider should then be erased from the map cache, in such a way that those tiles would be subject to a fresh download the next time that they are displayed, in on-line mode. Hopefully, by re-using a lot of existing code, this could be achieved without too much extra programming effort

Furthermore, should this function detect any corruption in the cache database, it should attempt to repair it, or map the affected pages out of the database if it is beyond repair.

IF physical space can be reclaimed from this process, then that would be a nice to have, however, if this is not practical then perhaps an external database re-organisation (compact / repair) function could be provided at a later date.

Would you please add this to the requested features list.

Hi again,

Yes I remember your request.
I've just answered your other post on the storage corruption, so I understand why you need this!

It won't be possible to do it exactly what you're suggesting (I think this is what I answered you the last time, I'll explain what can be done just after).
The main reason is that the "Stored maps" cache is not intended to be managed by the user. It should stay simple to use: you plan to go somewhere for the week end, then store the area and use it. At some point in the future when you're low in memory (should only be after years based on the actual memory sizes), just clean the map cache. That's it.

If someone needs (wants) to have a better control on what is stored, to backup storage, delete only parts and keep others, then the file-based "on-board" maps are made for this. They can be moved, stored, etc. But it's only an option to use them since most users just don't want to bother with that...

Now, concerning what can be done (this is planned so it will be done), is let the user use the "Store area" tool not to only store data in the storage cache, but also to create on-board maps. In this way, you could select the area you want to keep, create your file-based on-boad map from that, then clear the complete cache. At the end, the result will be almost the same. Just keep in mind that all this is made phones, so depending on the data size those process may take time to run...

Let me know what you think

AlpineQuest wrote:Hi again,

Yes I remember your request.
I've just answered your other post on the storage corruption, so I understand why you need this!

It won't be possible to do it exactly what you're suggesting (I think this is what I answered you the last time, I'll explain what can be done just after).
The main reason is that the "Stored maps" cache is not intended to be managed by the user. It should stay simple to use: you plan to go somewhere for the week end, then store the area and use it. At some point in the future when you're low in memory (should only be after years based on the actual memory sizes), just clean the map cache. That's it.

If someone needs (wants) to have a better control on what is stored, to backup storage, delete only parts and keep others, then the file-based "on-board" maps are made for this. They can be moved, stored, etc. But it's only an option to use them since most users just don't want to bother with that...

Now, concerning what can be done (this is planned so it will be done), is let the user use the "Store area" tool not to only store data in the storage cache, but also to create on-board maps. In this way, you could select the area you want to keep, create your file-based on-boad map from that, then clear the complete cache. At the end, the result will be almost the same. Just keep in mind that all this is made phones, so depending on the data size those process may take time to run...

Let me know what you think

I agree that an offline (R/O) map is both a safer and more space efficient option than the tile cache, however, given that my goal is to generate a comprehensive OSGB map for the entire UK at all available zoom levels, can you please explain how this would be achieved with your proposed changes to Store Area? Having spent many, many, hours downloading the tiles (I'm about 80% complete, but now waiting for a 128Gb SDXC card to arrive), I can state that it is completely impractical (impossible) to do this all in one go. So any offline map storing option would have to be cumulative, merging into an existing prior version of the same map. This is the only way that I can see this as being a viable solution.

Couldn't you consider to split your big storage into smaller on-board map pieces? Like for example based on the British National Grid. It would allow you not to necessarily embed the entire data on your device.

If you put all these split maps into a single folder on your device, the app is able to automatically switch (load) the map needed for the currently displayed (so you don't have to bother about selecting the good map).