Description of how maps can be stored for offline use.
Continuous storage of maps
Norgeskart continuously stores all map tiles that the device loads and displays on the screen while the user pans and zooms.
If you do not see any maps when you are offline, you are probably on a zoom level where maps has not previously been loaded. You should then check other zoom levels for the area you are in.
Preload of maps for an area
In order to preload maps for an area, one must go to the list of maps. You can open the list by seleting “Maps and layers” in the left side navigation panel of the app. From the list, you must open the detailed information and functions for a map by clicking the vertical three dots ⋮
Preloading of map is started by pressing the PRELOAD FOR AREA button. You will then specify the wanted area by dragging the blue corners of the rectangle displayed in the map and pressing the √ button when satisfied. The operation can be canceled by pressing the X button.
In the dialog which is presented, you can select how many zoom levels you want to load maps for. This is the number of zoom levels further in from where you are now. The number of levels available is limited by the number of tiles that will be loaded. The services of the Norwegian mapping authorities has a limit of 10.000 tiles per IP-address per day.
NB: If you close the dialog or app, the download of tiles will stop. We will improve this in the future.
The user can also choose whether or not to download tiles that have already been downloaded. In the “Reload tiles” menu one can select the following:
- All – All tiles for the area is downloaded, even if they have been downloaded previously.
- > 1 day old – Tiles older than one day will be loaded again during the operation.
- > 3 days old – Tiles older than three days will be loaded again during the operation.
- > 7 days old – Tiles older than seven days will be loaded again during the operation.
- Expired – Tiles older than two weeks (expired for users not having a subscription) will be loaded again during the operation.
The dialog also shows which levels for which map tiles will be loaded, the number of tiles and progress. It is not possible to give a good estimate of the amount of data that will be downloaded due to the variation in image size for the tiles.
How long is the map tiles stored
Map tiles are deleted automatically after two weeks for users without a pro subscription. This is according to the rules specified by the Norwegian mapping authorities back when the app was originally developed. The app then also had to be free and without advertising. The Norwegian mapping authorities has now lifted these restrictions.
Users with a subscription can now keep the maps for as long as they want, but we have chosen to still delete tiles older than two weeks for users without a subscription.