Make Map available offline

[doneill]

Provide feature and workflow for viewing maps when offline.

Feature

• Taking basemap offline
• Set a reasonable extent such that the user does not have to select Tile Levels as all levels below extent should be taken by default.

Workflow
User initiated

• Add a icon and text in the drawer
• The app will use the existing extent as candidate for offline.

Auto

• App automatically caches areas where the user has been. There will be a defined limit on space and saved to app data space. These tiles will be private to the app and should be placed in the directory returned by Context.getExternalFilesDir then the system will take care of deleting if the app is uninstalled. With Android 4.4 we can use getExternalCacheDir().

[doneill]

#27 and #7 related to this research

[fallsdownhill]

To get an example of the offline usage, you can use this app instead: https://github.com/Esri/mapbook-android

It's unlikely that offline functionality will be added to this app.