Adding featues to NextGIS android mobile app

[sharmapn]

Hi there,

I am interested in extending the NextGIS Mobile Android application and would appreciate some guidance on getting started with development.

In particular, I would like to understand:

• What is the recommended development environment/IDE for working with the project (e.g., Android Studio)?
• Are there any setup instructions or build guidelines for compiling and running the app locally?
• Is there any developer-focused documentation or tutorials available for understanding the codebase and adding new features?

As a follow-up, I am specifically interested in adding custom geospatial processing functionality (e.g., geometry transformations on vector layers), so any pointers on where such logic would best fit within the architecture would also be very helpful.

Thank you for your time and for making this project available.

Kind regards,

[sharmapn]

Hi,

Just adding an update from my side after working through the project setup for some time.

From what I have found so far, Android Studio appears to be the appropriate development environment for working with the NextGIS Mobile Android project. The project is a multi-module Android project and includes modules such as:

:app
:maplib
:maplibui
:wizardpager
:easypicker-module

So it is best opened as a full Gradle project in Android Studio rather than trying to run individual Java/Kotlin files directly.

For setup, the key points I found were:

1. Clone the repository.
2. Make sure submodules/dependent modules are available.
3. Open the root project folder in Android Studio.
4. Use a compatible JDK/Gradle/Android Gradle Plugin combination.
5. Ensure local.properties points to the Android SDK.
6. Resolve signing/configuration values if the build expects them.
7. Then run the app on an emulator or physical Android device.

In my case, several early errors were caused by project configuration rather than source-code problems, for example missing JDK/module setup, missing SDK configuration, and build/signing-related properties. Once these are resolved, the project can be run from Android Studio like a normal Android app.

For understanding the architecture, the most relevant areas I have found are:

app/
Main Android application code

maplib/
Core GIS/map/layer/data functionality

maplibui/
UI components and layer editing/viewing support

For adding custom geospatial processing functionality, the most relevant classes/files appear to be around:

MainActivity.kt
MapFragment.kt
MainApplication.java
CreateVectorLayerActivity.java
LayersFragment.java

In particular, MainApplication.createEmptyVectorLayer(...) shows how the app creates an empty local vector layer, while CreateVectorLayerActivity.java shows how a newly created vector layer is added to the map and saved. MapFragment.kt is important because it maintains the selected/current vector layer and handles map interaction/editing workflows.

For geometry updates on existing vector features, the project appears to use the Android content-provider workflow, with ContentValues, Constants.FIELD_GEOM, and contentResolver.update(...) to update a feature geometry. So custom geometry transformations on existing vector layers may be possible by reading selected features, transforming their geometries, and updating them through the same pattern.

The part I am still investigating is the recommended way to programmatically insert multiple new features into a newly created local vector layer. The app clearly supports creating empty layers and editing features through the UI, but I am still looking for the cleanest internal API for bulk feature insertion — whether that should be done through VectorLayer, ContentResolver.insert(...), or a higher-level maplibui workflow.

So, in short, the project can be extended from Android Studio, and the best starting points seem to be:

MainActivity.kt menu/action entry points
MapFragment.kt selected layer and map interaction logic
MainApplication.java app-level map/layer creation helpers
CreateVectorLayerActivity example of creating and saving a new vector layer
maplib / maplibui core layer, feature, and editing APIs

I hope this helps others trying to get started with development.

Kind regards,
Pankaj