Flutter Guide

This guide explains how to create a new Flutter app on Android and use the Abrevva Flutter plugin to scan for EVVA components.

Prerequisites

• Install or update Android Studio to its latest version.
• Install or update Flutter to its latest version.
• Set up a bluetooth capable physical device to run your app.

Create example app

Use the flutter cli to setup a new Flutter app & run the App.

$ flutter create my_app --platforms=android && cd my_app
$ flutter run

In case you get gradle build errors you might need to exclude the META-INF files in the app’s build gradle file at the android level.

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android/app/build.gradle.kts

packagingOptions {
  ...
  resources.excludes.add("META-INF/*")
}

You should now see the example app.

Add dependency

Execute the following commands to add the Abrevva Flutter plugin to the pubspec.yaml.

$ flutter pub add abrevva

Set permissions

Open the AndroidManifest.xml and add the required permissions and features at the manifest level.

android/app/src/main/AndroidManifest.xml

<uses-permission
  android:maxSdkVersion="30"
  android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission
  android:maxSdkVersion="30"
  android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission
  android:maxSdkVersion="30"
  android:name="android.permission.BLUETOOTH" />
<uses-permission
  android:maxSdkVersion="30"
  android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission
  android:name="android.permission.BLUETOOTH_SCAN"
  android:usesPermissionFlags="neverForLocation"
  tools:targetApi="s" />
<uses-feature
  android:name="android.hardware.bluetooth_le"
  android:required="true" />

Create scan page

Open lib/main.dart to view the source of the created Demo App. To repurpose the HomePage, just replace the _MyHomePageState Class with the implementation below. Also include the two imports below.

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import 'package:abrevva/abrevva.dart';
import 'package:abrevva/abrevva_param_classes.dart';

...

class _MyHomePageState extends State<MyHomePage> {
  final _abrevvaBle = AbrevvaBle();
  List<BleDevice> scanResultList = [];

  Future<void> _scanForDevices() async {
    scanResultList.clear();
    return await _abrevvaBle.startScan(
      onScanResult: (device) {
        setState(() {
          scanResultList.add(device);
        });
      },
    );
  }

  @override
  void initState() {
    super.initState();
    _abrevvaBle.initialize(false);
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Ble Scanner (scroll down to scan)')),
      body: Row(
        children: [
          RefreshIndicator(
            onRefresh: _scanForDevices,
            child: ListView.builder(
              itemCount: scanResultList.length,
              itemBuilder: (context, index) {
                final result = scanResultList[index];
                return ListTile(
                  title: Text(
                    "${result.advertisementData?.manufacturerData?.identifier}",
                    style: const TextStyle(color: Colors.blueAccent),
                  ),
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}

Final result

Scroll down to trigger the RefreshIndicator and you should see bluetooth results flying in.

You can find the full example code on Github.