Fix MissingPluginException due to FlutterActivity reference

[mauriziopinotti]

Changed all references to FlutterActivity to android.app.Activity.

This fixes the following issues: #287 #283 #281 #209

The solution of changing FlutterActivity to FlutterFragmentActivity has been proposed in various comments but it's not actually needed since the reference is only used to call runOnUiThread() so using android.app.Activity is enough and provides the best compatibility.

[mauriziopinotti]

@AmolGangadhare @izzyaf @ahmadjehad anyone willing to review/merge this?

[kalvarez2]

good clean up

[mrprogramator]

Can anyone merge this PR please? this fix is critical for the lib to work in Android. Thanks!!!

[HasanBasheer]

Hi, the file does not have the change in all the necessary places and is still causing the issue.

This is how I changed it to work for me.

`package com.amolg.flutterbarcodescanner;

import android.app.Activity;
import android.app.Application;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;

import androidx.annotation.NonNull;
import androidx.lifecycle.DefaultLifecycleObserver;
import androidx.lifecycle.Lifecycle;
import androidx.lifecycle.LifecycleOwner;

import com.google.android.gms.common.api.CommonStatusCodes;
import com.google.android.gms.vision.barcode.Barcode;

import java.util.Map;

import io.flutter.embedding.engine.plugins.FlutterPlugin;
import io.flutter.embedding.engine.plugins.activity.ActivityAware;
import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
import io.flutter.plugin.common.BinaryMessenger;
import io.flutter.plugin.common.EventChannel;
import io.flutter.plugin.common.MethodCall;
import io.flutter.plugin.common.MethodChannel;
import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
import io.flutter.plugin.common.MethodChannel.Result;
import io.flutter.plugin.common.PluginRegistry;
import io.flutter.plugin.common.PluginRegistry.ActivityResultListener;
import io.flutter.plugin.common.EventChannel.StreamHandler;
import io.flutter.embedding.engine.plugins.lifecycle.FlutterLifecycleAdapter;

/**

• FlutterBarcodeScannerPlugin
  */
  public class FlutterBarcodeScannerPlugin implements MethodCallHandler, ActivityResultListener, StreamHandler, FlutterPlugin, ActivityAware {
  private static final String CHANNEL = "flutter_barcode_scanner";

  private static Activity activity;
  private static Result pendingResult;
  private Map<String, Object> arguments;

  private static final String TAG = FlutterBarcodeScannerPlugin.class.getSimpleName();
  private static final int RC_BARCODE_CAPTURE = 9001;
  public static String lineColor = "";
  public static boolean isShowFlashIcon = false;
  public static boolean isContinuousScan = false;
  static EventChannel.EventSink barcodeStream;
  private EventChannel eventChannel;

  /**

  • V2 embedding
  • @param activity
  • @param registrar
    */
    private MethodChannel channel;
    private FlutterPluginBinding pluginBinding;
    private ActivityPluginBinding activityBinding;
    private Application applicationContext;
    // This is null when not using v2 embedding;
    private Lifecycle lifecycle;
    private LifeCycleObserver observer;

  public FlutterBarcodeScannerPlugin() {
  }

  private FlutterBarcodeScannerPlugin(Activity activity, final PluginRegistry.Registrar registrar) {
  FlutterBarcodeScannerPlugin.activity = activity;
  }

  /**

  • Plugin registration.
    */
    public static void registerWith(final PluginRegistry.Registrar registrar) {
    if (registrar.activity() == null) {
    return;
    }
    Activity activity = registrar.activity();
    Application applicationContext = null;
    if (registrar.context() != null) {
    applicationContext = (Application) (registrar.context().getApplicationContext());
    }
    FlutterBarcodeScannerPlugin instance = new FlutterBarcodeScannerPlugin((Activity) registrar.activity(), registrar);
    instance.createPluginSetup(registrar.messenger(), applicationContext, activity, registrar, null);
    }

  @OverRide
  public void onMethodCall(@nonnull MethodCall call, @nonnull Result result) {
  try {
  pendingResult = result;

       if (call.method.equals("scanBarcode")) {
           if (!(call.arguments instanceof Map)) {
               throw new IllegalArgumentException("Plugin not passing a map as parameter: " + call.arguments);
           }
           arguments = (Map<String, Object>) call.arguments;
           lineColor = (String) arguments.get("lineColor");
           isShowFlashIcon = (boolean) arguments.get("isShowFlashIcon");
           if (null == lineColor || lineColor.equalsIgnoreCase("")) {
               lineColor = "#DC143C";
           }
           if (null != arguments.get("scanMode")) {
               if ((int) arguments.get("scanMode") == BarcodeCaptureActivity.SCAN_MODE_ENUM.DEFAULT.ordinal()) {
                   BarcodeCaptureActivity.SCAN_MODE = BarcodeCaptureActivity.SCAN_MODE_ENUM.QR.ordinal();
               } else {
                   BarcodeCaptureActivity.SCAN_MODE = (int) arguments.get("scanMode");
               }
           } else {
               BarcodeCaptureActivity.SCAN_MODE = BarcodeCaptureActivity.SCAN_MODE_ENUM.QR.ordinal();
           }
  
           isContinuousScan = (boolean) arguments.get("isContinuousScan");
  
           startBarcodeScannerActivityView((String) arguments.get("cancelButtonText"), isContinuousScan);
       }
   } catch (Exception e) {
       Log.e(TAG, "onMethodCall: " + e.getLocalizedMessage());
   }
  

  }

  private void startBarcodeScannerActivityView(String buttonText, boolean isContinuousScan) {
  try {
  Intent intent = new Intent(activity, BarcodeCaptureActivity.class).putExtra("cancelButtonText", buttonText);
  if (isContinuousScan) {
  activity.startActivity(intent);
  } else {
  activity.startActivityForResult(intent, RC_BARCODE_CAPTURE);
  }
  } catch (Exception e) {
  Log.e(TAG, "startView: " + e.getLocalizedMessage());
  }
  }

  /**

  • Get the barcode scanning results in onActivityResult
  • @param requestCode
  • @param resultCode
  • @param data
  • @return
    */
    @OverRide
    public boolean onActivityResult(int requestCode, int resultCode, Intent data) {
    if (requestCode == RC_BARCODE_CAPTURE) {
    if (resultCode == CommonStatusCodes.SUCCESS) {
    if (data != null) {
    try {
    Barcode barcode = data.getParcelableExtra(BarcodeCaptureActivity.BarcodeObject);
    String barcodeResult = barcode.rawValue;
    pendingResult.success(barcodeResult);
    } catch (Exception e) {
    pendingResult.success("-1");
    }
    } else {
    pendingResult.success("-1");
    }
    pendingResult = null;
    arguments = null;
    return true;
    } else {
    pendingResult.success("-1");
    }
    }
    return false;
    }

  @OverRide
  public void onListen(Object o, EventChannel.EventSink eventSink) {
  try {
  barcodeStream = eventSink;
  } catch (Exception e) {
  }
  }

  @OverRide
  public void onCancel(Object o) {
  try {
  barcodeStream = null;
  } catch (Exception e) {

   }
  

  }

  /**

  • Continuous receive barcode
  • @param barcode
    */
    public static void onBarcodeScanReceiver(final Barcode barcode) {
    try {
    if (barcode != null && !barcode.displayValue.isEmpty()) {
    activity.runOnUiThread(new Runnable() {
    @OverRide
    public void run() {
    barcodeStream.success(barcode.rawValue);
    }
    });
    }
    } catch (Exception e) {
    Log.e(TAG, "onBarcodeScanReceiver: " + e.getLocalizedMessage());
    }
    }

  @OverRide
  public void onAttachedToEngine(FlutterPluginBinding binding) {
  pluginBinding = binding;
  }

  @OverRide
  public void onDetachedFromEngine(FlutterPluginBinding binding) {
  pluginBinding = null;
  }

  @OverRide
  public void onDetachedFromActivityForConfigChanges() {
  onDetachedFromActivity();
  }

  @OverRide
  public void onReattachedToActivityForConfigChanges(ActivityPluginBinding binding) {
  onAttachedToActivity(binding);
  }

  /**

  • Setup method

  • Created after Embedding V2 API release

  • @param messenger

  • @param applicationContext

  • @param activity

  • @param registrar

  • @param activityBinding
    */
    private void createPluginSetup(
    final BinaryMessenger messenger,
    final Application applicationContext,
    final Activity activity,
    final PluginRegistry.Registrar registrar,
    final ActivityPluginBinding activityBinding) {

    this.activity = activity;
    eventChannel =
    new EventChannel(messenger, "flutter_barcode_scanner_receiver");
    eventChannel.setStreamHandler(this);

    this.applicationContext = applicationContext;
    channel = new MethodChannel(messenger, CHANNEL);
    channel.setMethodCallHandler(this);
    if (registrar != null) {
    // V1 embedding setup for activity listeners.
    observer = new LifeCycleObserver(activity);
    applicationContext.registerActivityLifecycleCallbacks(
    observer); // Use getApplicationContext() to avoid casting failures.
    registrar.addActivityResultListener(this);
    } else {
    // V2 embedding setup for activity listeners.
    activityBinding.addActivityResultListener(this);
    lifecycle = FlutterLifecycleAdapter.getActivityLifecycle(activityBinding);
    observer = new LifeCycleObserver(activity);
    lifecycle.addObserver(observer);
    }
    }

  @OverRide
  public void onAttachedToActivity(ActivityPluginBinding binding) {
  activityBinding = binding;
  createPluginSetup(
  pluginBinding.getBinaryMessenger(),
  (Application) pluginBinding.getApplicationContext(),
  activityBinding.getActivity(),
  null,
  activityBinding);
  }

  @OverRide
  public void onDetachedFromActivity() {
  clearPluginSetup();
  }

  /**

  • Clear plugin setup
    */
    private void clearPluginSetup() {
    activity = null;
    activityBinding.removeActivityResultListener(this);
    activityBinding = null;
    lifecycle.removeObserver(observer);
    lifecycle = null;
    channel.setMethodCallHandler(null);
    eventChannel.setStreamHandler(null);
    channel = null;
    applicationContext.unregisterActivityLifecycleCallbacks(observer);
    applicationContext = null;
    }

  /**

  • Activity lifecycle observer
    */
    private class LifeCycleObserver
    implements Application.ActivityLifecycleCallbacks, DefaultLifecycleObserver {
    private final Activity thisActivity;

    LifeCycleObserver(Activity activity) {
    this.thisActivity = activity;
    }

    @OverRide
    public void onCreate(@nonnull LifecycleOwner owner) {
    }

    @OverRide
    public void onStart(@nonnull LifecycleOwner owner) {
    }

    @OverRide
    public void onResume(@nonnull LifecycleOwner owner) {
    }

    @OverRide
    public void onPause(@nonnull LifecycleOwner owner) {
    }

    @OverRide
    public void onStop(@nonnull LifecycleOwner owner) {
    onActivityStopped(thisActivity);
    }

    @OverRide
    public void onDestroy(@nonnull LifecycleOwner owner) {
    onActivityDestroyed(thisActivity);
    }

    @OverRide
    public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
    }

    @OverRide
    public void onActivityStarted(Activity activity) {
    }

    @OverRide
    public void onActivityResumed(Activity activity) {
    }

    @OverRide
    public void onActivityPaused(Activity activity) {
    }

    @OverRide
    public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
    }

    @OverRide
    public void onActivityDestroyed(Activity activity) {
    if (thisActivity == activity && activity.getApplicationContext() != null) {
    ((Application) activity.getApplicationContext())
    .unregisterActivityLifecycleCallbacks(
    this);
    }
    }

    @OverRide
    public void onActivityStopped(Activity activity) {

    }
    }
    }`

[itsAyyazdev]

use this forked version until the author merges the changes

flutter_barcode_scanner: git: url: https://github.com/itsAyyazdev/flutter_barcode_scanner.git