• Flashlight Altert on Sms and Call in Android

  Posted by Bhriguraj Salponia | Last Updated: 21-Dec-16
  

  
  
  I'm not going to share the full fledged code of the Flashlight Alert app but I will share the code behind the main logic i.e.of Flashlight, Flashlight blink and register BroadcastReceiver for Sms & Incoming Calls dynamically.

  Flashlight: As the Camera API deprecated in API level 21, it is recommended to use Camere2 API for new Applications. Camera2 does not provide back-support to API level below 21, so I had to write separate code for API level below 21 and above.

  if (sdkVersion < Build.VERSION_CODES.M) {
  
                      //code for Camera API- 1-20
  
                      if (isChecked) {   //if the ToggleButton is checked
  
                          camera = Camera.open();
                          Camera.Parameters parameters = camera.getParameters();
                          parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
                          camera.setParameters(parameters);
                          camera.startPreview();and upward
                      }
                      else {
                          camera.stopPreview();
                          camera.release();
                      }
  
                  } else{
  
                      //code for Camera2 API- 21 or higher
  
                      mCameraManager = (CameraManager) getSystemService(Context.CAMERA_SERVICE);
                      try {
                          mCameraId = mCameraManager.getCameraIdList()[0];
                          if(isChecked){
                              mCameraManager.setTorchMode(mCameraId, true);
                          }else{
                              mCameraManager.setTorchMode(mCameraId, false);
                          }
                      } catch (Exception e) {
                          e.printStackTrace();
                      }
  
                  }
  }
  

  Flashlight blink: There are many ways to do this but I find this way more suitable than others for my need. Below code works perfectly on API Level upto 21[Tested]. The same can be easily done using Camera2 for API level 21 and above.

  String string= "01010101010101010101"; //flashlight will blink 10 times
                              long longDelay= 50;
                              for(int i=0; i<string.length();i++){
                                  if(string.charAt(i)== '0'){
                                      camera = Camera.open();
                                      Camera.Parameters parameters = camera.getParameters();
                                      parameters.setFlashMode(Camera.Parameters.FLASH_MODE_TORCH);
                                      camera.setParameters(parameters);
                                      camera.startPreview();
                                  }else{
                                      camera.stopPreview();
                                      camera.release();
                                  }
                                  try{
                                      Thread.sleep(longDelay);
                                  }catch (Exception e){
                                      Log.i("exceptionException", "This is an blinking exception");
                                      e.printStackTrace();
                                  }
                              }
  

  Broadcast Receiver for Call/Sms: Here I have implemented the Broadcast Receiver dynamically rather than creating a class and extending it to BroadcastReceiver and mentioning the class name in the AndroidManifest.xml.

  private BroadcastReceiver broadcastReceiverSms, broadcastReceiverCall;
  
  //Sms Intent Filter
  IntentFilter intentFilter= new IntentFilter();
  intentFilter.addAction("android.provider.Telephony.SMS_RECEIVED");
  
  //Call Intent Filter
  IntentFilter intentFilter= new IntentFilter();
  intentFilter.addAction("android.intent.action.PHONE_STATE");
  
  //broadcast receiver 
  broadcastReceiverCall= new BroadcastReceiver() {
                          @Override
                          public void onReceive(Context context, Intent intent) {
                              
  			//flashlight blink logic for call & sms
  
                          }
                      };
  
  //start the broadcast receiver
  registerReceiver(broadcastReceiverCall, intentFilter); //same can be done for sms
  
  //stop the broadcast receiver
  unregisterReceiver(broadcastReceiverCall);
  

  At last don't forget to add the permissions for Sms and Call in the AndroidManifest.xml file.

   

  Thanks.

Tags: android