global functions accessing system features android

Question

hi i have created a global actions class and created functions inside this class which i'm trying to access inside another activity the problem i'm having is that in eclipse I'm getting coding errors around the functions that access system feature such as getSystemService() and getApplicationContext() does anyone know why or how to let a global class accept system features?

heres what i have so far heres my GloblActions.java

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.util.Log;

public class GlobalActions{
        Context mContext;

        // constructor
        public GlobalActions(Context context){
            this.mContext = context;
        }


        public final static boolean isOnline (Context someContext){ {

            Log.v("globals", "isonline");

    ConnectivityManager cm = (ConnectivityManager) someContext.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo netInfo = cm.getActiveNetworkInfo();

        if (netInfo != null && netInfo.isConnectedOrConnecting()) {
            return true;
        }
        return false;
        }

}



        public final static void checkInternet(Context someContext){

                    isOnline(someContext);
                    if(isOnline(someContext) == false){
                       Log.v("globals", "isOnline = false");
                       Intent register = new Intent(someContext.getApplicationContext(), LoginForm.class);
                       someContext.startActivity(register);
                    }
                }



        }   

heres where i'm using the function in an activity. my goal is is to check internet connection on every activity by just calling the global function and if no connection is found go to an activity that says no internet connection.

import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.view.animation.Animation;
import android.view.animation.AnimationUtils;
import android.widget.TextView;
import android.os.Handler;
import com.myApp.myApp.GlobalActions;

public class IntroLoader extends Activity {

    public Handler handler;
    public TextView loadText = null;
    public Animation AniFadein = null;



    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.lo_introloader);
        findViewById(R.id.progressBar1).setVisibility(View.GONE);
        findViewById(R.id.loadTextView).setVisibility(View.GONE);
         GlobalActions.isOnline(null);
         GlobalActions.checkInternet(null);

        handler = new Handler();
        final Runnable fadeIn = new Runnable()
        {
            public void run() 
            {
               animations();
               findViewById(R.id.progressBar1).setVisibility(View.VISIBLE);
               findViewById(R.id.loadTextView).setVisibility(View.VISIBLE);
                         }
        };
        handler.postDelayed(fadeIn, 3000);

        final Runnable aSyncTask= new Runnable()
        {
            public void run() 
            {

               PostTask posttask;
               posttask = new PostTask();
               posttask.execute();

            }
        };
        handler.postDelayed(aSyncTask, 4000);

    }

    public void animations(){

        loadText = (TextView)findViewById(R.id.loadTextView);
        AniFadein = AnimationUtils.loadAnimation(this, R.anim.fadein);  
        loadText.startAnimation(AniFadein); 

    }


  public class PostTask extends AsyncTask<Void, String, Boolean> {

        protected void onPreExecute() {
            super.onPreExecute();

        }

        @Override
        protected Boolean doInBackground(Void... params) {
            boolean result = false;
            publishProgress("progress");
            return result;
        }

        protected void onProgressUpdate(String... progress) {
            StringBuilder str = new StringBuilder();
                for (int i = 1; i < progress.length; i++) {
                    str.append(progress[i] + " ");

                }
        }

            @Override
        protected void onPostExecute(Boolean result) {
            super.onPostExecute(result);
            checkLoginData();
          }
    }

  public void checkLoginData(){

      Intent register = new Intent(getApplicationContext(), LoginForm.class);
      startActivity(register);


  }         



}

Answer 1

Do

 ConnectivityManager cm = (ConnectivityManager) mContext.getSystemService(Context.CONNECTIVITY_SERVICE);

Contexts can use the method getSystemService() but your class isn't a Context, you need to use your mContext variable.

This means that you can also replace getApplicationContext() with mContext. And if you really need getApplicationContext() (unlikely - normal Contexts should work fine), use

mContext.getApplicationContext()

Also, you declare your isOnline() method as static, but then you need to use a Context for checking and making the toast. Either don't make it static or change it so it accepts in a Context, eg

public final static boolean isOnline (Context someContext){

And replace calls there that need a Context with someContext. Static methods don't need an instance of the class, and so, you can't use mContext. Once you fix the getApplicationContext() issue you have now, the compiler should throw an error about accessing a non static field in a static way. Same with your checkInternet(). I suggest you revaluate your logic, there are multiple problems with your class - I suggest making everything a static method that accepts in a Context which will be given by the calling Activity.

Lastly be careful about showing Toasts and other UI Elements in a global non-ui class. Toasts should be fine since they run on top of windows, but a Dialog will need a window, and if mContext is not an instance of Activity, that will fail (Activities have a window, other Contexts (like getApplicationContext()), do not.