Activity Instance does not exist- null object reference

Question

I am trying to develop an Android application. For my use case I want to use a custom typeface and I wrote a that gathers all available TextViews in a View, so that I can set the typeface easily by a loop. I thought I should source out the text manipulation things to an own class named TextManager.class . But now when I am executing the app I am getting an error:

java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.res.Resources android.content.Context.getResources()' on a null object reference

It occurs when I am trying to set Typeface in TextMangaer.class . I did a bit of research and found out that it is because the activity instance does not exist at this point. But I don't get it why, cause when I am trying to do this in Start.class there is no problem.

//Start.class
public class Start extends AppCompatActivity {
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); // set fullscreen

    //Initialize shared preferences
    prefs = getSharedPreferences("User", Context.MODE_PRIVATE);
    editor=prefs.edit();

    setContentView(R.layout.start_screen);
    TextManager textManager= new TextManager();

    textManager.setTypeface(getTextViews((ViewGroup) findViewById(R.id.root_menu)));

}
}

and my TextManager.class:

public class TextManager extends Start{

public TextManager(){
super();
}

public void setTypeface(List<Integer> idsOfTextViews){
    Typeface typeFaceIkarosLight= Typeface.createFromAsset(getAssets(), "font/ikaros_light.otf");
    for(int i=0; i < idsOfTextViews.size();i++){
        ((TextView)findViewById(idsOfTextViews.get(i))).setTypeface(typeFaceIkarosLight);
    }

}
}

So how could I fix this or how should I write this? If anybody could help me figure it out that would be great. Thanks in advance.

where are you calling super() to inherit parent classes context? — paul_hundal, Feb 12 '18 at 07:30
@Paul_hundal I just added it in the constructor, but still the same issue. — Chinaedu Onwukwe, Feb 12 '18 at 07:42
follow this it will helps you -https://stackoverflow.com/questions/27588965/how-to-use-custom-font-in-android-studio — Adil, Feb 12 '18 at 07:51
If `TextManager` is not being used as an `Activity`, it should not extend an `Activity`. That's why the `Context` is null. Remove `extends Start`, and pass a `Context` to `TextManager`, either in a constructor, or a method. — Mike M., Feb 12 '18 at 08:28

score 1 · Answer 1 · edited Feb 12 '18 at 07:35

1

Problem is context is null for getting assets.

Use getContext() or getApplicationContext() in case of being used in an activity but if it is being used in a fragment then use getActivity().getContext()

Typeface font = Typeface.createFromAsset(getContext().getAssets(),  "font/ikaros_light.otf");

Instead of

Typeface typeFaceIkarosLight= Typeface.createFromAsset(getAssets(), "font/ikaros_light.otf");

edited Feb 12 '18 at 07:35

Rohit5k2

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answered Feb 12 '18 at 07:28

sasikumar

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Either wit getContext() nor with getApplicationContext() it does not work. Still the same error. – Chinaedu Onwukwe Feb 12 '18 at 07:41

score 0 · Answer 2 · answered Feb 12 '18 at 07:24

Its better to make method which return typeface instead passing textview ids as an argument. you can do it like this :

public Typeface getTypeFace(Context context){
    Typeface typeFaceIkarosLight = Typeface.createFromAsset(context.getAssets(), "font/ikaros_light.otf");
    return typeFaceIkarosLight;
}

score 0 · Answer 3 · answered Feb 12 '18 at 07:27

If you want to use custom fonts then you can take this example

This tutorial will show you how to set custom font on TextView, EditText and on Button.

http://androiderstack.com/index.php/2017/08/14/use-custom-font-in-textview-edittext-and-button-in-android/

This will surely help you

Activity Instance does not exist- null object reference

3 Answers3