Question

I have a compound control that needs to access the Application object. My control extends LinearLayout, so because it isn’t an Activity I can’t call getApplication(). Is there a way I can do this from a Layout/View or pass the Application in?

Answer 1

There are a couple of things you could be depending on what you need the Application object for.

If you need the specific application instance, you could try casting your Context object to an Activity:

public class MyLinearLayout extends LinearLayout {
  private Application mApplication; 

  public MyLinearLayout(Context context, AttributeSet attrs) {
    super(context, attrs);

    //As this is a custom ViewGroup, Context will be an Activity, but just to make sure..
    if(context instanceof Activity)
        mApplication = ((Activity) context).getApplication();
    else
        throw new IllegalArguementException("Context must be an Activity");
  }
}

The code above checks to make sure that the Context passed to your custom view is an Activity, but in reality this should always be the case.

If you only need your Application object to use as a `Context’, then you can call the ‘context.getApplicationContext()’ method:

public class MyLinearLayout extends LinearLayout {
  private Context mAppContext; 

  public MyLinearLayout(Context context, AttributeSet attrs) {
    super(context, attrs);
    mAppContext = context.getApplicationContext();
  }
}