How to pass a java class name as parameter and use it as casting in method

Question

I am trying to implement a general dialog method that every activity can call it. The public static method shall be something like this. But I have problem to cast mContent to its activity class name.

  public static void  openDialogEntry(Class activityClassName, Context mContext,  String title,  ... ) {
    Dialog_Entries   dialog = new Dialog_Entries(  title,   ...  );
    dialog.show( ((activityClassName) mContext).getSupportFragmentManager(), tag);
}

I want to call this method from fragments of any activity for example from a fragment(view) of SecondActivity.java using

 openDialogEntry(view.getContext().getClass, view.getContext(),  title,  ... ) ; 

What I expect to do is doing something like next line in openDialogEntry method

 dialog.show( ((SecondActivity) mContext).getSupportFragmentManager(), tag);

It seems that ((activityClassName) mContext) is not working. I want to call the public static method from MainActivity.java and ThirdActivity.java too (and their fragments which would need the casting).

How to realize this goal ?

Answer 1

Class has a method Class.cast(Object) that is you could do this:

public static void openDialogEntry(Class<? extends Context> activityClassName, Context mContext, String title, ...) {
    Dialog_Entries dialog = new Dialog_Entries(title, ...);
    dialog.show(activityClassName.cast(mContext).getSupportFragmentManager(), tag);
}

Note that cast only makes sense when providing generic information on the Class parameter

However as @Zabuzard already mentioned. This makes not much sense. If you can cast mContext to activityClassName why not use this class instead of Context as method parameter?

Context probably implements some interface or extends some class that provides the getSupportFragmentManager method. So there is no need to cast at all.