Working With A Non-activity Class, Which Should Be Able To Handle The Instance Variable Of The Calling Activity

I have two activities A and B, and a non activity class C. To use the methods of C, I create an instance c of C from the currently running activity (say A is in the foreground, and

Solution 1:

Even though a but vague, your Class C seems to be a helper class. Now, since you want to access instance variables (and possibly other information) in your C class, you need to pass them manually. Depending on what you are passing, it can be provided to Class C either in its constructor or via instance methods of the Class C itself.

For eg: based on the last statement of your question you can pass a ViewGroup reference from your activity to Class C via something like this:

public void initLayout(ViewGroup parent) {

    // Hide/unhide/perform actions/etc based on current activity needs

}

Similarly, you can also pass an enum value to Class C to differentiate between your activities in Class C. For a Class C to activity communication, you can look at interface in Java. Hope this helps.