Android - Clearing backstack with an Intent NOT called from an Activity

Question

I'm trying to implement a small slideshow similar to those used by many apps as an intro, such as Google Docs.

I separated the adapter from the activity as to keep everything tidy:

public class IntroActivity extends FragmentActivity {

    private int[] mResources = {
            R.drawable.slide1,
            R.drawable.slide2,
            R.drawable.slide3,
            R.drawable.slide4
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_intro);

        CustomPagerAdapter customPagerAdapter = new CustomPagerAdapter(this, mResources);

        ViewPager viewPager = (ViewPager) findViewById(R.id.pager);
        viewPager.setAdapter(customPagerAdapter);
    }

}

And the following code in my CustomPagerAdapter handles the click event of a button on the last slide which opens the MainActivity through an intent. Pretty standard stuff:

    @Override
    public Object instantiateItem(ViewGroup container, int position) {

        if (position == (mResources.length - 1)) {
            System.out.println("POSITION " + position);

            View itemView = mLayoutInflater.inflate(R.layout.pager_last_item, container, false);

            ImageView imageView = (ImageView) itemView.findViewById(R.id.lastImageView);
            imageView.setImageResource(mResources[position]);

            Button btn = (Button) itemView.findViewById(R.id.btn_open_main_activity);
            btn.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    Intent intent = new Intent(mContext, MainActivity.class);
                    intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                    mContext.startActivity(intent);
                    //TODO destroy IntroActivity.java
                }
            });

            container.addView(itemView);

            return itemView;
          }
         (...) //if not the last slide...

   }

But it doesn't seem to work, even with those Intent flags. I have no way to access the finish() method from the IntroActivity . The app runs fine, but when I press the back button in the MainActivity , it brings me back to the last slide. Is there a way to fix it?

EDIT - This is how I'm creating the PagerAdapter. I'm just passing the context and the resource array from IntroActivity:

public class CustomPagerAdapter extends PagerAdapter {

    private Context mContext;
    private LayoutInflater mLayoutInflater;
    private int[] mResources;

    public CustomPagerAdapter(Context context, int[] mResources) {
        this.mContext = context;
        this.mLayoutInflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        this.mResources = mResources;
    }

Answer 1

You can add android:noHistory="true" attribute in IntroActivity declaration in manifest.

refer this

Or you can pass activity reference to the fragment or the adapter claa via a constructor and call activity.finish()

something like new Adapter(mActivity) and call mActivity.finish()