EndlessPager

EndlessOnPageChangeListener

private class EndlessOnPageChangeListener implements OnPageChangeListener {
    private static final int NO_PAGE = -1;
    int loadingPage = NO_PAGE;

    @Override
    public void onPageSelected(int currentPage) {
        // we're not on the loading element
        if (loadingPage != currentPage) {
            loadingPage = NO_PAGE;
            currentAdapter.setLoadingData(false);

            if (!currentAdapter.isFooterPosition(currentPage)) {
                // create footer view
            } else {
                // create default view
            }
        }
    }

    @Override
    public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
        int nextPosition = position + 1;
        // set loading data if it's not the last page (where lastPage() is a method defined somewhere)
        if (nextPosition == currentAdapter.getCount() && !lastPage()) {
            loadingPage = nextPosition;
            currentAdapter.setLoadingData(true);
        }
    }

    @Override
    public void onPageScrollStateChanged(int state) {
    }

    public void setLoadingPage(int loadingPage) {
        this.loadingPage = loadingPage;
    }
}

EndlessPagerAdapter.java

import java.util.ArrayList;
import java.util.List;

import android.os.Parcelable;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.View;

public abstract class EndlessPagerAdapter<ItemT> extends PagerAdapter {

    private boolean isLoadingData;

    protected ArrayList<ItemT> data = new ArrayList<ItemT>();

    protected View progressView;

    /**
     * Create the page for the given position. The adapter is responsible for adding the view to the
     * container given here, although it only must ensure this is done by the time it returns from
     * {@link #finishUpdate()}.
     * 
     * @param container
     *            The containing View in which the page will be shown.
     * @param position
     *            The page position to be instantiated.
     * @return Returns an Object representing the new page. This does not need to be a View, but can
     *         be some other container of the page.
     */
    @Override
    public Object instantiateItem(View container, int position) {
        if (isPositionOfProgressElement(position)) {
            return doInstatiateProgressItem(container);
        }
        return doInstantiateItem(container, position);
    }

    protected abstract Object doInstantiateItem(View container, int position);

    protected abstract Object doInstatiateProgressItem(View container);

    /**
     * Remove a page for the given position. The adapter is responsible for removing the view from
     * its container, although it only must ensure this is done by the time it returns from
     * {@link #finishUpdate()}.
     * 
     * @param container
     *            The containing View from which the page will be removed.
     * @param position
     *            The page position to be removed.
     * @param object
     *            The same object that was returned by {@link #instantiateItem(View, int)}.
     */
    @Override
    public void destroyItem(View container, int position, Object view) {
        ((ViewPager) container).removeView((View) view);
    }

    @Override
    public boolean isViewFromObject(View view, Object object) {
        return view.equals(object);
    }

    /**
     * Called when the a change in the shown pages has been completed. At this point you must ensure
     * that all of the pages have actually been added or removed from the container as appropriate.
     * 
     * @param container
     *            The containing View which is displaying this adapter's page views.
     */
    @Override
    public void finishUpdate(View container) {
    }

    @Override
    public void restoreState(Parcelable arg0, ClassLoader arg1) {
    }

    @Override
    public Parcelable saveState() {
        return null;
    }

    @Override
    public void startUpdate(View container) {
    }

    public void setLoadingData(boolean isLoadingData) {
        this.isLoadingData = isLoadingData;
    }

    public boolean isLoadingData() {
        return isLoadingData;
    }

    public boolean isPositionOfProgressElement(int position) {
        return isLoadingData && position == data.size();
    }

    @Override
    public int getItemPosition(Object object) {
        if (object.equals(progressView) && !isLoadingData) {
            return PagerAdapter.POSITION_NONE;
        }
        return PagerAdapter.POSITION_UNCHANGED;
    }

    @Override
    public int getCount() {
        int size = 0;
        if (data != null) {
            size += data.size();
        }
        if (isLoadingData) {
            size += 1;
        }
        return size;
    }

    public void addAll(List<ItemT> list) {
        addAll(list, true);
    }

    public void addAll(List<ItemT> list, boolean redrawPager) {
        data.addAll(list);
        if (redrawPager) {
            notifyDataSetChanged();
        }
    }

    public void add(ItemT item) {
        add(item, true);
    }

    public void add(ItemT item, boolean redrawPager) {
        data.add(item);
        if (redrawPager) {
            notifyDataSetChanged();
        }
    }

    public void add(int index, ItemT item) {
        add(index, item, true);
    }

    public void add(int index, ItemT item, boolean redrawPager) {
        data.add(index, item);
        if (redrawPager) {
            notifyDataSetChanged();
        }
    }

    public void addAll(int index, List<ItemT> list) {
        addAll(index, list, true);
    }

    public void addAll(int index, List<ItemT> list, boolean redrawPager) {
        data.addAll(index, list);
        if (redrawPager) {
            notifyDataSetChanged();
        }
    }

    public void clear(ViewPager pager) {
        for (int i = 0; i < getCount(); i++) {
            destroyItem(pager, i, pager.getChildAt(i));
        }
        data.clear();
    }

}