RequestPagerAdapter.java

package what.whatandroid.request;

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.view.ViewGroup;

import api.requests.Request;
import what.whatandroid.callbacks.LoadingListener;

/**
 * Fragment pager adapter to show the request details and comments
 */
public class RequestPagerAdapter extends FragmentPagerAdapter implements LoadingListener<Request> {
    /**
     * The request details and comments fragments being shown
     */
    private RequestDetailFragment detail;
    private RequestCommentsFragment comments;
    private DescriptionFragment description;
    private Request request;

    public RequestPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int position) {
        switch (position) {
            case 0:
                return new RequestDetailFragment();
            case 1:
                return new DescriptionFragment();
            default:
                return new RequestCommentsFragment();
        }
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        switch (position) {
            case 0:
                return "Request";
            case 1:
                return "Description";
            default:
                return "Comments";
        }
    }

    @Override
    public Object instantiateItem(ViewGroup container, int position) {
        Fragment f = (Fragment) super.instantiateItem(container, position);
        if (position == 0) {
            detail = (RequestDetailFragment) f;
            if (request != null) {
                detail.onLoadingComplete(request);
            }
        } else if (position == 1) {
            description = (DescriptionFragment) f;
            if (request != null) {
                description.onLoadingComplete(request.getResponse().getDescription());
            }
        } else {
            comments = (RequestCommentsFragment) f;
            if (request != null) {
                comments.onLoadingComplete(request);
            }
        }
        return f;
    }

    @Override
    public void destroyItem(ViewGroup container, int position, Object object) {
        super.destroyItem(container, position, object);
        switch (position) {
            case 0:
                detail = null;
                break;
            case 1:
                description = null;
                break;
            default:
                comments = null;
        }
    }

    @Override
    public void onLoadingComplete(Request data) {
        request = data;
        if (detail != null) {
            detail.onLoadingComplete(data);
        }
        if (description != null) {
            description.onLoadingComplete(request.getResponse().getDescription());
        }
        if (comments != null) {
            comments.onLoadingComplete(data);
        }
    }
}