PagerFragmentAdapter.java

package cn.zhaiyifan.github.ui;

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

import java.util.List;

import cn.zhaiyifan.github.ui.base.FragmentProvider;

public class PagerFragmentAdapter extends FragmentStatePagerAdapter implements FragmentProvider {
    private List<Fragment> mFragments;
    private List<String> mTitles;
    private Fragment selected;

    public PagerFragmentAdapter(FragmentManager fm, List<Fragment> fragments, List<String> titles) {
        super(fm);
        mFragments = fragments;
        mTitles = titles;
    }

    @Override
    public void setPrimaryItem(ViewGroup container, int position, Object object) {
        super.setPrimaryItem(container, position, object);

        boolean changed = false;
        if (object instanceof Fragment) {
            changed = object != selected;
            selected = (Fragment) object;
        } else {
            changed = object != null;
            selected = null;
        }
    }

    @Override
    public Fragment getItem(int position) {
        return mFragments.get(position);
    }

    @Override
    public int getCount() {
        return mFragments.size();
    }

    @Override
    public CharSequence getPageTitle(int position) {
        return mTitles.get(position);
    }

    @Override
    public Fragment getSelected() {
        return selected;
    }
}