Send data to fragment from Activity

Question

I have Main Activity with View Pager inside that activity. So, I have also FragmentStatePager adapter for handling which fragment is display inside ViewPager.

Anyway, as you know ViewPager loads previous, current and next fragment in memory and that's problem because I want to change content values in next fragment from current fragment based on user interaction from current fragment.

public class StageOneActivity extends FragmentActivity 

  @Override
  protected void onCreate(Bundle savedInstanceState) {

    setContentView(R.layout.activity_stage_one);

    //ViewPager for Introduction
    mStageOnePager = (ViewPager) findViewById(R.id.vp_stage_one);
    mStageOnePager.setAdapter(new IntroFragmentPagerAdapter(getSupportFragmentManager()));
    mStageOnePager.setOffscreenPageLimit(1);
    //mStageOnePager.setCurrentItem(8);
}

 private class IntroFragmentPagerAdapter extends FragmentStatePagerAdapter {

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

    @Override
    public Fragment getItem(int pos) {
        switch(pos) {

            case 0:
                return StageOneFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_01);
            case 1:
                return StageOneFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_02);
            case 2:
                return TitleSpinnerFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_03, R.drawable.bkg_page_1_50);
            case 3:
                return CurrencySpinnerFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_03, R.drawable.pack_of_20);
            case 4:
                return SimpleSpinnerFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_05, R.drawable.bkg_page_1_50);
            case 5:
                return MoneySpentFragment.newInstance(getResources().getColor(R.color.green), R.drawable.money_spent_1, R.drawable.money_spent_2, "0");
            case 6:
                return StageOneFragment.newInstance(getResources().getColor(R.color.green), R.drawable.stage1_07);

How I can send data to fragment who is already loaded and content is added in ViewPager?

I decided to try to use ViewPager.setOnPageChangeListener and detected when user scrolled to selected screen, but problem is how I can send that data to that Fragment and show it?

Answer 1

You can use eventbus:

https://github.com/greenrobot/EventBus

It's easy to setup and use.

HOWTO with example and code snippets:

https://github.com/greenrobot/EventBus/blob/master/HOWTO.md

Answer 2

You need to define an interface in the fragment and implement it within the Activity.Google documentation:

http://developer.android.com/training/basics/fragments/communicating.html

In your class it'd be something like this:

public Fragment StageOneFragment{

public interface itf{

}

... }

public class StageOneActivity extends FragmentActivity implements StageOneFragment.itf{ ... }

Hope it helps, you should be able to implement the interface that way.