ViewPager indicator with custom ListView

Question

First of all, I apologize for my English, as this is not very good. Thank you There are several ListWiews with adapters in my application. The data for ListViews is taken from a parsed XML file located on the Internet. Now I have one TabHost with three tabs and different ListViews on each tab. I want to change TabHost to a new and minor method - the ViewPager indicator by Jake Wharton (https://github.com/JakeWharton/Android-ViewPagerIndicator), because there is a slippery effect.

I tried to include this code in a sample project and it works well. At the moment, I have a ListView in one ViewPager fragment and a simple TextView in two other fragments. He works.

ViewPagerAdapter code is shown below:

package com.formatbce.pager; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import android.content.Context; import android.os.Parcelable; import android.support.v4.view.PagerAdapter; import android.support.v4.view.ViewPager; import android.view.View; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.ListView; import android.widget.SimpleAdapter; import android.widget.TextView; import com.viewpagerindicator.TitleProvider; public class ViewPagerAdapter extends PagerAdapter implements TitleProvider { private int[] scrollPosition = new int[titles.length]; private static String[] titles = new String[] { "News", "Bio", "Music" }; private final Context context; public ViewPagerAdapter( Context context ) { this.context = context; for ( int i = 0; i < titles.length; i++ ) { scrollPosition[i] = 0; } } @Override public String getTitle( int position ) { return titles[ position ]; } @Override public int getCount() { return titles.length; } @Override public Object instantiateItem( View pager, final int position ) { if (position == 0) { ListView v = new ListView( context ); String[] from = new String[] { "str" }; int[] to = new int[] { android.R.id.text1 }; List<Map<String, String>> items = new ArrayList<Map<String, String>>(); for ( int i = 0; i < 20; i++ ) { Map<String, String> map = new HashMap<String, String>(); map.put( "str", String.format( "Item %d", i + 1 ) ); items.add( map ); } SimpleAdapter adapter = new SimpleAdapter( context, items, android.R.layout.simple_list_item_1, from, to ); v.setAdapter( adapter ); ( (ViewPager) pager ).addView( v, 0 ); v.setOnScrollListener( new OnScrollListener() { @Override public void onScroll( AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount ) { scrollPosition[ position ] = firstVisibleItem; } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { // TODO Auto-generated method stub } } ); return v;} else { TextView v = new TextView( context ); v.setText( titles[ position ] ); ((ViewPager)pager).addView( v, 0 ); return v; } } @Override public void destroyItem( View pager, int position, Object view ) { if (position == 0){ ( (ViewPager) pager ).removeView( (ListView) view );} else { ( (ViewPager) pager ).removeView( (TextView) view );} } @Override public boolean isViewFromObject( View view, Object object ) { return view.equals( object ); } @Override public void finishUpdate( View view ) {} @Override public void restoreState( Parcelable p, ClassLoader c ) {} @Override public Parcelable saveState() { return null; } @Override public void startUpdate( View view ) {} } 

So, with the ListView sample, everything is fine.

But my problems begin when I try to add my custom ListView there. In my old project, this ListView has the code:

 package com.formatbce.mdrive; import java.util.ArrayList; import android.app.AlertDialog; import android.app.ListActivity; import android.app.ProgressDialog; import android.content.Context; import android.content.DialogInterface; import android.content.Intent; import android.os.AsyncTask; import android.os.Bundle; import android.view.View; import android.widget.ListView; public class Concerts extends ListActivity { private ArrayList<Rss_PostItem> messages; private Rss_PostAdapter adapter; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (savedInstanceState != null) { messages = savedInstanceState.getParcelableArrayList("messages"); adapter = new Rss_PostAdapter(Concerts.this, R.layout.post_entry, messages); setListAdapter(adapter); } else new GetParserResult().execute(); } @Override protected void onListItemClick(ListView l, View v, int position, long id) { super.onListItemClick(l, v, position, id); Intent postActivity = new Intent(this, Rss_PostActivity.class); Bundle store = new Bundle(); store.putString("title", messages.get(position).title); store.putString("description", messages.get(position).description); store.putString("link", messages.get(position).link); postActivity.putExtras(store); startActivity(postActivity); } protected void onSaveInstanceState(Bundle savedInstanceState) { super.onSaveInstanceState(savedInstanceState); savedInstanceState.putParcelableArrayList("messages", messages); } private class GetParserResult extends AsyncTask<Context, Integer, ArrayList<Rss_PostItem>> { private ProgressDialog loadingDialog; private Concerts_Parser parser; protected void onPreExecute() { parser = new Concerts_Parser(); loadingDialog = ProgressDialog.show(Concerts.this, "", "Loading concerts list...", true); } @Override protected ArrayList<Rss_PostItem> doInBackground(Context... arg0) { return parser.parse(); } protected void onPostExecute(ArrayList<Rss_PostItem> result) { if (result == null) { AlertDialog.Builder builder = new AlertDialog.Builder( Concerts.this); builder.setMessage( "Cannot load list... \nIs Internet ON?") .setCancelable(false) .setPositiveButton("Ok", new DialogInterface.OnClickListener() { public void onClick(DialogInterface dialog, int id) { dialog.cancel(); loadingDialog.dismiss(); } }); AlertDialog alert = builder.create(); alert.show(); } else { messages = result; loadingDialog.dismiss(); adapter = new Rss_PostAdapter(Concerts.this, R.layout.post_entry, messages); setListAdapter(adapter); } } } } 

Therefore, I do not understand how to correctly place the ViewPager code. I tried setting ListFragment, but for me it is quite new, so I can not get it to work.

Google cannot help me, just like in various developer forums.

Truly, the question is how to get a custom ListView to be displayed in the ViewPager?

Thank you, I hope you help.

UPD:

Thanks to the first answer, I tried to convert one of my actions into a fragment using this lesson: http://www.e-nature.ch/tech/?p=55 .

Firstly, it was one mistake that I could not pass: this variable is not converted, and I do not know how to make it work.

 dm = (DownloadManager) getSystemService(DOWNLOAD_SERVICE); 

Now one more thing: when I tried to put the Fragment result in the FragmentPagerAdapter - I found the correct code here:

 @Override public Fragment getItem(int arg0) { // TODO Auto-generated method stub return ?????????; } 

Please tell me what should this method return? Thanks!

Answer 1

you said

I have one TabHost with three tabs and different ListView on each tab

I assume that you have three different listActivity and their passed tabHost. Therefore, convert the three actions into three fragments.

Based on the following code example, change your ViewPagerAdapter

 class GoogleMusicAdapter extends FragmentPagerAdapter implements TitleProvider { public GoogleMusicAdapter(FragmentManager fm) { super(fm); } @Override public Fragment getItem(int position) { if(position ==0 ) // return your Fragment1 else if(position==1) // return your Fragment2 else // return fragment3 } @Override public int getCount() { return 3; } @Override public String getTitle(int position) { if(position ==0 ) return "One" else if(position ==1) return "two" else return "three" } }