Question

I am Implementing a custom Horizontal View Pager. My Intention is to populate the entries of a particular table in a ListView. The method have to detect how many tables are there in the database and set as many pages for the horizontal view pager. (One Page for One TABLE – Each page contains only one ListView to showing entries of the corresponding TABLE).

Here’s my tries.

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.viewp);
    MyPagerAdapter adapter = new MyPagerAdapter();
    ViewPager myPager = (ViewPager) findViewById(R.id.threepageviewer);
    myPager.setAdapter(adapter);
    DbHelper helper = new DbHelper(this);
    count = helper.countTables();
    myPager.setCurrentItem(count);
    temp = helper.countTables() - 1;
    temp1 = helper.countTables() - 1;
}

here’s the page adapter class.

private class MyPagerAdapter extends PagerAdapter {

    public int getCount() {
        return count;
    }

    public Object instantiateItem(View collection, int position) {

        LayoutInflater inflater = (LayoutInflater) collection.getContext()
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        View view = null;


        if (position == count-1) {
            view = inflater.inflate(R.layout.middle, null);
            ListView list = (ListView) view.findViewById(R.id.listView1);
            helper = new DbHelper(Listing.this);
            String tabName = helper.getTableName(temp1);
            dataset_cursor = helper.getAll(tabName);
            startManagingCursor(dataset_cursor);
            adapter = new NoteAdapter(dataset_cursor);
            list.setAdapter(adapter);
            adapter.notifyDataSetChanged();
        }
        if (position < temp) {
            temp--;
            temp1--;
            // int hg = temp - position;
            // int tempo = temp - hg;
            view = inflater.inflate(R.layout.left, null);
            ListView list1 = (ListView) view.findViewById(R.id.listView1);
            helper = new DbHelper(Listing.this);
            String tabName = helper.getTableName(temp1);
            dataset_cursor1 = helper.getAll(tabName);
            startManagingCursor(dataset_cursor1);
            adapter1 = new NoteAdapter(dataset_cursor1);
            list1.setAdapter(adapter1);
            adapter1.notifyDataSetChanged();
            Toast.makeText(getBaseContext(), tabName, Toast.LENGTH_LONG);
            temp--;
            temp1--;
        }
        if (position > temp) {
            temp++;
            temp1++;
            // int hg = position - temp;
            // int tempo = temp - hg;
            view = inflater.inflate(R.layout.right, null);
            ListView list2 = (ListView) view.findViewById(R.id.listView1);
            helper = new DbHelper(Listing.this);
            String tabName = helper.getTableName(temp1);
            dataset_cursor2 = helper.getAll(tabName);
            startManagingCursor(dataset_cursor2);
            adapter2 = new NoteAdapter(dataset_cursor2);
            list2.setAdapter(adapter2);
            adapter2.notifyDataSetChanged();
        }

        ((ViewPager) collection).addView(view, 0);
        return view;
    }

I want the Last Database Table to be the default page. when I swipe left It should go to the second-last Table and so on. While trying this I almost get what I need. Except this problem .

END—TABLE6–(left swipe)–TABLE5–(left swipe)–TABLE5–(left swipe)–TABLE3–(left swipe)–TABLE2–(left swipe)–TABLE1—END

END—TABLE1–(right swipe)–TABLE2–(right swipe)–TABLE2–(right swipe)–TABLE3–(right swipe)–TABLE4–(right swipe)–TABLE5—END

I am doing it correctly. what could be the mistake here. Is there any other way to implement the same ?

Answer 1

The problem is because of your temp and temp1 variables. Do the following..

public Object instantiateItem(View collection, int position) {
     ...
     ...
     ListView list = (ListView) view.findViewById(R.id.listView1);
     helper = new DbHelper(Listing.this);
     String tabName = helper.getTableName(position+1);
     dataset_cursor[position] = helper.getAll(tabName);
     startManagingCursor(dataset_cursor[position]);
     adapter = new NoteAdapter(dataset_cursor[position]);
     list.setAdapter(adapter);
     adapter.notifyDataSetChanged();

     ((ViewPager) collection).addView(view, 0);

     return view;
}

If you want to maintain multiple dataset cursors then have dataset cursor array declared, which can be easily accessed like dataset_cursor[position] as shown above.