Question

I want to use three previously created Activities in a ViewPager (with PagerAdapter) so the user can scroll smoothly horizontally through them.
I followed a tutorial which worked great. The problem is in the tutorial they use TextViews to demonstrate. I already have finished Activities (of which the layouts are in XML files). I want to use these Activities in that slider now but it looks like I can only use Views for that.
I could not figure out how I have to change the code of the classes (from “implements Activity” to “extends View”) that I can use it in the slider.

The my current code looks like this:

public class HorizontalSliderBeispielActivity extends Activity {

    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.main);

       cxt = this;
       awesomeAdapter = new AwesomePagerAdapter();
       awesomePager = (ViewPager) findViewById(R.id.awesomepager);
       awesomePager.setAdapter(awesomeAdapter);
    }
...

then the inner class with the PageAdapter:

...
private class AwesomePagerAdapter extends PagerAdapter {

    public Object instantiateItem(View collection, int position) {
        TextView tv = new TextView(cxt);
        tv.setText("Bonjour PAUG " + position);
        tv.setTextColor(Color.WHITE);
        tv.setTextSize(30);

        view_01 = new SubmitCheatInstructions(cxt);

        ((ViewPager) collection).addView(tv, 0);
        ((ViewPager) collection).addView(view_01 , 1);

        return tv;
    }
}

Instead of that TextView “tv” I want to use Activities (i.e. SubmitCheatInstructions). Previously this class looked like:

public class SubmitCheatInstructions implements Activity {

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.submitcheat_instructions);
}

}

but as far as I know I have to change it to

public class SubmitCheatInstructions extends View {
    ????
}

in order to be able to use it for the ViewPager.

My problem now is that I want to load the layout from the layout xml file (submitcheat_instructions.xml) into that view and not do everything in code. I could not figure out how I have to do this.

Thanks for any help.

Answer 1

I followed the same tutorial and like you i was unable to achieve this at first but after some tinkering and trial and error the following code worked like a charm:

        /**
     * Create the page for the given position. The adapter is responsible
     * for adding the view to the container given here, although it only
     * must ensure this is done by the time it returns from
     * {@link #finishUpdate()}.
     * 
     * @param container
     *            The containing View in which the page will be shown.
     * @param position
     *            The page position to be instantiated.
     * @return Returns an Object representing the new page. This does not
     *         need to be a View, but can be some other container of the
     *         page.
     */
    @Override
    public Object instantiateItem(View collection, int position) {
        View v = new View(PatientView.this.getApplicationContext());
        final LayoutInflater inflater = (LayoutInflater) PatientView.this
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        switch (position) {
        case 0:
            v = inflater.inflate(R.layout.patientp1,
                    (ViewGroup) null, false);
            ((Button) v.findViewById(R.id.pp1btnbck)).setOnClickListener(new OnClickListener() {

                @Override
                public void onClick(View arg0) {
                    finish();
                }
            });

            break;
        case 1:
            v = inflater.inflate(R.layout.patientp2, null, false
                    );
            break;
        default:

            TextView tv = new TextView(PatientView.this.context);
            tv.setText("Page " + position);
            tv.setTextColor(Color.WHITE);
            tv.setTextSize(30);
            v = tv;
            break;
        }
        ((ViewPager) collection).addView(v, 0);

        return v;
    }

Hope this helps, Good luck
Shereef Marzouk