Background video in Sketchware

UI design #1

Code:
final android.support.v4.view.ViewPager viewPager = new android.support.v4.view.ViewPager(this);
viewPager.setLayoutParams(new ViewGroup.LayoutParams( ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT));
MyPagerAdapter adapter = new MyPagerAdapter();
viewPager.setAdapter(adapter);
viewPager.setCurrentItem(0);
linear1.addView(viewPager);
viewPager.addOnPageChangeListener(new android.support.v4.view.ViewPager.OnPageChangeListener() { public void onPageSelected(int position) { 
View noview = (View) viewPager.findViewWithTag("myview" + viewPager.getCurrentItem());
if (position == 0) {
_a();
}
if (position == 1) {
_b
();
}
if (position == 2) {
_c();
}
}
@Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { }
@Override public void onPageScrollStateChanged(int state) { }
});
}
private class MyPagerAdapter extends android.support.v4.view.PagerAdapter {
public int getCount() {
return 3;
}
public Object instantiateItem(View collection, int position) {
LayoutInflater inflater = (LayoutInflater) collection.getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
int resId = 0;
switch (position) {
case 0:
resId = R.layout.custom1;
break;
case 1:
resId = R.layout.custom2;
break;
case 2:
resId = R.layout.custom3;
break;

}
View view = inflater.inflate(resId, null);
((android.support.v4.view.ViewPager)collection).addView(view, 0);
view.setTag("myview" + position);
return view;
}
@Override
public void destroyItem(View arg0, int arg1, Object arg2) {
((android.support.v4.view.ViewPager) arg0).removeView((View) arg2);
}
@Override
public boolean isViewFromObject(View arg0, Object arg1) {
return arg0 == ((View) arg1);
}
@Override
public Parcelable saveState() {
return null;
}