So it appears that when using a ViewPager, the onPageSelected listener does not get called for the first page same issue as this.
I have some logic that populates some more expensive UI elements for the currently selected page and this works when page is changed, but it doesn't work for the first page.
If I set the current item after the listener, the callback gets fired for the first page, but the view has not been initialized yet, so I can't manipulate it:
// Inside PagerAdapter.instantiateItem
ViewHolder vh = new ViewHolder();
cursor.moveToPosition(position);
vh.view = adapter.newView(context, cursor, null);
// Set position as tag so we can retrieve it with findViewByTag
vh.view.setTag(position);
((ViewPager) collection).addView(vh.view,0);
return vh;
// Inside MyActivity.onCreate
pagerAdapter = new SingleMessagePagerAdapter(this, cursor);
pager = (ViewPager)findViewById(R.id.message_pager);
pager.setAdapter(pagerAdapter);
pager.setOnPageSelectedListener(this);
pager.setCurrentItem(selectedItem);
// Inside MyActivity.onPageSelected
// Retrieve tagged view
View view = pager.findViewWithTag(position);
Here view
ends up being null because PagerAdapter.instantiateItem
has not yet been run. So I guess my question is, at which point in the activity lifecycle can I be certain that the ViewPager has initialized the view? I tried doing this inside Activity.onAttachedToWindow
and Activity.onResume
but it appears both of these get fired before PagerAdapter.instantiateItem
.