Android ScrollView, scroll before visible

Question

how can I set scroll of scrollview to x pixels, before it's even shown?

In ScrollView I have some Views and i know that it will fill screen. Can I scroll to let say second View, so that first View is not visible when activity is started?

Now I have sth like this, but I think it's not perfect, sometimes, I see first View, and then it's scrolled to the second one

@Override
public void onGlobalLayout() {
    if (mHorizontalScrollView.getChildCount() > 0 && mHorizontalScrollView.getChildAt(0).getWidth() > mScreenWidth) {
            hsv.scrollTo(100, 0);
    }
}

EDIT!!

Second attempt was to use http://developer.android.com/reference/android/view/ViewTreeObserver.OnPreDrawListener.html instead of http://developer.android.com/reference/android/view/ViewTreeObserver.OnGlobalLayoutListener.html In OnPreDrawListener we can read that At this point, all views in the tree have been measured and given a frame. Clients can use this to adjust their scroll bounds or even to request a new layout before drawing occurs. so basically at this point we should adjust scrolling. So I created:

@Override
public boolean onPreDraw() {
    if (hsv.getChildCount() > 0 && hsv.getChildAt(0).getWidth() > mScreenWidth) {
        hsv.scrollTo(100, 0);
        return false;
    }
    return true;
}

but now it's never working for me.

Answer 1

I combined onGlobalLayout with code below. It's not so great to use that hack but it still quite efficient. When I get onGlobalLayout event I check if layouts are done and then if it's ok I use method below.

// hsv - horizontal scroll view
private void forceShowColumn(final int column) {
    int scrollTo = childViewWidth * column;
    if (scrollTo == hsv.getScrollX()) {
        return;
    }
    hsv.scrollTo(scrollTo, 0);

    hsv.postDelayed(new Runnable() {

        @Override
        public void run() {
            forceShowColumn(column);
        }
    }, 10);
}

Answer 2

try View.post(Runnable) in onCreate-method.

Answer 3

I solved this issue by implementing View.OnLayoutChangeListener in the fragment that controls my ScrollView.

public class YourFragment extends Fragment implements View.OnLayoutChangeListener{

...

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    // Inflate the layout for this fragment
    view = inflater.inflate(R.layout.your_fragment_layout, container, false);

    //set scrollview layout change listener to be handled in this fragment
    sv = (ScrollView) view.findViewById(R.id.your_scroll_view);
    sv.addOnLayoutChangeListener(this);

    return view;
}

...

public void onLayoutChange (View v, int left, int top, int right, int bottom, int oldLeft, int oldTop, int oldRight, int oldBottom){
    switch (v.getId())
    {
        case R.id.your_scroll_view:
        {
                sv.scrollTo(0, sv.getTop());
        }
    }
}