How to get the scrollview total height = Scrollview.getScrollY() on Android

Question

I have already look on some forums but the tricks do not work for me.

I have this code:

scrollview = (ScrollView)v.findViewById(R.id.scrollView);
    scrollview.getViewTreeObserver().addOnScrollChangedListener(new OnScrollChangedListener() {

        @Override
        public void onScrollChanged() {

            Log.d(MainActivity.TAG, "scroll ch: "+scrollview.getScrollY()+"/"+scrollview.getChildAt(0).getHeight());
        }
    });

In my layout.xml

<ScrollView
    android:id="@+id/scrollView"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true" >

    <LinearLayout
        android:id="@+id/principal"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@drawable/horiz"
        android:orientation="vertical"
        android:showDividers="end|middle" >
    </LinearLayout>
</ScrollView>

When I scroll down to the last I get the getScrollY() smaller than getChildAt(0).getHeight().

How can I get both having the same total size ?

score 7 · Answer 1 · edited May 23 '17 at 12:16

7

Just to formally answer this, since I ran into the same issue.

If you log: scrollView.getScrollY(); and scroll down to the bottom of your view you'll get a number that represents the height of your ScrollView. You'll notice that scrollView.getHeight() only gives you the height of the currently visible view. So you want to use: scrollView.getChildAt(0).getHeight(); as seen here. But that gives you a number greater than the maximum value of scrollView.getScrollY(). So you need to subtract it by the height of the scrollView.

TLDR:

totalHeightOfScrollView = scrollView.getChildAt(0).getHeight() 
    - scrollView.getHeight();

This will equal scrollView.getScrollY() at the bottom-most point.

edited May 23 '17 at 12:16

Community

1
1

answered Jun 16 '16 at 18:42

Ali Hirani

191
1
8

Ok. but a better way to know if the Listview has reached the latest view or his end, you can try `listview.setOnScrollListener(new AbsListView.OnScrollListener() { @Override public void onScrollStateChanged(AbsListView view, int scrollState) { } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { Log.d(getClass().getSimpleName(), "total now:"+(firstVisibleItem+visibleItemCount)+"/"+totalItemCount); } });` – user3502626 Jun 16 '16 at 23:02
I believe that's a different question, perhaps that was your originally intended question, but I was just outlining your own answer (in the form of a comment) to your original question. – Ali Hirani Jun 17 '16 at 19:39

score 0 · Accepted Answer · answered Sep 26 '15 at 04:28

0

Maybe change

layout_height="wrap_content"

to

layout_height="match_parent"

answered Sep 26 '15 at 04:28

Patricia

2,885
2
26
32

I do what u wrote. Now I have both layout_height="match_parent". But it does not work. I got **scroll ch: 992/1758** from the log. – user3502626 Sep 26 '15 at 05:11
I get it now. 1758-992 = 766 = scrollview.getHeight(). so I did scrollview.getScrollY()+scrollview.getHeight() = scrollview.getChildAt(0).getBottom(). – user3502626 Sep 26 '15 at 05:18
Thanks for your answer – user3502626 Sep 26 '15 at 05:18

How to get the scrollview total height = Scrollview.getScrollY() on Android

2 Answers2