ScrollView scrolls down when view size changes

Question

I currently have a ScrollView with a LinearLayout. I'm changing some content dynamically, e.g. setting a long text passage dynamically, and adding dynamic layouts (buttons etc.). This causes the linear layout's height to change, which causes the ScrollView to scroll down. How can I keep the current scroll position while the layout is being dynamically updated?

<ScrollView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fillViewport="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical
        android:gravity="center_horizontal"
        >

        <!-- Dynamic Content Here -->
    </LinearLayout>
</ScrollView>

Try this? or downvote me into oblivion... see if i care. http://stackoverflow.com/questions/25648526/manage-scroll-position-in-scrollview-during-orientation-change? — Frenchie, Dec 31 '14 at 19:27
I could try storing the position and then restoring, but that would mean I would have to listen for each individual view's layout which will get pretty messy, especially if we take user touches into consideration. I'll save this if there is no alternative. — lumi, Dec 31 '14 at 19:36
I had the same problem, i fix it with the solution posted by mjp66 http://stackoverflow.com/a/14632456/4712031 — Leo, Apr 15 '16 at 13:48
@Leo's link to mjp66's answer worked for me. At the time of writing it is the correct answer and has 220 up-votes including mine. — Chucky, Mar 08 '17 at 12:23

score -1 · Answer 1 · answered Dec 31 '14 at 19:29

One option i would suggest is to save the scroll position in a bundle and restore it.

@Override
protected void onSaveInstanceState(Bundle outState) {
    outState.putInt("xPos", scrollView.getScrollX());
    outState.putInt("yPos", scrollView.getScrollY());
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...
    int scrollX = savedInstanceState.getInt("xPos"); // Default value 0
    int scrollY = savedInstanceState.getInt("yPos");
    scrollView.scrollTo(scrollX, scrollY);
}

score -1 · Answer 2 · answered Dec 31 '14 at 19:32

-1

I think with this steps you can do it :

Create a custom scroll view that extends from scrollview
Define a boolean property for enabling and disabling scroll
Check the boolean variable on the onScollChanged method and return false if is true
Set the boolean variable true before adding dynamic views to it's container
Set it to false when adding done

I hope these help you

answered Dec 31 '14 at 19:32

Morteza Soleimani

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I'm not sure if this will work due to the fact that computeScroll is called some time after the view has been added to the layout, which would mean that I would again have to keep track of layout changes... – lumi Dec 31 '14 at 19:49
You want add the views dynamically after that activity loaded and content view set ? Or you are setting the content view after adding new views to root view ? – Morteza Soleimani Dec 31 '14 at 19:57
I am loading the activity, fetching some data then adding the data and adding dynamic views into the layout. – lumi Dec 31 '14 at 20:04

ScrollView scrolls down when view size changes

2 Answers2