How to Programmatically Scroll a ScrollView to Bottom

54
votes

I've a problem I can't solve: inside a ScrollView I only have a LinearLayout. By a user action I'm programmatically adding 2 TextView on this LinearLayout, but by the default the scroll keeps on the top. Since I controll the user action, I should be easy to scroll to the bottom with something like:

ScrollView scroll = (ScrollView) this.findViewById(R.id.scroll);
scroll.scrollTo(0, scroll.getBottom());

But actually not. Because immediately after adding this two new elements getBottom() still returns the previous two. I tried to refresh the state invoking refreshDrawableState(), but I doesn't work.

Do you have any idea how could I get the actual bottom of a ScrollView after adding some elements?

6
javaandroidandroid-layoutandroid-scrollview
Actually ScrollView may change or not change it's height(it is a container for LinearLayout). Try to use getBottom() of ScrollView's first(and single) child LinearLayout. – Olsavage
Both containers (ScrollView and LinearLayout) look that they have the same issue: the bottom position doesn't reflect the last added items :-/ – wikier
Post the code, where you're adding new elements. It is hard to say without your code. I think, it may be weights issue or something. – Olsavage

6 Answers

134
votes

You need to use the message queue or else it won't work. Try this:

scrollView.post(new Runnable() {
    @Override
    public void run() {
        scrollView.fullScroll(ScrollView.FOCUS_DOWN);
    }
});

This is what worked for me.

81
votes

This doesn't actually answer your question. But it's an alternative which pretty much does the same thing.

Instead of Scrolling to the bottom of the screen, change the focus to a view which is located at the bottom of the screen.

That is, Replace:

scroll.scrollTo(0, scroll.getBottom());

with:

Footer.requestFocus();

Make sure you specify that the view, say 'Footer' is focusable.

android:focusable="true"
android:focusableInTouchMode="true"
18
votes

this will be ok

scrollView.post(new Runnable() {
    @Override

    public void run() {

        scroll.scrollTo(0, scroll.getBottom());

    }
});
5
votes

Have you tried scroll.fullScroll(View.FOCUS_DOWN)?

0
votes

you can apply this also

 mScrollviewHomepage.setScrollY(View.FOCUS_DOWN);
0
votes

Since, I am also using hide keyboard, below code with a delay of 200 milli second worked better for me. Note: I just replaced post() with postDelayed() from above examples:

    final ScrollView scrollView_main = (ScrollView) findViewById(R.id.scrollView_main);
    scrollView_main.postDelayed(new Runnable() {
        @Override
        public void run() {
            scrollView_main.fullScroll(View.FOCUS_DOWN);
        }
    }, 200);