Scroll ScrollView to middle

Question

I'm trying to scroll in Android a HorizontalScrollView programmatically.

However I just found this method:

scroll.fullScroll(View.FOCUS_DOWN)

And I'm looking forward to scroll the view to exactly the middle.

Any tip?

I know that there's a method to scroll to an exact position: setScrollX but the parameter should be calculated somehow I don't know.

Alexis C. · Answer 1 · 2013-09-24T14:28:40.030

7

You could use scrollTo and scroll it by getting the y bottom coordinate divided by 2.

myScrollView.scrollTo(0, myScrollView.getBottom()/2);

For an horizontal scroll view :

myScrollView.scrollTo(widthOfScrollView/2, 0);

edited Sep 24 '13 at 14:28

answered Sep 24 '13 at 13:43

Alexis C.

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I'm looking for HorizontalScrollView. This is for a vertical. – Reinherd Sep 24 '13 at 14:09
@SergiCastellsaguéMillán You can also use scrollTo but with `getRight()` on the x coordinate. Does it works ? – Alexis C. Sep 24 '13 at 14:15
1

No. This is my code `HorizontalScrollView scrollViewSplash = (HorizontalScrollView) this.findViewById(R.id.scrollViewSplash); scrollViewSplash.scrollTo(scrollViewSplash.getRight()/2, 0);` – Reinherd Sep 24 '13 at 14:25
May look a this post http://stackoverflow.com/questions/7635903/get-maximum-horizontalscrollview-scroll-amount and try to get the width of the scroll view. – Alexis C. Sep 24 '13 at 14:28

score 3 · Answer 2 · answered Aug 16 '18 at 06:42

This is an old question but I found the other answers didn't work for me. The following worked well.

val vto = viewTreeObserver
vto.addOnGlobalLayoutListener(object : ViewTreeObserver.OnGlobalLayoutListener {
    override fun onGlobalLayout() {
        val maxScroll = scrollView.getChildAt(0).width - scrollView.width
        scrollView.scrollTo(maxScroll / 2, 0)

        viewTreeObserver.removeOnGlobalLayoutListener(this)
    }
})

score 2 · Accepted Answer · answered Sep 25 '13 at 07:35

2

ViewTreeObserver vto = scroll.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
    public void onGlobalLayout() {
         scroll.scrollTo(scroll.getChildAt(0).getWidth()/2, 0);
    }
});

This is working!

answered Sep 25 '13 at 07:35

Reinherd

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score 1 · Answer 4 · answered Jun 25 '20 at 13:51

1

Here's an easy way to do it in Kotlin without using a OnGlobalLayoutListener, where wideView is the view within the ScrollView.

wideView.apply { post { scrollView.scrollTo((left + right - scrollView.width) / 2, 0) } }

answered Jun 25 '20 at 13:51

scottt

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Scroll ScrollView to middle

4 Answers4