Android - HorizontalScrollView - get view in focus (or index of it)

Question

I have a HorizontalScrollView containing a LinearLayout, which in turn contains a couple of FrameLayouts. Each FrameLayout contains the layout of a Fragment. Now I'm trying to get the view, i.e. FrameLayout, which is currently visible or in focus within the HorizontalScrollView. As soon as I have the view in focus I could get it's index within the LinearLayout.

I've tried the following, but nothing works:

HorizontalScrollView.findFocus() - returns null
LinearLayout.findFocus() - returns null
LinearLayout.getFocusedChild() - returns null
FrameLayout.hasFocus() - returns false for all FrameLayouts

I could also try to figure out which child of the LinearLayout has focus, by doing calculations based on current X-position of each child. However, calling getX() on each child always returns "0.0".

Does anyone have an idea how to get the view in focus (or even better it's index within the LinearLayout)?

Would you mind sharing with us why you'd want to do such thing? I'm just curious. — Zsombor Erdődy-Nagy, Apr 15 '12 at 18:07
I need to keep track which of the fragments is visible for logging purposes — Schnodahipfe, Apr 15 '12 at 19:01

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

7

Using the answer to this question: android-how-to-check-if-a-view-inside-of-scrollview-is-visible I came up with the following solution:

Rect scrollBounds = new Rect();
MyHorizontalScrollView.getDrawingRect(scrollBounds);
Rect childBounds = new Rect();      
for (int i = 0; i < MyLinearLayout.getChildCount(); i++) {
    MyLinearLayout.getChildAt(i).getHitRect(childBounds);
    if(scrollBounds.contains(childBounds)) {
        IndexOfVisibleChild = i;
        return;
    }
}

edited May 23 '17 at 12:12

Community

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answered Apr 16 '12 at 10:44

Schnodahipfe

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how can get count of child views that are currently visible for scrollbar view? – CoDe Oct 03 '12 at 10:28
any solution/suggestion here? – CoDe Jan 30 '13 at 10:00
haven't done anything with Android in ages, but if you incrementing a counter in the above if-statement should do the trick – Schnodahipfe Jun 20 '13 at 13:02

Android - HorizontalScrollView - get view in focus (or index of it)

1 Answers1