Develop Reference

How can I disable ScrollView scrolling if it's not needed?

My UI consists of a ScrollView that takes the top 50% of the screen and under that two buttons that are attached to the bottom of the screen; YES and NO. The content of Scrollview is text that for most phones does not fill up the visual area of the ScrollView. However sometimes the text can be longer, such that it fills beyond the visual area of the ScrollView, hence the reason I added the ScrollView.
My problem is this; even when the ScrollView has very little text and does not need to scroll to show all of its content it still scrolls. The user can scroll the content up a slight amount. I'd like the View to instead not allow any scrolling if all the content is visible.
Is there an easy way to achieve this? Or do I have to implement that myself?

You cannot disable the scrolling of a ScrollView. You would need to extend to ScrollView and override the onTouchEvent method to return false when some condition is matched. To get help with extending, please read the answers to Disable ScrollView Programmatically?

How to make a bi-directional RecyclerView?

I need to be able to make a bi-directional RecyclerView. Basically, it would scroll vertically, but each row would be a horizontal list of tiles that could scroll. The initial scroll position would be at the top and left. The user could scroll down, and scroll to the right with each row.
Any ideas on how to do this? (e.g. with a custom LayoutManager or touch event interception).

I was able to solve the issue using a custom view implementation.
At the root, I have a custom ScrollView; when onMeasure is called, the ScrollView tells its children how tall they should. In this case, they are half the height of the ScrollView. The width matches the height so they display as square tiles.
Each of the ScrollView children are RecyclerView's with a horizontal LinearLayoutManager. Since the ScrollView tells each child how tall to be, there's no issues with measurement and they actually scroll very well in both directions (vertically and horizontally).

Scrollview jumps/repositions when trying to scroll on a clickable child of it

I am using two (embedded) ScrollViews like suggested here, in order to create a '2D Scrollview'.
I add multiple childs to this view, and to some of them I set OnClickListener (I also tried with OnLongClickListener as well).
Functionally the result is what I have expected, although if I try to scroll (starting from a child, that has either of the listeners), the scrollview jumps/repositions to the ~opposite direction, I started the scroll to. So if I scroll like this e.g. upwards, the view jumps a big downwards so that I can scroll up at most to the original position.
I have been trying to play around with calling setFocusable(false) on the childs and setFocusable(true) on the ScrollView(s) (but also tried different permutations of it, as I am not sure about setFocusable()), but couldn't really get on top of it.. Any suggestions?

Just encase you are still wondering this is happening because when you start scrolling the other scroll view, ACTION_CANCEL is posted to the on touch method of the original ScrollView which causes a default scroll view to jump back to its original position.

Android check either scrollview is scrollable or not

In my app I have a scroll view with n number of data to be listed out. There are two buttons one is named as UP placed above scroll view and the other is DOWN placed below scroll view.
Using the UP and DOWN buttons the list of views can be scrolled.
When the scroll bar is in top the Up button will be invisible and when the scroll bar reaches the bottom the DOWN button will become invisible, I have written logic for this using the getScrollX() method.
Now my problem is when there is very few data for example 3, the scroll bar will not be visible and the layout cannot be scrolled, in such a case both the UP and DOWN buttons need to be in invisible. How to do this, please suggest me a way?

You can try and use a ViewTreeObserver to check the dimension of the View inside your ScrollView. If the dimension exceeds a certain limit (such as the screen size), the ScrollView will be scrollable. See this preview SO answer for more details. Hope that helps!

Is it possible to have a ScrollView inside another ScrollView?

I want to learn how to solve this problem. I want to have a Horizontal scrollview with the scroll blocked (the user should not be able to scroll it) and inside that horizontal scrollview i want to have another horizontal scroll view, and this scrollview must be able to be scrolled by the user (it haves more content that the width of the screen).
Is it possible to do it?
I tried using this on the parent horizontal scroll view:
((HorizontalScrollView) view).setHorizontalScrollBarEnabled(false);
((HorizontalScrollView) view).setEnabled(false);
((HorizontalScrollView) view).setFocusable(false);
((HorizontalScrollView) view).setFocusableInTouchMode(false);
and this on the child horizontal scroll view:
((HorizontalScrollView) view).requestFocus();
It is not working, the child appears to have a scroll bar, but it cannot be scrolled.
How can this be solved?
PD: I know that this is not a good practice, but I want to learn how to achieve this goal.

You should never use a
HorizontalScrollView with a ListView,
since ListView takes care of its own
scrolling. Most importantly, doing
this defeats all of the important
optimizations in ListView for dealing
with large lists, since it effectively
forces the ListView to display its
entire list of items to fill up the
infinite container supplied by
HorizontalScrollView.
http://developer.android.com/reference/android/widget/HorizontalScrollView.html
UPDATE:
Since you may be forced to use a two dimensional scrollview, you may consider using this:
http://blog.gorges.us/2010/06/android-two-dimensional-scrollview/
I haven't used this but it may be a reasonable approach.

you can do it. But you have to handle child layouts in scrollview i.e ScrollView can host only one direct child.