How to use RecyclerView.scrollToPosition() to move the position to the top of current view?
AndroidScrollAndroid RecyclerviewAndroid Problem Overview
The RecyclerView.scrollToPosition()
is extremely strange.
for example, supposed a RecyclerView
named "rv"
.
-
if now item 10 is under the current
RecyclerView
, callrv.scrollToPosition(10)
, theRecyclerView
will scroll item 10 to bottom. -
if now item 10 is in the current
RecyclerView
, callrv.scrollToPosition(10)
, there won't be any scrolling, nothing will be done. -
if now item 10 is on the top of the current
RecyclerView
, callrv.scrollToPosition(10)
, theRecyclerView
will scroll item 10 to top.
To help understanding, look at this picture
But what i need is that, whenever i call it, the RecyclerView
will scroll the supposed position to the top of current view just like case 3. How to do that?
Android Solutions
Solution 1 - Android
If I understand the question, you want to scroll to a specific position but that position is the adapter's position and not the RecyclerView
's item position.
You can only achieve this through the LayoutManager
.
Do something like:
rv.getLayoutManager().scrollToPosition(youPositionInTheAdapter).
Solution 2 - Android
Below link might solve your problem:
https://stackoverflow.com/a/43505830/4849554
Just create a SmoothScroller with the preference SNAP_TO_START:
RecyclerView.SmoothScroller smoothScroller = new
LinearSmoothScroller(context) {
@Override protected int getVerticalSnapPreference() {
return LinearSmoothScroller.SNAP_TO_START;
}
};
Now you set the position where you want to scroll to:
smoothScroller.setTargetPosition(position);
And pass that SmoothScroller to the LayoutManager:
layoutManager.startSmoothScroll(smoothScroller);
Solution 3 - Android
If you want to scroll to a specific position and that position is the adapter's position, then you can use StaggeredGridLayoutManager
scrollToPosition
StaggeredGridLayoutManager staggeredGridLayoutManager = new StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL);
staggeredGridLayoutManager.scrollToPosition(10);
recyclerView.setLayoutManager(staggeredGridLayoutManager);
Solution 4 - Android
This is the Kotlin code snippet but you can just get the point for scrolling to the item by position properly. The point is to declare the member variable for the layout manager and use its method to scroll.
lateinit var layoutManager: LinearLayoutManager
fun setupView() {
...
layoutManager = LinearLayoutManager(applicationContext)
mainRecyclerView.layoutManager = layoutManager
...
}
fun moveToPosition(position: Int) {
layoutManager.scrollToPositionWithOffset(position, 0)
}
Solution 5 - Android
try recycler_view.smoothScrollBy(0, 100);
here 0 represents x-coordinate
and 100 represents y-coordinate
I used this in vertical recyclerView where I wanted to scroll to next position in the vertical list and for coming to the previous position I simply replaced 100 with -100