How to disable overscroll effect on RecyclerView ONLY when you can't scroll anyway ?

Question

Background

Sometimes, all items of the recyclerView are already visible to the user.

In this case, it wouldn\'t matter to the user to see overscroll effect, be

Answer 1

Longer workaround, based on here (to solve this issue), handles more cases, but still a workaround:

/**a temporary workaround to make RecyclerView handle android:overScrollMode="ifContentScrolls"  */
class NoOverScrollWhenNotNeededRecyclerView : RecyclerView {
    private var enableOverflowModeOverriding: Boolean? = null
    private var isOverFlowModeChangingAccordingToSize = false

    constructor(context: Context) : super(context)
    constructor(context: Context, attrs: AttributeSet?) : super(context, attrs)
    constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(context, attrs, defStyleAttr)

    override fun setOverScrollMode(overScrollMode: Int) {
        if (!isOverFlowModeChangingAccordingToSize)
            enableOverflowModeOverriding = overScrollMode == View.OVER_SCROLL_IF_CONTENT_SCROLLS
        else isOverFlowModeChangingAccordingToSize = false
        super.setOverScrollMode(overScrollMode)
    }

    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
        super.onLayout(changed, l, t, r, b)
        if (enableOverflowModeOverriding == null)
            enableOverflowModeOverriding = overScrollMode == View.OVER_SCROLL_IF_CONTENT_SCROLLS
        if (enableOverflowModeOverriding == true) {
            val canScrollVertical = computeVerticalScrollRange() > height
            val canScrollHorizontally = computeHorizontalScrollRange() > width
            isOverFlowModeChangingAccordingToSize = true
            overScrollMode = if (canScrollVertical || canScrollHorizontally) OVER_SCROLL_ALWAYS else OVER_SCROLL_NEVER
        }
    }
}

Answer 2

<android.support.v7.widget.RecyclerView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:overScrollMode="never"/>

Just add android:overScrollMode="never" in XML

Answer 3

Since android:overScrollMode="ifContentScrolls" is not working for RecyclerView(see https://issuetracker.google.com/issues/37076456) I found some kind of a workaround which want to share with you:

class MyRecyclerView @JvmOverloads constructor(
context: Context, attrs: AttributeSet? = null, defStyleAttr: Int = 0
) : RecyclerView(context, attrs, defStyleAttr) {

    override fun onLayout(changed: Boolean, l: Int, t: Int, r: Int, b: Int) {
        super.onLayout(changed, l, t, r, b)
        val canScrollVertical = computeVerticalScrollRange() > height
        overScrollMode = if (canScrollVertical) OVER_SCROLL_ALWAYS else OVER_SCROLL_NEVER
    }
}

Answer 4

you could give OVER_SCROLL_IF_CONTENT_SCROLLS a try. Accordingly to the documentation

Allow a user to over-scroll this view only if the content is large enough to meaningfully scroll, provided it is a view that can scroll.

Or you could check if you have enough items to trigger the scroll and enable/disable the over scroll mode, depending on it. Eg

boolean notAllVisible = layoutManager.findLastCompletelyVisibleItemPosition() < adapter.getItemCount() - 1;
if (notAllVisible) {
   recyclerView.setOverScrollMode(allVisible ? View.OVER_SCROLL_NEVER);
}

Answer 5

You could try something like this:

totalItemCount = linearLayoutManager.getItemCount();
firstVisibleItem = linearLayoutManager.findFirstCompletelyVisibleItemPosition()
lastVisibleItem = linearLayoutManager.findLastCompletelyVisibleItemPosition();

if(firstVisibleItem == 0 && lastVisibleItem -1 == totalItemCount){
    // trigger the overscroll effect
}

Which you could add in the onScrolled() of an OnScrollListener that you add on your RecyclerView.