Empty space at the bottom

[taweewong]

I just try version 3.0.2 when I scroll down to the bottom I found an empty space like this

I also add items at the start to show that empty space is still at the bottom

What I want to ask is, is this normal or I just did something wrong?

Setup layout

val layoutManager = SpannedGridLayoutManager(SpannedGridLayoutManager.Orientation.VERTICAL, 4)
        layoutManager.spanSizeLookup = SpannedGridLayoutManager.SpanSizeLookup { position ->
            when (position) {
                0 -> SpanSize(4, 2)
                1, 2 -> SpanSize(2, 2)
                else -> SpanSize(1, 1)
            }
        }
layoutManager.itemOrderIsStable = true

MainActivity's layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".MainActivity">

    <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="0dp"
            android:layout_height="0dp"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>

Item's layout

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    xmlns:tools="http://schemas.android.com/tools">

    <android.support.constraint.ConstraintLayout
        android:id="@+id/item_layout_bg"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintDimensionRatio="H,1:1">

        <TextView
                android:id="@+id/item_layout_text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                tools:text="TEST"/>

    </android.support.constraint.ConstraintLayout>

</android.support.constraint.ConstraintLayout>

[manfcas]

It is an overscroll issue, it happens in horizontal mode too. I think there is some error in the scrollBy method and, more specifically, in how the end value is computed (the overscroll seems to be exactly one extra span).

[dsolgalov]

Dear @manfcas,
do you have any news regarding the issue fixing?
I have the latest version 3.0.2 and I faced with the same bug.

Please recommend any suitable workaround if possible.

Thanks in advance,
Dmitry

[manfcas]

Try to override the scrollBy method and replace the line:

val end = layoutEnd + rectsHelper.itemSize + paddingEndLayout

with:

        var end = 0
        for (i in (state.itemCount - 1) downTo 0) {
            val rect = childFrames[state.itemCount - 1]
            if (rect != null) {
                end = rect.right + paddingEndLayout
                break
            }
        }

and the line:

if (scroll + size > end && (firstVisiblePosition + childCount + spans) >= state.itemCount) {

with:

if (end != 0 && scroll + size > end && (firstVisiblePosition + childCount + spans) >= state.itemCount) {

and let me know.