FlexboxLayoutManager did not display all items in NestedScrollView (item not displayed is hidden)

• I have searched existing issues and confirmed this is not a duplicate

Issues and steps to reproduce

Hello, I’m using a default configuration of FlexboxLayoutManager but does not able to display all items, from my log i can only receive 45/60 items (i’ve listed variations of results in ‘Expected Behavior’ column), I looked into issue 286 and 208 (and others) and it seems that they are all solved with latest version, as you can see below i’m using the latest version but i’m facing this issue, I apologized if i missed anything on my part, any suggestions and helps are really appreciated 😃, my configurations are as follows,

I’m using a default FlexboxLayoutManager such as this:

adapterCategory = new AdapterCategory(getActivity(), categories, this);
        flmCategory = new FlexboxLayoutManager(getActivity());
        rlvCategory.setAdapter(adapterCategory);
        rlvCategory.setLayoutManager(flmCategory);
        rlvCategory.setNestedScrollingEnabled(false);
        rlvCategory.getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
            @Override
            public void onGlobalLayout() {
                if (adapterCategory.holdersG.size() > 0) {
                    switchAllCategories.setChecked(true);
                    adapterCategory.setAllCategoriesTrue();
                    rlvCategory.getViewTreeObserver().removeOnGlobalLayoutListener(this);
                }
            }
        });

with a layout like this for recyclerview (rlvCategory), as you can see i’m using it under LinearLayout and NestedScrollView:

<android.support.v4.widget.NestedScrollView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="16dp">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView ... />

            <TextView ... />

            <android.support.v7.widget.RecyclerView ... />

            <RelativeLayout ... />

            <android.support.v7.widget.RecyclerView
                android:id="@+id/rlvCategory"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                tools:listitem="@layout/row_search_category" />
        </LinearLayout>
    </android.support.v4.widget.NestedScrollView>

with something like this in my item layout:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="6dp">
    <ToggleButton
        android:id="@+id/tbCategory"
        style="?attr/borderlessButtonStyle"
        android:layout_width="wrap_content"
        android:layout_height="35dp"
        android:background="@drawable/background_rounded_gray_full"
        android:paddingEnd="16dp"
        android:paddingStart="16dp"
        android:textAllCaps="false"
        android:textColor="@android:color/black"
        android:textSize="12sp" />
</RelativeLayout>

Expected behavior

I’m expecting my list to display all the items from my adapter but it does not display all of them. Currently my adapter would have 60 items and this is what i test:

• If I use flmCategory.setFlexDirection(FlexDirection.ROW);, list will display up to 45 items.

• If I use flmCategory.setFlexDirection(FlexDirection.ROW); and set a fix height and remove paddings on my item layout, list will display up to 53 items.

• If I use flmCategory.setFlexDirection(FlexDirection.COLUMN);, list will display all 60 items.

Version of the flexbox library

Im using the latest 'com.google.android:flexbox:0.3.2' version

Link to code

Please link to the code we can use to reproduce this issue. A complete project we can build/run is preferred, if you can’t provide one, please show us relevant code

[phcannessondkt]

I’ve looked into this and the issue seems to come from lines 620 - 629 in FlexboxHelper.

Commenting out this block does the trick :

if (sumCrossSize > needsCalcAmount && reachedToIndex) {
    // Stop the calculation if the sum of cross size calculated reached to the point
    // beyond the needsCalcAmount value to avoid unneeded calculation in a
    // RecyclerView.
    // To be precise, the decoration length may be added to the sumCrossSize,
    // but we omit adding the decoration length because even without the decorator
    // length, it's guaranteed that calculation is done at least beyond the
    // needsCalcAmount
    break;
}

I haven’t had the time to understand what this is supposed to optimize.

Hope this helps to solve the issue

[bakonMa]

v1.0.0, Is there a solution to this issue? the same problem I encountered?