Large gap forms between RecyclerView items when scrolling down

PlanetAstro_William picture PlanetAstro_William · Mar 5, 2016 · Viewed 30.1k times · Source

I'm making a ToDo list app, and while testing it, for some reason, a huge gap forms between the items whenever I try to scroll down. It always happens whenever I Drag and Drop the items, but I don't see any errors with my ItemTouchHelper adapter and callback class. It would be awesome if you can help me out.

Before: Before

After: After

RecyclerAdapter.java

public class RecyclerAdapter extends                                                                                                                                 

RecyclerView.Adapter<RecyclerAdapter.RecyclerVH> implements ItemTouchHelperAdapter{
private LayoutInflater layoutInflater;
ArrayList<Info> data;
Context context;

public RecyclerAdapter(Context context) {
    layoutInflater = LayoutInflater.from(context);
    this.context = context;
}

public void setData(ArrayList<Info> data) {
    this.data = data;
    notifyDataSetChanged();
}

@Override
public RecyclerVH onCreateViewHolder(ViewGroup viewGroup, int position) {
    View view = layoutInflater.inflate(R.layout.custom_row, viewGroup, false);
    view.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Log.d("R.A onClick Owen", "onClick method triggered");
        }
    });
    RecyclerVH recyclerVH = new RecyclerVH(view);
    return recyclerVH;
}

@Override
public void onBindViewHolder(RecyclerVH recyclerVH, int position) {
    Log.d("RecyclerView", "onBindVH called: " + position);

    final Info currentObject = data.get(position);
    // Current Info object retrieved for current RecyclerView item - USED FOR DELETE
    recyclerVH.listTitle.setText(currentObject.title);
    recyclerVH.listContent.setText(currentObject.content);

    /*recyclerVH.listTitle.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Open new Activity containing note content
            Toast.makeText(this, "Opening: " + currentObject.title, Toast.LENGTH_LONG).show();
        }
    });*/
}

public void deleteItem(int position) {
    DBInfo dbInfo = new DBInfo(context);
    dbInfo.deleteNote(data.get(position));
    // Deletes RV item/position's Info object

    data.remove(position);
    // Removes Info object at specified position

    notifyItemRemoved(position);
    // Notifies the RV that item has been removed
}


@Override
public int getItemCount() {
    return data.size();
}

// This is where the Swipe and Drag-And-Drog methods come into place
@Override
public boolean onItemMove(int fromPosition, int toPosition) {
    // Swapping positions
    // ATTEMPT TO UNDERSTAND WHAT IS GOING ON HERE
    Collections.swap(data, fromPosition, toPosition);
    notifyItemMoved(fromPosition, toPosition);
    return true;
}

@Override
public void onItemDismiss(int position) {
    // Deleting item from RV and DB
    deleteItem(position);
}

class RecyclerVH extends RecyclerView.ViewHolder implements View.OnClickListener{
    // OnClickListener is implemented here
    // Can also be added at onBindViewHolder above
    TextView listTitle, listContent;

    public RecyclerVH(View itemView) {
        super(itemView);

        listTitle = (TextView) itemView.findViewById(R.id.title);
        listContent = (TextView) itemView.findViewById(R.id.content);

        listTitle.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Toast.makeText(context, "Opening: Note" + getLayoutPosition(), Toast.LENGTH_SHORT).show();
        // PS NEVER ADD listTitle VARIABLE AS PUBLIC VARIABLE ABOVE WHICH IS GIVEN VALUE AT ONBINDVH
        // THIS IS BECAUSE THE VALUE WILL CHANGE IF ITEM IS ADDED OR DELETED
    }
}
}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:fab="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:orientation="vertical"
android:weightSum="1">

<android.support.v7.widget.Toolbar
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/rounded_corners" />

<FrameLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

    <RelativeLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent">

        <com.melnykov.fab.FloatingActionButton
            android:id="@+id/fab_add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:layout_alignParentRight="true"
            android:layout_alignParentEnd="true"
            android:layout_marginBottom="16dp"
            android:layout_marginRight="16dp"
            android:layout_marginEnd="16dp"
            android:gravity="bottom|end"
            android:onClick="addNote"
            android:src="@drawable/fab_ic_add"
            fab:fab_colorNormal="@color/colorPrimary"
            fab:fab_colorPressed="@color/colorPrimaryDark"
            fab:fab_colorRipple="@color/colorPrimaryDark" />
    </RelativeLayout>
</FrameLayout>
</LinearLayout>

custom_row.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">

<LinearLayout
    android:id="@+id/main"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:padding="8dp"
        android:text="@string/test"
        android:textSize="18sp"
        android:textStyle="bold" />
</LinearLayout>
<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/main"
    android:paddingLeft="8dp">
    <TextView
        android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/test"
        android:textSize="15sp" />
</LinearLayout>
</RelativeLayout>

Thank you so much to whoever can help me out. I am pulling my hair out as I type.

EDIT: I have confirmed that it is not my ItemTouchHelper class that's the problem. (Tried running without it being called, problem still occurs.) Also, it seems that when a dialog is shown and the keyboard brought up, the RecyclerView in the background resolves the problem by itself. After dialog is removed, the problem repeats (i.e. Scrolling puts massive space between items)

Answer

PlanetAstro_William picture PlanetAstro_William · Mar 6, 2016

Luksprog's answer to Gabriele Mariotti's answer works.

According to the doc

With the release 2.3.0 there is an exciting new feature to the LayoutManager API: auto-measurement! This allows a RecyclerView to size itself based on the size of its contents. >This means that previously unavailable scenarios, such as using WRAP_CONTENT >for a dimension of the RecyclerView, are now possible. You’ll find all built in LayoutManagers now support auto-measurement.

Due to this change, make sure to double check the layout parameters of your item views: previously ignored layout parameters (such as MATCH_PARENT in the scroll direction) will now be fully respected.

In your item layout you have to change:

android:layout_height="match_parent"

with

android:layout_height="wrap_content"