Horizontal RecyclerView with dynamic item’s Height

Question

I’m trying to implement a RecyclerView with horizontal scrolling, so I’m using this a LinearLayoutManager with horizontal orientation. The problem is that I’m populating the RecyclerView using 2 different types of items, with different heights. This is the layout I’m using for the item:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
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="wrap_content"
android:layout_height="wrap_content"
android:layout_marginEnd="10dp">

<LinearLayout
    android:id="@+id/document_view"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:background="@drawable/ic_rounded"
    android:backgroundTint="@color/ms_black_ms_gray"
    android:gravity="center"
    android:layout_gravity="bottom"
    android:padding="5dp"
    android:paddingStart="15dp">

    <TextView
        android:id="@+id/name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/white"
        android:textSize="13sp"
        android:singleLine="true"
        android:maxWidth="80dp"
        tools:text="example_form"/>

    <TextView
        android:id="@+id/format"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textColor="@color/white"
        android:textSize="13sp" />

    …
</LinearLayout>

<android.support.v7.widget.CardView
    android:id="@+id/image_view"
    android:layout_width="120dp"
    android:layout_height="80dp"
    android:layout_gravity="bottom"
    app:cardCornerRadius="25dp"
    app:cardElevation="0dp">

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

        <ImageView
            android:id="@+id/preview_image"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="fitXY"/>

        …

    </RelativeLayout>
</android.support.v7.widget.CardView>

and this is the layout that contains the RecyclerView, which is basically like this:

<LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        android:paddingStart="14dp"
        android:paddingEnd="14dp">

        <ImageView
            android:id="@+id/attach"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:layout_gravity="bottom"
            android:layout_marginBottom="19dp"
            android:visibility="visible"/>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="5dp"
            android:layout_marginBottom="10dp"
            android:layout_marginTop="5dp"
            android:padding="3dp"
            android:foreground="@drawable/ic_rounded_stroke"
            android:foregroundTint="@color/white">
            <android.support.constraint.ConstraintLayout
                android:id="@+id/chatEdit"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:background="@drawable/ic_rounded"
                android:foreground="@drawable/ic_rounded_stroke"
                android:padding="6dp"
                android:visibility="visible">

                <EditText
                    android:id="@+id/editText"
                    android:textSize="17sp"
                    android:textColor="#121212"
                    android:letterSpacing="-0.02"
                    android:lineSpacingExtra="0sp"
                    android:padding="10dp"
                    android:paddingStart="15dp"
                    android:layout_width="0dp"
                    android:layout_height="wrap_content"
                    android:maxLines="5"
                    android:hint="@string/chat_hint"
                    android:inputType="textCapSentences|textMultiLine"
                    android:maxLength="2500"
                    android:background="@null"
                    app:layout_constraintRight_toLeftOf="@id/buttonsContainer"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toTopOf="parent" />


                    <TextView
                        android:id="@+id/send"
                        android:layout_gravity="bottom"
                        android:visibility="visible"
                        android:paddingLeft="15dp"
                        android:paddingRight="15dp"
                        android:paddingBottom="10dp"
                        android:paddingTop="8dp"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:textSize="18sp"
                        android:textColor="#ffffff"
                        android:letterSpacing="-0.02"
                        android:gravity="center_horizontal"
                        android:text="@string/send"
                        app:layout_constraintRight_toRightOf="parent"
                        app:layout_constraintBottom_toBottomOf="parent"
                        />

                <android.support.v7.widget.RecyclerView
                    android:id="@+id/filesList"
                    android:layout_width="0dp"
                    android:layout_height="match_parent"
                    android:layout_marginTop="10dp"
                    android:paddingTop="5dp"
                    android:paddingEnd="5dp"
                    android:visibility="gone"
                    app:layout_constraintRight_toLeftOf="@id/send"
                    app:layout_constraintLeft_toLeftOf="parent"
                    app:layout_constraintTop_toBottomOf="@id/editText"
                    app:layout_constraintBottom_toBottomOf="parent"/>
            </android.support.constraint.ConstraintLayout>
        </LinearLayout>
    </LinearLayout>

I’m using a single ViewHolder, I just change the visibility of the 2 child views.

The result I expect to get is this one:

But what I’m getting is this; the CardView being cut in half, using the height of the second type of item:

I saw this post, which is similar to my problem. It recommends using Google’s Flexbox. So, I tried to implement FlexboxLayoutManager:

FlexboxLayoutManager layoutManager = new FlexboxLayoutManager(getContext());
layoutManager.setFlexDirection(FlexDirection.ROW);
layoutManager.setFlexWrap(FlexWrap.NOWRAP);

I’m using row direction and It is showing items on next lines if it does not fit in single line. So, I also added No_wrap. And now it is showing items in a single line but do not provide scrolling. Also in this case it tries to fit all items in a single line by decreasing width of items.

I also played with the flex box sample app, but I couldn’t get the result I want.

Is there a way I can achieve horizontal scrolling with the Flexbox integrated with RecyclerView? Or should I use a different approach?

Thanks

EDIT

Thanks for the tips and everything, but it is not solving it. So, I stripped down the code to bare minimum to reproduce this.

MainActivity:

public class MainActivity extends AppCompatActivity {

private static final int REQUEST_CODE = 1;

private RecyclerView recyclerView;
private FilesAdapter filesAdapter;
private List<File> filesList = new ArrayList<>();

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    recyclerView = findViewById(R.id.recyclerView);
    LinearLayoutManager filesLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
    recyclerView.setLayoutManager(filesLayoutManager);
    filesAdapter = new FilesAdapter(filesList);
    recyclerView.setAdapter(filesAdapter);

    ImageView attach = findViewById(R.id.attach);
    attach.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent();
            intent.setType("*/*");
            intent.addCategory(Intent.CATEGORY_OPENABLE);
            intent.setAction(Intent.ACTION_GET_CONTENT);
            intent.putExtra(Intent.EXTRA_ALLOW_MULTIPLE, true);
            startActivityForResult(Intent.createChooser(intent,"Select Files"), REQUEST_CODE);
        }
    });
}

@Override
protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
    if (requestCode == REQUEST_CODE && resultCode == RESULT_OK) {
        try {
            if (data != null) {
                List<File> uriList = new ArrayList<>();
                if (data.getClipData() != null) { // Multiple files
                    for (int i = 0; i < data.getClipData().getItemCount(); i++) {
                        Uri uri = data.getClipData().getItemAt(i).getUri();
                        Pair<Boolean, File> isValid = isFileValid(uri);
                        if (isValid.first) {
                            uriList.add(isValid.second);
                        }
                    }
                } else { // Single file
                    Uri uri = data.getData();
                    Pair<Boolean, File> isValid = isFileValid(uri);
                    if (isValid.first) {
                        uriList.add(isValid.second);
                    }
                }

                if (uriList.size() > 0) {
                    for (File file : uriList) {
                        filesList.add(filesList.size(), file);
                        filesAdapter.notifyItemInserted(filesList.size());
                    }
                }
            }
        } catch (Throwable e) {
            e.printStackTrace();
        }
    }
    super.onActivityResult(requestCode, resultCode, data);
}

private Pair<Boolean, File> isFileValid(Uri uri) throws NullPointerException {
    Pair<Boolean, File> defaultResponse = Pair.create(false, null);
    Cursor c = getContentResolver().query(uri, null, null, null, null);
    if (c != null) {
        c.moveToFirst();

        String filename = c.getString(c.getColumnIndex(OpenableColumns.DISPLAY_NAME));

        if (isSupported(filename)) {
            c.close();
            return Pair.create(true, new File(StringUtils.endsWithIgnoreCase(filename, ".pdf") ? DOCUMENT : IMAGE));
        } else {
            Toast.makeText(this, "File format not supported", Toast.LENGTH_SHORT).show();
            c.close();
            return defaultResponse;
        }
    }
    return defaultResponse;
}

private boolean isSupported(String filename) {
    String[] supportedFormats = { ".pdf", ".jpg", ".gif", ".png" };

    for (String format : supportedFormats) {
        if (StringUtils.endsWithIgnoreCase(filename, format)) {
            return true;
        }
    }
    return false;
}
}

Main activity layout:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="bottom"
android:orientation="vertical"
tools:context=".MainActivity">

   <androidx.recyclerview.widget.RecyclerView
   android:id="@+id/recyclerView"
   android:layout_width="match_parent"
   android:layout_height="wrap_content" />

<ImageView
    android:id="@+id/attach"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|center"
    android:layout_marginBottom="19dp"
    android:padding="10dp"
    android:src="@drawable/ic_attach" />
</LinearLayout>

File:

public class File {

public enum Type {
    DOCUMENT,
    IMAGE
}

private Type type;

public File(Type type) {
    this.type = type;
}

public Type getType() {
    return type;
}
}

File Adapter:

public class FilesAdapter extends RecyclerView.Adapter<FilesAdapter.BaseViewHolder> {

private List<File> files;

public FilesAdapter(List<File> files) {
    this.files = files;
}

@NonNull
@Override
public FilesAdapter.BaseViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(parent.getContext()).inflate(viewType == 0 ? R.layout.document_item : R.layout.image_item, parent, false);
    if (viewType == 0) {
        return new DocumentViewHolder(view);
    } else {
        return new ImageViewHolder(view);
    }
}

@Override
public void onBindViewHolder(@NonNull FilesAdapter.BaseViewHolder viewHolder, int position) {
    viewHolder.bind(files.get(position));
}

@Override
public int getItemViewType(int position) {
    if (files.get(position).getType() == File.Type.DOCUMENT) {
        return 0;
    } else {
        return 1;
    }
}

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

abstract static class BaseViewHolder extends RecyclerView.ViewHolder {
    public BaseViewHolder(@NonNull View itemView) {
        super(itemView);
    }
    abstract void bind(File file);
}

static class ImageViewHolder extends BaseViewHolder {

    public ImageViewHolder(@NonNull View itemView) {
        super(itemView);
    }

    @Override
    void bind(File file) { }
}

static class DocumentViewHolder extends BaseViewHolder {

    public DocumentViewHolder(@NonNull View itemView) {
        super(itemView);
    }

    public void bind(File file) { }
}
}

document item:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="150dp"
android:layout_height="40dp"
android:background="@drawable/ic_rounded"
android:backgroundTint="#888888"
android:layout_margin="5dp">

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:gravity="center"
    android:text="PDF"
    android:textColor="@android:color/white"/>

</LinearLayout>

image item:

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="120dp"
android:layout_height="80dp"
android:layout_margin="5dp"
app:cardBackgroundColor="#000000"
app:cardCornerRadius="10dp"
app:cardElevation="0dp">

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    android:gravity="center"
    android:text="IMAGE"
    android:textColor="@android:color/white"/>

</androidx.cardview.widget.CardView>

if I select an image first, and the several pdfs, it works fine:

But if I first select 3 pdfs, and then an image, this happens:

Any idea how to solve this?

Answer 1

I had a similar issue in another project and i solved it by using the Google library FlexboxLayoutManager.

1. Get the latest FlexboxLayoutManager Library (https://github.com/google/flexbox-layout) and add it into your grandle dependencies (implementation 'com.google.android:flexbox:2.0.1')
2. In your Activity add the below lines of code:

   FlexboxLayoutManager layoutManager = new FlexboxLayoutManager(this); 
    layoutManager.setFlexDirection(FlexDirection.ROW);
    layoutManager.setFlexWrap(FlexWrap.NOWRAP);
    recyclerView.setLayoutManager(layoutManager);

3. To make FlexboxLayoutManager work with horizontal scroll add the below code in your adapter (FilesAdapter) in BaseViewHolder class:

   abstract static class BaseViewHolder extends RecyclerView.ViewHolder {
        public BaseViewHolder(@NonNull View itemView) {
            super(itemView);
            ViewGroup.LayoutParams lp = itemView.getLayoutParams();
            if (lp instanceof FlexboxLayoutManager.LayoutParams) {
                FlexboxLayoutManager.LayoutParams flexboxLp = (FlexboxLayoutManager.LayoutParams) lp;
                flexboxLp.setFlexShrink(0.0f);
                flexboxLp.setAlignSelf(AlignItems.FLEX_START); //this will align each itemView on Top or use AlignItems.FLEX_END to align it at Bottom
            }
        }
        abstract void bind(File file);
    }

Answer 2

In case it helps anyone else, Kotlin version of MariosP's answer with minor refactors below, but 100% kudos to @MariosP. His answer saved the day for us!

RecyclerView setup (this was from a fragment, called in onViewCreated):

private fun setupRecyclerView() {
    val flexBoxLayoutManager = FlexboxLayoutManager(requireContext(), FlexDirection.ROW, FlexWrap.NOWRAP)
    with(recycler_view) {
        layoutManager = flexBoxLayoutManager
        adapter = myAdapter
    }
}

Adapter setup:

var items : List<Item>

override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
    holder.bindItem(items[position])
}

In the ViewHolder:

class MyViewHolder(private val itemView: View): RecyclerView.ViewHolder(itemView) {

    fun bindItem(item: Item) {
        // Do things with item
        updateLayoutParamsToAllowHorizontalScrolling()
    }

    private fun updateLayoutParamsToAllowHorizontalScrolling() {
        (itemView.layoutParams as? FlexboxLayoutManager.LayoutParams)?.let {
            it.flexShrink = 0.0f
            it.alignSelf = AlignItems.FLEX_START
        }
    }

}