Google Glass CardScrollView Example in Android

In this article, we will learn how to create a Google Glass CardScrollView in Android. It is a view that displays cards, or children’s views, that scroll horizontally. A custom RecyclerView is used to display a list of cards that users may scroll through when creating a card scroll view. Here is a detailed instruction.

Step-by-Step Implementation

Step 1:

Create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio as the programming language.

Step 2:

In your project’s res/layout folder, create a new XML layout file called “card_layout.xml” for the card item. Here, we’ll create a simple card layout with a TextView to display some text.

XML

<!-- card_layout.xml -->
<!-- This XML layout defines a simple
      card layout with a text view. -->
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:padding="24dp">

      <!-- This TextView displays the text
         "GeeksforGeeks" with mentioned properties -->
    <TextView
        android:id="@+id/textViewCard"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="18sp"
        android:textColor="#0F9D58"
        android:text="GeeksforGeeks" />

</LinearLayout>

Step 3:

In “activity_main.xml” add the “RecyclerView” widget .

XML

<!-- activity_main.xml -->
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

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

</LinearLayout>

Step 4:

In the MainActivity.java file , create a LinearLayoutManager with a horizontal orientation and a RecyclerView with the custom adapter in your activity or fragment.

Java

import android.app.Activity;
import android.os.Bundle;
import com.google.android.glass.widget.CardScrollView;
import com.google.android.glass.widget.CardBuilder;

public class MainActivity extends Activity {

    private CardScrollView mCardScrollView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Create a CardScrollView widget
        mCardScrollView = new CardScrollView(this);

        // Set it as the content view of your activity
        setContentView(mCardScrollView);

        // Create a CardScrollAdapter to
          // supply cards to the CardScrollView
        class MyCardAdapter extends CardScrollAdapter {
            @Override
            public int getCount() {
                // Return the number of cards
                  // that you want to display
                return 2;
            }
            @Override
            public CardBuilder getCard(int position) {
                // Create a CardBuilder object for
                  // each card that you want to display
                if (position == 0) {
                    return new CardBuilder(this).setText("Card 1");
                } else if (position == 1) {
                    return new CardBuilder(this).setText("Card 2");
                } else {
                    // Return null if the position is out of range
                    return null;
                }
            }
        }
        // Set the CardScrollView's adapter
          // to the CardScrollAdapter that you created
        mCardScrollView.setAdapter(new MyCardAdapter());
    }
}

This will set up the LinearLayoutManager.

Step 5:

Create a RecyclerView.Adapter class named “CardAdapter.java” to fill the RecyclerView with the card items.

Java

public class CardAdapter extends RecyclerView.Adapter<CardAdapter.CardViewHolder> {

      // This field stores the list of
      // cards that the adapter will display.
    private List<String> cardData;

      // This constructor initializes the adapter
      // with the specified list of cards.
    public CardAdapter(List<String> cardData) {
        this.cardData = cardData;
    }

    // This method inflates the layout for a
      // card view and returns a new CardViewHolder object.
    @Override
    public CardViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout, parent, false);
        return new CardViewHolder(view);
    }

    // This method binds the data for a card view
      // to the corresponding CardViewHolder object.
    @Override
    public void onBindViewHolder(CardViewHolder holder, int position) {
        String cardText = cardData.get(position);
        holder.textViewCard.setText(cardText);
    }

    // This method returns the number of cards in the list.
    @Override
    public int getItemCount() {
        return cardData.size();
    }

    // This static class defines a ViewHolder object that
      // stores references to the views in a card view.
    public static class CardViewHolder extends RecyclerView.ViewHolder {
        TextView textViewCard;

          // This constructor initializes the ViewHolder object
          // with the references to the views in a card view.
        public CardViewHolder(View itemView) {
            super(itemView);
            textViewCard = itemView.findViewById(R.id.textViewCard);
        }
    }
}

Above code will implement the adapter.

These steps are required to create a CardScrollView for google glass. We’ve successfully built an Android Google Glass CardScrollView. The cards will appear when the user taps on the Google Glass touchpad. The associated object will then be called after the user selects one of the cards. It is important to note that Google Glass production has been halted,but utilizing Android for different devices is worth knowing.