android mobile app development grimoire

<LinearLayout
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:keepScreenOn="true">

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="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=".SelectDeviceActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/deviceList"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.os.Bundle;

import java.util.ArrayList;
import java.util.List;
import java.util.Set;

public class SelectDeviceActivity extends AppCompatActivity {

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

        // Instantiate RecyclerView
        RecyclerView recyclerView = findViewById(R.id.deviceList);

        List<Object> deviceList = new ArrayList<>();//list with displayed objects
        

        // Setting Up RecyclerView
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        ListAdapter listAdapter = new ListAdapter(this,deviceList);
        recyclerView.setAdapter(listAdapter);


    }
}

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

    <TextView
        android:id="@+id/textItem"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <View
        android:id="@+id/divider"
        android:layout_width="409dp"
        android:layout_height="1dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="8dp"
        android:background="?android:attr/listDivider"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textItem" />
</androidx.constraintlayout.widget.ConstraintLayout>

public class DeviceInfoModel {

    private String deviceName, deviceHardwareAddress;

    public DeviceInfoModel(){}

    public DeviceInfoModel(String deviceName, String deviceHardwareAddress){
        this.deviceName = deviceName;
        this.deviceHardwareAddress = deviceHardwareAddress;
    }

    public String getDeviceName(){return deviceName;}

    public String getDeviceHardwareAddress(){return deviceHardwareAddress;}

}

import android.content.Context;
import android.content.Intent;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import androidx.recyclerview.widget.RecyclerView;

import java.util.List;

public class ListAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private Context context;
    private List<Object> deviceList;

    public static class ViewHolder extends RecyclerView.ViewHolder {
        TextView textName;

        public ViewHolder(View view){
            super(view);
            textName = view.findViewById(R.id.textItem);
        }
    }

    public ListAdapter(Context context, List<Object> deviceList){
        this.context = context;
        this.deviceList = deviceList;
    }

    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType){
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item_layout,parent,false);
        ViewHolder viewHolder = new ViewHolder(view);
        return viewHolder;
    }

    public void onBindViewHolder(RecyclerView.ViewHolder holder,int position){
        // Get Device Name and Device Address
        DeviceInfoModel deviceInfoModel = (DeviceInfoModel) deviceList.get(position);
        String deviceName = deviceInfoModel.getDeviceName();
        final String deviceAddress = deviceInfoModel.getDeviceHardwareAddress();

        // Assign Device name to the list
        ViewHolder itemHolder = (ViewHolder) holder;
        itemHolder.textName.setText(deviceName);

        // Return to Main Screen when a device is selected
        // And pass device Address information to create connection
        itemHolder.textName.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Intent intent = new Intent(context, MainActivity.class);
                intent.putExtra("deviceAddress",deviceAddress);
                context.startActivity(intent);
            }
        });

    }

    public int getItemCount(){
        int dataCount = deviceList.size();
        return dataCount;
    }

}

<set xmlns:android="http://schemas.android.com/apk/res/android"

    android:duration="2000">



    <translate

        android:fromYDelta="-20%"

        android:toYDelta="0"

        android:interpolator="@android:anim/decelerate_interpolator"

        />



    <alpha

        android:fromAlpha="0"

        android:toAlpha="1"

        android:interpolator="@android:anim/decelerate_interpolator"

        />



    <scale

        android:fromXScale="105%"

        android:fromYScale="105%"

        android:toXScale="100%"

        android:toYScale="100%"

        android:pivotX="50%"

        android:pivotY="50%"

        android:interpolator="@android:anim/decelerate_interpolator"

        />



</set>

<?xml version="1.0" encoding="utf-8"?>

<layoutAnimation

    xmlns:android="http://schemas.android.com/apk/res/android"

    android:animation="@anim/item_animation_fall_down"

    android:delay="15%"

    android:animationOrder="normal"

    />