//MainAvtivity
package com.example.media;

import android.Manifest;
import android.content.pm.PackageManager;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.media.MediaRecorder;
import android.media.audiofx.Visualizer;
import android.net.Uri;
import android.os.Handler;
import android.os.Message;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.SeekBar;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.app.ActivityCompat;

import com.example.media.R;
import com.example.media.VisualizerView;

import java.io.IOException;

public class MainActivity extends AppCompatActivity {

    Button playBtn;
    SeekBar positionBar;
    SeekBar volumeBar;
    TextView elapsedTimeLabel;
    TextView remainingTimeLabel;
    MediaPlayer mp;
    int totalTime;
    Spinner dropdown;
    final String[] items = {"music_mp3", "music_amr", "music_flac", "music_m4a", "music_m4r", "music_mp2", "music_ogg", "music_wav"};
    private Button play, stop, record;
    private MediaRecorder myAudioRecorder;
    private String outputFile;
    VisualizerView mVisualizerView;
    private Visualizer mVisualizer;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        playBtn = (Button) findViewById(R.id.playBtn);
        elapsedTimeLabel = (TextView) findViewById(R.id.elapsedTimeLabel);
        remainingTimeLabel = (TextView) findViewById(R.id.remainingTimeLabel);
        positionBar = (SeekBar) findViewById(R.id.positionBar);
        volumeBar = (SeekBar) findViewById(R.id.volumeBar);

        // Media Player
        mp = MediaPlayer.create(this, Uri.parse("android.resource://com.example.media/raw/" + items[0]));
        mp.setLooping(true);
        mp.seekTo(0);
        mp.setVolume(0.5f, 0.5f);
        totalTime = mp.getDuration();

        // Position Bar
        positionBar.setMax(totalTime);
        positionBar.setOnSeekBarChangeListener(
                new SeekBar.OnSeekBarChangeListener() {
                    @Override
                    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                        if (fromUser) {
                            mp.seekTo(progress);
                            positionBar.setProgress(progress);
                        }
                    }

                    @Override
                    public void onStartTrackingTouch(SeekBar seekBar) {

                    }

                    @Override
                    public void onStopTrackingTouch(SeekBar seekBar) {

                    }
                }
        );


        // Volume Bar
        volumeBar.setOnSeekBarChangeListener(
                new SeekBar.OnSeekBarChangeListener() {
                    @Override
                    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                        float volumeNum = progress / 100f;
                        mp.setVolume(volumeNum, volumeNum);
                    }

                    @Override
                    public void onStartTrackingTouch(SeekBar seekBar) {

                    }

                    @Override
                    public void onStopTrackingTouch(SeekBar seekBar) {

                    }
                }
        );

        // Thread (Update positionBar & timeLabel)
        new Thread(new Runnable() {
            @Override
            public void run() {
                while (mp != null) {
                    try {
                        Message msg = new Message();
                        msg.what = mp.getCurrentPosition();
                        handler.sendMessage(msg);
                        Thread.sleep(1000);
                    } catch (InterruptedException e) {
                    }
                }
            }
        }).start();

        //spinner

        dropdown = (Spinner) findViewById(R.id.spinner1);
        ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_spinner_dropdown_item, items);
        dropdown.setAdapter(adapter);
        dropdown.setSelection(0, false);
        dropdown.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                Log.d("listener", "wybrano obiekt " + id);
                // Media Player
                mp.stop();
                mp.release();
                mp = null;
                playBtn.setBackgroundResource(R.drawable.play);
                mp = MediaPlayer.create(getApplicationContext(), Uri.parse("android.resource://com.example.lab6/raw/" + items[(int) id]));
                mp.setLooping(true);
                mp.seekTo(0);
                mp.setVolume(0.5f, 0.5f);
                totalTime = mp.getDuration();

                // Position Bar
                positionBar.setMax(totalTime);

                mVisualizer.release();
                mVisualizer = null;
                mVisualizerView = null;

                mVisualizerView = (VisualizerView) findViewById(R.id.myvisualizerview);
                initAudio();

            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {

            }
        });

        mVisualizerView = (VisualizerView) findViewById(R.id.myvisualizerview);
        initAudio();

        //Recorder


        play = (Button) findViewById(R.id.play);
        stop = (Button) findViewById(R.id.stop);
        record = (Button) findViewById(R.id.record);
        stop.setEnabled(false);
        play.setEnabled(false);
        outputFile = getExternalFilesDir(null) + "/recording.mp3";
        myAudioRecorder = new MediaRecorder();
        if (ActivityCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.checkSelfPermission(this, Manifest.permission.RECORD_AUDIO)
                    != PackageManager.PERMISSION_GRANTED) {
                ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.RECORD_AUDIO},
                        10);
            }
        }
        myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
        myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
        myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.MPEG_4);
        myAudioRecorder.setOutputFile(outputFile);

        record.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (myAudioRecorder == null) {
                    myAudioRecorder = new MediaRecorder();
                    myAudioRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                    myAudioRecorder.setOutputFormat(MediaRecorder.OutputFormat.MPEG_4);
                    myAudioRecorder.setAudioEncoder(MediaRecorder.OutputFormat.MPEG_4);
                    myAudioRecorder.setOutputFile(outputFile);
                }
                try {
                    myAudioRecorder.prepare();
                    myAudioRecorder.start();
                } catch (IllegalStateException ise) {
                    Log.e("Record ERROR ise", "error");
                } catch (IOException ioe) {
                    Log.e("Record ERROR ioe", "error");
                }
                record.setEnabled(false);
                stop.setEnabled(true);
                Toast.makeText(getApplicationContext(), "Recording started", Toast.LENGTH_LONG).show();
            }
        });

        stop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                try {
                    myAudioRecorder.stop();
                } catch (RuntimeException e) {
                    Log.e("Stop recording ERROR", "error");
                } finally {
                    myAudioRecorder.release();
                    myAudioRecorder = null;
                }
                record.setEnabled(true);
                stop.setEnabled(false);
                play.setEnabled(true);
                Toast.makeText(getApplicationContext(), "Audio Recorder successfully", Toast.LENGTH_LONG).show();
            }
        });

        play.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                MediaPlayer mediaPlayer = new MediaPlayer();
                try {
                    mediaPlayer.setDataSource(outputFile);
                    mediaPlayer.prepare();
                    mediaPlayer.start();
                    Toast.makeText(getApplicationContext(), "Playing Audio", Toast.LENGTH_LONG).show();
                } catch (Exception e) {
                    Log.e("Play ERROR", "error playing recorded song");
                }
            }
        });
        Log.d("Path to output file:", outputFile);
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (isFinishing() && mp != null) {
            mVisualizer.release();
            mp.release();
            mp = null;
            myAudioRecorder.release();
            myAudioRecorder = null;
        }
    }

    private Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            int currentPosition = msg.what;
            // Update positionBar.
            positionBar.setProgress(currentPosition);

            // Update Labels.
            String elapsedTime = createTimeLabel(currentPosition);
            elapsedTimeLabel.setText(elapsedTime);

            String remainingTime = createTimeLabel(totalTime - currentPosition);
            remainingTimeLabel.setText("- " + remainingTime);
        }
    };

    public String createTimeLabel(int time) {
        String timeLabel = "";
        int min = time / 1000 / 60;
        int sec = time / 1000 % 60;

        timeLabel = min + ":";
        if (sec < 10) timeLabel += "0";
        timeLabel += sec;

        return timeLabel;
    }

    public void playBtnClick(View view) {

        if (!mp.isPlaying()) {
            // Stopping
            mp.start();
            playBtn.setBackgroundResource(R.drawable.stop);

        } else {
            // Playing
            mp.pause();
            playBtn.setBackgroundResource(R.drawable.play);
        }

    }

    private void initAudio() {
        setVolumeControlStream(AudioManager.STREAM_MUSIC);

        setupVisualizerFxAndUI();
        // Make sure the visualizer is enabled only when you actually want to
        // receive data, and
        // when it makes sense to receive data.
        mVisualizer.setEnabled(true);
        // When the stream ends, we don't need to collect any more data. We
        // don't do this in
        // setupVisualizerFxAndUI because we likely want to have more,
        // non-Visualizer related code
        // in this callback.
        mp
                .setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
                    public void onCompletion(MediaPlayer mediaPlayer) {
                        mVisualizer.setEnabled(false);
                    }
                });
    }

    private void setupVisualizerFxAndUI() {

        // Create the Visualizer object and attach it to our media player.
        mVisualizer = new Visualizer(mp.getAudioSessionId());
        mVisualizer.setCaptureSize(Visualizer.getCaptureSizeRange()[1]);
        mVisualizer.setDataCaptureListener(
                new Visualizer.OnDataCaptureListener() {
                    public void onWaveFormDataCapture(Visualizer visualizer,
                                                      byte[] bytes, int samplingRate) {
                        mVisualizerView.updateVisualizer(bytes);
                    }

                    public void onFftDataCapture(Visualizer visualizer,
                                                 byte[] bytes, int samplingRate) {
                    }
                }, Visualizer.getMaxCaptureRate() / 2, true, false);
    }
}

-------------------------------------------------------
//VisualView


package com.example.media;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.View;

public class VisualizerView extends View {

    private byte[] mBytes;
    private float[] mPoints;
    private Rect mRect = new Rect();
    private Paint mForePaint = new Paint();

    public VisualizerView(Context context) {
        super(context);
        init();
    }

    public VisualizerView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    public VisualizerView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init();
    }

    private void init() {
        mBytes = null;
        mForePaint.setStrokeWidth(1f);
        mForePaint.setAntiAlias(true);
        mForePaint.setColor(Color.rgb(0, 128, 255));
    }

    public void updateVisualizer(byte[] bytes) {
        mBytes = bytes;
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mBytes == null) {
            return;
        }
        if (mPoints == null || mPoints.length < mBytes.length * 4) {
            mPoints = new float[mBytes.length * 4];
        }
        mRect.set(0, 0, getWidth(), getHeight());
        for (int i = 0; i < mBytes.length - 1; i++) {
            mPoints[i * 4] = mRect.width() * i / (mBytes.length - 1);
            mPoints[i * 4 + 1] = mRect.height() / 2
                    + ((byte) (mBytes[i] + 128)) * (mRect.height() / 2) / 128;
            mPoints[i * 4 + 2] = mRect.width() * (i + 1) / (mBytes.length - 1);
            mPoints[i * 4 + 3] = mRect.height() / 2
                    + ((byte) (mBytes[i + 1] + 128)) * (mRect.height() / 2)
                    / 128;
        }
        canvas.drawLines(mPoints, mForePaint);
    }

}

-----------------------------------------------------------------------------------------------

// Manifest
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.RECORD_AUDIO" />


-----------------------------------------------------------------------------------------------------

XML layout


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

<LinearLayout 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="com.example.lab6.MainActivity" android:orientation="vertical" android:gravity="center_horizontal">
    <Spinner android:id="@+id/spinner1" android:layout_width="match_parent" android:layout_height="wrap_content"/>
    <SeekBar android:id="@+id/positionBar" android:layout_width="300dp" android:layout_height="wrap_content" android:layout_marginTop="30dp"/>
    <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content">
        <TextView android:id="@+id/elapsedTimeLabel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="0:11" android:layout_marginLeft="40dp"/>
        <TextView android:id="@+id/remainingTimeLabel" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="-1:49" android:layout_marginLeft="240dp"/>
    </LinearLayout>
    <Button android:id="@+id/playBtn" android:layout_width="30dp" android:layout_height="30dp" android:background="@drawable/play" android:layout_marginTop="40dp" android:onClick="playBtnClick"/>
    <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="horizontal" android:layout_marginTop="40dp" android:gravity="center">
        <ImageView android:layout_width="18dp" android:layout_height="18dp" android:src="@drawable/sound1"/>
        <SeekBar android:id="@+id/volumeBar" android:layout_width="300dp" android:layout_height="wrap_content" android:progress="50" android:max="100"/>
        <ImageView android:layout_width="26dp" android:layout_height="26dp" android:src="@drawable/sound2"/>
    </LinearLayout>
    <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Record" android:textSize="20sp" android:id="@+id/record" android:layout_centerHorizontal="true" android:layout_marginTop="15dp"/>
    <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Stop" android:textSize="20sp" android:id="@+id/stop" android:layout_below="@id/record" android:layout_marginTop="10dp" android:layout_centerHorizontal="true"/>
    <Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Play" android:textSize="20sp" android:id="@+id/play" android:layout_below="@id/stop" android:layout_marginTop="10dp" android:layout_centerHorizontal="true"/>
    <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:orientation="vertical" tools:context="com.example.androidaudiovisualizer.MainActivity">
        <com.example.lab6.VisualizerView android:id="@+id/myvisualizerview" android:layout_width="match_parent" android:layout_height="match_parent"/>
    </LinearLayout>
</LinearLayout>