Added lots of visualizer code.

app/src/main/AndroidManifest.xml

@@ -2,6 +2,9 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
           package="com.ambergleam.visualizer">
 
+    <uses-permission android:name="android.permission.RECORD_AUDIO"/>
+    <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
+
     <application
         android:allowBackup="true"
         android:icon="@drawable/ic_launcher"

app/src/main/java/com/ambergleam/visualizer/AudioPlayer.java

@@ -0,0 +1,62 @@
+package com.ambergleam.visualizer;
+
+import android.content.Context;
+import android.media.MediaPlayer;
+
+public class AudioPlayer extends MediaPlayer {
+
+    private MediaPlayer mPlayer;
+
+    public enum STATE {
+        PLAYING,
+        PAUSED,
+        STOPPED
+    }
+
+    private int mLength;
+    private STATE mState;
+
+    public AudioPlayer() {
+        mState = STATE.STOPPED;
+    }
+
+    public void play(Context c, int id) {
+        stop();
+
+        mState = STATE.PLAYING;
+        mPlayer = MediaPlayer.create(c, id);
+        mPlayer.setOnCompletionListener(new MediaPlayer.OnCompletionListener() {
+            @Override
+            public void onCompletion(MediaPlayer mp) {
+                stop();
+            }
+        });
+
+        mPlayer.start();
+    }
+
+    public void pause() {
+        mState = STATE.PAUSED;
+        mPlayer.pause();
+        mLength = mPlayer.getCurrentPosition();
+    }
+
+    public void stop() {
+        mState = STATE.STOPPED;
+        if (mPlayer != null) {
+            mPlayer.release();
+            mPlayer = null;
+        }
+    }
+
+    public void resume() {
+        mState = STATE.PLAYING;
+        mPlayer.seekTo(mLength);
+        mPlayer.start();
+    }
+
+    public STATE getState() {
+        return mState;
+    }
+
+}

app/src/main/java/com/ambergleam/visualizer/SingleFragmentActivity.java

@@ -26,4 +26,4 @@ protected void onCreate(Bundle savedInstanceState) {
         }
     }
 
-}
+}

app/src/main/java/com/ambergleam/visualizer/VisualizerActivity.java

@@ -9,4 +9,4 @@ protected Fragment createFragment() {
         return new VisualizerFragment();
     }
 
-}
+}

app/src/main/java/com/ambergleam/visualizer/VisualizerFragment.java

@@ -1,60 +1,113 @@
 package com.ambergleam.visualizer;
 
-import android.animation.AnimatorSet;
-import android.animation.ObjectAnimator;
-import android.annotation.TargetApi;
-import android.os.Build;
+import android.media.AudioManager;
+import android.media.audiofx.Visualizer;
 import android.os.Bundle;
 import android.support.v4.app.Fragment;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
-import android.view.animation.AccelerateInterpolator;
+import android.widget.ImageButton;
+import android.widget.LinearLayout;
 
-import java.util.Random;
+import com.ambergleam.visualizer.AudioPlayer.STATE;
 
 public class VisualizerFragment extends Fragment {
 
-    private static Random sRandom = new Random();
-    private AnimatorSet mAnimatorSet;
+    private static final float VISUALIZER_HEIGHT_DIP = 50f;
 
-    private View mOrbView;
-    private int orb_x;
-    private int orb_y;
+    private AudioPlayer mAudioPlayer;
+    private Visualizer mVisualizer;
+
+    private LinearLayout mFrame;
+    private VisualizerView mVisualizerView;
+    private ImageButton mPlayButton;
+    private ImageButton mPauseButton;
 
     @Override
     public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
-        View view = inflater.inflate(R.layout.fragment_sunset, container, false);
+        View view = inflater.inflate(R.layout.fragment_visualizer, container, false);
 
-        mOrbView = view.findViewById(R.id.orb);
+        getActivity().setVolumeControlStream(AudioManager.STREAM_MUSIC);
+        mAudioPlayer = new AudioPlayer();
 
-        view.setOnClickListener(new View.OnClickListener() {
-            @TargetApi(Build.VERSION_CODES.KITKAT)
+        mPlayButton = (ImageButton) view.findViewById(R.id.play);
+        mPlayButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                startVisualizer();
+                if (mAudioPlayer.getState() == STATE.PAUSED) {
+                    mAudioPlayer.resume();
+                } else {
+                    mAudioPlayer.play(getActivity(), R.raw.test_audio);
+                    mVisualizer = new Visualizer(mAudioPlayer.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);
+                }
+                updateUI();
             }
         });
 
-        orb_x = view.getWidth() / 2;
-        orb_y = view.getHeight() / 2;
+        mPauseButton = (ImageButton) view.findViewById(R.id.pause);
+        mPauseButton.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                mAudioPlayer.pause();
+                updateUI();
+            }
+        });
 
-        mOrbView.setX(orb_x);
-        mOrbView.setX(orb_y);
+        mFrame = (LinearLayout) view.findViewById(R.id.frame);
+        mVisualizerView = new VisualizerView(getActivity());
+        mVisualizerView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, (int) (VISUALIZER_HEIGHT_DIP * getResources().getDisplayMetrics().density)));
+        mFrame.addView(mVisualizerView);
 
         return view;
     }
 
-    private void startVisualizer() {
-        ObjectAnimator orbAnimatorX = ObjectAnimator.ofFloat(mOrbView, "x", orb_x, orb_x + sRandom.nextInt(400)).setDuration(1000);
-        orbAnimatorX.setInterpolator(new AccelerateInterpolator());
+    @Override
+    public void onResume() {
+        super.onResume();
+        updateUI();
+    }
 
-        ObjectAnimator orbAnimatorY = ObjectAnimator.ofFloat(mOrbView, "y", orb_y, orb_y + sRandom.nextInt(400)).setDuration(1000);
-        orbAnimatorY.setInterpolator(new AccelerateInterpolator());
+    @Override
+    public void onPause() {
+        super.onPause();
+        if (mVisualizer != null) {
+            mVisualizer.release();
+        }
+        mAudioPlayer.stop();
+    }
 
-        mAnimatorSet = new AnimatorSet();
-        mAnimatorSet.play(orbAnimatorX).with(orbAnimatorY);
-        mAnimatorSet.start();
+    private void updateUI() {
+        switch (mAudioPlayer.getState()) {
+            case PAUSED:
+            case STOPPED:
+                if (mVisualizer != null) {
+                    mVisualizerView.setEnabled(false);
+                }
+                mPauseButton.setEnabled(false);
+                mPlayButton.setEnabled(true);
+                break;
+            case PLAYING:
+                if (mVisualizer != null) {
+                    mVisualizerView.setEnabled(true);
+                }
+                mPauseButton.setEnabled(true);
+                mPlayButton.setEnabled(false);
+                break;
+            default:
+                break;
+        }
     }
 
 }

app/src/main/java/com/ambergleam/visualizer/VisualizerView.java

@@ -0,0 +1,77 @@
+package com.ambergleam.visualizer;
+
+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;
+
+/**
+ * A simple class that draws waveform data received from a
+ * {@link android.media.audiofx.Visualizer.OnDataCaptureListener#onWaveFormDataCapture }
+ */
+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 defStyle) {
+        super(context, attrs, defStyle);
+        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);
+    }
+
+}

app/src/main/res/layout/activity_fragment.xml

@@ -1,7 +1,8 @@
+<?xml version="1.0" encoding="utf-8"?>
 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
-    xmlns:tools="http://schemas.android.com/tools"
-    android:id="@+id/fragmentContainer"
-    android:layout_width="match_parent"
-    android:layout_height="match_parent" >
+             xmlns:tools="http://schemas.android.com/tools"
+             android:id="@+id/fragmentContainer"
+             android:layout_width="match_parent"
+             android:layout_height="match_parent">
 
-</FrameLayout>
+</FrameLayout>

app/src/main/res/layout/fragment_visualizer.xml

@@ -0,0 +1,32 @@
+<?xml version="1.0" encoding="utf-8"?>
+<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
+              android:id="@+id/frame"
+              android:orientation="vertical"
+              android:layout_width="match_parent"
+              android:layout_height="match_parent"
+              android:layout_margin="@dimen/activity_horizontal_margin">
+
+    <LinearLayout
+        android:layout_width="match_parent"
+        android:layout_height="wrap_content"
+        android:layout_gravity="center|bottom">
+
+        <ImageButton
+            android:id="@+id/play"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:src="@android:drawable/ic_media_play"
+            />
+
+        <ImageButton
+            android:id="@+id/pause"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_weight="1"
+            android:src="@android:drawable/ic_media_pause"
+            />
+
+    </LinearLayout>
+
+</LinearLayout>