From 00fe87a2abefea7faca75888205a70a0a34b4ed4 Mon Sep 17 00:00:00 2001
From: Rafael Pinto <raprp@posteo.de>
Date: Tue, 5 Jun 2018 23:04:20 +0100
Subject: [PATCH] replaced channel with stereoPan attribute

---
 README.md                                     |  2 +-
 Video.js                                      |  2 +-
 .../exoplayer/ReactExoplayerView.java         |  4 +--
 .../exoplayer/ReactExoplayerViewManager.java  |  6 ++--
 .../com/brentvatne/react/ReactVideoView.java  | 30 ++++++++++++-------
 .../react/ReactVideoViewManager.java          |  8 ++---
 6 files changed, 30 insertions(+), 22 deletions(-)

diff --git a/README.md b/README.md
index 4697e990..0266a1d1 100644
--- a/README.md
+++ b/README.md
@@ -188,7 +188,7 @@ using System.Collections.Generic;
        }}                                      // Store reference
        rate={1.0}                              // 0 is paused, 1 is normal.
        volume={1.0}                            // 0 is muted, 1 is normal.
-       channel="both"                          // [Android only] Target channel for audio panning: left, right or both (default).
+       stereoPan={0}                           // [Android only] The audio player’s stereo pan position. A value of –1.0 is full left, 0.0 is center, and 1.0 is full right. Default 0.0
        muted={true|false}                      // Mutes the audio entirely. Default false
        paused={true|false}                     // Pauses playback entirely. Default false
        resizeMode="cover"                      // Fill the whole screen at aspect ratio.*
diff --git a/Video.js b/Video.js
index 0510f416..40216f8b 100644
--- a/Video.js
+++ b/Video.js
@@ -277,7 +277,7 @@ Video.propTypes = {
   paused: PropTypes.bool,
   muted: PropTypes.bool,
   volume: PropTypes.number,
-  channel: PropTypes.string,
+  stereoPan: PropTypes.number,
   rate: PropTypes.number,
   playInBackground: PropTypes.bool,
   playWhenInactive: PropTypes.bool,
diff --git a/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java b/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java
index 6ccce609..11296fdd 100644
--- a/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java
+++ b/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerView.java
@@ -650,9 +650,9 @@ class ReactExoplayerView extends FrameLayout implements
         }
     }
 
-    public void setChannel(String channel) {
+    public void setStereoPan(float stereoPan) {
         if (player != null) {
-            player.setChannel(channel);
+            player.setStereoPan(stereoPan);
         }
     }
 
diff --git a/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerViewManager.java b/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerViewManager.java
index 161a3648..c15b59c1 100644
--- a/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerViewManager.java
+++ b/android-exoplayer/src/main/java/com/brentvatne/exoplayer/ReactExoplayerViewManager.java
@@ -132,9 +132,9 @@ public class ReactExoplayerViewManager extends ViewGroupManager<ReactExoplayerVi
         videoView.setVolumeModifier(volume);
     }
 
-    @ReactProp(name = PROP_CHANNEL)
-    public void setChannel(final ReactExoplayerView videoView, final String channel) {
-        videoView.setChannel(channel);
+    @ReactProp(name = PROP_STEREO_PAN)
+    public void setStereoPan(final ReactExoplayerView videoView, final float stereoPan) {
+        videoView.setStereoPan(stereoPan);
     }
 
     @ReactProp(name = PROP_PROGRESS_UPDATE_INTERVAL, defaultFloat = 250.0f)
diff --git a/android/src/main/java/com/brentvatne/react/ReactVideoView.java b/android/src/main/java/com/brentvatne/react/ReactVideoView.java
index 1fd4d9a6..a2e0f276 100644
--- a/android/src/main/java/com/brentvatne/react/ReactVideoView.java
+++ b/android/src/main/java/com/brentvatne/react/ReactVideoView.java
@@ -28,6 +28,7 @@ import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import java.lang.Math;
+import java.math.BigDecimal;
 
 @SuppressLint("ViewConstructor")
 public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnPreparedListener, MediaPlayer
@@ -77,10 +78,6 @@ public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnP
     public static final String EVENT_PROP_WHAT = "what";
     public static final String EVENT_PROP_EXTRA = "extra";
 
-    public static final String CHANNEL_LEFT = "left";
-    public static final String CHANNEL_BOTH = "both";
-    public static final String CHANNEL_RIGHT = "right";
-
     private ThemedReactContext mThemedReactContext;
     private RCTEventEmitter mEventEmitter;
 
@@ -99,7 +96,7 @@ public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnP
     private boolean mPaused = false;
     private boolean mMuted = false;
     private float mVolume = 1.0f;
-    private String mChannel = CHANNEL_BOTH;
+    private float mStereoPan = 0.0f;
     private float mProgressUpdateInterval = 250.0f;
     private float mRate = 1.0f;
     private float mActiveRate = 1.0f;
@@ -364,6 +361,14 @@ public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnP
         }
     }
 
+    // reduces the volume based on stereoPan
+    private float calulateRelativeVolume() {
+        float relativeVolume = (mVolume * (1 - Math.abs(mStereoPan)));
+        // only one decimal allowed
+        BigDecimal roundRelativeVolume = new BigDecimal(relativeVolume).setScale(1, BigDecimal.ROUND_HALF_UP);
+        return roundRelativeVolume.floatValue();
+    }
+
     public void setMutedModifier(final boolean muted) {
         mMuted = muted;
 
@@ -373,11 +378,14 @@ public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnP
 
         if (mMuted) {
             setVolume(0, 0);
-        } else if (CHANNEL_LEFT.equals(mChannel)){
-            setVolume(mVolume, 0);
-        } else if (CHANNEL_RIGHT.equals(mChannel)){
-            setVolume(0, mVolume);
+        } else if (mStereoPan < 0) {
+            // louder on the left channel
+            setVolume(mVolume, calulateRelativeVolume());
+        } else if (mStereoPan > 0) {
+            // louder on the right channel
+            setVolume(calulateRelativeVolume(), mVolume);
         } else {
+            // same volume on both channels
             setVolume(mVolume, mVolume);
         }
     }
@@ -387,8 +395,8 @@ public class ReactVideoView extends ScalableVideoView implements MediaPlayer.OnP
         setMutedModifier(mMuted);
     }
 
-    public void setChannel(final String channel) {
-        mChannel = channel;
+    public void setStereoPan(final float stereoPan) {
+        mStereoPan = stereoPan;
         setMutedModifier(mMuted);
     }
 
diff --git a/android/src/main/java/com/brentvatne/react/ReactVideoViewManager.java b/android/src/main/java/com/brentvatne/react/ReactVideoViewManager.java
index 3f29d417..eff426a2 100644
--- a/android/src/main/java/com/brentvatne/react/ReactVideoViewManager.java
+++ b/android/src/main/java/com/brentvatne/react/ReactVideoViewManager.java
@@ -30,7 +30,7 @@ public class ReactVideoViewManager extends SimpleViewManager<ReactVideoView> {
     public static final String PROP_PAUSED = "paused";
     public static final String PROP_MUTED = "muted";
     public static final String PROP_VOLUME = "volume";
-    public static final String PROP_CHANNEL = "channel";
+    public static final String PROP_STEREO_PAN = "stereoPan";
     public static final String PROP_PROGRESS_UPDATE_INTERVAL = "progressUpdateInterval";
     public static final String PROP_SEEK = "seek";
     public static final String PROP_RATE = "rate";
@@ -125,9 +125,9 @@ public class ReactVideoViewManager extends SimpleViewManager<ReactVideoView> {
         videoView.setVolumeModifier(volume);
     }
 
-    @ReactProp(name = PROP_CHANNEL)
-    public void setChannel(final ReactVideoView videoView, final String channel) {
-        videoView.setChannel(channel);
+    @ReactProp(name = PROP_STEREO_PAN)
+    public void setStereoPan(final ReactVideoView videoView, final float stereoPan) {
+        videoView.setStereoPan(stereoPan);
     }
 
     @ReactProp(name = PROP_PROGRESS_UPDATE_INTERVAL, defaultFloat = 250.0f)