Add missing @Nullable to SimpleExoPlayer fields and methods.

Issue:#5402
PiperOrigin-RevId: 229758525

library/core/src/main/java/com/google/android/exoplayer2/SimpleExoPlayer.java

@@ -94,25 +94,25 @@ public class SimpleExoPlayer extends BasePlayer
 
   private final AudioFocusManager audioFocusManager;
 
-  private Format videoFormat;
-  private Format audioFormat;
+  @Nullable private Format videoFormat;
+  @Nullable private Format audioFormat;
 
-  private Surface surface;
+  @Nullable private Surface surface;
   private boolean ownsSurface;
   private @C.VideoScalingMode int videoScalingMode;
-  private SurfaceHolder surfaceHolder;
-  private TextureView textureView;
+  @Nullable private SurfaceHolder surfaceHolder;
+  @Nullable private TextureView textureView;
   private int surfaceWidth;
   private int surfaceHeight;
-  private DecoderCounters videoDecoderCounters;
-  private DecoderCounters audioDecoderCounters;
+  @Nullable private DecoderCounters videoDecoderCounters;
+  @Nullable private DecoderCounters audioDecoderCounters;
   private int audioSessionId;
   private AudioAttributes audioAttributes;
   private float audioVolume;
-  private MediaSource mediaSource;
+  @Nullable private MediaSource mediaSource;
   private List<Cue> currentCues;
-  private VideoFrameMetadataListener videoFrameMetadataListener;
-  private CameraMotionListener cameraMotionListener;
+  @Nullable private VideoFrameMetadataListener videoFrameMetadataListener;
+  @Nullable private CameraMotionListener cameraMotionListener;
   private boolean hasNotifiedFullWrongThreadWarning;
 
   /**
@@ -558,30 +558,26 @@ public class SimpleExoPlayer extends BasePlayer
     setPlaybackParameters(playbackParameters);
   }
 
-  /**
-   * Returns the video format currently being played, or null if no video is being played.
-   */
+  /** Returns the video format currently being played, or null if no video is being played. */
+  @Nullable
   public Format getVideoFormat() {
     return videoFormat;
   }
 
-  /**
-   * Returns the audio format currently being played, or null if no audio is being played.
-   */
+  /** Returns the audio format currently being played, or null if no audio is being played. */
+  @Nullable
   public Format getAudioFormat() {
     return audioFormat;
   }
 
-  /**
-   * Returns {@link DecoderCounters} for video, or null if no video is being played.
-   */
+  /** Returns {@link DecoderCounters} for video, or null if no video is being played. */
+  @Nullable
   public DecoderCounters getVideoDecoderCounters() {
     return videoDecoderCounters;
   }
 
-  /**
-   * Returns {@link DecoderCounters} for audio, or null if no audio is being played.
-   */
+  /** Returns {@link DecoderCounters} for audio, or null if no audio is being played. */
+  @Nullable
   public DecoderCounters getAudioDecoderCounters() {
     return audioDecoderCounters;
   }
@@ -1053,7 +1049,8 @@ public class SimpleExoPlayer extends BasePlayer
   }
 
   @Override
-  public @Nullable Object getCurrentManifest() {
+  @Nullable
+  public Object getCurrentManifest() {
     verifyApplicationThread();
     return player.getCurrentManifest();
   }

library/ui/src/main/java/com/google/android/exoplayer2/ui/DebugTextViewHelper.java

@@ -137,23 +137,40 @@ public class DebugTextViewHelper implements Player.EventListener, Runnable {
   /** Returns a string containing video debugging information. */
   protected String getVideoString() {
     Format format = player.getVideoFormat();
-    if (format == null) {
+    DecoderCounters decoderCounters = player.getVideoDecoderCounters();
+    if (format == null || decoderCounters == null) {
       return "";
     }
-    return "\n" + format.sampleMimeType + "(id:" + format.id + " r:" + format.width + "x"
-        + format.height + getPixelAspectRatioString(format.pixelWidthHeightRatio)
-        + getDecoderCountersBufferCountString(player.getVideoDecoderCounters()) + ")";
+    return "\n"
+        + format.sampleMimeType
+        + "(id:"
+        + format.id
+        + " r:"
+        + format.width
+        + "x"
+        + format.height
+        + getPixelAspectRatioString(format.pixelWidthHeightRatio)
+        + getDecoderCountersBufferCountString(decoderCounters)
+        + ")";
   }
 
   /** Returns a string containing audio debugging information. */
   protected String getAudioString() {
     Format format = player.getAudioFormat();
-    if (format == null) {
+    DecoderCounters decoderCounters = player.getAudioDecoderCounters();
+    if (format == null || decoderCounters == null) {
       return "";
     }
-    return "\n" + format.sampleMimeType + "(id:" + format.id + " hz:" + format.sampleRate + " ch:"
+    return "\n"
+        + format.sampleMimeType
+        + "(id:"
+        + format.id
+        + " hz:"
+        + format.sampleRate
+        + " ch:"
         + format.channelCount
-        + getDecoderCountersBufferCountString(player.getAudioDecoderCounters()) + ")";
+        + getDecoderCountersBufferCountString(decoderCounters)
+        + ")";
   }
 
   private static String getDecoderCountersBufferCountString(DecoderCounters counters) {