From 49b57b8da390e5fd42ea97df6447cad1c4df1657 Mon Sep 17 00:00:00 2001
From: ibaker <ibaker@google.com>
Date: Fri, 25 Apr 2025 06:03:03 -0700
Subject: [PATCH] Integrate `PlayerControlView` with new scrubbing mode

This also tweaks the logic in `Util.shouldShowPlayButton` to
special-case the 'scrubbing' suppression reason. In most cases of
playback suppression (e.g. transient loss of audio focus due to a phone
call), the recommended UX is to show a 'play' button (i.e. the UI looks
like the player is paused). This doesn't look right when scrubbing
since although 'ongoing' playback is suppressed, the image on screen
is constantly changing, so a 'pause' button is kept (i.e. the UI looks
like the player is playing).

PiperOrigin-RevId: 751385521
---
 RELEASENOTES.md                               |  7 ++
 .../androidx/media3/common/util/Util.java     |  4 +-
 libraries/ui/proguard-rules.txt               |  2 +
 .../androidx/media3/ui/PlayerControlView.java | 93 ++++++++++++++++++-
 .../java/androidx/media3/ui/PlayerView.java   | 13 +++
 libraries/ui/src/main/res/values/attrs.xml    |  3 +
 6 files changed, 119 insertions(+), 3 deletions(-)

diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index b8905d66dc..cedebcb51b 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -64,6 +64,13 @@
         being enabled). Any changes made to the Player outside of the
         observation period are now picked up
         ([#2313](https://github.com/androidx/media/issues/2313)).
+    *   Add support for ExoPlayer's scrubbing mode to `PlayerControlView`. When
+        enabled, this puts the player into scrubbing mode when the user starts
+        dragging the scrubber bar, issues a `player.seekTo` call for every
+        movement, and then exits scrubbing mode when the touch is lifted from
+        the screen. This integration can be enabled with either
+        `time_bar_scrubbing_enabled = true` in XML or the
+        `setTimeBarScrubbingEnabled(boolean)` method from Java/Kotlin.
 *   Downloads:
     *   Add partial download support for progressive streams. Apps can prepare a
         progressive stream with `DownloadHelper`, and request a
diff --git a/libraries/common/src/main/java/androidx/media3/common/util/Util.java b/libraries/common/src/main/java/androidx/media3/common/util/Util.java
index 4de9b0ca95..6734f41d0f 100644
--- a/libraries/common/src/main/java/androidx/media3/common/util/Util.java
+++ b/libraries/common/src/main/java/androidx/media3/common/util/Util.java
@@ -3713,7 +3713,9 @@ public final class Util {
         || player.getPlaybackState() == Player.STATE_IDLE
         || player.getPlaybackState() == Player.STATE_ENDED
         || (shouldShowPlayIfSuppressed
-            && player.getPlaybackSuppressionReason() != Player.PLAYBACK_SUPPRESSION_REASON_NONE);
+            && player.getPlaybackSuppressionReason() != Player.PLAYBACK_SUPPRESSION_REASON_NONE
+            && player.getPlaybackSuppressionReason()
+                != Player.PLAYBACK_SUPPRESSION_REASON_SCRUBBING);
   }
 
   /**
diff --git a/libraries/ui/proguard-rules.txt b/libraries/ui/proguard-rules.txt
index c6f7553c44..288c5d050a 100644
--- a/libraries/ui/proguard-rules.txt
+++ b/libraries/ui/proguard-rules.txt
@@ -12,6 +12,8 @@
 -keepnames class androidx.media3.exoplayer.ExoPlayer {}
 -keepclassmembers class androidx.media3.exoplayer.ExoPlayer {
   void setImageOutput(androidx.media3.exoplayer.image.ImageOutput);
+  void setScrubbingModeEnabled(boolean);
+  boolean isScrubbingModeEnabled();
 }
 -keepclasseswithmembers class androidx.media3.exoplayer.image.ImageOutput {
   void onImageAvailable(long, android.graphics.Bitmap);
diff --git a/libraries/ui/src/main/java/androidx/media3/ui/PlayerControlView.java b/libraries/ui/src/main/java/androidx/media3/ui/PlayerControlView.java
index 5456b4847f..f901b26825 100644
--- a/libraries/ui/src/main/java/androidx/media3/ui/PlayerControlView.java
+++ b/libraries/ui/src/main/java/androidx/media3/ui/PlayerControlView.java
@@ -79,12 +79,15 @@ import androidx.media3.common.TrackSelectionOverride;
 import androidx.media3.common.TrackSelectionParameters;
 import androidx.media3.common.Tracks;
 import androidx.media3.common.util.Assertions;
+import androidx.media3.common.util.Log;
 import androidx.media3.common.util.RepeatModeUtil;
 import androidx.media3.common.util.UnstableApi;
 import androidx.media3.common.util.Util;
 import androidx.recyclerview.widget.LinearLayoutManager;
 import androidx.recyclerview.widget.RecyclerView;
 import com.google.common.collect.ImmutableList;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -92,6 +95,7 @@ import java.util.Formatter;
 import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.CopyOnWriteArrayList;
+import org.checkerframework.checker.nullness.qual.EnsuresNonNullIf;
 
 /**
  * A view for controlling {@link Player} instances.
@@ -156,6 +160,14 @@ import java.util.concurrent.CopyOnWriteArrayList;
  *         <li>Corresponding method: {@link #setAnimationEnabled(boolean)}
  *         <li>Default: true
  *       </ul>
+ *   <li><b>{@code time_bar_scrubbing_enabled}</b> - Whether the time bar should {@linkplain
+ *       Player#seekTo seek} immediately as the user drags the scrubber around (true), or only seek
+ *       when the user releases the scrubber (false). This can only be used if the {@linkplain
+ *       #setPlayer connected player} is an instance of {@code androidx.media3.exoplayer.ExoPlayer}.
+ *       <ul>
+ *         <li>Corresponding method: {@link #setTimeBarScrubbingEnabled(boolean)}
+ *         <li>Default: {@code false}
+ *       </ul>
  *   <li><b>{@code time_bar_min_update_interval}</b> - Specifies the minimum interval between time
  *       bar position updates.
  *       <ul>
@@ -352,6 +364,8 @@ public class PlayerControlView extends FrameLayout {
   /** The maximum number of windows that can be shown in a multi-window time bar. */
   public static final int MAX_WINDOWS_FOR_MULTI_WINDOW_TIME_BAR = 100;
 
+  private static final String TAG = "PlayerControlView";
+
   /** The maximum interval between time bar position updates. */
   private static final int MAX_UPDATE_INTERVAL_MS = 1_000;
 
@@ -366,6 +380,9 @@ public class PlayerControlView extends FrameLayout {
   private final PlayerControlViewLayoutManager controlViewLayoutManager;
   private final Resources resources;
   private final ComponentListener componentListener;
+  @Nullable private final Class<?> exoplayerClazz;
+  @Nullable private final Method setScrubbingModeEnabledMethod;
+  @Nullable private final Method isScrubbingModeEnabledMethod;
 
   @SuppressWarnings("deprecation") // Using the deprecated type for now.
   private final CopyOnWriteArrayList<VisibilityListener> visibilityListeners;
@@ -442,6 +459,7 @@ public class PlayerControlView extends FrameLayout {
   private boolean multiWindowTimeBar;
   private boolean scrubbing;
   private int showTimeoutMs;
+  private boolean timeBarScrubbingEnabled;
   private int timeBarMinUpdateIntervalMs;
   private @RepeatModeUtil.RepeatToggleModes int repeatToggleModes;
   private long[] adGroupTimesMs;
@@ -572,6 +590,8 @@ public class PlayerControlView extends FrameLayout {
         showSubtitleButton =
             a.getBoolean(R.styleable.PlayerControlView_show_subtitle_button, showSubtitleButton);
         showVrButton = a.getBoolean(R.styleable.PlayerControlView_show_vr_button, showVrButton);
+        timeBarScrubbingEnabled =
+            a.getBoolean(R.styleable.PlayerControlView_time_bar_scrubbing_enabled, false);
         setTimeBarMinUpdateInterval(
             a.getInt(
                 R.styleable.PlayerControlView_time_bar_min_update_interval,
@@ -598,6 +618,21 @@ public class PlayerControlView extends FrameLayout {
     extraPlayedAdGroups = new boolean[0];
     updateProgressAction = this::updateProgress;
 
+    Class<?> exoplayerClazz = null;
+    Method setScrubbingModeEnabledMethod = null;
+    Method isScrubbingModeEnabledMethod = null;
+    try {
+      exoplayerClazz = Class.forName("androidx.media3.exoplayer.ExoPlayer");
+      setScrubbingModeEnabledMethod =
+          exoplayerClazz.getMethod("setScrubbingModeEnabled", boolean.class);
+      isScrubbingModeEnabledMethod = exoplayerClazz.getMethod("isScrubbingModeEnabled");
+    } catch (ClassNotFoundException | NoSuchMethodException e) {
+      // Expected if ExoPlayer module not available.
+    }
+    this.exoplayerClazz = exoplayerClazz;
+    this.setScrubbingModeEnabledMethod = setScrubbingModeEnabledMethod;
+    this.isScrubbingModeEnabledMethod = isScrubbingModeEnabledMethod;
+
     durationView = findViewById(R.id.exo_duration);
     positionView = findViewById(R.id.exo_position);
 
@@ -1088,6 +1123,17 @@ public class PlayerControlView extends FrameLayout {
     return controlViewLayoutManager.isAnimationEnabled();
   }
 
+  /**
+   * Sets whether the time bar should {@linkplain Player#seekTo seek} immediately as the user drags
+   * the scrubber around (true), or only seek when the user releases the scrubber (false).
+   *
+   * <p>This can only be used if the {@linkplain #setPlayer connected player} is an instance of
+   * {@code androidx.media3.exoplayer.ExoPlayer}.
+   */
+  public void setTimeBarScrubbingEnabled(boolean timeBarScrubbingEnabled) {
+    this.timeBarScrubbingEnabled = timeBarScrubbingEnabled;
+  }
+
   /**
    * Sets the minimum interval between time bar position updates.
    *
@@ -1852,6 +1898,21 @@ public class PlayerControlView extends FrameLayout {
         positionView.setText(Util.getStringForTime(formatBuilder, formatter, position));
       }
       controlViewLayoutManager.removeHideCallbacks();
+      if (player != null && timeBarScrubbingEnabled) {
+        if (isExoPlayer(player)) {
+          try {
+            checkNotNull(setScrubbingModeEnabledMethod).invoke(player, true);
+          } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new RuntimeException(e);
+          }
+        } else {
+          Log.w(
+              TAG,
+              "Time bar scrubbing is enabled, but player is not an ExoPlayer instance, so ignoring"
+                  + " (because we can't enable scrubbing mode). player.class="
+                  + checkNotNull(player).getClass());
+        }
+      }
     }
 
     @Override
@@ -1859,17 +1920,45 @@ public class PlayerControlView extends FrameLayout {
       if (positionView != null) {
         positionView.setText(Util.getStringForTime(formatBuilder, formatter, position));
       }
+      boolean isScrubbingModeEnabled;
+      try {
+        isScrubbingModeEnabled =
+            isExoPlayer(player)
+                && (boolean)
+                    checkNotNull(checkNotNull(isScrubbingModeEnabledMethod).invoke(player));
+      } catch (IllegalAccessException | InvocationTargetException e) {
+        throw new RuntimeException(e);
+      }
+      if (isScrubbingModeEnabled) {
+        seekToTimeBarPosition(checkNotNull(player), position);
+      }
     }
 
     @Override
     public void onScrubStop(TimeBar timeBar, long position, boolean canceled) {
       scrubbing = false;
-      if (!canceled && player != null) {
-        seekToTimeBarPosition(player, position);
+      if (player != null) {
+        if (!canceled) {
+          seekToTimeBarPosition(player, position);
+        }
+        if (isExoPlayer(player)) {
+          try {
+            checkNotNull(setScrubbingModeEnabledMethod).invoke(player, false);
+          } catch (IllegalAccessException | InvocationTargetException e) {
+            throw new RuntimeException(e);
+          }
+        }
       }
       controlViewLayoutManager.resetHideCallbacks();
     }
 
+    @EnsuresNonNullIf(result = true, expression = "#1")
+    private boolean isExoPlayer(@Nullable Player player) {
+      return player != null
+          && exoplayerClazz != null
+          && exoplayerClazz.isAssignableFrom(player.getClass());
+    }
+
     @Override
     public void onDismiss() {
       if (needToHideBars) {
diff --git a/libraries/ui/src/main/java/androidx/media3/ui/PlayerView.java b/libraries/ui/src/main/java/androidx/media3/ui/PlayerView.java
index 8ea0c175ce..b25ed50ef0 100644
--- a/libraries/ui/src/main/java/androidx/media3/ui/PlayerView.java
+++ b/libraries/ui/src/main/java/androidx/media3/ui/PlayerView.java
@@ -1283,6 +1283,19 @@ public class PlayerView extends FrameLayout implements AdViewProvider {
     controller.setShowMultiWindowTimeBar(showMultiWindowTimeBar);
   }
 
+  /**
+   * Sets whether the time bar should {@linkplain Player#seekTo seek} immediately as the user drags
+   * the scrubber around (true), or only seek when the user releases the scrubber (false).
+   *
+   * <p>This can only be used if the {@linkplain #setPlayer connected player} is an instance of
+   * {@code androidx.media3.exoplayer.ExoPlayer}.
+   */
+  @UnstableApi
+  public void setTimeBarScrubbingEnabled(boolean timeBarScrubbingEnabled) {
+    Assertions.checkStateNotNull(controller);
+    controller.setTimeBarScrubbingEnabled(timeBarScrubbingEnabled);
+  }
+
   /**
    * Sets whether a play button is shown if playback is {@linkplain
    * Player#getPlaybackSuppressionReason() suppressed}.
diff --git a/libraries/ui/src/main/res/values/attrs.xml b/libraries/ui/src/main/res/values/attrs.xml
index 38d090bba8..55694a3ddf 100644
--- a/libraries/ui/src/main/res/values/attrs.xml
+++ b/libraries/ui/src/main/res/values/attrs.xml
@@ -90,6 +90,7 @@
   <attr name="subtitle_off_icon" format="reference"/>
   <attr name="show_vr_button" format="boolean"/>
   <attr name="vr_icon" format="reference"/>
+  <attr name="time_bar_scrubbing_enabled" format="boolean"/>
   <attr name="time_bar_min_update_interval" format="integer"/>
   <attr name="controller_layout_id" format="reference"/>
   <attr name="animation_enabled" format="boolean"/>
@@ -146,6 +147,7 @@
     <attr name="subtitle_on_icon"/>
     <attr name="show_vr_button"/>
     <attr name="vr_icon"/>
+    <attr name="time_bar_scrubbing_enabled"/>
     <attr name="time_bar_min_update_interval"/>
     <attr name="controller_layout_id"/>
     <attr name="animation_enabled"/>
@@ -227,6 +229,7 @@
     <attr name="subtitle_off_icon"/>
     <attr name="show_vr_button"/>
     <attr name="vr_icon"/>
+    <attr name="time_bar_scrubbing_enabled"/>
     <attr name="time_bar_min_update_interval"/>
     <attr name="controller_layout_id"/>
     <attr name="animation_enabled"/>